This change allows to connect to the mail server that we were using before the app was restarted. Separate loop is listening for whisper events, and when we receive event that request was completed we will update time on a peer record.
Records are stored in leveldb. Body of the record is marshaled using json. At this point the only field is a timestamp when record was used.
This loop doesn't control connections, it only tracks what mail server we ended up using. It works asynchronously to connection management loop. Which tracks events that are related to connection state and expiry of the requests.
When app starts we look into the database and select the most recently used record. This record is added to connection management loop first. So if this server is available we will stick to using it. If we weren't able to connect to the same server in configured timeout (5s) we will try to connect to any other server from list of active servers.
closes: #1285
This change implements connection manager that monitors 3 types of events:
1. update of the selected mail servers
2. disconnect from a mail server
3. errors for requesting mail history
When selected mail servers provided we will try to connect with as many as possible, and later disconnect the surplus. For example if we want to connect with one mail server and 3 were selected, we try to connect with all (3), and later disconnect with 2. It will to establish connection with live mail server faster.
If mail server disconnects we will choose any other mail server from the list of selected. Unless we have only one mail server. In such case we don't have any other choice and we will leave things as is.
If request for history was expired we will disconnect such peer and try to find another one. We will follow same rules as described above.
We will have two components that will rely on this logic:
1. requesting history
If target peer is provided we will use that peer, otherwise we will request history from any selected mail server that is connected at the time of request.
2. confirmation from selected mail server
Confirmation from any selected mail server will bee used to send a feedback that envelope was sent.
I will add several extensions, but probably in separate PRs:
1. prioritize connection with mail server that was used before reboot
2. disconnect from mail servers if history request wasn't expired but failed.
3. wait some time in RequestsMessage RPC to establish connection with any mail server
Currently this feature is hidden, as certain changes will be necessary in status-react.
partially implements: https://github.com/status-im/status-go/issues/1285
* mailserver sends envelopes in descending order
* add limit value in mailserver request payload
* mailserver sends messages up to the limit specified in the request
* update Archive method to return key and error
* processRequest returns the next page cursor
* add cursor to mailserver request
* add limit and cursor to request payload
* fix request limit encoding
* wait for request completed event in TrackerSuite/TestRequestCompleted
* add cursor to mailserver response
* fix cursor position in payload
* add e2e test for mail server pagination
* validate mail server response size
* remove old limitReached var
* fix lint warnings
* add whisper patch
* fix tests after rebase
* check all return values to avoid lint warnings
* check that all messages have been retrieved after 2 paginated requests
* fix lint warnings
* rename geth patch
* merge mailserver patches into one
* add last envelope hash to mailserver response and EventEnvelopeAvailable event
* update whisper patch
* add docs to MailServerResponse
* update whisper patch
* fix tests and lint warnings
* send mailserver response data on EventMailServerRequestCompleted signal
* update tracker tests
* optimise pagination test waiting for mailserver to archive only before requesting
* rollback mailserver interface changes
* refactoring and docs changes
* fix payload size check to determine if a limit is specified
* add more docs to the processRequest method
* add constants for request payload field lengths
* add const noLimits to specify that limit=0 means no limits
* refactor TestRequestMessageFromMailboxAsync to use s.requestHistoricMessages helper
* send p2pRequestResponseCode from mailserver
* send p2p message response to after sending all historic messages
* mailserver sends `whisper.NewSentMessage` as response
* add mailserver Client and p2pRequestAckCode watchers
* send event with envelopeFeed when p2pRequestAckCode is received
* test request completed event in tracker
* rename mailserver response events and code to RequestCompleteCode
* wait for mailserver response in e2e test
* use SendHistoricMessageResponse method name for mailserver response
* fix lint warnings
* add mailserver request expiration
* send mailserver response without envelope
* add `ttl` to Request struct in shhext_requestMessages
* test that tracker calls handler.MailServerRequestExpired
* add geth patch
* rename TTL to Timeout
* split tracker.handleEvent in multiple methods
This change adds adds an ability to use different source of time for whisper:
when envelope is created it is used to set expiry
to track when envelope needs to be expired
This time is then used to check validity of the envelope when it is received. Currently If we receive an envelope that is sent from future - peer will get disconnected. If envelope that was received has an expiry less then now it will be simply dropped, if expiry is less than now + 10*2 seconds peer will get dropped.
So, it is clear that whisper depends on time. And any time we get a skew with peers that is > 20s reliability will be grealy reduced.
In this change another source of time for whisper will be used. This time source will use ntp servers from pool.ntp.org to compute offset. When whisper queries time - this offset will be added/substracted from current time.
Query is executed every 2 mins, queries 5 different servers, cut offs min and max and the computes mean value. pool.ntp.org is resolved to different servers and according to documentation you will rarely hit the same.
Closes: #687
* Add RequestMessage to sshext
* E2E tests now use shhext_requestMessages
* Typo in comment
* Enhanced maintainability
* Drop former mailservice
* Code reorg after review
* Fix missed changes after update to 1.8.5
Dmitry Shulyak
Andrea Maria Piana
Igor Mandrigin
Adrià Cidre
Adam Babik
Andrea Franz
Igor Mandrigin
Pedro Pombeiro
Frank Mueller