mirror of https://github.com/waku-org/nwaku.git
95 lines
2.3 KiB
Nim
95 lines
2.3 KiB
Nim
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## Waku topics definition and namespacing utils
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##
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## See 14/WAKU2-MESSAGE RFC: https://rfc.vac.dev/spec/14/
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## See 23/WAKU2-TOPICS RFC: https://rfc.vac.dev/spec/23/
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when (NimMajor, NimMinor) < (1, 4):
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{.push raises: [Defect].}
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else:
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{.push raises: [].}
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import
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std/strutils,
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stew/results
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## Topics
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type
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PubsubTopic* = string
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ContentTopic* = string
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const
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DefaultPubsubTopic* = PubsubTopic("/waku/2/default-waku/proto")
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DefaultContentTopic* = ContentTopic("/waku/2/default-content/proto")
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## Namespacing
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type
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NamespacedTopic* = object
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application*: string
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version*: string
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name*: string
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encoding*: string
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type
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NamespacingErrorKind* {.pure.} = enum
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InvalidFormat
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NamespacingError* = object
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case kind*: NamespacingErrorKind
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of InvalidFormat:
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cause*: string
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NamespacingResult*[T] = Result[T, NamespacingError]
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proc invalidFormat(T: type NamespacingError, cause = "invalid format"): T =
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NamespacingError(kind: NamespacingErrorKind.InvalidFormat, cause: cause)
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proc `$`*(err: NamespacingError): string =
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case err.kind:
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of NamespacingErrorKind.InvalidFormat:
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return "invalid format: " & err.cause
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proc parse*(T: type NamespacedTopic, topic: PubsubTopic|ContentTopic|string): NamespacingResult[NamespacedTopic] =
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## Splits a namespaced topic string into its constituent parts.
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## The topic string has to be in the format `/<application>/<version>/<topic-name>/<encoding>`
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if not topic.startsWith("/"):
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return err(NamespacingError.invalidFormat("topic must start with slash"))
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let parts = topic.split('/')
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# Check that we have an expected number of substrings
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if parts.len != 5:
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return err(NamespacingError.invalidFormat("invalid topic structure"))
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let namespaced = NamespacedTopic(
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application: parts[1],
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version: parts[2],
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name: parts[3],
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encoding: parts[4]
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)
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return ok(namespaced)
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proc `$`*(namespacedTopic: NamespacedTopic): string =
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## Returns a string representation of a namespaced topic
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## in the format `/<application>/<version>/<topic-name>/<encoding>`
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var str = newString(0)
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str.add("/")
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str.add(namespacedTopic.application)
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str.add("/")
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str.add(namespacedTopic.version)
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str.add("/")
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str.add(namespacedTopic.name)
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str.add("/")
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str.add(namespacedTopic.encoding)
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return str
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