mirror of https://github.com/waku-org/nwaku.git
66 lines
2.1 KiB
Nim
66 lines
2.1 KiB
Nim
import
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std/tables,
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chronos,
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waku_message
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## The Message Notification system is a method to notify various protocols
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## running on a node when a new message was received.
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#
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## Protocols can subscribe to messages of specific topics, then when one is received
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## The notification handler function will be called.
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##
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## This works as follows:
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##
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## .. code-block::
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## var topic = "foo"
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##
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## proc handle(topic: string, msg: WakuMessage) {.async.} =
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## info "new message", msg = msg
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##
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## MessageNotificationSubscription.init(@[topic], handle)
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##
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## var subscriptions = newTable[string, MessageNotificationSubscription]()
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## subscriptions["identifier"] = subscription
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##
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## await subscriptions.notify(topic, WakuMessage(payload: @[byte 1, 2, 3], contentTopic: ContentTopic(1)))
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type
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MessageNotificationHandler* = proc(topic: string, msg: WakuMessage): Future[
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void] {.gcsafe, closure.}
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MessageNotificationSubscriptionIdentifier* = string
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MessageNotificationSubscription* = object
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topics*: seq[string] # @TODO TOPIC
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handler*: MessageNotificationHandler
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MessageNotificationSubscriptions* = TableRef[MessageNotificationSubscriptionIdentifier, MessageNotificationSubscription]
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proc subscribe*(subscriptions: MessageNotificationSubscriptions, name: string, subscription: MessageNotificationSubscription) =
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subscriptions.add(name, subscription)
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proc init*(T: type MessageNotificationSubscription, topics: seq[string], handler: MessageNotificationHandler): T =
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result = T(
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topics: topics,
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handler: handler
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)
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proc containsMatch(lhs: seq[string], rhs: seq[string]): bool =
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for leftItem in lhs:
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if leftItem in rhs:
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return true
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return false
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proc notify*(subscriptions: MessageNotificationSubscriptions, topic: string, msg: WakuMessage) {.async, gcsafe.} =
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var futures = newSeq[Future[void]]()
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for subscription in subscriptions.mvalues:
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# @TODO WILL NEED TO CHECK SUBTOPICS IN FUTURE FOR WAKU TOPICS NOT LIBP2P ONES
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if subscription.topics.len > 0 and topic notin subscription.topics:
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continue
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futures.add(subscription.handler(topic, msg))
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await allFutures(futures)
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