status-go/protocol/messenger_linkpreview_test.go

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package protocol
URL unfurling (initial implementation) (#3471) This is the initial implementation for the new URL unfurling requirements. The most important one is that only the message sender will pay the privacy cost for unfurling and extracting metadata from websites. Once the message is sent, the unfurled data will be stored at the protocol level and receivers will just profit and happily decode the metadata to render it. Further development of this URL unfurling capability will be mostly guided by issues created on clients. For the moment in status-mobile: https://github.com/status-im/status-mobile/labels/url-preview - https://github.com/status-im/status-mobile/issues/15918 - https://github.com/status-im/status-mobile/issues/15917 - https://github.com/status-im/status-mobile/issues/15910 - https://github.com/status-im/status-mobile/issues/15909 - https://github.com/status-im/status-mobile/issues/15908 - https://github.com/status-im/status-mobile/issues/15906 - https://github.com/status-im/status-mobile/issues/15905 ### Terminology In the code, I've tried to stick to the word "unfurl URL" to really mean the process of extracting metadata from a website, sort of lower level. I use "link preview" to mean a higher level structure which is enriched by unfurled data. "link preview" is also how designers refer to it. ### User flows 1. Carol needs to see link previews while typing in the chat input field. Notice from the diagram nothing is persisted and that status-go endpoints are essentially stateless. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_getTextURLs Server-->>Client: Normalized URLs Client->>Client: Render cached unfurled URLs Client->>Server: Unfurl non-cached URLs.\nCall wakuext_unfurlURLs Server->>Website: Fetch metadata Website-->>Server: Metadata (thumbnail URL, title, etc) Server->>Website: Fetch thumbnail Server->>Website: Fetch favicon Website-->>Server: Favicon bytes Website-->>Server: Thumbnail bytes Server->>Server: Decode & process images Server-->>Client: Unfurled data (thumbnail data URI, etc) #+end_src ``` ``` ,------. ,------. ,-------. |Client| |Server| |Website| `--+---' `--+---' `---+---' | Call wakuext_getTextURLs | | | ---------------------------------------> | | | | | Normalized URLs | | | <- - - - - - - - - - - - - - - - - - - - | | | | |----. | | | | Render cached unfurled URLs | | |<---' | | | | | | Unfurl non-cached URLs. | | | Call wakuext_unfurlURLs | | | ---------------------------------------> | | | | | | Fetch metadata | | | ------------------------------------> | | | | | Metadata (thumbnail URL, title, etc)| | | <- - - - - - - - - - - - - - - - - - | | | | | Fetch thumbnail | | | ------------------------------------> | | | | | Fetch favicon | | | ------------------------------------> | | | | | Favicon bytes | | | <- - - - - - - - - - - - - - - - - - | | | | | Thumbnail bytes | | | <- - - - - - - - - - - - - - - - - - | | | | |----. | | | | Decode & process images | | |<---' | | | | | Unfurled data (thumbnail data URI, etc)| | | <- - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,---+---. |Client| |Server| |Website| `------' `------' `-------' ``` 2. Carol sends the text message with link previews in the RPC request wakuext_sendChatMessages. status-go assumes the link previews are good because it can't and shouldn't attempt to re-unfurl them. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_sendChatMessages Server->>Server: Transform link previews to\nbe proto-marshalled Server->DB: Write link previews serialized as JSON Server-->>Client: Updated message response #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | Call wakuext_sendChatMessages| | | -----------------------------> | | | | | |----. | | | | Transform link previews to | | |<---' be proto-marshalled | | | | | | | | | Write link previews serialized as JSON| | | --------------------------------------> | | | | Updated message response | | | <- - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` 3. The message was sent over waku and persisted locally in Carol's device. She should now see the link previews in the chat history. There can be many link previews shared by other chat members, therefore it is important to serve the assets via the media server to avoid overloading the ReactNative bridge with lots of big JSON payloads containing base64 encoded data URIs (maybe this concern is meaningless for desktop). When a client is rendering messages with link previews, they will have the field linkPreviews, and the thumbnail URL will point to the local media server. ``` #+begin_src plantuml :results verbatim Client->>Server: GET /link-preview/thumbnail (media server) Server->>DB: Read from user_messages.unfurled_links Server->Server: Unmarshal JSON Server-->>Client: HTTP Content-Type: image/jpeg/etc #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | GET /link-preview/thumbnail (media server)| | | ------------------------------------------> | | | | | | Read from user_messages.unfurled_links| | | --------------------------------------> | | | | |----. | | | | Unmarshal JSON | | |<---' | | | | | HTTP Content-Type: image/jpeg/etc | | | <- - - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` ### Some limitations of the current implementation The following points will become separate issues in status-go that I'll work on over the next couple weeks. In no order of importance: - Improve how multiple links are fetched; retries on failure and testing how unfurling behaves around the timeout limits (deterministically, not by making real HTTP calls as I did). https://github.com/status-im/status-go/issues/3498 - Unfurl favicons and store them in the protobuf too. - For this PR, I added unfurling support only for websites with OpenGraph https://ogp.me/ meta tags. Other unfurlers will be implemented on demand. The next one will probably be for oEmbed https://oembed.com/, the protocol supported by YouTube, for example. - Resize and/or compress thumbnails (and favicons). Often times, thumbnails are huge for the purposes of link previews. There is already support for compressing JPEGs in status-go, but I prefer to work with compression in a separate PR because I'd like to also solve the problem for PNGs (probably convert them to JPEGs, plus compress them). This would be a safe choice for thumbnails, favicons not so much because transparency is desirable. - Editing messages is not yet supported. - I haven't coded any artificial limit on the number of previews or on the size of the thumbnail payload. This will be done in a separate issue. I have heard the ideal solution may be to split messages into smaller chunks of ~125 KiB because of libp2p, but that might be too complicated at this stage of the product (?). - Link preview deletion. - For the moment, OpenGraph metadata is extracted by requesting data for the English language (and fallback to whatever is available). In the future, we'll want to unfurl by respecting the user's local device language. Some websites, like GoDaddy, are already localized based on the device's IP, but many aren't. - The website's description text should be limited by a certain number of characters, especially because it's outside our control. Exactly how much has not been decided yet, so it'll be done separately. - URL normalization can be tricky, so I implemented only the basics to help with caching. For example, the url https://status.im and HTTPS://status.im are considered identical. Also, a URL is considered valid for unfurling if its TLD exists according to publicsuffix.EffectiveTLDPlusOne. This was essential, otherwise the default Go url.Parse approach would consider many invalid URLs valid, and thus the server would waste resources trying to unfurl the unfurleable. ### Other requirements - If the message is edited, the link previews should reflect the edited text, not the original one. This has been aligned with the design team as well. - If the website's thumbnail or the favicon can't be fetched, just ignore them. The only mandatory piece of metadata is the website's title and URL. - Link previews in clients should be generated in near real-time, that is, as the user types, previews are updated. In mobile this performs very well, and it's what other clients like WhatsApp, Telegram, and Facebook do. ### Decisions - While the user typing in the input field, the client is constantly (debounced) asking status-go to parse the text and extract normalized URLs and then the client checks if they're already in its in-memory cache. If they are, no RPC call is made. I chose this approach to achieve the best possible performance in mobile and avoid the whole RPC overhead, since the chat experience is already not smooth enough. The mobile client uses URLs as cache keys in a hashmap, i.e. if the key is present, it means the preview is readily available (naive, but good enough for now). This decision also gave me more flexibility to find the best UX at this stage of the feature. - Due to the requirement that users should be able to see independent loading indicators for each link preview, when status-go can't unfurl a URL, it doesn't return it in the response. - As an initial implementation, I added the BLOB column unfurled_links to the user_messages table. The preview data is then serialized as JSON before being stored in this column. I felt that creating a separate table and the related code for this initial PR would be inconvenient. Is that reasonable to you? Once things stabilize I can create a proper table if we want to avoid this kind of solution with serialized columns.
2023-05-18 18:43:06 +00:00
import (
"bytes"
"fmt"
"io/ioutil"
URL unfurling (initial implementation) (#3471) This is the initial implementation for the new URL unfurling requirements. The most important one is that only the message sender will pay the privacy cost for unfurling and extracting metadata from websites. Once the message is sent, the unfurled data will be stored at the protocol level and receivers will just profit and happily decode the metadata to render it. Further development of this URL unfurling capability will be mostly guided by issues created on clients. For the moment in status-mobile: https://github.com/status-im/status-mobile/labels/url-preview - https://github.com/status-im/status-mobile/issues/15918 - https://github.com/status-im/status-mobile/issues/15917 - https://github.com/status-im/status-mobile/issues/15910 - https://github.com/status-im/status-mobile/issues/15909 - https://github.com/status-im/status-mobile/issues/15908 - https://github.com/status-im/status-mobile/issues/15906 - https://github.com/status-im/status-mobile/issues/15905 ### Terminology In the code, I've tried to stick to the word "unfurl URL" to really mean the process of extracting metadata from a website, sort of lower level. I use "link preview" to mean a higher level structure which is enriched by unfurled data. "link preview" is also how designers refer to it. ### User flows 1. Carol needs to see link previews while typing in the chat input field. Notice from the diagram nothing is persisted and that status-go endpoints are essentially stateless. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_getTextURLs Server-->>Client: Normalized URLs Client->>Client: Render cached unfurled URLs Client->>Server: Unfurl non-cached URLs.\nCall wakuext_unfurlURLs Server->>Website: Fetch metadata Website-->>Server: Metadata (thumbnail URL, title, etc) Server->>Website: Fetch thumbnail Server->>Website: Fetch favicon Website-->>Server: Favicon bytes Website-->>Server: Thumbnail bytes Server->>Server: Decode & process images Server-->>Client: Unfurled data (thumbnail data URI, etc) #+end_src ``` ``` ,------. ,------. ,-------. |Client| |Server| |Website| `--+---' `--+---' `---+---' | Call wakuext_getTextURLs | | | ---------------------------------------> | | | | | Normalized URLs | | | <- - - - - - - - - - - - - - - - - - - - | | | | |----. | | | | Render cached unfurled URLs | | |<---' | | | | | | Unfurl non-cached URLs. | | | Call wakuext_unfurlURLs | | | ---------------------------------------> | | | | | | Fetch metadata | | | ------------------------------------> | | | | | Metadata (thumbnail URL, title, etc)| | | <- - - - - - - - - - - - - - - - - - | | | | | Fetch thumbnail | | | ------------------------------------> | | | | | Fetch favicon | | | ------------------------------------> | | | | | Favicon bytes | | | <- - - - - - - - - - - - - - - - - - | | | | | Thumbnail bytes | | | <- - - - - - - - - - - - - - - - - - | | | | |----. | | | | Decode & process images | | |<---' | | | | | Unfurled data (thumbnail data URI, etc)| | | <- - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,---+---. |Client| |Server| |Website| `------' `------' `-------' ``` 2. Carol sends the text message with link previews in the RPC request wakuext_sendChatMessages. status-go assumes the link previews are good because it can't and shouldn't attempt to re-unfurl them. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_sendChatMessages Server->>Server: Transform link previews to\nbe proto-marshalled Server->DB: Write link previews serialized as JSON Server-->>Client: Updated message response #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | Call wakuext_sendChatMessages| | | -----------------------------> | | | | | |----. | | | | Transform link previews to | | |<---' be proto-marshalled | | | | | | | | | Write link previews serialized as JSON| | | --------------------------------------> | | | | Updated message response | | | <- - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` 3. The message was sent over waku and persisted locally in Carol's device. She should now see the link previews in the chat history. There can be many link previews shared by other chat members, therefore it is important to serve the assets via the media server to avoid overloading the ReactNative bridge with lots of big JSON payloads containing base64 encoded data URIs (maybe this concern is meaningless for desktop). When a client is rendering messages with link previews, they will have the field linkPreviews, and the thumbnail URL will point to the local media server. ``` #+begin_src plantuml :results verbatim Client->>Server: GET /link-preview/thumbnail (media server) Server->>DB: Read from user_messages.unfurled_links Server->Server: Unmarshal JSON Server-->>Client: HTTP Content-Type: image/jpeg/etc #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | GET /link-preview/thumbnail (media server)| | | ------------------------------------------> | | | | | | Read from user_messages.unfurled_links| | | --------------------------------------> | | | | |----. | | | | Unmarshal JSON | | |<---' | | | | | HTTP Content-Type: image/jpeg/etc | | | <- - - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` ### Some limitations of the current implementation The following points will become separate issues in status-go that I'll work on over the next couple weeks. In no order of importance: - Improve how multiple links are fetched; retries on failure and testing how unfurling behaves around the timeout limits (deterministically, not by making real HTTP calls as I did). https://github.com/status-im/status-go/issues/3498 - Unfurl favicons and store them in the protobuf too. - For this PR, I added unfurling support only for websites with OpenGraph https://ogp.me/ meta tags. Other unfurlers will be implemented on demand. The next one will probably be for oEmbed https://oembed.com/, the protocol supported by YouTube, for example. - Resize and/or compress thumbnails (and favicons). Often times, thumbnails are huge for the purposes of link previews. There is already support for compressing JPEGs in status-go, but I prefer to work with compression in a separate PR because I'd like to also solve the problem for PNGs (probably convert them to JPEGs, plus compress them). This would be a safe choice for thumbnails, favicons not so much because transparency is desirable. - Editing messages is not yet supported. - I haven't coded any artificial limit on the number of previews or on the size of the thumbnail payload. This will be done in a separate issue. I have heard the ideal solution may be to split messages into smaller chunks of ~125 KiB because of libp2p, but that might be too complicated at this stage of the product (?). - Link preview deletion. - For the moment, OpenGraph metadata is extracted by requesting data for the English language (and fallback to whatever is available). In the future, we'll want to unfurl by respecting the user's local device language. Some websites, like GoDaddy, are already localized based on the device's IP, but many aren't. - The website's description text should be limited by a certain number of characters, especially because it's outside our control. Exactly how much has not been decided yet, so it'll be done separately. - URL normalization can be tricky, so I implemented only the basics to help with caching. For example, the url https://status.im and HTTPS://status.im are considered identical. Also, a URL is considered valid for unfurling if its TLD exists according to publicsuffix.EffectiveTLDPlusOne. This was essential, otherwise the default Go url.Parse approach would consider many invalid URLs valid, and thus the server would waste resources trying to unfurl the unfurleable. ### Other requirements - If the message is edited, the link previews should reflect the edited text, not the original one. This has been aligned with the design team as well. - If the website's thumbnail or the favicon can't be fetched, just ignore them. The only mandatory piece of metadata is the website's title and URL. - Link previews in clients should be generated in near real-time, that is, as the user types, previews are updated. In mobile this performs very well, and it's what other clients like WhatsApp, Telegram, and Facebook do. ### Decisions - While the user typing in the input field, the client is constantly (debounced) asking status-go to parse the text and extract normalized URLs and then the client checks if they're already in its in-memory cache. If they are, no RPC call is made. I chose this approach to achieve the best possible performance in mobile and avoid the whole RPC overhead, since the chat experience is already not smooth enough. The mobile client uses URLs as cache keys in a hashmap, i.e. if the key is present, it means the preview is readily available (naive, but good enough for now). This decision also gave me more flexibility to find the best UX at this stage of the feature. - Due to the requirement that users should be able to see independent loading indicators for each link preview, when status-go can't unfurl a URL, it doesn't return it in the response. - As an initial implementation, I added the BLOB column unfurled_links to the user_messages table. The preview data is then serialized as JSON before being stored in this column. I felt that creating a separate table and the related code for this initial PR would be inconvenient. Is that reasonable to you? Once things stabilize I can create a proper table if we want to avoid this kind of solution with serialized columns.
2023-05-18 18:43:06 +00:00
"math"
"net/http"
"net/url"
"regexp"
"strings"
URL unfurling (initial implementation) (#3471) This is the initial implementation for the new URL unfurling requirements. The most important one is that only the message sender will pay the privacy cost for unfurling and extracting metadata from websites. Once the message is sent, the unfurled data will be stored at the protocol level and receivers will just profit and happily decode the metadata to render it. Further development of this URL unfurling capability will be mostly guided by issues created on clients. For the moment in status-mobile: https://github.com/status-im/status-mobile/labels/url-preview - https://github.com/status-im/status-mobile/issues/15918 - https://github.com/status-im/status-mobile/issues/15917 - https://github.com/status-im/status-mobile/issues/15910 - https://github.com/status-im/status-mobile/issues/15909 - https://github.com/status-im/status-mobile/issues/15908 - https://github.com/status-im/status-mobile/issues/15906 - https://github.com/status-im/status-mobile/issues/15905 ### Terminology In the code, I've tried to stick to the word "unfurl URL" to really mean the process of extracting metadata from a website, sort of lower level. I use "link preview" to mean a higher level structure which is enriched by unfurled data. "link preview" is also how designers refer to it. ### User flows 1. Carol needs to see link previews while typing in the chat input field. Notice from the diagram nothing is persisted and that status-go endpoints are essentially stateless. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_getTextURLs Server-->>Client: Normalized URLs Client->>Client: Render cached unfurled URLs Client->>Server: Unfurl non-cached URLs.\nCall wakuext_unfurlURLs Server->>Website: Fetch metadata Website-->>Server: Metadata (thumbnail URL, title, etc) Server->>Website: Fetch thumbnail Server->>Website: Fetch favicon Website-->>Server: Favicon bytes Website-->>Server: Thumbnail bytes Server->>Server: Decode & process images Server-->>Client: Unfurled data (thumbnail data URI, etc) #+end_src ``` ``` ,------. ,------. ,-------. |Client| |Server| |Website| `--+---' `--+---' `---+---' | Call wakuext_getTextURLs | | | ---------------------------------------> | | | | | Normalized URLs | | | <- - - - - - - - - - - - - - - - - - - - | | | | |----. | | | | Render cached unfurled URLs | | |<---' | | | | | | Unfurl non-cached URLs. | | | Call wakuext_unfurlURLs | | | ---------------------------------------> | | | | | | Fetch metadata | | | ------------------------------------> | | | | | Metadata (thumbnail URL, title, etc)| | | <- - - - - - - - - - - - - - - - - - | | | | | Fetch thumbnail | | | ------------------------------------> | | | | | Fetch favicon | | | ------------------------------------> | | | | | Favicon bytes | | | <- - - - - - - - - - - - - - - - - - | | | | | Thumbnail bytes | | | <- - - - - - - - - - - - - - - - - - | | | | |----. | | | | Decode & process images | | |<---' | | | | | Unfurled data (thumbnail data URI, etc)| | | <- - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,---+---. |Client| |Server| |Website| `------' `------' `-------' ``` 2. Carol sends the text message with link previews in the RPC request wakuext_sendChatMessages. status-go assumes the link previews are good because it can't and shouldn't attempt to re-unfurl them. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_sendChatMessages Server->>Server: Transform link previews to\nbe proto-marshalled Server->DB: Write link previews serialized as JSON Server-->>Client: Updated message response #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | Call wakuext_sendChatMessages| | | -----------------------------> | | | | | |----. | | | | Transform link previews to | | |<---' be proto-marshalled | | | | | | | | | Write link previews serialized as JSON| | | --------------------------------------> | | | | Updated message response | | | <- - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` 3. The message was sent over waku and persisted locally in Carol's device. She should now see the link previews in the chat history. There can be many link previews shared by other chat members, therefore it is important to serve the assets via the media server to avoid overloading the ReactNative bridge with lots of big JSON payloads containing base64 encoded data URIs (maybe this concern is meaningless for desktop). When a client is rendering messages with link previews, they will have the field linkPreviews, and the thumbnail URL will point to the local media server. ``` #+begin_src plantuml :results verbatim Client->>Server: GET /link-preview/thumbnail (media server) Server->>DB: Read from user_messages.unfurled_links Server->Server: Unmarshal JSON Server-->>Client: HTTP Content-Type: image/jpeg/etc #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | GET /link-preview/thumbnail (media server)| | | ------------------------------------------> | | | | | | Read from user_messages.unfurled_links| | | --------------------------------------> | | | | |----. | | | | Unmarshal JSON | | |<---' | | | | | HTTP Content-Type: image/jpeg/etc | | | <- - - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` ### Some limitations of the current implementation The following points will become separate issues in status-go that I'll work on over the next couple weeks. In no order of importance: - Improve how multiple links are fetched; retries on failure and testing how unfurling behaves around the timeout limits (deterministically, not by making real HTTP calls as I did). https://github.com/status-im/status-go/issues/3498 - Unfurl favicons and store them in the protobuf too. - For this PR, I added unfurling support only for websites with OpenGraph https://ogp.me/ meta tags. Other unfurlers will be implemented on demand. The next one will probably be for oEmbed https://oembed.com/, the protocol supported by YouTube, for example. - Resize and/or compress thumbnails (and favicons). Often times, thumbnails are huge for the purposes of link previews. There is already support for compressing JPEGs in status-go, but I prefer to work with compression in a separate PR because I'd like to also solve the problem for PNGs (probably convert them to JPEGs, plus compress them). This would be a safe choice for thumbnails, favicons not so much because transparency is desirable. - Editing messages is not yet supported. - I haven't coded any artificial limit on the number of previews or on the size of the thumbnail payload. This will be done in a separate issue. I have heard the ideal solution may be to split messages into smaller chunks of ~125 KiB because of libp2p, but that might be too complicated at this stage of the product (?). - Link preview deletion. - For the moment, OpenGraph metadata is extracted by requesting data for the English language (and fallback to whatever is available). In the future, we'll want to unfurl by respecting the user's local device language. Some websites, like GoDaddy, are already localized based on the device's IP, but many aren't. - The website's description text should be limited by a certain number of characters, especially because it's outside our control. Exactly how much has not been decided yet, so it'll be done separately. - URL normalization can be tricky, so I implemented only the basics to help with caching. For example, the url https://status.im and HTTPS://status.im are considered identical. Also, a URL is considered valid for unfurling if its TLD exists according to publicsuffix.EffectiveTLDPlusOne. This was essential, otherwise the default Go url.Parse approach would consider many invalid URLs valid, and thus the server would waste resources trying to unfurl the unfurleable. ### Other requirements - If the message is edited, the link previews should reflect the edited text, not the original one. This has been aligned with the design team as well. - If the website's thumbnail or the favicon can't be fetched, just ignore them. The only mandatory piece of metadata is the website's title and URL. - Link previews in clients should be generated in near real-time, that is, as the user types, previews are updated. In mobile this performs very well, and it's what other clients like WhatsApp, Telegram, and Facebook do. ### Decisions - While the user typing in the input field, the client is constantly (debounced) asking status-go to parse the text and extract normalized URLs and then the client checks if they're already in its in-memory cache. If they are, no RPC call is made. I chose this approach to achieve the best possible performance in mobile and avoid the whole RPC overhead, since the chat experience is already not smooth enough. The mobile client uses URLs as cache keys in a hashmap, i.e. if the key is present, it means the preview is readily available (naive, but good enough for now). This decision also gave me more flexibility to find the best UX at this stage of the feature. - Due to the requirement that users should be able to see independent loading indicators for each link preview, when status-go can't unfurl a URL, it doesn't return it in the response. - As an initial implementation, I added the BLOB column unfurled_links to the user_messages table. The preview data is then serialized as JSON before being stored in this column. I felt that creating a separate table and the related code for this initial PR would be inconvenient. Is that reasonable to you? Once things stabilize I can create a proper table if we want to avoid this kind of solution with serialized columns.
2023-05-18 18:43:06 +00:00
"testing"
"time"
URL unfurling (initial implementation) (#3471) This is the initial implementation for the new URL unfurling requirements. The most important one is that only the message sender will pay the privacy cost for unfurling and extracting metadata from websites. Once the message is sent, the unfurled data will be stored at the protocol level and receivers will just profit and happily decode the metadata to render it. Further development of this URL unfurling capability will be mostly guided by issues created on clients. For the moment in status-mobile: https://github.com/status-im/status-mobile/labels/url-preview - https://github.com/status-im/status-mobile/issues/15918 - https://github.com/status-im/status-mobile/issues/15917 - https://github.com/status-im/status-mobile/issues/15910 - https://github.com/status-im/status-mobile/issues/15909 - https://github.com/status-im/status-mobile/issues/15908 - https://github.com/status-im/status-mobile/issues/15906 - https://github.com/status-im/status-mobile/issues/15905 ### Terminology In the code, I've tried to stick to the word "unfurl URL" to really mean the process of extracting metadata from a website, sort of lower level. I use "link preview" to mean a higher level structure which is enriched by unfurled data. "link preview" is also how designers refer to it. ### User flows 1. Carol needs to see link previews while typing in the chat input field. Notice from the diagram nothing is persisted and that status-go endpoints are essentially stateless. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_getTextURLs Server-->>Client: Normalized URLs Client->>Client: Render cached unfurled URLs Client->>Server: Unfurl non-cached URLs.\nCall wakuext_unfurlURLs Server->>Website: Fetch metadata Website-->>Server: Metadata (thumbnail URL, title, etc) Server->>Website: Fetch thumbnail Server->>Website: Fetch favicon Website-->>Server: Favicon bytes Website-->>Server: Thumbnail bytes Server->>Server: Decode & process images Server-->>Client: Unfurled data (thumbnail data URI, etc) #+end_src ``` ``` ,------. ,------. ,-------. |Client| |Server| |Website| `--+---' `--+---' `---+---' | Call wakuext_getTextURLs | | | ---------------------------------------> | | | | | Normalized URLs | | | <- - - - - - - - - - - - - - - - - - - - | | | | |----. | | | | Render cached unfurled URLs | | |<---' | | | | | | Unfurl non-cached URLs. | | | Call wakuext_unfurlURLs | | | ---------------------------------------> | | | | | | Fetch metadata | | | ------------------------------------> | | | | | Metadata (thumbnail URL, title, etc)| | | <- - - - - - - - - - - - - - - - - - | | | | | Fetch thumbnail | | | ------------------------------------> | | | | | Fetch favicon | | | ------------------------------------> | | | | | Favicon bytes | | | <- - - - - - - - - - - - - - - - - - | | | | | Thumbnail bytes | | | <- - - - - - - - - - - - - - - - - - | | | | |----. | | | | Decode & process images | | |<---' | | | | | Unfurled data (thumbnail data URI, etc)| | | <- - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,---+---. |Client| |Server| |Website| `------' `------' `-------' ``` 2. Carol sends the text message with link previews in the RPC request wakuext_sendChatMessages. status-go assumes the link previews are good because it can't and shouldn't attempt to re-unfurl them. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_sendChatMessages Server->>Server: Transform link previews to\nbe proto-marshalled Server->DB: Write link previews serialized as JSON Server-->>Client: Updated message response #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | Call wakuext_sendChatMessages| | | -----------------------------> | | | | | |----. | | | | Transform link previews to | | |<---' be proto-marshalled | | | | | | | | | Write link previews serialized as JSON| | | --------------------------------------> | | | | Updated message response | | | <- - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` 3. The message was sent over waku and persisted locally in Carol's device. She should now see the link previews in the chat history. There can be many link previews shared by other chat members, therefore it is important to serve the assets via the media server to avoid overloading the ReactNative bridge with lots of big JSON payloads containing base64 encoded data URIs (maybe this concern is meaningless for desktop). When a client is rendering messages with link previews, they will have the field linkPreviews, and the thumbnail URL will point to the local media server. ``` #+begin_src plantuml :results verbatim Client->>Server: GET /link-preview/thumbnail (media server) Server->>DB: Read from user_messages.unfurled_links Server->Server: Unmarshal JSON Server-->>Client: HTTP Content-Type: image/jpeg/etc #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | GET /link-preview/thumbnail (media server)| | | ------------------------------------------> | | | | | | Read from user_messages.unfurled_links| | | --------------------------------------> | | | | |----. | | | | Unmarshal JSON | | |<---' | | | | | HTTP Content-Type: image/jpeg/etc | | | <- - - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` ### Some limitations of the current implementation The following points will become separate issues in status-go that I'll work on over the next couple weeks. In no order of importance: - Improve how multiple links are fetched; retries on failure and testing how unfurling behaves around the timeout limits (deterministically, not by making real HTTP calls as I did). https://github.com/status-im/status-go/issues/3498 - Unfurl favicons and store them in the protobuf too. - For this PR, I added unfurling support only for websites with OpenGraph https://ogp.me/ meta tags. Other unfurlers will be implemented on demand. The next one will probably be for oEmbed https://oembed.com/, the protocol supported by YouTube, for example. - Resize and/or compress thumbnails (and favicons). Often times, thumbnails are huge for the purposes of link previews. There is already support for compressing JPEGs in status-go, but I prefer to work with compression in a separate PR because I'd like to also solve the problem for PNGs (probably convert them to JPEGs, plus compress them). This would be a safe choice for thumbnails, favicons not so much because transparency is desirable. - Editing messages is not yet supported. - I haven't coded any artificial limit on the number of previews or on the size of the thumbnail payload. This will be done in a separate issue. I have heard the ideal solution may be to split messages into smaller chunks of ~125 KiB because of libp2p, but that might be too complicated at this stage of the product (?). - Link preview deletion. - For the moment, OpenGraph metadata is extracted by requesting data for the English language (and fallback to whatever is available). In the future, we'll want to unfurl by respecting the user's local device language. Some websites, like GoDaddy, are already localized based on the device's IP, but many aren't. - The website's description text should be limited by a certain number of characters, especially because it's outside our control. Exactly how much has not been decided yet, so it'll be done separately. - URL normalization can be tricky, so I implemented only the basics to help with caching. For example, the url https://status.im and HTTPS://status.im are considered identical. Also, a URL is considered valid for unfurling if its TLD exists according to publicsuffix.EffectiveTLDPlusOne. This was essential, otherwise the default Go url.Parse approach would consider many invalid URLs valid, and thus the server would waste resources trying to unfurl the unfurleable. ### Other requirements - If the message is edited, the link previews should reflect the edited text, not the original one. This has been aligned with the design team as well. - If the website's thumbnail or the favicon can't be fetched, just ignore them. The only mandatory piece of metadata is the website's title and URL. - Link previews in clients should be generated in near real-time, that is, as the user types, previews are updated. In mobile this performs very well, and it's what other clients like WhatsApp, Telegram, and Facebook do. ### Decisions - While the user typing in the input field, the client is constantly (debounced) asking status-go to parse the text and extract normalized URLs and then the client checks if they're already in its in-memory cache. If they are, no RPC call is made. I chose this approach to achieve the best possible performance in mobile and avoid the whole RPC overhead, since the chat experience is already not smooth enough. The mobile client uses URLs as cache keys in a hashmap, i.e. if the key is present, it means the preview is readily available (naive, but good enough for now). This decision also gave me more flexibility to find the best UX at this stage of the feature. - Due to the requirement that users should be able to see independent loading indicators for each link preview, when status-go can't unfurl a URL, it doesn't return it in the response. - As an initial implementation, I added the BLOB column unfurled_links to the user_messages table. The preview data is then serialized as JSON before being stored in this column. I felt that creating a separate table and the related code for this initial PR would be inconvenient. Is that reasonable to you? Once things stabilize I can create a proper table if we want to avoid this kind of solution with serialized columns.
2023-05-18 18:43:06 +00:00
"github.com/stretchr/testify/suite"
URL unfurling (initial implementation) (#3471) This is the initial implementation for the new URL unfurling requirements. The most important one is that only the message sender will pay the privacy cost for unfurling and extracting metadata from websites. Once the message is sent, the unfurled data will be stored at the protocol level and receivers will just profit and happily decode the metadata to render it. Further development of this URL unfurling capability will be mostly guided by issues created on clients. For the moment in status-mobile: https://github.com/status-im/status-mobile/labels/url-preview - https://github.com/status-im/status-mobile/issues/15918 - https://github.com/status-im/status-mobile/issues/15917 - https://github.com/status-im/status-mobile/issues/15910 - https://github.com/status-im/status-mobile/issues/15909 - https://github.com/status-im/status-mobile/issues/15908 - https://github.com/status-im/status-mobile/issues/15906 - https://github.com/status-im/status-mobile/issues/15905 ### Terminology In the code, I've tried to stick to the word "unfurl URL" to really mean the process of extracting metadata from a website, sort of lower level. I use "link preview" to mean a higher level structure which is enriched by unfurled data. "link preview" is also how designers refer to it. ### User flows 1. Carol needs to see link previews while typing in the chat input field. Notice from the diagram nothing is persisted and that status-go endpoints are essentially stateless. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_getTextURLs Server-->>Client: Normalized URLs Client->>Client: Render cached unfurled URLs Client->>Server: Unfurl non-cached URLs.\nCall wakuext_unfurlURLs Server->>Website: Fetch metadata Website-->>Server: Metadata (thumbnail URL, title, etc) Server->>Website: Fetch thumbnail Server->>Website: Fetch favicon Website-->>Server: Favicon bytes Website-->>Server: Thumbnail bytes Server->>Server: Decode & process images Server-->>Client: Unfurled data (thumbnail data URI, etc) #+end_src ``` ``` ,------. ,------. ,-------. |Client| |Server| |Website| `--+---' `--+---' `---+---' | Call wakuext_getTextURLs | | | ---------------------------------------> | | | | | Normalized URLs | | | <- - - - - - - - - - - - - - - - - - - - | | | | |----. | | | | Render cached unfurled URLs | | |<---' | | | | | | Unfurl non-cached URLs. | | | Call wakuext_unfurlURLs | | | ---------------------------------------> | | | | | | Fetch metadata | | | ------------------------------------> | | | | | Metadata (thumbnail URL, title, etc)| | | <- - - - - - - - - - - - - - - - - - | | | | | Fetch thumbnail | | | ------------------------------------> | | | | | Fetch favicon | | | ------------------------------------> | | | | | Favicon bytes | | | <- - - - - - - - - - - - - - - - - - | | | | | Thumbnail bytes | | | <- - - - - - - - - - - - - - - - - - | | | | |----. | | | | Decode & process images | | |<---' | | | | | Unfurled data (thumbnail data URI, etc)| | | <- - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,---+---. |Client| |Server| |Website| `------' `------' `-------' ``` 2. Carol sends the text message with link previews in the RPC request wakuext_sendChatMessages. status-go assumes the link previews are good because it can't and shouldn't attempt to re-unfurl them. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_sendChatMessages Server->>Server: Transform link previews to\nbe proto-marshalled Server->DB: Write link previews serialized as JSON Server-->>Client: Updated message response #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | Call wakuext_sendChatMessages| | | -----------------------------> | | | | | |----. | | | | Transform link previews to | | |<---' be proto-marshalled | | | | | | | | | Write link previews serialized as JSON| | | --------------------------------------> | | | | Updated message response | | | <- - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` 3. The message was sent over waku and persisted locally in Carol's device. She should now see the link previews in the chat history. There can be many link previews shared by other chat members, therefore it is important to serve the assets via the media server to avoid overloading the ReactNative bridge with lots of big JSON payloads containing base64 encoded data URIs (maybe this concern is meaningless for desktop). When a client is rendering messages with link previews, they will have the field linkPreviews, and the thumbnail URL will point to the local media server. ``` #+begin_src plantuml :results verbatim Client->>Server: GET /link-preview/thumbnail (media server) Server->>DB: Read from user_messages.unfurled_links Server->Server: Unmarshal JSON Server-->>Client: HTTP Content-Type: image/jpeg/etc #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | GET /link-preview/thumbnail (media server)| | | ------------------------------------------> | | | | | | Read from user_messages.unfurled_links| | | --------------------------------------> | | | | |----. | | | | Unmarshal JSON | | |<---' | | | | | HTTP Content-Type: image/jpeg/etc | | | <- - - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` ### Some limitations of the current implementation The following points will become separate issues in status-go that I'll work on over the next couple weeks. In no order of importance: - Improve how multiple links are fetched; retries on failure and testing how unfurling behaves around the timeout limits (deterministically, not by making real HTTP calls as I did). https://github.com/status-im/status-go/issues/3498 - Unfurl favicons and store them in the protobuf too. - For this PR, I added unfurling support only for websites with OpenGraph https://ogp.me/ meta tags. Other unfurlers will be implemented on demand. The next one will probably be for oEmbed https://oembed.com/, the protocol supported by YouTube, for example. - Resize and/or compress thumbnails (and favicons). Often times, thumbnails are huge for the purposes of link previews. There is already support for compressing JPEGs in status-go, but I prefer to work with compression in a separate PR because I'd like to also solve the problem for PNGs (probably convert them to JPEGs, plus compress them). This would be a safe choice for thumbnails, favicons not so much because transparency is desirable. - Editing messages is not yet supported. - I haven't coded any artificial limit on the number of previews or on the size of the thumbnail payload. This will be done in a separate issue. I have heard the ideal solution may be to split messages into smaller chunks of ~125 KiB because of libp2p, but that might be too complicated at this stage of the product (?). - Link preview deletion. - For the moment, OpenGraph metadata is extracted by requesting data for the English language (and fallback to whatever is available). In the future, we'll want to unfurl by respecting the user's local device language. Some websites, like GoDaddy, are already localized based on the device's IP, but many aren't. - The website's description text should be limited by a certain number of characters, especially because it's outside our control. Exactly how much has not been decided yet, so it'll be done separately. - URL normalization can be tricky, so I implemented only the basics to help with caching. For example, the url https://status.im and HTTPS://status.im are considered identical. Also, a URL is considered valid for unfurling if its TLD exists according to publicsuffix.EffectiveTLDPlusOne. This was essential, otherwise the default Go url.Parse approach would consider many invalid URLs valid, and thus the server would waste resources trying to unfurl the unfurleable. ### Other requirements - If the message is edited, the link previews should reflect the edited text, not the original one. This has been aligned with the design team as well. - If the website's thumbnail or the favicon can't be fetched, just ignore them. The only mandatory piece of metadata is the website's title and URL. - Link previews in clients should be generated in near real-time, that is, as the user types, previews are updated. In mobile this performs very well, and it's what other clients like WhatsApp, Telegram, and Facebook do. ### Decisions - While the user typing in the input field, the client is constantly (debounced) asking status-go to parse the text and extract normalized URLs and then the client checks if they're already in its in-memory cache. If they are, no RPC call is made. I chose this approach to achieve the best possible performance in mobile and avoid the whole RPC overhead, since the chat experience is already not smooth enough. The mobile client uses URLs as cache keys in a hashmap, i.e. if the key is present, it means the preview is readily available (naive, but good enough for now). This decision also gave me more flexibility to find the best UX at this stage of the feature. - Due to the requirement that users should be able to see independent loading indicators for each link preview, when status-go can't unfurl a URL, it doesn't return it in the response. - As an initial implementation, I added the BLOB column unfurled_links to the user_messages table. The preview data is then serialized as JSON before being stored in this column. I felt that creating a separate table and the related code for this initial PR would be inconvenient. Is that reasonable to you? Once things stabilize I can create a proper table if we want to avoid this kind of solution with serialized columns.
2023-05-18 18:43:06 +00:00
2023-10-13 12:25:34 +00:00
"github.com/status-im/status-go/eth-node/crypto"
"github.com/status-im/status-go/images"
"github.com/status-im/status-go/multiaccounts/accounts"
2023-10-13 14:31:56 +00:00
"github.com/status-im/status-go/multiaccounts/settings"
URL unfurling (initial implementation) (#3471) This is the initial implementation for the new URL unfurling requirements. The most important one is that only the message sender will pay the privacy cost for unfurling and extracting metadata from websites. Once the message is sent, the unfurled data will be stored at the protocol level and receivers will just profit and happily decode the metadata to render it. Further development of this URL unfurling capability will be mostly guided by issues created on clients. For the moment in status-mobile: https://github.com/status-im/status-mobile/labels/url-preview - https://github.com/status-im/status-mobile/issues/15918 - https://github.com/status-im/status-mobile/issues/15917 - https://github.com/status-im/status-mobile/issues/15910 - https://github.com/status-im/status-mobile/issues/15909 - https://github.com/status-im/status-mobile/issues/15908 - https://github.com/status-im/status-mobile/issues/15906 - https://github.com/status-im/status-mobile/issues/15905 ### Terminology In the code, I've tried to stick to the word "unfurl URL" to really mean the process of extracting metadata from a website, sort of lower level. I use "link preview" to mean a higher level structure which is enriched by unfurled data. "link preview" is also how designers refer to it. ### User flows 1. Carol needs to see link previews while typing in the chat input field. Notice from the diagram nothing is persisted and that status-go endpoints are essentially stateless. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_getTextURLs Server-->>Client: Normalized URLs Client->>Client: Render cached unfurled URLs Client->>Server: Unfurl non-cached URLs.\nCall wakuext_unfurlURLs Server->>Website: Fetch metadata Website-->>Server: Metadata (thumbnail URL, title, etc) Server->>Website: Fetch thumbnail Server->>Website: Fetch favicon Website-->>Server: Favicon bytes Website-->>Server: Thumbnail bytes Server->>Server: Decode & process images Server-->>Client: Unfurled data (thumbnail data URI, etc) #+end_src ``` ``` ,------. ,------. ,-------. |Client| |Server| |Website| `--+---' `--+---' `---+---' | Call wakuext_getTextURLs | | | ---------------------------------------> | | | | | Normalized URLs | | | <- - - - - - - - - - - - - - - - - - - - | | | | |----. | | | | Render cached unfurled URLs | | |<---' | | | | | | Unfurl non-cached URLs. | | | Call wakuext_unfurlURLs | | | ---------------------------------------> | | | | | | Fetch metadata | | | ------------------------------------> | | | | | Metadata (thumbnail URL, title, etc)| | | <- - - - - - - - - - - - - - - - - - | | | | | Fetch thumbnail | | | ------------------------------------> | | | | | Fetch favicon | | | ------------------------------------> | | | | | Favicon bytes | | | <- - - - - - - - - - - - - - - - - - | | | | | Thumbnail bytes | | | <- - - - - - - - - - - - - - - - - - | | | | |----. | | | | Decode & process images | | |<---' | | | | | Unfurled data (thumbnail data URI, etc)| | | <- - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,---+---. |Client| |Server| |Website| `------' `------' `-------' ``` 2. Carol sends the text message with link previews in the RPC request wakuext_sendChatMessages. status-go assumes the link previews are good because it can't and shouldn't attempt to re-unfurl them. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_sendChatMessages Server->>Server: Transform link previews to\nbe proto-marshalled Server->DB: Write link previews serialized as JSON Server-->>Client: Updated message response #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | Call wakuext_sendChatMessages| | | -----------------------------> | | | | | |----. | | | | Transform link previews to | | |<---' be proto-marshalled | | | | | | | | | Write link previews serialized as JSON| | | --------------------------------------> | | | | Updated message response | | | <- - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` 3. The message was sent over waku and persisted locally in Carol's device. She should now see the link previews in the chat history. There can be many link previews shared by other chat members, therefore it is important to serve the assets via the media server to avoid overloading the ReactNative bridge with lots of big JSON payloads containing base64 encoded data URIs (maybe this concern is meaningless for desktop). When a client is rendering messages with link previews, they will have the field linkPreviews, and the thumbnail URL will point to the local media server. ``` #+begin_src plantuml :results verbatim Client->>Server: GET /link-preview/thumbnail (media server) Server->>DB: Read from user_messages.unfurled_links Server->Server: Unmarshal JSON Server-->>Client: HTTP Content-Type: image/jpeg/etc #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | GET /link-preview/thumbnail (media server)| | | ------------------------------------------> | | | | | | Read from user_messages.unfurled_links| | | --------------------------------------> | | | | |----. | | | | Unmarshal JSON | | |<---' | | | | | HTTP Content-Type: image/jpeg/etc | | | <- - - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` ### Some limitations of the current implementation The following points will become separate issues in status-go that I'll work on over the next couple weeks. In no order of importance: - Improve how multiple links are fetched; retries on failure and testing how unfurling behaves around the timeout limits (deterministically, not by making real HTTP calls as I did). https://github.com/status-im/status-go/issues/3498 - Unfurl favicons and store them in the protobuf too. - For this PR, I added unfurling support only for websites with OpenGraph https://ogp.me/ meta tags. Other unfurlers will be implemented on demand. The next one will probably be for oEmbed https://oembed.com/, the protocol supported by YouTube, for example. - Resize and/or compress thumbnails (and favicons). Often times, thumbnails are huge for the purposes of link previews. There is already support for compressing JPEGs in status-go, but I prefer to work with compression in a separate PR because I'd like to also solve the problem for PNGs (probably convert them to JPEGs, plus compress them). This would be a safe choice for thumbnails, favicons not so much because transparency is desirable. - Editing messages is not yet supported. - I haven't coded any artificial limit on the number of previews or on the size of the thumbnail payload. This will be done in a separate issue. I have heard the ideal solution may be to split messages into smaller chunks of ~125 KiB because of libp2p, but that might be too complicated at this stage of the product (?). - Link preview deletion. - For the moment, OpenGraph metadata is extracted by requesting data for the English language (and fallback to whatever is available). In the future, we'll want to unfurl by respecting the user's local device language. Some websites, like GoDaddy, are already localized based on the device's IP, but many aren't. - The website's description text should be limited by a certain number of characters, especially because it's outside our control. Exactly how much has not been decided yet, so it'll be done separately. - URL normalization can be tricky, so I implemented only the basics to help with caching. For example, the url https://status.im and HTTPS://status.im are considered identical. Also, a URL is considered valid for unfurling if its TLD exists according to publicsuffix.EffectiveTLDPlusOne. This was essential, otherwise the default Go url.Parse approach would consider many invalid URLs valid, and thus the server would waste resources trying to unfurl the unfurleable. ### Other requirements - If the message is edited, the link previews should reflect the edited text, not the original one. This has been aligned with the design team as well. - If the website's thumbnail or the favicon can't be fetched, just ignore them. The only mandatory piece of metadata is the website's title and URL. - Link previews in clients should be generated in near real-time, that is, as the user types, previews are updated. In mobile this performs very well, and it's what other clients like WhatsApp, Telegram, and Facebook do. ### Decisions - While the user typing in the input field, the client is constantly (debounced) asking status-go to parse the text and extract normalized URLs and then the client checks if they're already in its in-memory cache. If they are, no RPC call is made. I chose this approach to achieve the best possible performance in mobile and avoid the whole RPC overhead, since the chat experience is already not smooth enough. The mobile client uses URLs as cache keys in a hashmap, i.e. if the key is present, it means the preview is readily available (naive, but good enough for now). This decision also gave me more flexibility to find the best UX at this stage of the feature. - Due to the requirement that users should be able to see independent loading indicators for each link preview, when status-go can't unfurl a URL, it doesn't return it in the response. - As an initial implementation, I added the BLOB column unfurled_links to the user_messages table. The preview data is then serialized as JSON before being stored in this column. I felt that creating a separate table and the related code for this initial PR would be inconvenient. Is that reasonable to you? Once things stabilize I can create a proper table if we want to avoid this kind of solution with serialized columns.
2023-05-18 18:43:06 +00:00
"github.com/status-im/status-go/protocol/common"
"github.com/status-im/status-go/protocol/protobuf"
2023-10-13 12:25:34 +00:00
"github.com/status-im/status-go/protocol/requests"
URL unfurling (initial implementation) (#3471) This is the initial implementation for the new URL unfurling requirements. The most important one is that only the message sender will pay the privacy cost for unfurling and extracting metadata from websites. Once the message is sent, the unfurled data will be stored at the protocol level and receivers will just profit and happily decode the metadata to render it. Further development of this URL unfurling capability will be mostly guided by issues created on clients. For the moment in status-mobile: https://github.com/status-im/status-mobile/labels/url-preview - https://github.com/status-im/status-mobile/issues/15918 - https://github.com/status-im/status-mobile/issues/15917 - https://github.com/status-im/status-mobile/issues/15910 - https://github.com/status-im/status-mobile/issues/15909 - https://github.com/status-im/status-mobile/issues/15908 - https://github.com/status-im/status-mobile/issues/15906 - https://github.com/status-im/status-mobile/issues/15905 ### Terminology In the code, I've tried to stick to the word "unfurl URL" to really mean the process of extracting metadata from a website, sort of lower level. I use "link preview" to mean a higher level structure which is enriched by unfurled data. "link preview" is also how designers refer to it. ### User flows 1. Carol needs to see link previews while typing in the chat input field. Notice from the diagram nothing is persisted and that status-go endpoints are essentially stateless. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_getTextURLs Server-->>Client: Normalized URLs Client->>Client: Render cached unfurled URLs Client->>Server: Unfurl non-cached URLs.\nCall wakuext_unfurlURLs Server->>Website: Fetch metadata Website-->>Server: Metadata (thumbnail URL, title, etc) Server->>Website: Fetch thumbnail Server->>Website: Fetch favicon Website-->>Server: Favicon bytes Website-->>Server: Thumbnail bytes Server->>Server: Decode & process images Server-->>Client: Unfurled data (thumbnail data URI, etc) #+end_src ``` ``` ,------. ,------. ,-------. |Client| |Server| |Website| `--+---' `--+---' `---+---' | Call wakuext_getTextURLs | | | ---------------------------------------> | | | | | Normalized URLs | | | <- - - - - - - - - - - - - - - - - - - - | | | | |----. | | | | Render cached unfurled URLs | | |<---' | | | | | | Unfurl non-cached URLs. | | | Call wakuext_unfurlURLs | | | ---------------------------------------> | | | | | | Fetch metadata | | | ------------------------------------> | | | | | Metadata (thumbnail URL, title, etc)| | | <- - - - - - - - - - - - - - - - - - | | | | | Fetch thumbnail | | | ------------------------------------> | | | | | Fetch favicon | | | ------------------------------------> | | | | | Favicon bytes | | | <- - - - - - - - - - - - - - - - - - | | | | | Thumbnail bytes | | | <- - - - - - - - - - - - - - - - - - | | | | |----. | | | | Decode & process images | | |<---' | | | | | Unfurled data (thumbnail data URI, etc)| | | <- - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,---+---. |Client| |Server| |Website| `------' `------' `-------' ``` 2. Carol sends the text message with link previews in the RPC request wakuext_sendChatMessages. status-go assumes the link previews are good because it can't and shouldn't attempt to re-unfurl them. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_sendChatMessages Server->>Server: Transform link previews to\nbe proto-marshalled Server->DB: Write link previews serialized as JSON Server-->>Client: Updated message response #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | Call wakuext_sendChatMessages| | | -----------------------------> | | | | | |----. | | | | Transform link previews to | | |<---' be proto-marshalled | | | | | | | | | Write link previews serialized as JSON| | | --------------------------------------> | | | | Updated message response | | | <- - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` 3. The message was sent over waku and persisted locally in Carol's device. She should now see the link previews in the chat history. There can be many link previews shared by other chat members, therefore it is important to serve the assets via the media server to avoid overloading the ReactNative bridge with lots of big JSON payloads containing base64 encoded data URIs (maybe this concern is meaningless for desktop). When a client is rendering messages with link previews, they will have the field linkPreviews, and the thumbnail URL will point to the local media server. ``` #+begin_src plantuml :results verbatim Client->>Server: GET /link-preview/thumbnail (media server) Server->>DB: Read from user_messages.unfurled_links Server->Server: Unmarshal JSON Server-->>Client: HTTP Content-Type: image/jpeg/etc #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | GET /link-preview/thumbnail (media server)| | | ------------------------------------------> | | | | | | Read from user_messages.unfurled_links| | | --------------------------------------> | | | | |----. | | | | Unmarshal JSON | | |<---' | | | | | HTTP Content-Type: image/jpeg/etc | | | <- - - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` ### Some limitations of the current implementation The following points will become separate issues in status-go that I'll work on over the next couple weeks. In no order of importance: - Improve how multiple links are fetched; retries on failure and testing how unfurling behaves around the timeout limits (deterministically, not by making real HTTP calls as I did). https://github.com/status-im/status-go/issues/3498 - Unfurl favicons and store them in the protobuf too. - For this PR, I added unfurling support only for websites with OpenGraph https://ogp.me/ meta tags. Other unfurlers will be implemented on demand. The next one will probably be for oEmbed https://oembed.com/, the protocol supported by YouTube, for example. - Resize and/or compress thumbnails (and favicons). Often times, thumbnails are huge for the purposes of link previews. There is already support for compressing JPEGs in status-go, but I prefer to work with compression in a separate PR because I'd like to also solve the problem for PNGs (probably convert them to JPEGs, plus compress them). This would be a safe choice for thumbnails, favicons not so much because transparency is desirable. - Editing messages is not yet supported. - I haven't coded any artificial limit on the number of previews or on the size of the thumbnail payload. This will be done in a separate issue. I have heard the ideal solution may be to split messages into smaller chunks of ~125 KiB because of libp2p, but that might be too complicated at this stage of the product (?). - Link preview deletion. - For the moment, OpenGraph metadata is extracted by requesting data for the English language (and fallback to whatever is available). In the future, we'll want to unfurl by respecting the user's local device language. Some websites, like GoDaddy, are already localized based on the device's IP, but many aren't. - The website's description text should be limited by a certain number of characters, especially because it's outside our control. Exactly how much has not been decided yet, so it'll be done separately. - URL normalization can be tricky, so I implemented only the basics to help with caching. For example, the url https://status.im and HTTPS://status.im are considered identical. Also, a URL is considered valid for unfurling if its TLD exists according to publicsuffix.EffectiveTLDPlusOne. This was essential, otherwise the default Go url.Parse approach would consider many invalid URLs valid, and thus the server would waste resources trying to unfurl the unfurleable. ### Other requirements - If the message is edited, the link previews should reflect the edited text, not the original one. This has been aligned with the design team as well. - If the website's thumbnail or the favicon can't be fetched, just ignore them. The only mandatory piece of metadata is the website's title and URL. - Link previews in clients should be generated in near real-time, that is, as the user types, previews are updated. In mobile this performs very well, and it's what other clients like WhatsApp, Telegram, and Facebook do. ### Decisions - While the user typing in the input field, the client is constantly (debounced) asking status-go to parse the text and extract normalized URLs and then the client checks if they're already in its in-memory cache. If they are, no RPC call is made. I chose this approach to achieve the best possible performance in mobile and avoid the whole RPC overhead, since the chat experience is already not smooth enough. The mobile client uses URLs as cache keys in a hashmap, i.e. if the key is present, it means the preview is readily available (naive, but good enough for now). This decision also gave me more flexibility to find the best UX at this stage of the feature. - Due to the requirement that users should be able to see independent loading indicators for each link preview, when status-go can't unfurl a URL, it doesn't return it in the response. - As an initial implementation, I added the BLOB column unfurled_links to the user_messages table. The preview data is then serialized as JSON before being stored in this column. I felt that creating a separate table and the related code for this initial PR would be inconvenient. Is that reasonable to you? Once things stabilize I can create a proper table if we want to avoid this kind of solution with serialized columns.
2023-05-18 18:43:06 +00:00
)
const (
exampleIdenticonURI = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAADIAAAAyCAYAAAAeP4ixA" +
"AAAiklEQVR4nOzWwQmFQAwG4ffEXmzLIizDImzLarQBhSwSGH7mO+9hh0DI9AthCI0hNIbQGEJjCI0hNIbQxITM1YfHfl69X3m2bsu/8i5mI" +
"obQGEJjCI0hNIbQlG+tUW83UtfNFjMRQ2gMofm8tUa3U9c2i5mIITSGqEnMRAyhMYTGEBpDaO4AAAD//5POEGncqtj1AAAAAElFTkSuQmCC"
)
func TestMessengerLinkPreviews(t *testing.T) {
suite.Run(t, new(MessengerLinkPreviewsTestSuite))
}
type MessengerLinkPreviewsTestSuite struct {
MessengerBaseTestSuite
}
// StubMatcher should either return an http.Response or nil in case the request
// doesn't match.
type StubMatcher func(req *http.Request) *http.Response
type StubTransport struct {
// fallbackToDefaultTransport when true will make the transport use
// http.DefaultTransport in case no matcher is found.
fallbackToDefaultTransport bool
// disabledStubs when true, will skip all matchers and use
// http.DefaultTransport.
//
// Useful while testing to toggle between the original and stubbed responses.
disabledStubs bool
// matchers are http.RoundTripper functions.
matchers []StubMatcher
}
// RoundTrip returns a stubbed response if any matcher returns a non-nil
// http.Response. If no matcher is found and fallbackToDefaultTransport is true,
// then it executes the HTTP request using the default http transport.
//
// If StubTransport#disabledStubs is true, the default http transport is used.
func (t *StubTransport) RoundTrip(req *http.Request) (*http.Response, error) {
if t.disabledStubs {
return http.DefaultTransport.RoundTrip(req)
}
for _, matcher := range t.matchers {
res := matcher(req)
if res != nil {
return res, nil
}
}
if t.fallbackToDefaultTransport {
return http.DefaultTransport.RoundTrip(req)
}
return nil, fmt.Errorf("no HTTP matcher found")
}
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func (t *StubTransport) AddURLMatcherRoundTrip(urlRegexp string, roundTrip func(r *http.Request) *http.Response) {
matcher := func(req *http.Request) *http.Response {
rx, err := regexp.Compile(regexp.QuoteMeta(urlRegexp))
if err != nil {
return nil
}
if !rx.MatchString(req.URL.String()) {
return nil
}
return roundTrip(req)
}
t.matchers = append(t.matchers, matcher)
}
// Add a matcher based on a URL regexp. If a given request URL matches the
// regexp, then responseBody will be returned with a hardcoded 200 status code.
// If headers is non-nil, use it as the value of http.Response.Header.
func (t *StubTransport) AddURLMatcher(urlRegexp string, responseBody []byte, headers map[string]string) {
matcher := func(req *http.Request) *http.Response {
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res := &http.Response{
StatusCode: http.StatusOK,
Body: ioutil.NopCloser(bytes.NewBuffer(responseBody)),
}
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if headers != nil {
res.Header = http.Header{}
for k, v := range headers {
res.Header.Set(k, v)
}
}
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return res
}
t.AddURLMatcherRoundTrip(urlRegexp, matcher)
}
URL unfurling (initial implementation) (#3471) This is the initial implementation for the new URL unfurling requirements. The most important one is that only the message sender will pay the privacy cost for unfurling and extracting metadata from websites. Once the message is sent, the unfurled data will be stored at the protocol level and receivers will just profit and happily decode the metadata to render it. Further development of this URL unfurling capability will be mostly guided by issues created on clients. For the moment in status-mobile: https://github.com/status-im/status-mobile/labels/url-preview - https://github.com/status-im/status-mobile/issues/15918 - https://github.com/status-im/status-mobile/issues/15917 - https://github.com/status-im/status-mobile/issues/15910 - https://github.com/status-im/status-mobile/issues/15909 - https://github.com/status-im/status-mobile/issues/15908 - https://github.com/status-im/status-mobile/issues/15906 - https://github.com/status-im/status-mobile/issues/15905 ### Terminology In the code, I've tried to stick to the word "unfurl URL" to really mean the process of extracting metadata from a website, sort of lower level. I use "link preview" to mean a higher level structure which is enriched by unfurled data. "link preview" is also how designers refer to it. ### User flows 1. Carol needs to see link previews while typing in the chat input field. Notice from the diagram nothing is persisted and that status-go endpoints are essentially stateless. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_getTextURLs Server-->>Client: Normalized URLs Client->>Client: Render cached unfurled URLs Client->>Server: Unfurl non-cached URLs.\nCall wakuext_unfurlURLs Server->>Website: Fetch metadata Website-->>Server: Metadata (thumbnail URL, title, etc) Server->>Website: Fetch thumbnail Server->>Website: Fetch favicon Website-->>Server: Favicon bytes Website-->>Server: Thumbnail bytes Server->>Server: Decode & process images Server-->>Client: Unfurled data (thumbnail data URI, etc) #+end_src ``` ``` ,------. ,------. ,-------. |Client| |Server| |Website| `--+---' `--+---' `---+---' | Call wakuext_getTextURLs | | | ---------------------------------------> | | | | | Normalized URLs | | | <- - - - - - - - - - - - - - - - - - - - | | | | |----. | | | | Render cached unfurled URLs | | |<---' | | | | | | Unfurl non-cached URLs. | | | Call wakuext_unfurlURLs | | | ---------------------------------------> | | | | | | Fetch metadata | | | ------------------------------------> | | | | | Metadata (thumbnail URL, title, etc)| | | <- - - - - - - - - - - - - - - - - - | | | | | Fetch thumbnail | | | ------------------------------------> | | | | | Fetch favicon | | | ------------------------------------> | | | | | Favicon bytes | | | <- - - - - - - - - - - - - - - - - - | | | | | Thumbnail bytes | | | <- - - - - - - - - - - - - - - - - - | | | | |----. | | | | Decode & process images | | |<---' | | | | | Unfurled data (thumbnail data URI, etc)| | | <- - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,---+---. |Client| |Server| |Website| `------' `------' `-------' ``` 2. Carol sends the text message with link previews in the RPC request wakuext_sendChatMessages. status-go assumes the link previews are good because it can't and shouldn't attempt to re-unfurl them. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_sendChatMessages Server->>Server: Transform link previews to\nbe proto-marshalled Server->DB: Write link previews serialized as JSON Server-->>Client: Updated message response #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | Call wakuext_sendChatMessages| | | -----------------------------> | | | | | |----. | | | | Transform link previews to | | |<---' be proto-marshalled | | | | | | | | | Write link previews serialized as JSON| | | --------------------------------------> | | | | Updated message response | | | <- - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` 3. The message was sent over waku and persisted locally in Carol's device. She should now see the link previews in the chat history. There can be many link previews shared by other chat members, therefore it is important to serve the assets via the media server to avoid overloading the ReactNative bridge with lots of big JSON payloads containing base64 encoded data URIs (maybe this concern is meaningless for desktop). When a client is rendering messages with link previews, they will have the field linkPreviews, and the thumbnail URL will point to the local media server. ``` #+begin_src plantuml :results verbatim Client->>Server: GET /link-preview/thumbnail (media server) Server->>DB: Read from user_messages.unfurled_links Server->Server: Unmarshal JSON Server-->>Client: HTTP Content-Type: image/jpeg/etc #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | GET /link-preview/thumbnail (media server)| | | ------------------------------------------> | | | | | | Read from user_messages.unfurled_links| | | --------------------------------------> | | | | |----. | | | | Unmarshal JSON | | |<---' | | | | | HTTP Content-Type: image/jpeg/etc | | | <- - - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` ### Some limitations of the current implementation The following points will become separate issues in status-go that I'll work on over the next couple weeks. In no order of importance: - Improve how multiple links are fetched; retries on failure and testing how unfurling behaves around the timeout limits (deterministically, not by making real HTTP calls as I did). https://github.com/status-im/status-go/issues/3498 - Unfurl favicons and store them in the protobuf too. - For this PR, I added unfurling support only for websites with OpenGraph https://ogp.me/ meta tags. Other unfurlers will be implemented on demand. The next one will probably be for oEmbed https://oembed.com/, the protocol supported by YouTube, for example. - Resize and/or compress thumbnails (and favicons). Often times, thumbnails are huge for the purposes of link previews. There is already support for compressing JPEGs in status-go, but I prefer to work with compression in a separate PR because I'd like to also solve the problem for PNGs (probably convert them to JPEGs, plus compress them). This would be a safe choice for thumbnails, favicons not so much because transparency is desirable. - Editing messages is not yet supported. - I haven't coded any artificial limit on the number of previews or on the size of the thumbnail payload. This will be done in a separate issue. I have heard the ideal solution may be to split messages into smaller chunks of ~125 KiB because of libp2p, but that might be too complicated at this stage of the product (?). - Link preview deletion. - For the moment, OpenGraph metadata is extracted by requesting data for the English language (and fallback to whatever is available). In the future, we'll want to unfurl by respecting the user's local device language. Some websites, like GoDaddy, are already localized based on the device's IP, but many aren't. - The website's description text should be limited by a certain number of characters, especially because it's outside our control. Exactly how much has not been decided yet, so it'll be done separately. - URL normalization can be tricky, so I implemented only the basics to help with caching. For example, the url https://status.im and HTTPS://status.im are considered identical. Also, a URL is considered valid for unfurling if its TLD exists according to publicsuffix.EffectiveTLDPlusOne. This was essential, otherwise the default Go url.Parse approach would consider many invalid URLs valid, and thus the server would waste resources trying to unfurl the unfurleable. ### Other requirements - If the message is edited, the link previews should reflect the edited text, not the original one. This has been aligned with the design team as well. - If the website's thumbnail or the favicon can't be fetched, just ignore them. The only mandatory piece of metadata is the website's title and URL. - Link previews in clients should be generated in near real-time, that is, as the user types, previews are updated. In mobile this performs very well, and it's what other clients like WhatsApp, Telegram, and Facebook do. ### Decisions - While the user typing in the input field, the client is constantly (debounced) asking status-go to parse the text and extract normalized URLs and then the client checks if they're already in its in-memory cache. If they are, no RPC call is made. I chose this approach to achieve the best possible performance in mobile and avoid the whole RPC overhead, since the chat experience is already not smooth enough. The mobile client uses URLs as cache keys in a hashmap, i.e. if the key is present, it means the preview is readily available (naive, but good enough for now). This decision also gave me more flexibility to find the best UX at this stage of the feature. - Due to the requirement that users should be able to see independent loading indicators for each link preview, when status-go can't unfurl a URL, it doesn't return it in the response. - As an initial implementation, I added the BLOB column unfurled_links to the user_messages table. The preview data is then serialized as JSON before being stored in this column. I felt that creating a separate table and the related code for this initial PR would be inconvenient. Is that reasonable to you? Once things stabilize I can create a proper table if we want to avoid this kind of solution with serialized columns.
2023-05-18 18:43:06 +00:00
// assertContainsLongString verifies if actual contains a slice of expected and
// correctly prints the cause of the failure. The default behavior of
// require.Contains with long strings is to not print the formatted message
// (varargs to require.Contains).
func (s *MessengerLinkPreviewsTestSuite) assertContainsLongString(expected string, actual string, maxLength int) {
URL unfurling (initial implementation) (#3471) This is the initial implementation for the new URL unfurling requirements. The most important one is that only the message sender will pay the privacy cost for unfurling and extracting metadata from websites. Once the message is sent, the unfurled data will be stored at the protocol level and receivers will just profit and happily decode the metadata to render it. Further development of this URL unfurling capability will be mostly guided by issues created on clients. For the moment in status-mobile: https://github.com/status-im/status-mobile/labels/url-preview - https://github.com/status-im/status-mobile/issues/15918 - https://github.com/status-im/status-mobile/issues/15917 - https://github.com/status-im/status-mobile/issues/15910 - https://github.com/status-im/status-mobile/issues/15909 - https://github.com/status-im/status-mobile/issues/15908 - https://github.com/status-im/status-mobile/issues/15906 - https://github.com/status-im/status-mobile/issues/15905 ### Terminology In the code, I've tried to stick to the word "unfurl URL" to really mean the process of extracting metadata from a website, sort of lower level. I use "link preview" to mean a higher level structure which is enriched by unfurled data. "link preview" is also how designers refer to it. ### User flows 1. Carol needs to see link previews while typing in the chat input field. Notice from the diagram nothing is persisted and that status-go endpoints are essentially stateless. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_getTextURLs Server-->>Client: Normalized URLs Client->>Client: Render cached unfurled URLs Client->>Server: Unfurl non-cached URLs.\nCall wakuext_unfurlURLs Server->>Website: Fetch metadata Website-->>Server: Metadata (thumbnail URL, title, etc) Server->>Website: Fetch thumbnail Server->>Website: Fetch favicon Website-->>Server: Favicon bytes Website-->>Server: Thumbnail bytes Server->>Server: Decode & process images Server-->>Client: Unfurled data (thumbnail data URI, etc) #+end_src ``` ``` ,------. ,------. ,-------. |Client| |Server| |Website| `--+---' `--+---' `---+---' | Call wakuext_getTextURLs | | | ---------------------------------------> | | | | | Normalized URLs | | | <- - - - - - - - - - - - - - - - - - - - | | | | |----. | | | | Render cached unfurled URLs | | |<---' | | | | | | Unfurl non-cached URLs. | | | Call wakuext_unfurlURLs | | | ---------------------------------------> | | | | | | Fetch metadata | | | ------------------------------------> | | | | | Metadata (thumbnail URL, title, etc)| | | <- - - - - - - - - - - - - - - - - - | | | | | Fetch thumbnail | | | ------------------------------------> | | | | | Fetch favicon | | | ------------------------------------> | | | | | Favicon bytes | | | <- - - - - - - - - - - - - - - - - - | | | | | Thumbnail bytes | | | <- - - - - - - - - - - - - - - - - - | | | | |----. | | | | Decode & process images | | |<---' | | | | | Unfurled data (thumbnail data URI, etc)| | | <- - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,---+---. |Client| |Server| |Website| `------' `------' `-------' ``` 2. Carol sends the text message with link previews in the RPC request wakuext_sendChatMessages. status-go assumes the link previews are good because it can't and shouldn't attempt to re-unfurl them. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_sendChatMessages Server->>Server: Transform link previews to\nbe proto-marshalled Server->DB: Write link previews serialized as JSON Server-->>Client: Updated message response #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | Call wakuext_sendChatMessages| | | -----------------------------> | | | | | |----. | | | | Transform link previews to | | |<---' be proto-marshalled | | | | | | | | | Write link previews serialized as JSON| | | --------------------------------------> | | | | Updated message response | | | <- - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` 3. The message was sent over waku and persisted locally in Carol's device. She should now see the link previews in the chat history. There can be many link previews shared by other chat members, therefore it is important to serve the assets via the media server to avoid overloading the ReactNative bridge with lots of big JSON payloads containing base64 encoded data URIs (maybe this concern is meaningless for desktop). When a client is rendering messages with link previews, they will have the field linkPreviews, and the thumbnail URL will point to the local media server. ``` #+begin_src plantuml :results verbatim Client->>Server: GET /link-preview/thumbnail (media server) Server->>DB: Read from user_messages.unfurled_links Server->Server: Unmarshal JSON Server-->>Client: HTTP Content-Type: image/jpeg/etc #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | GET /link-preview/thumbnail (media server)| | | ------------------------------------------> | | | | | | Read from user_messages.unfurled_links| | | --------------------------------------> | | | | |----. | | | | Unmarshal JSON | | |<---' | | | | | HTTP Content-Type: image/jpeg/etc | | | <- - - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` ### Some limitations of the current implementation The following points will become separate issues in status-go that I'll work on over the next couple weeks. In no order of importance: - Improve how multiple links are fetched; retries on failure and testing how unfurling behaves around the timeout limits (deterministically, not by making real HTTP calls as I did). https://github.com/status-im/status-go/issues/3498 - Unfurl favicons and store them in the protobuf too. - For this PR, I added unfurling support only for websites with OpenGraph https://ogp.me/ meta tags. Other unfurlers will be implemented on demand. The next one will probably be for oEmbed https://oembed.com/, the protocol supported by YouTube, for example. - Resize and/or compress thumbnails (and favicons). Often times, thumbnails are huge for the purposes of link previews. There is already support for compressing JPEGs in status-go, but I prefer to work with compression in a separate PR because I'd like to also solve the problem for PNGs (probably convert them to JPEGs, plus compress them). This would be a safe choice for thumbnails, favicons not so much because transparency is desirable. - Editing messages is not yet supported. - I haven't coded any artificial limit on the number of previews or on the size of the thumbnail payload. This will be done in a separate issue. I have heard the ideal solution may be to split messages into smaller chunks of ~125 KiB because of libp2p, but that might be too complicated at this stage of the product (?). - Link preview deletion. - For the moment, OpenGraph metadata is extracted by requesting data for the English language (and fallback to whatever is available). In the future, we'll want to unfurl by respecting the user's local device language. Some websites, like GoDaddy, are already localized based on the device's IP, but many aren't. - The website's description text should be limited by a certain number of characters, especially because it's outside our control. Exactly how much has not been decided yet, so it'll be done separately. - URL normalization can be tricky, so I implemented only the basics to help with caching. For example, the url https://status.im and HTTPS://status.im are considered identical. Also, a URL is considered valid for unfurling if its TLD exists according to publicsuffix.EffectiveTLDPlusOne. This was essential, otherwise the default Go url.Parse approach would consider many invalid URLs valid, and thus the server would waste resources trying to unfurl the unfurleable. ### Other requirements - If the message is edited, the link previews should reflect the edited text, not the original one. This has been aligned with the design team as well. - If the website's thumbnail or the favicon can't be fetched, just ignore them. The only mandatory piece of metadata is the website's title and URL. - Link previews in clients should be generated in near real-time, that is, as the user types, previews are updated. In mobile this performs very well, and it's what other clients like WhatsApp, Telegram, and Facebook do. ### Decisions - While the user typing in the input field, the client is constantly (debounced) asking status-go to parse the text and extract normalized URLs and then the client checks if they're already in its in-memory cache. If they are, no RPC call is made. I chose this approach to achieve the best possible performance in mobile and avoid the whole RPC overhead, since the chat experience is already not smooth enough. The mobile client uses URLs as cache keys in a hashmap, i.e. if the key is present, it means the preview is readily available (naive, but good enough for now). This decision also gave me more flexibility to find the best UX at this stage of the feature. - Due to the requirement that users should be able to see independent loading indicators for each link preview, when status-go can't unfurl a URL, it doesn't return it in the response. - As an initial implementation, I added the BLOB column unfurled_links to the user_messages table. The preview data is then serialized as JSON before being stored in this column. I felt that creating a separate table and the related code for this initial PR would be inconvenient. Is that reasonable to you? Once things stabilize I can create a proper table if we want to avoid this kind of solution with serialized columns.
2023-05-18 18:43:06 +00:00
var safeIdx float64
var actualShort string
var expectedShort string
if len(actual) > 0 {
safeIdx = math.Min(float64(maxLength), float64(len(actual)-1))
actualShort = actual[:int(safeIdx)]
}
if len(expected) > 0 {
safeIdx = math.Min(float64(maxLength), float64(len(expected)-1))
expectedShort = expected[:int(safeIdx)]
}
s.Require().Contains(
URL unfurling (initial implementation) (#3471) This is the initial implementation for the new URL unfurling requirements. The most important one is that only the message sender will pay the privacy cost for unfurling and extracting metadata from websites. Once the message is sent, the unfurled data will be stored at the protocol level and receivers will just profit and happily decode the metadata to render it. Further development of this URL unfurling capability will be mostly guided by issues created on clients. For the moment in status-mobile: https://github.com/status-im/status-mobile/labels/url-preview - https://github.com/status-im/status-mobile/issues/15918 - https://github.com/status-im/status-mobile/issues/15917 - https://github.com/status-im/status-mobile/issues/15910 - https://github.com/status-im/status-mobile/issues/15909 - https://github.com/status-im/status-mobile/issues/15908 - https://github.com/status-im/status-mobile/issues/15906 - https://github.com/status-im/status-mobile/issues/15905 ### Terminology In the code, I've tried to stick to the word "unfurl URL" to really mean the process of extracting metadata from a website, sort of lower level. I use "link preview" to mean a higher level structure which is enriched by unfurled data. "link preview" is also how designers refer to it. ### User flows 1. Carol needs to see link previews while typing in the chat input field. Notice from the diagram nothing is persisted and that status-go endpoints are essentially stateless. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_getTextURLs Server-->>Client: Normalized URLs Client->>Client: Render cached unfurled URLs Client->>Server: Unfurl non-cached URLs.\nCall wakuext_unfurlURLs Server->>Website: Fetch metadata Website-->>Server: Metadata (thumbnail URL, title, etc) Server->>Website: Fetch thumbnail Server->>Website: Fetch favicon Website-->>Server: Favicon bytes Website-->>Server: Thumbnail bytes Server->>Server: Decode & process images Server-->>Client: Unfurled data (thumbnail data URI, etc) #+end_src ``` ``` ,------. ,------. ,-------. |Client| |Server| |Website| `--+---' `--+---' `---+---' | Call wakuext_getTextURLs | | | ---------------------------------------> | | | | | Normalized URLs | | | <- - - - - - - - - - - - - - - - - - - - | | | | |----. | | | | Render cached unfurled URLs | | |<---' | | | | | | Unfurl non-cached URLs. | | | Call wakuext_unfurlURLs | | | ---------------------------------------> | | | | | | Fetch metadata | | | ------------------------------------> | | | | | Metadata (thumbnail URL, title, etc)| | | <- - - - - - - - - - - - - - - - - - | | | | | Fetch thumbnail | | | ------------------------------------> | | | | | Fetch favicon | | | ------------------------------------> | | | | | Favicon bytes | | | <- - - - - - - - - - - - - - - - - - | | | | | Thumbnail bytes | | | <- - - - - - - - - - - - - - - - - - | | | | |----. | | | | Decode & process images | | |<---' | | | | | Unfurled data (thumbnail data URI, etc)| | | <- - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,---+---. |Client| |Server| |Website| `------' `------' `-------' ``` 2. Carol sends the text message with link previews in the RPC request wakuext_sendChatMessages. status-go assumes the link previews are good because it can't and shouldn't attempt to re-unfurl them. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_sendChatMessages Server->>Server: Transform link previews to\nbe proto-marshalled Server->DB: Write link previews serialized as JSON Server-->>Client: Updated message response #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | Call wakuext_sendChatMessages| | | -----------------------------> | | | | | |----. | | | | Transform link previews to | | |<---' be proto-marshalled | | | | | | | | | Write link previews serialized as JSON| | | --------------------------------------> | | | | Updated message response | | | <- - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` 3. The message was sent over waku and persisted locally in Carol's device. She should now see the link previews in the chat history. There can be many link previews shared by other chat members, therefore it is important to serve the assets via the media server to avoid overloading the ReactNative bridge with lots of big JSON payloads containing base64 encoded data URIs (maybe this concern is meaningless for desktop). When a client is rendering messages with link previews, they will have the field linkPreviews, and the thumbnail URL will point to the local media server. ``` #+begin_src plantuml :results verbatim Client->>Server: GET /link-preview/thumbnail (media server) Server->>DB: Read from user_messages.unfurled_links Server->Server: Unmarshal JSON Server-->>Client: HTTP Content-Type: image/jpeg/etc #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | GET /link-preview/thumbnail (media server)| | | ------------------------------------------> | | | | | | Read from user_messages.unfurled_links| | | --------------------------------------> | | | | |----. | | | | Unmarshal JSON | | |<---' | | | | | HTTP Content-Type: image/jpeg/etc | | | <- - - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` ### Some limitations of the current implementation The following points will become separate issues in status-go that I'll work on over the next couple weeks. In no order of importance: - Improve how multiple links are fetched; retries on failure and testing how unfurling behaves around the timeout limits (deterministically, not by making real HTTP calls as I did). https://github.com/status-im/status-go/issues/3498 - Unfurl favicons and store them in the protobuf too. - For this PR, I added unfurling support only for websites with OpenGraph https://ogp.me/ meta tags. Other unfurlers will be implemented on demand. The next one will probably be for oEmbed https://oembed.com/, the protocol supported by YouTube, for example. - Resize and/or compress thumbnails (and favicons). Often times, thumbnails are huge for the purposes of link previews. There is already support for compressing JPEGs in status-go, but I prefer to work with compression in a separate PR because I'd like to also solve the problem for PNGs (probably convert them to JPEGs, plus compress them). This would be a safe choice for thumbnails, favicons not so much because transparency is desirable. - Editing messages is not yet supported. - I haven't coded any artificial limit on the number of previews or on the size of the thumbnail payload. This will be done in a separate issue. I have heard the ideal solution may be to split messages into smaller chunks of ~125 KiB because of libp2p, but that might be too complicated at this stage of the product (?). - Link preview deletion. - For the moment, OpenGraph metadata is extracted by requesting data for the English language (and fallback to whatever is available). In the future, we'll want to unfurl by respecting the user's local device language. Some websites, like GoDaddy, are already localized based on the device's IP, but many aren't. - The website's description text should be limited by a certain number of characters, especially because it's outside our control. Exactly how much has not been decided yet, so it'll be done separately. - URL normalization can be tricky, so I implemented only the basics to help with caching. For example, the url https://status.im and HTTPS://status.im are considered identical. Also, a URL is considered valid for unfurling if its TLD exists according to publicsuffix.EffectiveTLDPlusOne. This was essential, otherwise the default Go url.Parse approach would consider many invalid URLs valid, and thus the server would waste resources trying to unfurl the unfurleable. ### Other requirements - If the message is edited, the link previews should reflect the edited text, not the original one. This has been aligned with the design team as well. - If the website's thumbnail or the favicon can't be fetched, just ignore them. The only mandatory piece of metadata is the website's title and URL. - Link previews in clients should be generated in near real-time, that is, as the user types, previews are updated. In mobile this performs very well, and it's what other clients like WhatsApp, Telegram, and Facebook do. ### Decisions - While the user typing in the input field, the client is constantly (debounced) asking status-go to parse the text and extract normalized URLs and then the client checks if they're already in its in-memory cache. If they are, no RPC call is made. I chose this approach to achieve the best possible performance in mobile and avoid the whole RPC overhead, since the chat experience is already not smooth enough. The mobile client uses URLs as cache keys in a hashmap, i.e. if the key is present, it means the preview is readily available (naive, but good enough for now). This decision also gave me more flexibility to find the best UX at this stage of the feature. - Due to the requirement that users should be able to see independent loading indicators for each link preview, when status-go can't unfurl a URL, it doesn't return it in the response. - As an initial implementation, I added the BLOB column unfurled_links to the user_messages table. The preview data is then serialized as JSON before being stored in this column. I felt that creating a separate table and the related code for this initial PR would be inconvenient. Is that reasonable to you? Once things stabilize I can create a proper table if we want to avoid this kind of solution with serialized columns.
2023-05-18 18:43:06 +00:00
actual, expected,
"'%s' should contain '%s'",
actualShort,
expectedShort,
)
}
func (s *MessengerLinkPreviewsTestSuite) Test_GetLinks() {
URL unfurling (initial implementation) (#3471) This is the initial implementation for the new URL unfurling requirements. The most important one is that only the message sender will pay the privacy cost for unfurling and extracting metadata from websites. Once the message is sent, the unfurled data will be stored at the protocol level and receivers will just profit and happily decode the metadata to render it. Further development of this URL unfurling capability will be mostly guided by issues created on clients. For the moment in status-mobile: https://github.com/status-im/status-mobile/labels/url-preview - https://github.com/status-im/status-mobile/issues/15918 - https://github.com/status-im/status-mobile/issues/15917 - https://github.com/status-im/status-mobile/issues/15910 - https://github.com/status-im/status-mobile/issues/15909 - https://github.com/status-im/status-mobile/issues/15908 - https://github.com/status-im/status-mobile/issues/15906 - https://github.com/status-im/status-mobile/issues/15905 ### Terminology In the code, I've tried to stick to the word "unfurl URL" to really mean the process of extracting metadata from a website, sort of lower level. I use "link preview" to mean a higher level structure which is enriched by unfurled data. "link preview" is also how designers refer to it. ### User flows 1. Carol needs to see link previews while typing in the chat input field. Notice from the diagram nothing is persisted and that status-go endpoints are essentially stateless. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_getTextURLs Server-->>Client: Normalized URLs Client->>Client: Render cached unfurled URLs Client->>Server: Unfurl non-cached URLs.\nCall wakuext_unfurlURLs Server->>Website: Fetch metadata Website-->>Server: Metadata (thumbnail URL, title, etc) Server->>Website: Fetch thumbnail Server->>Website: Fetch favicon Website-->>Server: Favicon bytes Website-->>Server: Thumbnail bytes Server->>Server: Decode & process images Server-->>Client: Unfurled data (thumbnail data URI, etc) #+end_src ``` ``` ,------. ,------. ,-------. |Client| |Server| |Website| `--+---' `--+---' `---+---' | Call wakuext_getTextURLs | | | ---------------------------------------> | | | | | Normalized URLs | | | <- - - - - - - - - - - - - - - - - - - - | | | | |----. | | | | Render cached unfurled URLs | | |<---' | | | | | | Unfurl non-cached URLs. | | | Call wakuext_unfurlURLs | | | ---------------------------------------> | | | | | | Fetch metadata | | | ------------------------------------> | | | | | Metadata (thumbnail URL, title, etc)| | | <- - - - - - - - - - - - - - - - - - | | | | | Fetch thumbnail | | | ------------------------------------> | | | | | Fetch favicon | | | ------------------------------------> | | | | | Favicon bytes | | | <- - - - - - - - - - - - - - - - - - | | | | | Thumbnail bytes | | | <- - - - - - - - - - - - - - - - - - | | | | |----. | | | | Decode & process images | | |<---' | | | | | Unfurled data (thumbnail data URI, etc)| | | <- - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,---+---. |Client| |Server| |Website| `------' `------' `-------' ``` 2. Carol sends the text message with link previews in the RPC request wakuext_sendChatMessages. status-go assumes the link previews are good because it can't and shouldn't attempt to re-unfurl them. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_sendChatMessages Server->>Server: Transform link previews to\nbe proto-marshalled Server->DB: Write link previews serialized as JSON Server-->>Client: Updated message response #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | Call wakuext_sendChatMessages| | | -----------------------------> | | | | | |----. | | | | Transform link previews to | | |<---' be proto-marshalled | | | | | | | | | Write link previews serialized as JSON| | | --------------------------------------> | | | | Updated message response | | | <- - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` 3. The message was sent over waku and persisted locally in Carol's device. She should now see the link previews in the chat history. There can be many link previews shared by other chat members, therefore it is important to serve the assets via the media server to avoid overloading the ReactNative bridge with lots of big JSON payloads containing base64 encoded data URIs (maybe this concern is meaningless for desktop). When a client is rendering messages with link previews, they will have the field linkPreviews, and the thumbnail URL will point to the local media server. ``` #+begin_src plantuml :results verbatim Client->>Server: GET /link-preview/thumbnail (media server) Server->>DB: Read from user_messages.unfurled_links Server->Server: Unmarshal JSON Server-->>Client: HTTP Content-Type: image/jpeg/etc #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | GET /link-preview/thumbnail (media server)| | | ------------------------------------------> | | | | | | Read from user_messages.unfurled_links| | | --------------------------------------> | | | | |----. | | | | Unmarshal JSON | | |<---' | | | | | HTTP Content-Type: image/jpeg/etc | | | <- - - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` ### Some limitations of the current implementation The following points will become separate issues in status-go that I'll work on over the next couple weeks. In no order of importance: - Improve how multiple links are fetched; retries on failure and testing how unfurling behaves around the timeout limits (deterministically, not by making real HTTP calls as I did). https://github.com/status-im/status-go/issues/3498 - Unfurl favicons and store them in the protobuf too. - For this PR, I added unfurling support only for websites with OpenGraph https://ogp.me/ meta tags. Other unfurlers will be implemented on demand. The next one will probably be for oEmbed https://oembed.com/, the protocol supported by YouTube, for example. - Resize and/or compress thumbnails (and favicons). Often times, thumbnails are huge for the purposes of link previews. There is already support for compressing JPEGs in status-go, but I prefer to work with compression in a separate PR because I'd like to also solve the problem for PNGs (probably convert them to JPEGs, plus compress them). This would be a safe choice for thumbnails, favicons not so much because transparency is desirable. - Editing messages is not yet supported. - I haven't coded any artificial limit on the number of previews or on the size of the thumbnail payload. This will be done in a separate issue. I have heard the ideal solution may be to split messages into smaller chunks of ~125 KiB because of libp2p, but that might be too complicated at this stage of the product (?). - Link preview deletion. - For the moment, OpenGraph metadata is extracted by requesting data for the English language (and fallback to whatever is available). In the future, we'll want to unfurl by respecting the user's local device language. Some websites, like GoDaddy, are already localized based on the device's IP, but many aren't. - The website's description text should be limited by a certain number of characters, especially because it's outside our control. Exactly how much has not been decided yet, so it'll be done separately. - URL normalization can be tricky, so I implemented only the basics to help with caching. For example, the url https://status.im and HTTPS://status.im are considered identical. Also, a URL is considered valid for unfurling if its TLD exists according to publicsuffix.EffectiveTLDPlusOne. This was essential, otherwise the default Go url.Parse approach would consider many invalid URLs valid, and thus the server would waste resources trying to unfurl the unfurleable. ### Other requirements - If the message is edited, the link previews should reflect the edited text, not the original one. This has been aligned with the design team as well. - If the website's thumbnail or the favicon can't be fetched, just ignore them. The only mandatory piece of metadata is the website's title and URL. - Link previews in clients should be generated in near real-time, that is, as the user types, previews are updated. In mobile this performs very well, and it's what other clients like WhatsApp, Telegram, and Facebook do. ### Decisions - While the user typing in the input field, the client is constantly (debounced) asking status-go to parse the text and extract normalized URLs and then the client checks if they're already in its in-memory cache. If they are, no RPC call is made. I chose this approach to achieve the best possible performance in mobile and avoid the whole RPC overhead, since the chat experience is already not smooth enough. The mobile client uses URLs as cache keys in a hashmap, i.e. if the key is present, it means the preview is readily available (naive, but good enough for now). This decision also gave me more flexibility to find the best UX at this stage of the feature. - Due to the requirement that users should be able to see independent loading indicators for each link preview, when status-go can't unfurl a URL, it doesn't return it in the response. - As an initial implementation, I added the BLOB column unfurled_links to the user_messages table. The preview data is then serialized as JSON before being stored in this column. I felt that creating a separate table and the related code for this initial PR would be inconvenient. Is that reasonable to you? Once things stabilize I can create a proper table if we want to avoid this kind of solution with serialized columns.
2023-05-18 18:43:06 +00:00
examples := []struct {
args string
expected []string
}{
// Invalid URLs are not taken in consideration.
{args: "", expected: []string{}},
{args: " ", expected: []string{}},
{args: "https", expected: []string{}},
{args: "https://", expected: []string{}},
{args: "https://status", expected: []string{}},
{args: "https://status.", expected: []string{}},
// URLs must include the sheme.
{args: "status.com", expected: []string{}},
{args: "https://status.im", expected: []string{"https://status.im"}},
// Only the host should be lowercased.
{args: "HTTPS://STATUS.IM/path/to?Q=AbCdE", expected: []string{"https://status.im/path/to?Q=AbCdE"}},
// Remove trailing forward slash.
{args: "https://github.com/", expected: []string{"https://github.com"}},
{args: "https://www.youtube.com/watch?v=mzOyYtfXkb0/", expected: []string{"https://www.youtube.com/watch?v=mzOyYtfXkb0"}},
// Valid URL.
{args: "https://status.c", expected: []string{"https://status.c"}},
{args: "https://status.im/test", expected: []string{"https://status.im/test"}},
{args: "https://192.168.0.100:9999/xyz", expected: []string{"https://192.168.0.100:9999/xyz"}},
// There is a bug in the code that builds the AST from markdown text,
// because it removes the closing parenthesis, which means it won't be
// possible to unfurl this URL.
{args: "https://en.wikipedia.org/wiki/Status_message_(instant_messaging)", expected: []string{"https://en.wikipedia.org/wiki/Status_message_(instant_messaging"}},
// Multiple URLs.
{
args: "https://status.im/test https://www.youtube.com/watch?v=mzOyYtfXkb0",
expected: []string{"https://status.im/test", "https://www.youtube.com/watch?v=mzOyYtfXkb0"},
},
{
args: "status.im https://www.youtube.com/watch?v=mzOyYtfXkb0",
expected: []string{"https://www.youtube.com/watch?v=mzOyYtfXkb0"},
},
}
for _, ex := range examples {
links := s.m.GetURLs(ex.args)
s.Require().Equal(ex.expected, links, "Failed for args: '%s'", ex.args)
URL unfurling (initial implementation) (#3471) This is the initial implementation for the new URL unfurling requirements. The most important one is that only the message sender will pay the privacy cost for unfurling and extracting metadata from websites. Once the message is sent, the unfurled data will be stored at the protocol level and receivers will just profit and happily decode the metadata to render it. Further development of this URL unfurling capability will be mostly guided by issues created on clients. For the moment in status-mobile: https://github.com/status-im/status-mobile/labels/url-preview - https://github.com/status-im/status-mobile/issues/15918 - https://github.com/status-im/status-mobile/issues/15917 - https://github.com/status-im/status-mobile/issues/15910 - https://github.com/status-im/status-mobile/issues/15909 - https://github.com/status-im/status-mobile/issues/15908 - https://github.com/status-im/status-mobile/issues/15906 - https://github.com/status-im/status-mobile/issues/15905 ### Terminology In the code, I've tried to stick to the word "unfurl URL" to really mean the process of extracting metadata from a website, sort of lower level. I use "link preview" to mean a higher level structure which is enriched by unfurled data. "link preview" is also how designers refer to it. ### User flows 1. Carol needs to see link previews while typing in the chat input field. Notice from the diagram nothing is persisted and that status-go endpoints are essentially stateless. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_getTextURLs Server-->>Client: Normalized URLs Client->>Client: Render cached unfurled URLs Client->>Server: Unfurl non-cached URLs.\nCall wakuext_unfurlURLs Server->>Website: Fetch metadata Website-->>Server: Metadata (thumbnail URL, title, etc) Server->>Website: Fetch thumbnail Server->>Website: Fetch favicon Website-->>Server: Favicon bytes Website-->>Server: Thumbnail bytes Server->>Server: Decode & process images Server-->>Client: Unfurled data (thumbnail data URI, etc) #+end_src ``` ``` ,------. ,------. ,-------. |Client| |Server| |Website| `--+---' `--+---' `---+---' | Call wakuext_getTextURLs | | | ---------------------------------------> | | | | | Normalized URLs | | | <- - - - - - - - - - - - - - - - - - - - | | | | |----. | | | | Render cached unfurled URLs | | |<---' | | | | | | Unfurl non-cached URLs. | | | Call wakuext_unfurlURLs | | | ---------------------------------------> | | | | | | Fetch metadata | | | ------------------------------------> | | | | | Metadata (thumbnail URL, title, etc)| | | <- - - - - - - - - - - - - - - - - - | | | | | Fetch thumbnail | | | ------------------------------------> | | | | | Fetch favicon | | | ------------------------------------> | | | | | Favicon bytes | | | <- - - - - - - - - - - - - - - - - - | | | | | Thumbnail bytes | | | <- - - - - - - - - - - - - - - - - - | | | | |----. | | | | Decode & process images | | |<---' | | | | | Unfurled data (thumbnail data URI, etc)| | | <- - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,---+---. |Client| |Server| |Website| `------' `------' `-------' ``` 2. Carol sends the text message with link previews in the RPC request wakuext_sendChatMessages. status-go assumes the link previews are good because it can't and shouldn't attempt to re-unfurl them. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_sendChatMessages Server->>Server: Transform link previews to\nbe proto-marshalled Server->DB: Write link previews serialized as JSON Server-->>Client: Updated message response #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | Call wakuext_sendChatMessages| | | -----------------------------> | | | | | |----. | | | | Transform link previews to | | |<---' be proto-marshalled | | | | | | | | | Write link previews serialized as JSON| | | --------------------------------------> | | | | Updated message response | | | <- - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` 3. The message was sent over waku and persisted locally in Carol's device. She should now see the link previews in the chat history. There can be many link previews shared by other chat members, therefore it is important to serve the assets via the media server to avoid overloading the ReactNative bridge with lots of big JSON payloads containing base64 encoded data URIs (maybe this concern is meaningless for desktop). When a client is rendering messages with link previews, they will have the field linkPreviews, and the thumbnail URL will point to the local media server. ``` #+begin_src plantuml :results verbatim Client->>Server: GET /link-preview/thumbnail (media server) Server->>DB: Read from user_messages.unfurled_links Server->Server: Unmarshal JSON Server-->>Client: HTTP Content-Type: image/jpeg/etc #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | GET /link-preview/thumbnail (media server)| | | ------------------------------------------> | | | | | | Read from user_messages.unfurled_links| | | --------------------------------------> | | | | |----. | | | | Unmarshal JSON | | |<---' | | | | | HTTP Content-Type: image/jpeg/etc | | | <- - - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` ### Some limitations of the current implementation The following points will become separate issues in status-go that I'll work on over the next couple weeks. In no order of importance: - Improve how multiple links are fetched; retries on failure and testing how unfurling behaves around the timeout limits (deterministically, not by making real HTTP calls as I did). https://github.com/status-im/status-go/issues/3498 - Unfurl favicons and store them in the protobuf too. - For this PR, I added unfurling support only for websites with OpenGraph https://ogp.me/ meta tags. Other unfurlers will be implemented on demand. The next one will probably be for oEmbed https://oembed.com/, the protocol supported by YouTube, for example. - Resize and/or compress thumbnails (and favicons). Often times, thumbnails are huge for the purposes of link previews. There is already support for compressing JPEGs in status-go, but I prefer to work with compression in a separate PR because I'd like to also solve the problem for PNGs (probably convert them to JPEGs, plus compress them). This would be a safe choice for thumbnails, favicons not so much because transparency is desirable. - Editing messages is not yet supported. - I haven't coded any artificial limit on the number of previews or on the size of the thumbnail payload. This will be done in a separate issue. I have heard the ideal solution may be to split messages into smaller chunks of ~125 KiB because of libp2p, but that might be too complicated at this stage of the product (?). - Link preview deletion. - For the moment, OpenGraph metadata is extracted by requesting data for the English language (and fallback to whatever is available). In the future, we'll want to unfurl by respecting the user's local device language. Some websites, like GoDaddy, are already localized based on the device's IP, but many aren't. - The website's description text should be limited by a certain number of characters, especially because it's outside our control. Exactly how much has not been decided yet, so it'll be done separately. - URL normalization can be tricky, so I implemented only the basics to help with caching. For example, the url https://status.im and HTTPS://status.im are considered identical. Also, a URL is considered valid for unfurling if its TLD exists according to publicsuffix.EffectiveTLDPlusOne. This was essential, otherwise the default Go url.Parse approach would consider many invalid URLs valid, and thus the server would waste resources trying to unfurl the unfurleable. ### Other requirements - If the message is edited, the link previews should reflect the edited text, not the original one. This has been aligned with the design team as well. - If the website's thumbnail or the favicon can't be fetched, just ignore them. The only mandatory piece of metadata is the website's title and URL. - Link previews in clients should be generated in near real-time, that is, as the user types, previews are updated. In mobile this performs very well, and it's what other clients like WhatsApp, Telegram, and Facebook do. ### Decisions - While the user typing in the input field, the client is constantly (debounced) asking status-go to parse the text and extract normalized URLs and then the client checks if they're already in its in-memory cache. If they are, no RPC call is made. I chose this approach to achieve the best possible performance in mobile and avoid the whole RPC overhead, since the chat experience is already not smooth enough. The mobile client uses URLs as cache keys in a hashmap, i.e. if the key is present, it means the preview is readily available (naive, but good enough for now). This decision also gave me more flexibility to find the best UX at this stage of the feature. - Due to the requirement that users should be able to see independent loading indicators for each link preview, when status-go can't unfurl a URL, it doesn't return it in the response. - As an initial implementation, I added the BLOB column unfurled_links to the user_messages table. The preview data is then serialized as JSON before being stored in this column. I felt that creating a separate table and the related code for this initial PR would be inconvenient. Is that reasonable to you? Once things stabilize I can create a proper table if we want to avoid this kind of solution with serialized columns.
2023-05-18 18:43:06 +00:00
}
}
func (s *MessengerLinkPreviewsTestSuite) readAsset(filename string) []byte {
b, err := ioutil.ReadFile("../_assets/tests/" + filename)
s.Require().NoError(err)
return b
}
func (s *MessengerLinkPreviewsTestSuite) Test_GetFavicon() {
goodHTMLPNG := []byte(
`
<html>
<head>
<link rel="shortcut icon" href="https://www.somehost.com/favicon.png">
</head>
</html>`)
goodHTMLSVG := []byte(
`
<html>
<head>
<link rel="shortcut icon" href="https://www.somehost.com/favicon.svg">
</head>
</html>`)
goodHTMLICO := []byte(
`
<html>
<head>
<link rel="shortcut icon" href="https://www.somehost.com/favicon.ico">
</head>
</html>`)
badHTMLNoRelAttr := []byte(
`
<html>
<head>
<link href="https://www.somehost.com/favicon.png">
</head>
</html>`)
GoodHTMLRelAttributeIcon := []byte(
`
<html>
<head>
<link rel="icon" href="https://www.somehost.com/favicon.png">
</head>
</html>`)
faviconPath := GetFavicon(goodHTMLPNG)
s.Require().Equal("https://www.somehost.com/favicon.png", faviconPath)
faviconPath = GetFavicon(goodHTMLSVG)
s.Require().Equal("https://www.somehost.com/favicon.svg", faviconPath)
faviconPath = GetFavicon(goodHTMLICO)
s.Require().Equal("https://www.somehost.com/favicon.ico", faviconPath)
faviconPath = GetFavicon(GoodHTMLRelAttributeIcon)
s.Require().Equal("https://www.somehost.com/favicon.png", faviconPath)
faviconPath = GetFavicon(badHTMLNoRelAttr)
s.Require().Equal("", faviconPath)
}
func (s *MessengerLinkPreviewsTestSuite) Test_UnfurlURLs_YouTube() {
u := "https://www.youtube.com/watch?v=lE4UXdJSJM4"
thumbnailURL := "https://i.ytimg.com/vi/lE4UXdJSJM4/maxresdefault.jpg"
expected := common.LinkPreview{
Type: protobuf.UnfurledLink_LINK,
URL: u,
Hostname: "www.youtube.com",
Title: "Interview with a GNU/Linux user - Partition 1",
Description: "GNU/Linux Operating SystemInterview with a GNU/Linux user with Richie Guix - aired on © The GNU Linux.Programmer humorLinux humorProgramming jokesProgramming...",
Thumbnail: common.LinkPreviewThumbnail{
Width: 1,
Height: 1,
DataURI: "data:image/webp;base64,UklGRiQAAABXRUJQVlA4IBgAAAAwAQCdASoBAAEAAQAaJaQAA3AA/vpMgAA",
URL unfurling (initial implementation) (#3471) This is the initial implementation for the new URL unfurling requirements. The most important one is that only the message sender will pay the privacy cost for unfurling and extracting metadata from websites. Once the message is sent, the unfurled data will be stored at the protocol level and receivers will just profit and happily decode the metadata to render it. Further development of this URL unfurling capability will be mostly guided by issues created on clients. For the moment in status-mobile: https://github.com/status-im/status-mobile/labels/url-preview - https://github.com/status-im/status-mobile/issues/15918 - https://github.com/status-im/status-mobile/issues/15917 - https://github.com/status-im/status-mobile/issues/15910 - https://github.com/status-im/status-mobile/issues/15909 - https://github.com/status-im/status-mobile/issues/15908 - https://github.com/status-im/status-mobile/issues/15906 - https://github.com/status-im/status-mobile/issues/15905 ### Terminology In the code, I've tried to stick to the word "unfurl URL" to really mean the process of extracting metadata from a website, sort of lower level. I use "link preview" to mean a higher level structure which is enriched by unfurled data. "link preview" is also how designers refer to it. ### User flows 1. Carol needs to see link previews while typing in the chat input field. Notice from the diagram nothing is persisted and that status-go endpoints are essentially stateless. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_getTextURLs Server-->>Client: Normalized URLs Client->>Client: Render cached unfurled URLs Client->>Server: Unfurl non-cached URLs.\nCall wakuext_unfurlURLs Server->>Website: Fetch metadata Website-->>Server: Metadata (thumbnail URL, title, etc) Server->>Website: Fetch thumbnail Server->>Website: Fetch favicon Website-->>Server: Favicon bytes Website-->>Server: Thumbnail bytes Server->>Server: Decode & process images Server-->>Client: Unfurled data (thumbnail data URI, etc) #+end_src ``` ``` ,------. ,------. ,-------. |Client| |Server| |Website| `--+---' `--+---' `---+---' | Call wakuext_getTextURLs | | | ---------------------------------------> | | | | | Normalized URLs | | | <- - - - - - - - - - - - - - - - - - - - | | | | |----. | | | | Render cached unfurled URLs | | |<---' | | | | | | Unfurl non-cached URLs. | | | Call wakuext_unfurlURLs | | | ---------------------------------------> | | | | | | Fetch metadata | | | ------------------------------------> | | | | | Metadata (thumbnail URL, title, etc)| | | <- - - - - - - - - - - - - - - - - - | | | | | Fetch thumbnail | | | ------------------------------------> | | | | | Fetch favicon | | | ------------------------------------> | | | | | Favicon bytes | | | <- - - - - - - - - - - - - - - - - - | | | | | Thumbnail bytes | | | <- - - - - - - - - - - - - - - - - - | | | | |----. | | | | Decode & process images | | |<---' | | | | | Unfurled data (thumbnail data URI, etc)| | | <- - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,---+---. |Client| |Server| |Website| `------' `------' `-------' ``` 2. Carol sends the text message with link previews in the RPC request wakuext_sendChatMessages. status-go assumes the link previews are good because it can't and shouldn't attempt to re-unfurl them. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_sendChatMessages Server->>Server: Transform link previews to\nbe proto-marshalled Server->DB: Write link previews serialized as JSON Server-->>Client: Updated message response #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | Call wakuext_sendChatMessages| | | -----------------------------> | | | | | |----. | | | | Transform link previews to | | |<---' be proto-marshalled | | | | | | | | | Write link previews serialized as JSON| | | --------------------------------------> | | | | Updated message response | | | <- - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` 3. The message was sent over waku and persisted locally in Carol's device. She should now see the link previews in the chat history. There can be many link previews shared by other chat members, therefore it is important to serve the assets via the media server to avoid overloading the ReactNative bridge with lots of big JSON payloads containing base64 encoded data URIs (maybe this concern is meaningless for desktop). When a client is rendering messages with link previews, they will have the field linkPreviews, and the thumbnail URL will point to the local media server. ``` #+begin_src plantuml :results verbatim Client->>Server: GET /link-preview/thumbnail (media server) Server->>DB: Read from user_messages.unfurled_links Server->Server: Unmarshal JSON Server-->>Client: HTTP Content-Type: image/jpeg/etc #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | GET /link-preview/thumbnail (media server)| | | ------------------------------------------> | | | | | | Read from user_messages.unfurled_links| | | --------------------------------------> | | | | |----. | | | | Unmarshal JSON | | |<---' | | | | | HTTP Content-Type: image/jpeg/etc | | | <- - - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` ### Some limitations of the current implementation The following points will become separate issues in status-go that I'll work on over the next couple weeks. In no order of importance: - Improve how multiple links are fetched; retries on failure and testing how unfurling behaves around the timeout limits (deterministically, not by making real HTTP calls as I did). https://github.com/status-im/status-go/issues/3498 - Unfurl favicons and store them in the protobuf too. - For this PR, I added unfurling support only for websites with OpenGraph https://ogp.me/ meta tags. Other unfurlers will be implemented on demand. The next one will probably be for oEmbed https://oembed.com/, the protocol supported by YouTube, for example. - Resize and/or compress thumbnails (and favicons). Often times, thumbnails are huge for the purposes of link previews. There is already support for compressing JPEGs in status-go, but I prefer to work with compression in a separate PR because I'd like to also solve the problem for PNGs (probably convert them to JPEGs, plus compress them). This would be a safe choice for thumbnails, favicons not so much because transparency is desirable. - Editing messages is not yet supported. - I haven't coded any artificial limit on the number of previews or on the size of the thumbnail payload. This will be done in a separate issue. I have heard the ideal solution may be to split messages into smaller chunks of ~125 KiB because of libp2p, but that might be too complicated at this stage of the product (?). - Link preview deletion. - For the moment, OpenGraph metadata is extracted by requesting data for the English language (and fallback to whatever is available). In the future, we'll want to unfurl by respecting the user's local device language. Some websites, like GoDaddy, are already localized based on the device's IP, but many aren't. - The website's description text should be limited by a certain number of characters, especially because it's outside our control. Exactly how much has not been decided yet, so it'll be done separately. - URL normalization can be tricky, so I implemented only the basics to help with caching. For example, the url https://status.im and HTTPS://status.im are considered identical. Also, a URL is considered valid for unfurling if its TLD exists according to publicsuffix.EffectiveTLDPlusOne. This was essential, otherwise the default Go url.Parse approach would consider many invalid URLs valid, and thus the server would waste resources trying to unfurl the unfurleable. ### Other requirements - If the message is edited, the link previews should reflect the edited text, not the original one. This has been aligned with the design team as well. - If the website's thumbnail or the favicon can't be fetched, just ignore them. The only mandatory piece of metadata is the website's title and URL. - Link previews in clients should be generated in near real-time, that is, as the user types, previews are updated. In mobile this performs very well, and it's what other clients like WhatsApp, Telegram, and Facebook do. ### Decisions - While the user typing in the input field, the client is constantly (debounced) asking status-go to parse the text and extract normalized URLs and then the client checks if they're already in its in-memory cache. If they are, no RPC call is made. I chose this approach to achieve the best possible performance in mobile and avoid the whole RPC overhead, since the chat experience is already not smooth enough. The mobile client uses URLs as cache keys in a hashmap, i.e. if the key is present, it means the preview is readily available (naive, but good enough for now). This decision also gave me more flexibility to find the best UX at this stage of the feature. - Due to the requirement that users should be able to see independent loading indicators for each link preview, when status-go can't unfurl a URL, it doesn't return it in the response. - As an initial implementation, I added the BLOB column unfurled_links to the user_messages table. The preview data is then serialized as JSON before being stored in this column. I felt that creating a separate table and the related code for this initial PR would be inconvenient. Is that reasonable to you? Once things stabilize I can create a proper table if we want to avoid this kind of solution with serialized columns.
2023-05-18 18:43:06 +00:00
},
}
favicon := "https://www.youtube.com/s/desktop/87423d78/img/favicon.ico"
transport := StubTransport{}
transport.AddURLMatcher(
u,
[]byte(fmt.Sprintf(`
<html>
<head>
<meta property="og:title" content="%s">
<meta property="og:description" content="%s">
<meta property="og:image" content="%s">
<link rel="shortcut icon" href="%s">
</head>
</html>
`, expected.Title, expected.Description, thumbnailURL, favicon)),
nil,
)
transport.AddURLMatcher(thumbnailURL, s.readAsset("1.jpg"), nil)
stubbedClient := http.Client{Transport: &transport}
URL unfurling (initial implementation) (#3471) This is the initial implementation for the new URL unfurling requirements. The most important one is that only the message sender will pay the privacy cost for unfurling and extracting metadata from websites. Once the message is sent, the unfurled data will be stored at the protocol level and receivers will just profit and happily decode the metadata to render it. Further development of this URL unfurling capability will be mostly guided by issues created on clients. For the moment in status-mobile: https://github.com/status-im/status-mobile/labels/url-preview - https://github.com/status-im/status-mobile/issues/15918 - https://github.com/status-im/status-mobile/issues/15917 - https://github.com/status-im/status-mobile/issues/15910 - https://github.com/status-im/status-mobile/issues/15909 - https://github.com/status-im/status-mobile/issues/15908 - https://github.com/status-im/status-mobile/issues/15906 - https://github.com/status-im/status-mobile/issues/15905 ### Terminology In the code, I've tried to stick to the word "unfurl URL" to really mean the process of extracting metadata from a website, sort of lower level. I use "link preview" to mean a higher level structure which is enriched by unfurled data. "link preview" is also how designers refer to it. ### User flows 1. Carol needs to see link previews while typing in the chat input field. Notice from the diagram nothing is persisted and that status-go endpoints are essentially stateless. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_getTextURLs Server-->>Client: Normalized URLs Client->>Client: Render cached unfurled URLs Client->>Server: Unfurl non-cached URLs.\nCall wakuext_unfurlURLs Server->>Website: Fetch metadata Website-->>Server: Metadata (thumbnail URL, title, etc) Server->>Website: Fetch thumbnail Server->>Website: Fetch favicon Website-->>Server: Favicon bytes Website-->>Server: Thumbnail bytes Server->>Server: Decode & process images Server-->>Client: Unfurled data (thumbnail data URI, etc) #+end_src ``` ``` ,------. ,------. ,-------. |Client| |Server| |Website| `--+---' `--+---' `---+---' | Call wakuext_getTextURLs | | | ---------------------------------------> | | | | | Normalized URLs | | | <- - - - - - - - - - - - - - - - - - - - | | | | |----. | | | | Render cached unfurled URLs | | |<---' | | | | | | Unfurl non-cached URLs. | | | Call wakuext_unfurlURLs | | | ---------------------------------------> | | | | | | Fetch metadata | | | ------------------------------------> | | | | | Metadata (thumbnail URL, title, etc)| | | <- - - - - - - - - - - - - - - - - - | | | | | Fetch thumbnail | | | ------------------------------------> | | | | | Fetch favicon | | | ------------------------------------> | | | | | Favicon bytes | | | <- - - - - - - - - - - - - - - - - - | | | | | Thumbnail bytes | | | <- - - - - - - - - - - - - - - - - - | | | | |----. | | | | Decode & process images | | |<---' | | | | | Unfurled data (thumbnail data URI, etc)| | | <- - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,---+---. |Client| |Server| |Website| `------' `------' `-------' ``` 2. Carol sends the text message with link previews in the RPC request wakuext_sendChatMessages. status-go assumes the link previews are good because it can't and shouldn't attempt to re-unfurl them. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_sendChatMessages Server->>Server: Transform link previews to\nbe proto-marshalled Server->DB: Write link previews serialized as JSON Server-->>Client: Updated message response #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | Call wakuext_sendChatMessages| | | -----------------------------> | | | | | |----. | | | | Transform link previews to | | |<---' be proto-marshalled | | | | | | | | | Write link previews serialized as JSON| | | --------------------------------------> | | | | Updated message response | | | <- - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` 3. The message was sent over waku and persisted locally in Carol's device. She should now see the link previews in the chat history. There can be many link previews shared by other chat members, therefore it is important to serve the assets via the media server to avoid overloading the ReactNative bridge with lots of big JSON payloads containing base64 encoded data URIs (maybe this concern is meaningless for desktop). When a client is rendering messages with link previews, they will have the field linkPreviews, and the thumbnail URL will point to the local media server. ``` #+begin_src plantuml :results verbatim Client->>Server: GET /link-preview/thumbnail (media server) Server->>DB: Read from user_messages.unfurled_links Server->Server: Unmarshal JSON Server-->>Client: HTTP Content-Type: image/jpeg/etc #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | GET /link-preview/thumbnail (media server)| | | ------------------------------------------> | | | | | | Read from user_messages.unfurled_links| | | --------------------------------------> | | | | |----. | | | | Unmarshal JSON | | |<---' | | | | | HTTP Content-Type: image/jpeg/etc | | | <- - - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` ### Some limitations of the current implementation The following points will become separate issues in status-go that I'll work on over the next couple weeks. In no order of importance: - Improve how multiple links are fetched; retries on failure and testing how unfurling behaves around the timeout limits (deterministically, not by making real HTTP calls as I did). https://github.com/status-im/status-go/issues/3498 - Unfurl favicons and store them in the protobuf too. - For this PR, I added unfurling support only for websites with OpenGraph https://ogp.me/ meta tags. Other unfurlers will be implemented on demand. The next one will probably be for oEmbed https://oembed.com/, the protocol supported by YouTube, for example. - Resize and/or compress thumbnails (and favicons). Often times, thumbnails are huge for the purposes of link previews. There is already support for compressing JPEGs in status-go, but I prefer to work with compression in a separate PR because I'd like to also solve the problem for PNGs (probably convert them to JPEGs, plus compress them). This would be a safe choice for thumbnails, favicons not so much because transparency is desirable. - Editing messages is not yet supported. - I haven't coded any artificial limit on the number of previews or on the size of the thumbnail payload. This will be done in a separate issue. I have heard the ideal solution may be to split messages into smaller chunks of ~125 KiB because of libp2p, but that might be too complicated at this stage of the product (?). - Link preview deletion. - For the moment, OpenGraph metadata is extracted by requesting data for the English language (and fallback to whatever is available). In the future, we'll want to unfurl by respecting the user's local device language. Some websites, like GoDaddy, are already localized based on the device's IP, but many aren't. - The website's description text should be limited by a certain number of characters, especially because it's outside our control. Exactly how much has not been decided yet, so it'll be done separately. - URL normalization can be tricky, so I implemented only the basics to help with caching. For example, the url https://status.im and HTTPS://status.im are considered identical. Also, a URL is considered valid for unfurling if its TLD exists according to publicsuffix.EffectiveTLDPlusOne. This was essential, otherwise the default Go url.Parse approach would consider many invalid URLs valid, and thus the server would waste resources trying to unfurl the unfurleable. ### Other requirements - If the message is edited, the link previews should reflect the edited text, not the original one. This has been aligned with the design team as well. - If the website's thumbnail or the favicon can't be fetched, just ignore them. The only mandatory piece of metadata is the website's title and URL. - Link previews in clients should be generated in near real-time, that is, as the user types, previews are updated. In mobile this performs very well, and it's what other clients like WhatsApp, Telegram, and Facebook do. ### Decisions - While the user typing in the input field, the client is constantly (debounced) asking status-go to parse the text and extract normalized URLs and then the client checks if they're already in its in-memory cache. If they are, no RPC call is made. I chose this approach to achieve the best possible performance in mobile and avoid the whole RPC overhead, since the chat experience is already not smooth enough. The mobile client uses URLs as cache keys in a hashmap, i.e. if the key is present, it means the preview is readily available (naive, but good enough for now). This decision also gave me more flexibility to find the best UX at this stage of the feature. - Due to the requirement that users should be able to see independent loading indicators for each link preview, when status-go can't unfurl a URL, it doesn't return it in the response. - As an initial implementation, I added the BLOB column unfurled_links to the user_messages table. The preview data is then serialized as JSON before being stored in this column. I felt that creating a separate table and the related code for this initial PR would be inconvenient. Is that reasonable to you? Once things stabilize I can create a proper table if we want to avoid this kind of solution with serialized columns.
2023-05-18 18:43:06 +00:00
2023-10-13 12:25:34 +00:00
response, err := s.m.UnfurlURLs(&stubbedClient, []string{u})
s.Require().NoError(err)
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s.Require().Len(response.StatusLinkPreviews, 0)
s.Require().Len(response.LinkPreviews, 1)
preview := response.LinkPreviews[0]
s.Require().Equal(expected.Type, preview.Type)
s.Require().Equal(expected.URL, preview.URL)
s.Require().Equal(expected.Hostname, preview.Hostname)
s.Require().Equal(expected.Title, preview.Title)
s.Require().Equal(expected.Description, preview.Description)
s.Require().Equal(expected.Thumbnail.Width, preview.Thumbnail.Width)
s.Require().Equal(expected.Thumbnail.Height, preview.Thumbnail.Height)
s.Require().Equal(expected.Thumbnail.URL, preview.Thumbnail.URL)
s.Require().NotNil(preview.Favicon)
s.assertContainsLongString(expected.Thumbnail.DataURI, preview.Thumbnail.DataURI, 100)
}
func (s *MessengerLinkPreviewsTestSuite) Test_UnfurlURLs_Reddit() {
u := "https://www.reddit.com/r/Bitcoin/comments/13j0tzr/the_best_bitcoin_explanation_of_all_times/?utm_source=share"
expected := common.LinkPreview{
Type: protobuf.UnfurledLink_LINK,
URL: u,
Hostname: "www.reddit.com",
Title: "The best bitcoin explanation of all times.",
Description: "",
Thumbnail: common.LinkPreviewThumbnail{},
URL unfurling (initial implementation) (#3471) This is the initial implementation for the new URL unfurling requirements. The most important one is that only the message sender will pay the privacy cost for unfurling and extracting metadata from websites. Once the message is sent, the unfurled data will be stored at the protocol level and receivers will just profit and happily decode the metadata to render it. Further development of this URL unfurling capability will be mostly guided by issues created on clients. For the moment in status-mobile: https://github.com/status-im/status-mobile/labels/url-preview - https://github.com/status-im/status-mobile/issues/15918 - https://github.com/status-im/status-mobile/issues/15917 - https://github.com/status-im/status-mobile/issues/15910 - https://github.com/status-im/status-mobile/issues/15909 - https://github.com/status-im/status-mobile/issues/15908 - https://github.com/status-im/status-mobile/issues/15906 - https://github.com/status-im/status-mobile/issues/15905 ### Terminology In the code, I've tried to stick to the word "unfurl URL" to really mean the process of extracting metadata from a website, sort of lower level. I use "link preview" to mean a higher level structure which is enriched by unfurled data. "link preview" is also how designers refer to it. ### User flows 1. Carol needs to see link previews while typing in the chat input field. Notice from the diagram nothing is persisted and that status-go endpoints are essentially stateless. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_getTextURLs Server-->>Client: Normalized URLs Client->>Client: Render cached unfurled URLs Client->>Server: Unfurl non-cached URLs.\nCall wakuext_unfurlURLs Server->>Website: Fetch metadata Website-->>Server: Metadata (thumbnail URL, title, etc) Server->>Website: Fetch thumbnail Server->>Website: Fetch favicon Website-->>Server: Favicon bytes Website-->>Server: Thumbnail bytes Server->>Server: Decode & process images Server-->>Client: Unfurled data (thumbnail data URI, etc) #+end_src ``` ``` ,------. ,------. ,-------. |Client| |Server| |Website| `--+---' `--+---' `---+---' | Call wakuext_getTextURLs | | | ---------------------------------------> | | | | | Normalized URLs | | | <- - - - - - - - - - - - - - - - - - - - | | | | |----. | | | | Render cached unfurled URLs | | |<---' | | | | | | Unfurl non-cached URLs. | | | Call wakuext_unfurlURLs | | | ---------------------------------------> | | | | | | Fetch metadata | | | ------------------------------------> | | | | | Metadata (thumbnail URL, title, etc)| | | <- - - - - - - - - - - - - - - - - - | | | | | Fetch thumbnail | | | ------------------------------------> | | | | | Fetch favicon | | | ------------------------------------> | | | | | Favicon bytes | | | <- - - - - - - - - - - - - - - - - - | | | | | Thumbnail bytes | | | <- - - - - - - - - - - - - - - - - - | | | | |----. | | | | Decode & process images | | |<---' | | | | | Unfurled data (thumbnail data URI, etc)| | | <- - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,---+---. |Client| |Server| |Website| `------' `------' `-------' ``` 2. Carol sends the text message with link previews in the RPC request wakuext_sendChatMessages. status-go assumes the link previews are good because it can't and shouldn't attempt to re-unfurl them. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_sendChatMessages Server->>Server: Transform link previews to\nbe proto-marshalled Server->DB: Write link previews serialized as JSON Server-->>Client: Updated message response #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | Call wakuext_sendChatMessages| | | -----------------------------> | | | | | |----. | | | | Transform link previews to | | |<---' be proto-marshalled | | | | | | | | | Write link previews serialized as JSON| | | --------------------------------------> | | | | Updated message response | | | <- - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` 3. The message was sent over waku and persisted locally in Carol's device. She should now see the link previews in the chat history. There can be many link previews shared by other chat members, therefore it is important to serve the assets via the media server to avoid overloading the ReactNative bridge with lots of big JSON payloads containing base64 encoded data URIs (maybe this concern is meaningless for desktop). When a client is rendering messages with link previews, they will have the field linkPreviews, and the thumbnail URL will point to the local media server. ``` #+begin_src plantuml :results verbatim Client->>Server: GET /link-preview/thumbnail (media server) Server->>DB: Read from user_messages.unfurled_links Server->Server: Unmarshal JSON Server-->>Client: HTTP Content-Type: image/jpeg/etc #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | GET /link-preview/thumbnail (media server)| | | ------------------------------------------> | | | | | | Read from user_messages.unfurled_links| | | --------------------------------------> | | | | |----. | | | | Unmarshal JSON | | |<---' | | | | | HTTP Content-Type: image/jpeg/etc | | | <- - - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` ### Some limitations of the current implementation The following points will become separate issues in status-go that I'll work on over the next couple weeks. In no order of importance: - Improve how multiple links are fetched; retries on failure and testing how unfurling behaves around the timeout limits (deterministically, not by making real HTTP calls as I did). https://github.com/status-im/status-go/issues/3498 - Unfurl favicons and store them in the protobuf too. - For this PR, I added unfurling support only for websites with OpenGraph https://ogp.me/ meta tags. Other unfurlers will be implemented on demand. The next one will probably be for oEmbed https://oembed.com/, the protocol supported by YouTube, for example. - Resize and/or compress thumbnails (and favicons). Often times, thumbnails are huge for the purposes of link previews. There is already support for compressing JPEGs in status-go, but I prefer to work with compression in a separate PR because I'd like to also solve the problem for PNGs (probably convert them to JPEGs, plus compress them). This would be a safe choice for thumbnails, favicons not so much because transparency is desirable. - Editing messages is not yet supported. - I haven't coded any artificial limit on the number of previews or on the size of the thumbnail payload. This will be done in a separate issue. I have heard the ideal solution may be to split messages into smaller chunks of ~125 KiB because of libp2p, but that might be too complicated at this stage of the product (?). - Link preview deletion. - For the moment, OpenGraph metadata is extracted by requesting data for the English language (and fallback to whatever is available). In the future, we'll want to unfurl by respecting the user's local device language. Some websites, like GoDaddy, are already localized based on the device's IP, but many aren't. - The website's description text should be limited by a certain number of characters, especially because it's outside our control. Exactly how much has not been decided yet, so it'll be done separately. - URL normalization can be tricky, so I implemented only the basics to help with caching. For example, the url https://status.im and HTTPS://status.im are considered identical. Also, a URL is considered valid for unfurling if its TLD exists according to publicsuffix.EffectiveTLDPlusOne. This was essential, otherwise the default Go url.Parse approach would consider many invalid URLs valid, and thus the server would waste resources trying to unfurl the unfurleable. ### Other requirements - If the message is edited, the link previews should reflect the edited text, not the original one. This has been aligned with the design team as well. - If the website's thumbnail or the favicon can't be fetched, just ignore them. The only mandatory piece of metadata is the website's title and URL. - Link previews in clients should be generated in near real-time, that is, as the user types, previews are updated. In mobile this performs very well, and it's what other clients like WhatsApp, Telegram, and Facebook do. ### Decisions - While the user typing in the input field, the client is constantly (debounced) asking status-go to parse the text and extract normalized URLs and then the client checks if they're already in its in-memory cache. If they are, no RPC call is made. I chose this approach to achieve the best possible performance in mobile and avoid the whole RPC overhead, since the chat experience is already not smooth enough. The mobile client uses URLs as cache keys in a hashmap, i.e. if the key is present, it means the preview is readily available (naive, but good enough for now). This decision also gave me more flexibility to find the best UX at this stage of the feature. - Due to the requirement that users should be able to see independent loading indicators for each link preview, when status-go can't unfurl a URL, it doesn't return it in the response. - As an initial implementation, I added the BLOB column unfurled_links to the user_messages table. The preview data is then serialized as JSON before being stored in this column. I felt that creating a separate table and the related code for this initial PR would be inconvenient. Is that reasonable to you? Once things stabilize I can create a proper table if we want to avoid this kind of solution with serialized columns.
2023-05-18 18:43:06 +00:00
}
transport := StubTransport{}
transport.AddURLMatcher(
"https://www.reddit.com/oembed",
[]byte(`
{
"provider_url": "https://www.reddit.com/",
"version": "1.0",
"title": "The best bitcoin explanation of all times.",
"provider_name": "reddit",
"type": "rich",
"author_name": "DTheDev"
}
`),
nil,
)
stubbedClient := http.Client{Transport: &transport}
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response, err := s.m.UnfurlURLs(&stubbedClient, []string{u})
s.Require().NoError(err)
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s.Require().Len(response.StatusLinkPreviews, 0)
s.Require().Len(response.LinkPreviews, 1)
preview := response.LinkPreviews[0]
s.Require().Equal(expected.Type, preview.Type)
s.Require().Equal(expected.URL, preview.URL)
s.Require().Equal(expected.Hostname, preview.Hostname)
s.Require().Equal(expected.Title, preview.Title)
s.Require().Equal(expected.Description, preview.Description)
s.Require().Equal(expected.Thumbnail, preview.Thumbnail)
}
func (s *MessengerLinkPreviewsTestSuite) Test_UnfurlURLs_Timeout() {
httpClient := http.Client{Timeout: time.Nanosecond}
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response, err := s.m.UnfurlURLs(&httpClient, []string{"https://status.im"})
s.Require().NoError(err)
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s.Require().Len(response.StatusLinkPreviews, 0)
s.Require().Empty(response.LinkPreviews)
}
func (s *MessengerLinkPreviewsTestSuite) Test_UnfurlURLs_CommonFailures() {
httpClient := http.Client{}
URL unfurling (initial implementation) (#3471) This is the initial implementation for the new URL unfurling requirements. The most important one is that only the message sender will pay the privacy cost for unfurling and extracting metadata from websites. Once the message is sent, the unfurled data will be stored at the protocol level and receivers will just profit and happily decode the metadata to render it. Further development of this URL unfurling capability will be mostly guided by issues created on clients. For the moment in status-mobile: https://github.com/status-im/status-mobile/labels/url-preview - https://github.com/status-im/status-mobile/issues/15918 - https://github.com/status-im/status-mobile/issues/15917 - https://github.com/status-im/status-mobile/issues/15910 - https://github.com/status-im/status-mobile/issues/15909 - https://github.com/status-im/status-mobile/issues/15908 - https://github.com/status-im/status-mobile/issues/15906 - https://github.com/status-im/status-mobile/issues/15905 ### Terminology In the code, I've tried to stick to the word "unfurl URL" to really mean the process of extracting metadata from a website, sort of lower level. I use "link preview" to mean a higher level structure which is enriched by unfurled data. "link preview" is also how designers refer to it. ### User flows 1. Carol needs to see link previews while typing in the chat input field. Notice from the diagram nothing is persisted and that status-go endpoints are essentially stateless. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_getTextURLs Server-->>Client: Normalized URLs Client->>Client: Render cached unfurled URLs Client->>Server: Unfurl non-cached URLs.\nCall wakuext_unfurlURLs Server->>Website: Fetch metadata Website-->>Server: Metadata (thumbnail URL, title, etc) Server->>Website: Fetch thumbnail Server->>Website: Fetch favicon Website-->>Server: Favicon bytes Website-->>Server: Thumbnail bytes Server->>Server: Decode & process images Server-->>Client: Unfurled data (thumbnail data URI, etc) #+end_src ``` ``` ,------. ,------. ,-------. |Client| |Server| |Website| `--+---' `--+---' `---+---' | Call wakuext_getTextURLs | | | ---------------------------------------> | | | | | Normalized URLs | | | <- - - - - - - - - - - - - - - - - - - - | | | | |----. | | | | Render cached unfurled URLs | | |<---' | | | | | | Unfurl non-cached URLs. | | | Call wakuext_unfurlURLs | | | ---------------------------------------> | | | | | | Fetch metadata | | | ------------------------------------> | | | | | Metadata (thumbnail URL, title, etc)| | | <- - - - - - - - - - - - - - - - - - | | | | | Fetch thumbnail | | | ------------------------------------> | | | | | Fetch favicon | | | ------------------------------------> | | | | | Favicon bytes | | | <- - - - - - - - - - - - - - - - - - | | | | | Thumbnail bytes | | | <- - - - - - - - - - - - - - - - - - | | | | |----. | | | | Decode & process images | | |<---' | | | | | Unfurled data (thumbnail data URI, etc)| | | <- - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,---+---. |Client| |Server| |Website| `------' `------' `-------' ``` 2. Carol sends the text message with link previews in the RPC request wakuext_sendChatMessages. status-go assumes the link previews are good because it can't and shouldn't attempt to re-unfurl them. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_sendChatMessages Server->>Server: Transform link previews to\nbe proto-marshalled Server->DB: Write link previews serialized as JSON Server-->>Client: Updated message response #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | Call wakuext_sendChatMessages| | | -----------------------------> | | | | | |----. | | | | Transform link previews to | | |<---' be proto-marshalled | | | | | | | | | Write link previews serialized as JSON| | | --------------------------------------> | | | | Updated message response | | | <- - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` 3. The message was sent over waku and persisted locally in Carol's device. She should now see the link previews in the chat history. There can be many link previews shared by other chat members, therefore it is important to serve the assets via the media server to avoid overloading the ReactNative bridge with lots of big JSON payloads containing base64 encoded data URIs (maybe this concern is meaningless for desktop). When a client is rendering messages with link previews, they will have the field linkPreviews, and the thumbnail URL will point to the local media server. ``` #+begin_src plantuml :results verbatim Client->>Server: GET /link-preview/thumbnail (media server) Server->>DB: Read from user_messages.unfurled_links Server->Server: Unmarshal JSON Server-->>Client: HTTP Content-Type: image/jpeg/etc #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | GET /link-preview/thumbnail (media server)| | | ------------------------------------------> | | | | | | Read from user_messages.unfurled_links| | | --------------------------------------> | | | | |----. | | | | Unmarshal JSON | | |<---' | | | | | HTTP Content-Type: image/jpeg/etc | | | <- - - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` ### Some limitations of the current implementation The following points will become separate issues in status-go that I'll work on over the next couple weeks. In no order of importance: - Improve how multiple links are fetched; retries on failure and testing how unfurling behaves around the timeout limits (deterministically, not by making real HTTP calls as I did). https://github.com/status-im/status-go/issues/3498 - Unfurl favicons and store them in the protobuf too. - For this PR, I added unfurling support only for websites with OpenGraph https://ogp.me/ meta tags. Other unfurlers will be implemented on demand. The next one will probably be for oEmbed https://oembed.com/, the protocol supported by YouTube, for example. - Resize and/or compress thumbnails (and favicons). Often times, thumbnails are huge for the purposes of link previews. There is already support for compressing JPEGs in status-go, but I prefer to work with compression in a separate PR because I'd like to also solve the problem for PNGs (probably convert them to JPEGs, plus compress them). This would be a safe choice for thumbnails, favicons not so much because transparency is desirable. - Editing messages is not yet supported. - I haven't coded any artificial limit on the number of previews or on the size of the thumbnail payload. This will be done in a separate issue. I have heard the ideal solution may be to split messages into smaller chunks of ~125 KiB because of libp2p, but that might be too complicated at this stage of the product (?). - Link preview deletion. - For the moment, OpenGraph metadata is extracted by requesting data for the English language (and fallback to whatever is available). In the future, we'll want to unfurl by respecting the user's local device language. Some websites, like GoDaddy, are already localized based on the device's IP, but many aren't. - The website's description text should be limited by a certain number of characters, especially because it's outside our control. Exactly how much has not been decided yet, so it'll be done separately. - URL normalization can be tricky, so I implemented only the basics to help with caching. For example, the url https://status.im and HTTPS://status.im are considered identical. Also, a URL is considered valid for unfurling if its TLD exists according to publicsuffix.EffectiveTLDPlusOne. This was essential, otherwise the default Go url.Parse approach would consider many invalid URLs valid, and thus the server would waste resources trying to unfurl the unfurleable. ### Other requirements - If the message is edited, the link previews should reflect the edited text, not the original one. This has been aligned with the design team as well. - If the website's thumbnail or the favicon can't be fetched, just ignore them. The only mandatory piece of metadata is the website's title and URL. - Link previews in clients should be generated in near real-time, that is, as the user types, previews are updated. In mobile this performs very well, and it's what other clients like WhatsApp, Telegram, and Facebook do. ### Decisions - While the user typing in the input field, the client is constantly (debounced) asking status-go to parse the text and extract normalized URLs and then the client checks if they're already in its in-memory cache. If they are, no RPC call is made. I chose this approach to achieve the best possible performance in mobile and avoid the whole RPC overhead, since the chat experience is already not smooth enough. The mobile client uses URLs as cache keys in a hashmap, i.e. if the key is present, it means the preview is readily available (naive, but good enough for now). This decision also gave me more flexibility to find the best UX at this stage of the feature. - Due to the requirement that users should be able to see independent loading indicators for each link preview, when status-go can't unfurl a URL, it doesn't return it in the response. - As an initial implementation, I added the BLOB column unfurled_links to the user_messages table. The preview data is then serialized as JSON before being stored in this column. I felt that creating a separate table and the related code for this initial PR would be inconvenient. Is that reasonable to you? Once things stabilize I can create a proper table if we want to avoid this kind of solution with serialized columns.
2023-05-18 18:43:06 +00:00
// Test URL that doesn't return any OpenGraph title.
transport := StubTransport{}
transport.AddURLMatcher(
"https://wikipedia.org",
[]byte("<html><head></head></html>"),
nil,
)
stubbedClient := http.Client{Transport: &transport}
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response, err := s.m.UnfurlURLs(&stubbedClient, []string{"https://wikipedia.org"})
s.Require().NoError(err)
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s.Require().Len(response.StatusLinkPreviews, 0)
s.Require().Empty(response.LinkPreviews)
URL unfurling (initial implementation) (#3471) This is the initial implementation for the new URL unfurling requirements. The most important one is that only the message sender will pay the privacy cost for unfurling and extracting metadata from websites. Once the message is sent, the unfurled data will be stored at the protocol level and receivers will just profit and happily decode the metadata to render it. Further development of this URL unfurling capability will be mostly guided by issues created on clients. For the moment in status-mobile: https://github.com/status-im/status-mobile/labels/url-preview - https://github.com/status-im/status-mobile/issues/15918 - https://github.com/status-im/status-mobile/issues/15917 - https://github.com/status-im/status-mobile/issues/15910 - https://github.com/status-im/status-mobile/issues/15909 - https://github.com/status-im/status-mobile/issues/15908 - https://github.com/status-im/status-mobile/issues/15906 - https://github.com/status-im/status-mobile/issues/15905 ### Terminology In the code, I've tried to stick to the word "unfurl URL" to really mean the process of extracting metadata from a website, sort of lower level. I use "link preview" to mean a higher level structure which is enriched by unfurled data. "link preview" is also how designers refer to it. ### User flows 1. Carol needs to see link previews while typing in the chat input field. Notice from the diagram nothing is persisted and that status-go endpoints are essentially stateless. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_getTextURLs Server-->>Client: Normalized URLs Client->>Client: Render cached unfurled URLs Client->>Server: Unfurl non-cached URLs.\nCall wakuext_unfurlURLs Server->>Website: Fetch metadata Website-->>Server: Metadata (thumbnail URL, title, etc) Server->>Website: Fetch thumbnail Server->>Website: Fetch favicon Website-->>Server: Favicon bytes Website-->>Server: Thumbnail bytes Server->>Server: Decode & process images Server-->>Client: Unfurled data (thumbnail data URI, etc) #+end_src ``` ``` ,------. ,------. ,-------. |Client| |Server| |Website| `--+---' `--+---' `---+---' | Call wakuext_getTextURLs | | | ---------------------------------------> | | | | | Normalized URLs | | | <- - - - - - - - - - - - - - - - - - - - | | | | |----. | | | | Render cached unfurled URLs | | |<---' | | | | | | Unfurl non-cached URLs. | | | Call wakuext_unfurlURLs | | | ---------------------------------------> | | | | | | Fetch metadata | | | ------------------------------------> | | | | | Metadata (thumbnail URL, title, etc)| | | <- - - - - - - - - - - - - - - - - - | | | | | Fetch thumbnail | | | ------------------------------------> | | | | | Fetch favicon | | | ------------------------------------> | | | | | Favicon bytes | | | <- - - - - - - - - - - - - - - - - - | | | | | Thumbnail bytes | | | <- - - - - - - - - - - - - - - - - - | | | | |----. | | | | Decode & process images | | |<---' | | | | | Unfurled data (thumbnail data URI, etc)| | | <- - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,---+---. |Client| |Server| |Website| `------' `------' `-------' ``` 2. Carol sends the text message with link previews in the RPC request wakuext_sendChatMessages. status-go assumes the link previews are good because it can't and shouldn't attempt to re-unfurl them. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_sendChatMessages Server->>Server: Transform link previews to\nbe proto-marshalled Server->DB: Write link previews serialized as JSON Server-->>Client: Updated message response #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | Call wakuext_sendChatMessages| | | -----------------------------> | | | | | |----. | | | | Transform link previews to | | |<---' be proto-marshalled | | | | | | | | | Write link previews serialized as JSON| | | --------------------------------------> | | | | Updated message response | | | <- - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` 3. The message was sent over waku and persisted locally in Carol's device. She should now see the link previews in the chat history. There can be many link previews shared by other chat members, therefore it is important to serve the assets via the media server to avoid overloading the ReactNative bridge with lots of big JSON payloads containing base64 encoded data URIs (maybe this concern is meaningless for desktop). When a client is rendering messages with link previews, they will have the field linkPreviews, and the thumbnail URL will point to the local media server. ``` #+begin_src plantuml :results verbatim Client->>Server: GET /link-preview/thumbnail (media server) Server->>DB: Read from user_messages.unfurled_links Server->Server: Unmarshal JSON Server-->>Client: HTTP Content-Type: image/jpeg/etc #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | GET /link-preview/thumbnail (media server)| | | ------------------------------------------> | | | | | | Read from user_messages.unfurled_links| | | --------------------------------------> | | | | |----. | | | | Unmarshal JSON | | |<---' | | | | | HTTP Content-Type: image/jpeg/etc | | | <- - - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` ### Some limitations of the current implementation The following points will become separate issues in status-go that I'll work on over the next couple weeks. In no order of importance: - Improve how multiple links are fetched; retries on failure and testing how unfurling behaves around the timeout limits (deterministically, not by making real HTTP calls as I did). https://github.com/status-im/status-go/issues/3498 - Unfurl favicons and store them in the protobuf too. - For this PR, I added unfurling support only for websites with OpenGraph https://ogp.me/ meta tags. Other unfurlers will be implemented on demand. The next one will probably be for oEmbed https://oembed.com/, the protocol supported by YouTube, for example. - Resize and/or compress thumbnails (and favicons). Often times, thumbnails are huge for the purposes of link previews. There is already support for compressing JPEGs in status-go, but I prefer to work with compression in a separate PR because I'd like to also solve the problem for PNGs (probably convert them to JPEGs, plus compress them). This would be a safe choice for thumbnails, favicons not so much because transparency is desirable. - Editing messages is not yet supported. - I haven't coded any artificial limit on the number of previews or on the size of the thumbnail payload. This will be done in a separate issue. I have heard the ideal solution may be to split messages into smaller chunks of ~125 KiB because of libp2p, but that might be too complicated at this stage of the product (?). - Link preview deletion. - For the moment, OpenGraph metadata is extracted by requesting data for the English language (and fallback to whatever is available). In the future, we'll want to unfurl by respecting the user's local device language. Some websites, like GoDaddy, are already localized based on the device's IP, but many aren't. - The website's description text should be limited by a certain number of characters, especially because it's outside our control. Exactly how much has not been decided yet, so it'll be done separately. - URL normalization can be tricky, so I implemented only the basics to help with caching. For example, the url https://status.im and HTTPS://status.im are considered identical. Also, a URL is considered valid for unfurling if its TLD exists according to publicsuffix.EffectiveTLDPlusOne. This was essential, otherwise the default Go url.Parse approach would consider many invalid URLs valid, and thus the server would waste resources trying to unfurl the unfurleable. ### Other requirements - If the message is edited, the link previews should reflect the edited text, not the original one. This has been aligned with the design team as well. - If the website's thumbnail or the favicon can't be fetched, just ignore them. The only mandatory piece of metadata is the website's title and URL. - Link previews in clients should be generated in near real-time, that is, as the user types, previews are updated. In mobile this performs very well, and it's what other clients like WhatsApp, Telegram, and Facebook do. ### Decisions - While the user typing in the input field, the client is constantly (debounced) asking status-go to parse the text and extract normalized URLs and then the client checks if they're already in its in-memory cache. If they are, no RPC call is made. I chose this approach to achieve the best possible performance in mobile and avoid the whole RPC overhead, since the chat experience is already not smooth enough. The mobile client uses URLs as cache keys in a hashmap, i.e. if the key is present, it means the preview is readily available (naive, but good enough for now). This decision also gave me more flexibility to find the best UX at this stage of the feature. - Due to the requirement that users should be able to see independent loading indicators for each link preview, when status-go can't unfurl a URL, it doesn't return it in the response. - As an initial implementation, I added the BLOB column unfurled_links to the user_messages table. The preview data is then serialized as JSON before being stored in this column. I felt that creating a separate table and the related code for this initial PR would be inconvenient. Is that reasonable to you? Once things stabilize I can create a proper table if we want to avoid this kind of solution with serialized columns.
2023-05-18 18:43:06 +00:00
// Test 404.
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response, err = s.m.UnfurlURLs(&httpClient, []string{"https://github.com/status-im/i_do_not_exist"})
s.Require().NoError(err)
2023-10-13 12:25:34 +00:00
s.Require().Len(response.StatusLinkPreviews, 0)
s.Require().Empty(response.LinkPreviews)
URL unfurling (initial implementation) (#3471) This is the initial implementation for the new URL unfurling requirements. The most important one is that only the message sender will pay the privacy cost for unfurling and extracting metadata from websites. Once the message is sent, the unfurled data will be stored at the protocol level and receivers will just profit and happily decode the metadata to render it. Further development of this URL unfurling capability will be mostly guided by issues created on clients. For the moment in status-mobile: https://github.com/status-im/status-mobile/labels/url-preview - https://github.com/status-im/status-mobile/issues/15918 - https://github.com/status-im/status-mobile/issues/15917 - https://github.com/status-im/status-mobile/issues/15910 - https://github.com/status-im/status-mobile/issues/15909 - https://github.com/status-im/status-mobile/issues/15908 - https://github.com/status-im/status-mobile/issues/15906 - https://github.com/status-im/status-mobile/issues/15905 ### Terminology In the code, I've tried to stick to the word "unfurl URL" to really mean the process of extracting metadata from a website, sort of lower level. I use "link preview" to mean a higher level structure which is enriched by unfurled data. "link preview" is also how designers refer to it. ### User flows 1. Carol needs to see link previews while typing in the chat input field. Notice from the diagram nothing is persisted and that status-go endpoints are essentially stateless. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_getTextURLs Server-->>Client: Normalized URLs Client->>Client: Render cached unfurled URLs Client->>Server: Unfurl non-cached URLs.\nCall wakuext_unfurlURLs Server->>Website: Fetch metadata Website-->>Server: Metadata (thumbnail URL, title, etc) Server->>Website: Fetch thumbnail Server->>Website: Fetch favicon Website-->>Server: Favicon bytes Website-->>Server: Thumbnail bytes Server->>Server: Decode & process images Server-->>Client: Unfurled data (thumbnail data URI, etc) #+end_src ``` ``` ,------. ,------. ,-------. |Client| |Server| |Website| `--+---' `--+---' `---+---' | Call wakuext_getTextURLs | | | ---------------------------------------> | | | | | Normalized URLs | | | <- - - - - - - - - - - - - - - - - - - - | | | | |----. | | | | Render cached unfurled URLs | | |<---' | | | | | | Unfurl non-cached URLs. | | | Call wakuext_unfurlURLs | | | ---------------------------------------> | | | | | | Fetch metadata | | | ------------------------------------> | | | | | Metadata (thumbnail URL, title, etc)| | | <- - - - - - - - - - - - - - - - - - | | | | | Fetch thumbnail | | | ------------------------------------> | | | | | Fetch favicon | | | ------------------------------------> | | | | | Favicon bytes | | | <- - - - - - - - - - - - - - - - - - | | | | | Thumbnail bytes | | | <- - - - - - - - - - - - - - - - - - | | | | |----. | | | | Decode & process images | | |<---' | | | | | Unfurled data (thumbnail data URI, etc)| | | <- - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,---+---. |Client| |Server| |Website| `------' `------' `-------' ``` 2. Carol sends the text message with link previews in the RPC request wakuext_sendChatMessages. status-go assumes the link previews are good because it can't and shouldn't attempt to re-unfurl them. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_sendChatMessages Server->>Server: Transform link previews to\nbe proto-marshalled Server->DB: Write link previews serialized as JSON Server-->>Client: Updated message response #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | Call wakuext_sendChatMessages| | | -----------------------------> | | | | | |----. | | | | Transform link previews to | | |<---' be proto-marshalled | | | | | | | | | Write link previews serialized as JSON| | | --------------------------------------> | | | | Updated message response | | | <- - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` 3. The message was sent over waku and persisted locally in Carol's device. She should now see the link previews in the chat history. There can be many link previews shared by other chat members, therefore it is important to serve the assets via the media server to avoid overloading the ReactNative bridge with lots of big JSON payloads containing base64 encoded data URIs (maybe this concern is meaningless for desktop). When a client is rendering messages with link previews, they will have the field linkPreviews, and the thumbnail URL will point to the local media server. ``` #+begin_src plantuml :results verbatim Client->>Server: GET /link-preview/thumbnail (media server) Server->>DB: Read from user_messages.unfurled_links Server->Server: Unmarshal JSON Server-->>Client: HTTP Content-Type: image/jpeg/etc #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | GET /link-preview/thumbnail (media server)| | | ------------------------------------------> | | | | | | Read from user_messages.unfurled_links| | | --------------------------------------> | | | | |----. | | | | Unmarshal JSON | | |<---' | | | | | HTTP Content-Type: image/jpeg/etc | | | <- - - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` ### Some limitations of the current implementation The following points will become separate issues in status-go that I'll work on over the next couple weeks. In no order of importance: - Improve how multiple links are fetched; retries on failure and testing how unfurling behaves around the timeout limits (deterministically, not by making real HTTP calls as I did). https://github.com/status-im/status-go/issues/3498 - Unfurl favicons and store them in the protobuf too. - For this PR, I added unfurling support only for websites with OpenGraph https://ogp.me/ meta tags. Other unfurlers will be implemented on demand. The next one will probably be for oEmbed https://oembed.com/, the protocol supported by YouTube, for example. - Resize and/or compress thumbnails (and favicons). Often times, thumbnails are huge for the purposes of link previews. There is already support for compressing JPEGs in status-go, but I prefer to work with compression in a separate PR because I'd like to also solve the problem for PNGs (probably convert them to JPEGs, plus compress them). This would be a safe choice for thumbnails, favicons not so much because transparency is desirable. - Editing messages is not yet supported. - I haven't coded any artificial limit on the number of previews or on the size of the thumbnail payload. This will be done in a separate issue. I have heard the ideal solution may be to split messages into smaller chunks of ~125 KiB because of libp2p, but that might be too complicated at this stage of the product (?). - Link preview deletion. - For the moment, OpenGraph metadata is extracted by requesting data for the English language (and fallback to whatever is available). In the future, we'll want to unfurl by respecting the user's local device language. Some websites, like GoDaddy, are already localized based on the device's IP, but many aren't. - The website's description text should be limited by a certain number of characters, especially because it's outside our control. Exactly how much has not been decided yet, so it'll be done separately. - URL normalization can be tricky, so I implemented only the basics to help with caching. For example, the url https://status.im and HTTPS://status.im are considered identical. Also, a URL is considered valid for unfurling if its TLD exists according to publicsuffix.EffectiveTLDPlusOne. This was essential, otherwise the default Go url.Parse approach would consider many invalid URLs valid, and thus the server would waste resources trying to unfurl the unfurleable. ### Other requirements - If the message is edited, the link previews should reflect the edited text, not the original one. This has been aligned with the design team as well. - If the website's thumbnail or the favicon can't be fetched, just ignore them. The only mandatory piece of metadata is the website's title and URL. - Link previews in clients should be generated in near real-time, that is, as the user types, previews are updated. In mobile this performs very well, and it's what other clients like WhatsApp, Telegram, and Facebook do. ### Decisions - While the user typing in the input field, the client is constantly (debounced) asking status-go to parse the text and extract normalized URLs and then the client checks if they're already in its in-memory cache. If they are, no RPC call is made. I chose this approach to achieve the best possible performance in mobile and avoid the whole RPC overhead, since the chat experience is already not smooth enough. The mobile client uses URLs as cache keys in a hashmap, i.e. if the key is present, it means the preview is readily available (naive, but good enough for now). This decision also gave me more flexibility to find the best UX at this stage of the feature. - Due to the requirement that users should be able to see independent loading indicators for each link preview, when status-go can't unfurl a URL, it doesn't return it in the response. - As an initial implementation, I added the BLOB column unfurled_links to the user_messages table. The preview data is then serialized as JSON before being stored in this column. I felt that creating a separate table and the related code for this initial PR would be inconvenient. Is that reasonable to you? Once things stabilize I can create a proper table if we want to avoid this kind of solution with serialized columns.
2023-05-18 18:43:06 +00:00
// Test no response when trying to get OpenGraph metadata.
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response, err = s.m.UnfurlURLs(&httpClient, []string{"https://wikipedia.o"})
s.Require().NoError(err)
2023-10-13 12:25:34 +00:00
s.Require().Len(response.StatusLinkPreviews, 0)
s.Require().Empty(response.LinkPreviews)
URL unfurling (initial implementation) (#3471) This is the initial implementation for the new URL unfurling requirements. The most important one is that only the message sender will pay the privacy cost for unfurling and extracting metadata from websites. Once the message is sent, the unfurled data will be stored at the protocol level and receivers will just profit and happily decode the metadata to render it. Further development of this URL unfurling capability will be mostly guided by issues created on clients. For the moment in status-mobile: https://github.com/status-im/status-mobile/labels/url-preview - https://github.com/status-im/status-mobile/issues/15918 - https://github.com/status-im/status-mobile/issues/15917 - https://github.com/status-im/status-mobile/issues/15910 - https://github.com/status-im/status-mobile/issues/15909 - https://github.com/status-im/status-mobile/issues/15908 - https://github.com/status-im/status-mobile/issues/15906 - https://github.com/status-im/status-mobile/issues/15905 ### Terminology In the code, I've tried to stick to the word "unfurl URL" to really mean the process of extracting metadata from a website, sort of lower level. I use "link preview" to mean a higher level structure which is enriched by unfurled data. "link preview" is also how designers refer to it. ### User flows 1. Carol needs to see link previews while typing in the chat input field. Notice from the diagram nothing is persisted and that status-go endpoints are essentially stateless. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_getTextURLs Server-->>Client: Normalized URLs Client->>Client: Render cached unfurled URLs Client->>Server: Unfurl non-cached URLs.\nCall wakuext_unfurlURLs Server->>Website: Fetch metadata Website-->>Server: Metadata (thumbnail URL, title, etc) Server->>Website: Fetch thumbnail Server->>Website: Fetch favicon Website-->>Server: Favicon bytes Website-->>Server: Thumbnail bytes Server->>Server: Decode & process images Server-->>Client: Unfurled data (thumbnail data URI, etc) #+end_src ``` ``` ,------. ,------. ,-------. |Client| |Server| |Website| `--+---' `--+---' `---+---' | Call wakuext_getTextURLs | | | ---------------------------------------> | | | | | Normalized URLs | | | <- - - - - - - - - - - - - - - - - - - - | | | | |----. | | | | Render cached unfurled URLs | | |<---' | | | | | | Unfurl non-cached URLs. | | | Call wakuext_unfurlURLs | | | ---------------------------------------> | | | | | | Fetch metadata | | | ------------------------------------> | | | | | Metadata (thumbnail URL, title, etc)| | | <- - - - - - - - - - - - - - - - - - | | | | | Fetch thumbnail | | | ------------------------------------> | | | | | Fetch favicon | | | ------------------------------------> | | | | | Favicon bytes | | | <- - - - - - - - - - - - - - - - - - | | | | | Thumbnail bytes | | | <- - - - - - - - - - - - - - - - - - | | | | |----. | | | | Decode & process images | | |<---' | | | | | Unfurled data (thumbnail data URI, etc)| | | <- - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,---+---. |Client| |Server| |Website| `------' `------' `-------' ``` 2. Carol sends the text message with link previews in the RPC request wakuext_sendChatMessages. status-go assumes the link previews are good because it can't and shouldn't attempt to re-unfurl them. ``` #+begin_src plantuml :results verbatim Client->>Server: Call wakuext_sendChatMessages Server->>Server: Transform link previews to\nbe proto-marshalled Server->DB: Write link previews serialized as JSON Server-->>Client: Updated message response #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | Call wakuext_sendChatMessages| | | -----------------------------> | | | | | |----. | | | | Transform link previews to | | |<---' be proto-marshalled | | | | | | | | | Write link previews serialized as JSON| | | --------------------------------------> | | | | Updated message response | | | <- - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` 3. The message was sent over waku and persisted locally in Carol's device. She should now see the link previews in the chat history. There can be many link previews shared by other chat members, therefore it is important to serve the assets via the media server to avoid overloading the ReactNative bridge with lots of big JSON payloads containing base64 encoded data URIs (maybe this concern is meaningless for desktop). When a client is rendering messages with link previews, they will have the field linkPreviews, and the thumbnail URL will point to the local media server. ``` #+begin_src plantuml :results verbatim Client->>Server: GET /link-preview/thumbnail (media server) Server->>DB: Read from user_messages.unfurled_links Server->Server: Unmarshal JSON Server-->>Client: HTTP Content-Type: image/jpeg/etc #+end_src ``` ``` ,------. ,------. ,--. |Client| |Server| |DB| `--+---' `--+---' `+-' | GET /link-preview/thumbnail (media server)| | | ------------------------------------------> | | | | | | Read from user_messages.unfurled_links| | | --------------------------------------> | | | | |----. | | | | Unmarshal JSON | | |<---' | | | | | HTTP Content-Type: image/jpeg/etc | | | <- - - - - - - - - - - - - - - - - - - - - | ,--+---. ,--+---. ,+-. |Client| |Server| |DB| `------' `------' `--' ``` ### Some limitations of the current implementation The following points will become separate issues in status-go that I'll work on over the next couple weeks. In no order of importance: - Improve how multiple links are fetched; retries on failure and testing how unfurling behaves around the timeout limits (deterministically, not by making real HTTP calls as I did). https://github.com/status-im/status-go/issues/3498 - Unfurl favicons and store them in the protobuf too. - For this PR, I added unfurling support only for websites with OpenGraph https://ogp.me/ meta tags. Other unfurlers will be implemented on demand. The next one will probably be for oEmbed https://oembed.com/, the protocol supported by YouTube, for example. - Resize and/or compress thumbnails (and favicons). Often times, thumbnails are huge for the purposes of link previews. There is already support for compressing JPEGs in status-go, but I prefer to work with compression in a separate PR because I'd like to also solve the problem for PNGs (probably convert them to JPEGs, plus compress them). This would be a safe choice for thumbnails, favicons not so much because transparency is desirable. - Editing messages is not yet supported. - I haven't coded any artificial limit on the number of previews or on the size of the thumbnail payload. This will be done in a separate issue. I have heard the ideal solution may be to split messages into smaller chunks of ~125 KiB because of libp2p, but that might be too complicated at this stage of the product (?). - Link preview deletion. - For the moment, OpenGraph metadata is extracted by requesting data for the English language (and fallback to whatever is available). In the future, we'll want to unfurl by respecting the user's local device language. Some websites, like GoDaddy, are already localized based on the device's IP, but many aren't. - The website's description text should be limited by a certain number of characters, especially because it's outside our control. Exactly how much has not been decided yet, so it'll be done separately. - URL normalization can be tricky, so I implemented only the basics to help with caching. For example, the url https://status.im and HTTPS://status.im are considered identical. Also, a URL is considered valid for unfurling if its TLD exists according to publicsuffix.EffectiveTLDPlusOne. This was essential, otherwise the default Go url.Parse approach would consider many invalid URLs valid, and thus the server would waste resources trying to unfurl the unfurleable. ### Other requirements - If the message is edited, the link previews should reflect the edited text, not the original one. This has been aligned with the design team as well. - If the website's thumbnail or the favicon can't be fetched, just ignore them. The only mandatory piece of metadata is the website's title and URL. - Link previews in clients should be generated in near real-time, that is, as the user types, previews are updated. In mobile this performs very well, and it's what other clients like WhatsApp, Telegram, and Facebook do. ### Decisions - While the user typing in the input field, the client is constantly (debounced) asking status-go to parse the text and extract normalized URLs and then the client checks if they're already in its in-memory cache. If they are, no RPC call is made. I chose this approach to achieve the best possible performance in mobile and avoid the whole RPC overhead, since the chat experience is already not smooth enough. The mobile client uses URLs as cache keys in a hashmap, i.e. if the key is present, it means the preview is readily available (naive, but good enough for now). This decision also gave me more flexibility to find the best UX at this stage of the feature. - Due to the requirement that users should be able to see independent loading indicators for each link preview, when status-go can't unfurl a URL, it doesn't return it in the response. - As an initial implementation, I added the BLOB column unfurled_links to the user_messages table. The preview data is then serialized as JSON before being stored in this column. I felt that creating a separate table and the related code for this initial PR would be inconvenient. Is that reasonable to you? Once things stabilize I can create a proper table if we want to avoid this kind of solution with serialized columns.
2023-05-18 18:43:06 +00:00
}
func (s *MessengerLinkPreviewsTestSuite) Test_isSupportedImageURL() {
examples := []struct {
url string
expected bool
}{
{url: "https://placehold.co/600x400@2x.png", expected: true},
{url: "https://placehold.co/600x400@2x.PNG", expected: true},
{url: "https://placehold.co/600x400@2x.jpg", expected: true},
{url: "https://placehold.co/600x400@2x.JPG", expected: true},
{url: "https://placehold.co/600x400@2x.jpeg", expected: true},
{url: "https://placehold.co/600x400@2x.Jpeg", expected: true},
{url: "https://placehold.co/600x400@2x.webp", expected: true},
{url: "https://placehold.co/600x400@2x.WebP", expected: true},
{url: "https://placehold.co/600x400@2x.PnGs", expected: false},
{url: "https://placehold.co/600x400@2x.tiff", expected: false},
}
for _, e := range examples {
parsedURL, err := url.Parse(e.url)
s.Require().NoError(err, e)
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s.Require().Equal(e.expected, IsSupportedImageURL(parsedURL), e.url)
}
}
func (s *MessengerLinkPreviewsTestSuite) Test_UnfurlURLs_Image() {
u := "https://placehold.co/600x400@3x.png"
expected := common.LinkPreview{
Type: protobuf.UnfurledLink_IMAGE,
URL: u,
Hostname: "placehold.co",
Title: "600x400@3x.png",
Description: "",
Thumbnail: common.LinkPreviewThumbnail{
Width: 1293,
Height: 1900,
DataURI: "data:image/jpeg;base64,/9j/2wCEABALDA4MChAODQ4SERATGCgaGBYWGDEjJR0oOjM9PDkzODdASFxOQERXRTc4UG1RV19iZ",
},
}
transport := StubTransport{}
// Use a larger image to verify Thumbnail.DataURI is compressed.
transport.AddURLMatcher(u, s.readAsset("IMG_1205.HEIC.jpg"), nil)
stubbedClient := http.Client{Transport: &transport}
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response, err := s.m.UnfurlURLs(&stubbedClient, []string{u})
s.Require().NoError(err)
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s.Require().Len(response.StatusLinkPreviews, 0)
s.Require().Len(response.LinkPreviews, 1)
preview := response.LinkPreviews[0]
s.Require().Equal(expected.Type, preview.Type)
s.Require().Equal(expected.URL, preview.URL)
s.Require().Equal(expected.Hostname, preview.Hostname)
s.Require().Equal(expected.Title, preview.Title)
s.Require().Equal(expected.Description, preview.Description)
s.Require().Equal(expected.Thumbnail.Width, preview.Thumbnail.Width)
s.Require().Equal(expected.Thumbnail.Height, preview.Thumbnail.Height)
s.Require().Equal(expected.Thumbnail.URL, preview.Thumbnail.URL)
s.assertContainsLongString(expected.Thumbnail.DataURI, preview.Thumbnail.DataURI, 100)
}
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func (s *MessengerLinkPreviewsTestSuite) Test_UnfurlURLs_StatusContactAdded() {
identity, err := crypto.GenerateKey()
s.Require().NoError(err)
c, err := BuildContactFromPublicKey(&identity.PublicKey)
s.Require().NoError(err)
s.Require().NotNil(c)
payload, err := images.GetPayloadFromURI(exampleIdenticonURI)
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s.Require().NoError(err)
icon := images.IdentityImage{
Width: 50,
Height: 50,
Payload: payload,
}
c.Bio = "TestBio_1"
c.DisplayName = "TestDisplayName_1"
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c.Images = map[string]images.IdentityImage{}
c.Images[images.SmallDimName] = icon
s.m.allContacts.Store(c.ID, c)
// Generate a shared URL
u, err := s.m.ShareUserURLWithData(c.ID)
s.Require().NoError(err)
// Update contact info locally after creating the shared URL
// This is required to test that URL-decoded data is not used in the preview.
c.Bio = "TestBio_2"
c.DisplayName = "TestDisplayName_2"
s.m.allContacts.Store(c.ID, c)
r, err := s.m.UnfurlURLs(nil, []string{u})
s.Require().NoError(err)
s.Require().Len(r.StatusLinkPreviews, 1)
s.Require().Len(r.LinkPreviews, 0)
preview := r.StatusLinkPreviews[0]
s.Require().Equal(u, preview.URL)
s.Require().Nil(preview.Community)
s.Require().Nil(preview.Channel)
s.Require().NotNil(preview.Contact)
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s.Require().Equal(c.ID, preview.Contact.PublicKey)
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s.Require().Equal(c.DisplayName, preview.Contact.DisplayName)
s.Require().Equal(c.Bio, preview.Contact.Description)
s.Require().Equal(icon.Width, preview.Contact.Icon.Width)
s.Require().Equal(icon.Height, preview.Contact.Icon.Height)
s.Require().Equal("", preview.Contact.Icon.URL)
expectedDataURI, err := images.GetPayloadDataURI(icon.Payload)
s.Require().NoError(err)
s.Require().Equal(expectedDataURI, preview.Contact.Icon.DataURI)
}
func (s *MessengerLinkPreviewsTestSuite) setProfileParameters(messenger *Messenger, displayName string, bio string, identityImages []images.IdentityImage) {
const timeout = 1 * time.Second
changes := SelfContactChangeEvent{}
SetSettingsAndWaitForChange(&s.Suite, messenger, timeout, func() {
err := messenger.SetDisplayName(displayName)
s.Require().NoError(err)
err = messenger.SetBio(bio)
s.Require().NoError(err)
}, func(event *SelfContactChangeEvent) bool {
if event.DisplayNameChanged {
changes.DisplayNameChanged = true
}
if event.BioChanged {
changes.BioChanged = true
}
return changes.DisplayNameChanged && changes.BioChanged
})
SetIdentityImagesAndWaitForChange(&s.Suite, messenger, timeout, func() {
err := messenger.multiAccounts.StoreIdentityImages(messenger.account.KeyUID, identityImages, false)
s.Require().NoError(err)
})
selfContact := messenger.GetSelfContact()
s.Require().Equal(selfContact.DisplayName, displayName)
s.Require().Equal(selfContact.Bio, bio)
for _, image := range identityImages {
saved, ok := selfContact.Images[image.Name]
s.Require().True(ok)
s.Require().Equal(saved, image)
}
s.Require().Equal(selfContact.DisplayName, displayName)
}
func (s *MessengerLinkPreviewsTestSuite) Test_UnfurlURLs_SelfLink() {
profileKp := accounts.GetProfileKeypairForTest(true, false, false)
profileKp.KeyUID = s.m.account.KeyUID
profileKp.Accounts[0].KeyUID = s.m.account.KeyUID
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err := s.m.settings.SaveOrUpdateKeypair(profileKp)
s.Require().NoError(err)
// Set initial profile parameters
identityImages := images.SampleIdentityImages()
s.setProfileParameters(s.m, "TestDisplayName_3", "TestBio_3", identityImages)
// Generate a shared URL
u, err := s.m.ShareUserURLWithData(s.m.IdentityPublicKeyString())
s.Require().NoError(err)
// Update contact info locally after creating the shared URL
// This is required to test that URL-decoded data is not used in the preview.
iconPayload, err := images.GetPayloadFromURI(exampleIdenticonURI)
s.Require().NoError(err)
icon := images.IdentityImage{
Name: images.SmallDimName,
Width: 50,
Height: 50,
Payload: iconPayload,
}
s.setProfileParameters(s.m, "TestDisplayName_4", "TestBio_4", []images.IdentityImage{icon})
r, err := s.m.UnfurlURLs(nil, []string{u})
s.Require().NoError(err)
s.Require().Len(r.StatusLinkPreviews, 1)
s.Require().Len(r.LinkPreviews, 0)
userSettings, err := s.m.getSettings()
s.Require().NoError(err)
preview := r.StatusLinkPreviews[0]
s.Require().Equal(u, preview.URL)
s.Require().Nil(preview.Community)
s.Require().Nil(preview.Channel)
s.Require().NotNil(preview.Contact)
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s.Require().Equal(s.m.IdentityPublicKeyString(), preview.Contact.PublicKey)
s.Require().Equal(userSettings.DisplayName, preview.Contact.DisplayName)
s.Require().Equal(userSettings.Bio, preview.Contact.Description)
s.Require().Equal(icon.Width, preview.Contact.Icon.Width)
s.Require().Equal(icon.Height, preview.Contact.Icon.Height)
s.Require().Equal("", preview.Contact.Icon.URL)
expectedDataURI, err := images.GetPayloadDataURI(icon.Payload)
s.Require().NoError(err)
s.Require().Equal(expectedDataURI, preview.Contact.Icon.DataURI)
}
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func (s *MessengerLinkPreviewsTestSuite) Test_UnfurlURLs_StatusCommunityJoined() {
description := &requests.CreateCommunity{
Membership: protobuf.CommunityPermissions_AUTO_ACCEPT,
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Name: "status",
Description: "status community description",
Color: "#123456",
Image: "../_assets/tests/status.png", // 256*256 px
ImageAx: 0,
ImageAy: 0,
ImageBx: 256,
ImageBy: 256,
Banner: images.CroppedImage{
ImagePath: "../_assets/tests/IMG_1205.HEIC.jpg", // 2282*3352 px
X: 0,
Y: 0,
Width: 160,
Height: 90,
},
}
response, err := s.m.CreateCommunity(description, false)
s.Require().NoError(err)
s.Require().NotNil(response)
community := response.Communities()[0]
communityImages := community.Images()
s.Require().Len(communityImages, 3)
// Get icon data
icon, ok := communityImages[images.SmallDimName]
s.Require().True(ok)
iconWidth, iconHeight, err := images.GetImageDimensions(icon.Payload)
s.Require().NoError(err)
iconDataURI, err := images.GetPayloadDataURI(icon.Payload)
s.Require().NoError(err)
// Get banner data
banner, ok := communityImages[images.BannerIdentityName]
s.Require().True(ok)
bannerWidth, bannerHeight, err := images.GetImageDimensions(banner.Payload)
s.Require().NoError(err)
bannerDataURI, err := images.GetPayloadDataURI(banner.Payload)
s.Require().NoError(err)
// Create shared URL
u, err := s.m.ShareCommunityURLWithData(community.ID())
s.Require().NoError(err)
// Unfurl community shared URL
r, err := s.m.UnfurlURLs(nil, []string{u})
s.Require().NoError(err)
s.Require().Len(r.StatusLinkPreviews, 1)
s.Require().Len(r.LinkPreviews, 0)
preview := r.StatusLinkPreviews[0]
s.Require().Equal(u, preview.URL)
s.Require().NotNil(preview.Community)
s.Require().Nil(preview.Channel)
s.Require().Nil(preview.Contact)
s.Require().Equal(community.IDString(), preview.Community.CommunityID)
s.Require().Equal(community.Name(), preview.Community.DisplayName)
s.Require().Equal(community.Identity().Description, preview.Community.Description)
s.Require().Equal(iconWidth, preview.Community.Icon.Width)
s.Require().Equal(iconHeight, preview.Community.Icon.Height)
s.Require().Equal(iconDataURI, preview.Community.Icon.DataURI)
s.Require().Equal(bannerWidth, preview.Community.Banner.Width)
s.Require().Equal(bannerHeight, preview.Community.Banner.Height)
s.Require().Equal(bannerDataURI, preview.Community.Banner.DataURI)
}
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func (s *MessengerLinkPreviewsTestSuite) Test_UnfurlURLs_Settings() {
// Create website stub
const ogLink = "https://github.com"
const statusUserLink = "https://status.app/c#zQ3shYSHp7GoiXaauJMnDcjwU2yNjdzpXLosAWapPS4CFxc11"
const gifLink = "https://media1.giphy.com/media/lcG3qwtTKSNI2i5vst/giphy.gif"
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linksToUnfurl := []string{ogLink, statusUserLink, gifLink}
text := strings.Join(linksToUnfurl, " ")
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// Test `AlwaysAsk`
err := s.m.settings.SaveSettingField(settings.URLUnfurlingMode, settings.URLUnfurlingAlwaysAsk)
s.Require().NoError(err)
plan := s.m.GetTextURLsToUnfurl(text)
s.Require().Len(plan.URLs, len(linksToUnfurl))
s.Require().Equal(plan.URLs[0].URL, ogLink)
s.Require().Equal(plan.URLs[0].IsStatusSharedURL, false)
s.Require().Equal(plan.URLs[0].Permission, URLUnfurlingAskUser)
s.Require().Equal(plan.URLs[1].URL, statusUserLink)
s.Require().Equal(plan.URLs[1].IsStatusSharedURL, true)
s.Require().Equal(plan.URLs[1].Permission, URLUnfurlingAllowed)
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s.Require().Equal(plan.URLs[2].URL, gifLink)
s.Require().Equal(plan.URLs[2].IsStatusSharedURL, false)
s.Require().Equal(plan.URLs[2].Permission, URLUnfurlingNotSupported)
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// Test `EnableAll`
err = s.m.settings.SaveSettingField(settings.URLUnfurlingMode, settings.URLUnfurlingEnableAll)
s.Require().NoError(err)
plan = s.m.GetTextURLsToUnfurl(text)
s.Require().Len(plan.URLs, len(linksToUnfurl))
s.Require().Equal(plan.URLs[0].URL, ogLink)
s.Require().Equal(plan.URLs[0].IsStatusSharedURL, false)
s.Require().Equal(plan.URLs[0].Permission, URLUnfurlingAllowed)
s.Require().Equal(plan.URLs[1].URL, statusUserLink)
s.Require().Equal(plan.URLs[1].IsStatusSharedURL, true)
s.Require().Equal(plan.URLs[1].Permission, URLUnfurlingAllowed)
s.Require().Equal(plan.URLs[2].URL, gifLink)
s.Require().Equal(plan.URLs[2].IsStatusSharedURL, false)
s.Require().Equal(plan.URLs[2].Permission, URLUnfurlingNotSupported)
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// Test `DisableAll`
err = s.m.settings.SaveSettingField(settings.URLUnfurlingMode, settings.URLUnfurlingDisableAll)
s.Require().NoError(err)
plan = s.m.GetTextURLsToUnfurl(text)
s.Require().Len(plan.URLs, len(linksToUnfurl))
s.Require().Equal(plan.URLs[0].URL, ogLink)
s.Require().Equal(plan.URLs[0].IsStatusSharedURL, false)
s.Require().Equal(plan.URLs[0].Permission, URLUnfurlingForbiddenBySettings)
s.Require().Equal(plan.URLs[1].URL, statusUserLink)
s.Require().Equal(plan.URLs[1].IsStatusSharedURL, true)
s.Require().Equal(plan.URLs[1].Permission, URLUnfurlingAllowed)
s.Require().Equal(plan.URLs[2].URL, gifLink)
s.Require().Equal(plan.URLs[2].IsStatusSharedURL, false)
s.Require().Equal(plan.URLs[2].Permission, URLUnfurlingNotSupported)
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}
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func (s *MessengerLinkPreviewsTestSuite) Test_UnfurlURLs_Limit() {
text := "https://www.youtube.com/watch?v=6dkDepLX0rk " +
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"https://www.youtube.com/watch?v=ferZnZ0_rSM " +
"https://www.youtube.com/watch?v=bdneye4pzMw " +
"https://www.youtube.com/watch?v=pRERgcQe-fQ " +
"https://www.youtube.com/watch?v=j82L3pLjb_0 " +
"https://www.youtube.com/watch?v=hxsJvKYyVyg " +
"https://www.youtube.com/watch?v=jIIuzB11dsA "
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urls := s.m.GetURLs(text)
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s.Require().Equal(UnfurledLinksPerMessageLimit, len(urls))
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}