mirror of
https://github.com/logos-messaging/nim-sds.git
synced 2026-05-18 07:59:54 +00:00
488 lines
19 KiB
Nim
488 lines
19 KiB
Nim
import std/[algorithm, times, locks, tables, sets, options]
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import chronos, results, chronicles
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import sds/[types, protobuf, sds_utils, rolling_bloom_filter]
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export types, protobuf, sds_utils, rolling_bloom_filter
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proc newReliabilityManager*(
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config: ReliabilityConfig = defaultConfig(),
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participantId: SdsParticipantID = "".SdsParticipantID,
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persistence: Persistence = noOpPersistence(),
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): Result[ReliabilityManager, ReliabilityError] =
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## Creates a new multi-channel ReliabilityManager.
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## `persistence` defaults to a no-op backend; supply a real one to durably
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## store SDS state across restarts.
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try:
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let rm = ReliabilityManager.new(config, participantId, persistence)
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return ok(rm)
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except Exception:
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error "Failed to create ReliabilityManager", msg = getCurrentExceptionMsg()
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return err(ReliabilityError.reOutOfMemory)
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proc isAcknowledged*(
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msg: UnacknowledgedMessage,
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causalHistory: seq[HistoryEntry],
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rbf: Option[RollingBloomFilter],
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): bool =
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if msg.message.messageId in causalHistory.getMessageIds():
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return true
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if rbf.isSome():
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return rbf.get().contains(msg.message.messageId)
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return false
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proc reviewAckStatus(rm: ReliabilityManager, msg: SdsMessage) {.gcsafe.} =
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var rbf: Option[RollingBloomFilter]
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if msg.bloomFilter.len > 0:
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let bfResult = deserializeBloomFilter(msg.bloomFilter)
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if bfResult.isOk():
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let bf = bfResult.get()
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rbf = some(
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RollingBloomFilter.init(
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filter = bf,
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capacity = bf.capacity,
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minCapacity = (bf.capacity.float * (100 - CapacityFlexPercent).float / 100.0).int,
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maxCapacity = (bf.capacity.float * (100 + CapacityFlexPercent).float / 100.0).int,
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)
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)
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else:
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error "Failed to deserialize bloom filter", error = bfResult.error
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rbf = none[RollingBloomFilter]()
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else:
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rbf = none[RollingBloomFilter]()
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if msg.channelId notin rm.channels:
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return
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let channel = rm.channels[msg.channelId]
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var toDelete: seq[(int, SdsMessageID)] = @[]
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var i = 0
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while i < channel.outgoingBuffer.len:
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let outMsg = channel.outgoingBuffer[i]
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if outMsg.isAcknowledged(msg.causalHistory, rbf):
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if not rm.onMessageSent.isNil():
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rm.onMessageSent(outMsg.message.messageId, outMsg.message.channelId)
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toDelete.add((i, outMsg.message.messageId))
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inc i
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for k in countdown(toDelete.high, 0):
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let (idx, ackedId) = toDelete[k]
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channel.outgoingBuffer.delete(idx)
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rm.persistence.removeOutgoing(msg.channelId, ackedId)
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proc wrapOutgoingMessage*(
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rm: ReliabilityManager,
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message: seq[byte],
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messageId: SdsMessageID,
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channelId: SdsChannelID,
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): Result[seq[byte], ReliabilityError] =
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## Wraps an outgoing message with reliability metadata.
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if message.len == 0:
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return err(ReliabilityError.reInvalidArgument)
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if message.len > MaxMessageSize:
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return err(ReliabilityError.reMessageTooLarge)
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withLock rm.lock:
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try:
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let channel = rm.getOrCreateChannel(channelId)
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rm.updateLamportTimestamp(getTime().toUnix, channelId)
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let bfResult = serializeBloomFilter(channel.bloomFilter.filter)
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if bfResult.isErr:
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error "Failed to serialize bloom filter", channelId = channelId
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return err(ReliabilityError.reSerializationError)
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# SDS-R: collect eligible expired repair requests to attach. Per
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# spec (sds-r-send-message, RECOMMENDED), prioritise the entries with
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# the smallest minTimeRepairReq — they are the most overdue and the
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# ones the network most needs us to ask about.
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var repairReqs: seq[HistoryEntry] = @[]
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let now = getTime()
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var expiredKeys: seq[SdsMessageID] = @[]
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var eligible: seq[(SdsMessageID, OutgoingRepairEntry)] = @[]
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for msgId, repairEntry in channel.outgoingRepairBuffer:
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if now >= repairEntry.minTimeRepairReq:
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eligible.add((msgId, repairEntry))
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eligible.sort do(a, b: (SdsMessageID, OutgoingRepairEntry)) -> int:
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cmp(a[1].minTimeRepairReq, b[1].minTimeRepairReq)
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let take = min(eligible.len, rm.config.maxRepairRequests)
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for i in 0 ..< take:
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repairReqs.add(eligible[i][1].outHistEntry)
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expiredKeys.add(eligible[i][0])
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for key in expiredKeys:
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channel.outgoingRepairBuffer.del(key)
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rm.persistence.removeOutgoingRepair(channelId, key)
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let msg = SdsMessage.init(
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messageId = messageId,
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lamportTimestamp = channel.lamportTimestamp,
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causalHistory = rm.getRecentHistoryEntries(rm.config.maxCausalHistory, channelId),
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channelId = channelId,
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content = message,
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bloomFilter = bfResult.get(),
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senderId = rm.participantId,
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repairRequest = repairReqs,
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)
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let unackMsg =
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UnacknowledgedMessage.init(message = msg, sendTime = getTime(), resendAttempts = 0)
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channel.outgoingBuffer.add(unackMsg)
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rm.persistence.saveOutgoing(channelId, unackMsg)
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channel.bloomFilter.add(msg.messageId)
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# The full SdsMessage carries senderId and content, so a single
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# addToHistory replaces the old triple-write to messageHistory,
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# messageCache, and messageSenders.
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rm.addToHistory(msg, channelId)
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return serializeMessage(msg)
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except Exception:
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error "Failed to wrap message",
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channelId = channelId, msg = getCurrentExceptionMsg()
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return err(ReliabilityError.reSerializationError)
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proc processIncomingBuffer(rm: ReliabilityManager, channelId: SdsChannelID) {.gcsafe.} =
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withLock rm.lock:
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if channelId notin rm.channels:
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error "Channel does not exist", channelId = channelId
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return
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let channel = rm.channels[channelId]
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if channel.incomingBuffer.len == 0:
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return
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var processed = initHashSet[SdsMessageID]()
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var readyToProcess = newSeq[SdsMessageID]()
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for msgId, entry in channel.incomingBuffer:
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if entry.missingDeps.len == 0:
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readyToProcess.add(msgId)
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while readyToProcess.len > 0:
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let msgId = readyToProcess.pop()
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if msgId in processed:
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continue
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if msgId in channel.incomingBuffer:
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rm.addToHistory(channel.incomingBuffer[msgId].message, channelId)
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if not rm.onMessageReady.isNil():
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rm.onMessageReady(msgId, channelId)
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processed.incl(msgId)
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for remainingId, entry in channel.incomingBuffer:
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if remainingId notin processed:
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if msgId in entry.missingDeps:
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channel.incomingBuffer[remainingId].missingDeps.excl(msgId)
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rm.persistence.saveIncoming(
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channelId, channel.incomingBuffer[remainingId]
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)
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if channel.incomingBuffer[remainingId].missingDeps.len == 0:
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readyToProcess.add(remainingId)
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for msgId in processed:
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channel.incomingBuffer.del(msgId)
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rm.persistence.removeIncoming(channelId, msgId)
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proc unwrapReceivedMessage*(
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rm: ReliabilityManager, message: seq[byte]
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): Result[
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tuple[message: seq[byte], missingDeps: seq[HistoryEntry], channelId: SdsChannelID],
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ReliabilityError,
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] =
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## Unwraps a received message and processes its reliability metadata.
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try:
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let channelId = extractChannelId(message).valueOr:
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return err(ReliabilityError.reDeserializationError)
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let msg = deserializeMessage(message).valueOr:
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return err(ReliabilityError.reDeserializationError)
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let channel = rm.getOrCreateChannel(channelId)
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# SDS-R: opportunistic repair-buffer cleanup — applies to duplicates too,
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# so rebroadcasts cancel redundant responses on peers that already have the message.
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channel.outgoingRepairBuffer.del(msg.messageId)
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rm.persistence.removeOutgoingRepair(channelId, msg.messageId)
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channel.incomingRepairBuffer.del(msg.messageId)
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rm.persistence.removeIncomingRepair(channelId, msg.messageId)
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if msg.messageId in channel.messageHistory:
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return ok((msg.content, @[], channelId))
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channel.bloomFilter.add(msg.messageId)
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rm.updateLamportTimestamp(msg.lamportTimestamp, channelId)
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rm.reviewAckStatus(msg)
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# SDS-R: process incoming repair requests from this message. We can only
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# answer for messages we have actually delivered (i.e. that live in
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# messageHistory) — buffered-but-undelivered messages are not in a state
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# to confidently rebroadcast.
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let now = getTime()
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for repairEntry in msg.repairRequest:
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# Remove from our own outgoing repair buffer (someone else is also requesting)
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channel.outgoingRepairBuffer.del(repairEntry.messageId)
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rm.persistence.removeOutgoingRepair(channelId, repairEntry.messageId)
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if repairEntry.messageId in channel.messageHistory and
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rm.participantId.len > 0 and repairEntry.senderId.len > 0:
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if isInResponseGroup(
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rm.participantId, repairEntry.senderId,
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repairEntry.messageId, rm.config.numResponseGroups
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):
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let serialized = serializeMessage(channel.messageHistory[repairEntry.messageId])
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if serialized.isOk():
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let tResp = computeTResp(
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rm.participantId, repairEntry.senderId,
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repairEntry.messageId, rm.config.repairTMax
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)
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let inEntry = IncomingRepairEntry(
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inHistEntry: repairEntry,
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cachedMessage: serialized.get(),
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minTimeRepairResp: now + tResp,
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)
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channel.incomingRepairBuffer[repairEntry.messageId] = inEntry
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rm.persistence.saveIncomingRepair(channelId, repairEntry.messageId, inEntry)
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var missingDeps = rm.checkDependencies(msg.causalHistory, channelId)
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if missingDeps.len == 0:
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var depsInBuffer = false
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for msgId, entry in channel.incomingBuffer.pairs():
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if msgId in msg.causalHistory.getMessageIds():
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depsInBuffer = true
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break
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if depsInBuffer:
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let entry =
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IncomingMessage.init(message = msg, missingDeps = initHashSet[SdsMessageID]())
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channel.incomingBuffer[msg.messageId] = entry
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rm.persistence.saveIncoming(channelId, entry)
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else:
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rm.addToHistory(msg, channelId)
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# Unblock any buffered messages that were waiting on this one.
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var unblocked: seq[SdsMessageID] = @[]
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for pendingId, entry in channel.incomingBuffer:
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if msg.messageId in entry.missingDeps:
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channel.incomingBuffer[pendingId].missingDeps.excl(msg.messageId)
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unblocked.add(pendingId)
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for pendingId in unblocked:
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rm.persistence.saveIncoming(channelId, channel.incomingBuffer[pendingId])
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rm.processIncomingBuffer(channelId)
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if not rm.onMessageReady.isNil():
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rm.onMessageReady(msg.messageId, channelId)
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else:
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let entry = IncomingMessage.init(
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message = msg,
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missingDeps = missingDeps.getMessageIds().toHashSet(),
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)
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channel.incomingBuffer[msg.messageId] = entry
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rm.persistence.saveIncoming(channelId, entry)
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if not rm.onMissingDependencies.isNil():
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rm.onMissingDependencies(msg.messageId, missingDeps, channelId)
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# SDS-R: add missing deps to outgoing repair buffer
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if rm.participantId.len > 0:
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for dep in missingDeps:
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if dep.messageId notin channel.outgoingRepairBuffer:
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let tReq = computeTReq(
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rm.participantId, dep.messageId,
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rm.config.repairTMin, rm.config.repairTMax
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)
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let outEntry = OutgoingRepairEntry(
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outHistEntry: dep,
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minTimeRepairReq: now + tReq,
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)
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channel.outgoingRepairBuffer[dep.messageId] = outEntry
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rm.persistence.saveOutgoingRepair(channelId, dep.messageId, outEntry)
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return ok((msg.content, missingDeps, channelId))
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except Exception:
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error "Failed to unwrap message", msg = getCurrentExceptionMsg()
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return err(ReliabilityError.reDeserializationError)
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proc markDependenciesMet*(
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rm: ReliabilityManager, messageIds: seq[SdsMessageID], channelId: SdsChannelID
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): Result[void, ReliabilityError] =
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## Marks the specified message dependencies as met.
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try:
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if channelId notin rm.channels:
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return err(ReliabilityError.reInvalidArgument)
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let channel = rm.channels[channelId]
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for msgId in messageIds:
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if not channel.bloomFilter.contains(msgId):
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channel.bloomFilter.add(msgId)
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var unblocked: seq[SdsMessageID] = @[]
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for pendingId, entry in channel.incomingBuffer:
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if msgId in entry.missingDeps:
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channel.incomingBuffer[pendingId].missingDeps.excl(msgId)
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unblocked.add(pendingId)
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for pendingId in unblocked:
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rm.persistence.saveIncoming(channelId, channel.incomingBuffer[pendingId])
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# SDS-R: clear from repair buffers (dependency now met)
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channel.outgoingRepairBuffer.del(msgId)
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rm.persistence.removeOutgoingRepair(channelId, msgId)
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channel.incomingRepairBuffer.del(msgId)
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rm.persistence.removeIncomingRepair(channelId, msgId)
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rm.processIncomingBuffer(channelId)
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return ok()
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except Exception:
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error "Failed to mark dependencies as met",
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channelId = channelId, msg = getCurrentExceptionMsg()
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return err(ReliabilityError.reInternalError)
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proc setCallbacks*(
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rm: ReliabilityManager,
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onMessageReady: MessageReadyCallback,
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onMessageSent: MessageSentCallback,
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onMissingDependencies: MissingDependenciesCallback,
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onPeriodicSync: PeriodicSyncCallback = nil,
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onRetrievalHint: RetrievalHintProvider = nil,
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onRepairReady: RepairReadyCallback = nil,
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) =
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## Sets the callback functions for various events in the ReliabilityManager.
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withLock rm.lock:
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rm.onMessageReady = onMessageReady
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rm.onMessageSent = onMessageSent
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rm.onMissingDependencies = onMissingDependencies
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rm.onPeriodicSync = onPeriodicSync
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rm.onRetrievalHint = onRetrievalHint
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rm.onRepairReady = onRepairReady
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proc checkUnacknowledgedMessages(
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rm: ReliabilityManager, channelId: SdsChannelID
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) {.gcsafe.} =
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withLock rm.lock:
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if channelId notin rm.channels:
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error "Channel does not exist", channelId = channelId
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return
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let channel = rm.channels[channelId]
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let now = getTime()
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var newOutgoingBuffer: seq[UnacknowledgedMessage] = @[]
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for unackMsg in channel.outgoingBuffer:
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let elapsed = now - unackMsg.sendTime
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if elapsed > rm.config.resendInterval:
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if unackMsg.resendAttempts < rm.config.maxResendAttempts:
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var updatedMsg = unackMsg
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updatedMsg.resendAttempts += 1
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updatedMsg.sendTime = now
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newOutgoingBuffer.add(updatedMsg)
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rm.persistence.saveOutgoing(channelId, updatedMsg)
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else:
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if not rm.onMessageSent.isNil():
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rm.onMessageSent(unackMsg.message.messageId, channelId)
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rm.persistence.removeOutgoing(channelId, unackMsg.message.messageId)
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else:
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newOutgoingBuffer.add(unackMsg)
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channel.outgoingBuffer = newOutgoingBuffer
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proc periodicBufferSweep(
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rm: ReliabilityManager
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) {.async: (raises: [CancelledError]), gcsafe.} =
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while true:
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try:
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for channelId, channel in rm.channels:
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try:
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rm.checkUnacknowledgedMessages(channelId)
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rm.cleanBloomFilter(channelId)
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except Exception:
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error "Error in buffer sweep for channel",
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channelId = channelId, msg = getCurrentExceptionMsg()
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except Exception:
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error "Error in periodic buffer sweep", msg = getCurrentExceptionMsg()
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await sleepAsync(chronos.milliseconds(rm.config.bufferSweepInterval.inMilliseconds))
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proc periodicSyncMessage(
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rm: ReliabilityManager
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) {.async: (raises: [CancelledError]), gcsafe.} =
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while true:
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try:
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if not rm.onPeriodicSync.isNil():
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rm.onPeriodicSync()
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except Exception:
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error "Error in periodic sync", msg = getCurrentExceptionMsg()
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await sleepAsync(chronos.seconds(rm.config.syncMessageInterval.inSeconds))
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proc runRepairSweep*(rm: ReliabilityManager) {.gcsafe, raises: [].} =
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## SDS-R: Runs a single pass of the repair sweep.
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## - Incoming: fires onRepairReady for expired T_resp entries and removes them
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## - Outgoing: drops entries past T_max window
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## Exposed so it can be driven directly in tests; also invoked by periodicRepairSweep.
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## Acquires rm.lock so the repair buffers cannot be observed mid-mutation by
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## a concurrent wrapOutgoingMessage / unwrapReceivedMessage on another thread.
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withLock rm.lock:
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try:
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let now = getTime()
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for channelId, channel in rm.channels:
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try:
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# Check incoming repair buffer for expired T_resp (time to rebroadcast)
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var toRebroadcast: seq[SdsMessageID] = @[]
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for msgId, entry in channel.incomingRepairBuffer:
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if now >= entry.minTimeRepairResp:
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toRebroadcast.add(msgId)
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for msgId in toRebroadcast:
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let entry = channel.incomingRepairBuffer[msgId]
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channel.incomingRepairBuffer.del(msgId)
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rm.persistence.removeIncomingRepair(channelId, msgId)
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if not rm.onRepairReady.isNil():
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rm.onRepairReady(entry.cachedMessage, channelId)
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# Drop expired outgoing repair entries past T_max
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var toRemove: seq[SdsMessageID] = @[]
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let tMaxDuration = rm.config.repairTMax
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for msgId, entry in channel.outgoingRepairBuffer:
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if now - entry.minTimeRepairReq > tMaxDuration:
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toRemove.add(msgId)
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for msgId in toRemove:
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channel.outgoingRepairBuffer.del(msgId)
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rm.persistence.removeOutgoingRepair(channelId, msgId)
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except Exception:
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error "Error in repair sweep for channel",
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channelId = channelId, msg = getCurrentExceptionMsg()
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except Exception:
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error "Error in repair sweep", msg = getCurrentExceptionMsg()
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proc periodicRepairSweep(
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rm: ReliabilityManager
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) {.async: (raises: [CancelledError]), gcsafe.} =
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## SDS-R: Periodically checks repair buffers for expired entries.
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while true:
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rm.runRepairSweep()
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await sleepAsync(chronos.milliseconds(rm.config.repairSweepInterval.inMilliseconds))
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proc startPeriodicTasks*(rm: ReliabilityManager) =
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## Starts the periodic tasks for buffer sweeping and sync message sending.
|
|
asyncSpawn rm.periodicBufferSweep()
|
|
asyncSpawn rm.periodicSyncMessage()
|
|
asyncSpawn rm.periodicRepairSweep()
|
|
|
|
proc resetReliabilityManager*(rm: ReliabilityManager): Result[void, ReliabilityError] =
|
|
## Resets the ReliabilityManager to its initial state.
|
|
withLock rm.lock:
|
|
try:
|
|
for channelId, channel in rm.channels:
|
|
rm.dropChannelFromPersistence(channelId)
|
|
channel.lamportTimestamp = 0
|
|
channel.messageHistory.clear()
|
|
channel.outgoingBuffer.setLen(0)
|
|
channel.incomingBuffer.clear()
|
|
channel.outgoingRepairBuffer.clear()
|
|
channel.incomingRepairBuffer.clear()
|
|
channel.bloomFilter =
|
|
RollingBloomFilter.init(rm.config.bloomFilterCapacity, rm.config.bloomFilterErrorRate)
|
|
rm.channels.clear()
|
|
return ok()
|
|
except Exception:
|
|
error "Failed to reset ReliabilityManager", msg = getCurrentExceptionMsg()
|
|
return err(ReliabilityError.reInternalError)
|