nwaku/waku/v2/protocol/waku_store/protocol.nim

490 lines
17 KiB
Nim

## Waku Store protocol for historical messaging support.
## See spec for more details:
## https://github.com/vacp2p/specs/blob/master/specs/waku/v2/waku-store.md
{.push raises: [Defect].}
import
std/[tables, times, sequtils, options, algorithm],
stew/results,
chronicles,
chronos,
bearssl/rand,
libp2p/crypto/crypto,
libp2p/protocols/protocol,
libp2p/protobuf/minprotobuf,
libp2p/stream/connection,
metrics
import
../../node/storage/message/message_retention_policy,
../../node/storage/message/waku_store_queue,
../../node/peer_manager/peer_manager,
../../utils/time,
../../utils/requests,
../waku_message,
../waku_swap/waku_swap,
./rpc,
./rpc_codec,
./pagination,
./message_store
declarePublicGauge waku_store_messages, "number of historical messages", ["type"]
declarePublicGauge waku_store_peers, "number of store peers"
declarePublicGauge waku_store_errors, "number of store protocol errors", ["type"]
declarePublicGauge waku_store_queries, "number of store queries received"
declarePublicHistogram waku_store_insert_duration_seconds, "message insertion duration"
declarePublicHistogram waku_store_query_duration_seconds, "history query duration"
logScope:
topics = "wakustore"
const
WakuStoreCodec* = "/vac/waku/store/2.0.0-beta4"
DefaultTopic* = "/waku/2/default-waku/proto"
MaxMessageTimestampVariance* = Timestamp(20.seconds.nanoseconds) # 20 seconds maximum allowable sender timestamp "drift"
# Error types (metric label values)
const
invalidMessage = "invalid_message"
insertFailure = "insert_failure"
retPolicyFailure = "retpolicy_failure"
dialFailure = "dial_failure"
decodeRpcFailure = "decode_rpc_failure"
peerNotFoundFailure = "peer_not_found_failure"
type
WakuStoreResult*[T] = Result[T, string]
WakuStore* = ref object of LPProtocol
peerManager*: PeerManager
rng*: ref rand.HmacDrbgContext
store*: MessageStore
wakuSwap*: WakuSwap
retentionPolicy: Option[MessageRetentionPolicy]
proc executeMessageRetentionPolicy*(w: WakuStore) =
if w.retentionPolicy.isNone():
return
if w.store.isNil():
return
let policy = w.retentionPolicy.get()
let retPolicyRes = policy.execute(w.store)
if retPolicyRes.isErr():
waku_store_errors.inc(labelValues = [retPolicyFailure])
debug "failed execution of retention policy", error=retPolicyRes.error
proc reportStoredMessagesMetric*(w: WakuStore) =
if w.store.isNil():
return
let resCount = w.store.getMessagesCount()
if resCount.isErr():
return
waku_store_messages.set(resCount.value, labelValues = ["stored"])
proc findMessages(w: WakuStore, query: HistoryQuery): HistoryResponse {.gcsafe.} =
## Query history to return a single page of messages matching the query
# Extract query criteria. All query criteria are optional
let
qContentTopics = if (query.contentFilters.len != 0): some(query.contentFilters.mapIt(it.contentTopic))
else: none(seq[ContentTopic])
qPubSubTopic = if (query.pubsubTopic != ""): some(query.pubsubTopic)
else: none(string)
qCursor = if query.pagingInfo.cursor != PagingIndex(): some(query.pagingInfo.cursor)
else: none(PagingIndex)
qStartTime = if query.startTime != Timestamp(0): some(query.startTime)
else: none(Timestamp)
qEndTime = if query.endTime != Timestamp(0): some(query.endTime)
else: none(Timestamp)
qMaxPageSize = if query.pagingInfo.pageSize <= 0: DefaultPageSize
else: min(query.pagingInfo.pageSize, MaxPageSize)
qAscendingOrder = query.pagingInfo.direction == PagingDirection.FORWARD
let queryStartTime = getTime().toUnixFloat()
let queryRes = w.store.getMessagesByHistoryQuery(
contentTopic = qContentTopics,
pubsubTopic = qPubSubTopic,
cursor = qCursor,
startTime = qStartTime,
endTime = qEndTime,
maxPageSize = qMaxPageSize + 1,
ascendingOrder = qAscendingOrder
)
let queryDuration = getTime().toUnixFloat() - queryStartTime
waku_store_query_duration_seconds.observe(queryDuration)
# Build response
# TODO: Improve error reporting
if queryRes.isErr():
return HistoryResponse(messages: @[], pagingInfo: PagingInfo(), error: HistoryResponseError.INVALID_CURSOR)
let rows = queryRes.get()
if rows.len <= 0:
return HistoryResponse(messages: @[], error: HistoryResponseError.NONE)
var messages = if rows.len <= int(qMaxPageSize): rows.mapIt(it[1])
else: rows[0..^2].mapIt(it[1])
var pagingInfo = none(PagingInfo)
# The retrieved messages list should always be in chronological order
if not qAscendingOrder:
messages.reverse()
if rows.len > int(qMaxPageSize):
# Build last message cursor
let (pubsubTopic, message, digest, storeTimestamp) = rows[^1]
# TODO: Improve coherence of MessageDigest type
var messageDigest: array[32, byte]
for i in 0..<min(digest.len, 32):
messageDigest[i] = digest[i]
let pagingIndex = PagingIndex(
pubsubTopic: pubsubTopic,
senderTime: message.timestamp,
receiverTime: storeTimestamp,
digest: MessageDigest(data: messageDigest)
)
pagingInfo = some(PagingInfo(
pageSize: uint64(messages.len),
cursor: pagingIndex,
direction: if qAscendingOrder: PagingDirection.FORWARD
else: PagingDirection.BACKWARD
))
HistoryResponse(
messages: messages,
pagingInfo: pagingInfo.get(PagingInfo()),
error: HistoryResponseError.NONE
)
proc initProtocolHandler*(ws: WakuStore) =
proc handler(conn: Connection, proto: string) {.async.} =
let buf = await conn.readLp(MaxRpcSize.int)
let resReq = HistoryRPC.init(buf)
if resReq.isErr():
error "failed to decode rpc", peerId=conn.peerId
waku_store_errors.inc(labelValues = [decodeRpcFailure])
return
let req = resReq.value
info "received history query", peerId=conn.peerId, requestId=req.requestId, query=req.query
waku_store_queries.inc()
let resp = if not ws.store.isNil(): ws.findMessages(req.query)
# TODO: Improve error reporting
else: HistoryResponse(error: HistoryResponseError.SERVICE_UNAVAILABLE)
if not ws.wakuSwap.isNil():
info "handle store swap", peerId=conn.peerId, requestId=req.requestId, text=ws.wakuSwap.text
# Perform accounting operation
# TODO: Do accounting here, response is HistoryResponse. How do we get node or swap context?
let peerId = conn.peerId
let messages = resp.messages
ws.wakuSwap.credit(peerId, messages.len)
info "sending history response", peerId=conn.peerId, requestId=req.requestId, messages=resp.messages.len
let rpc = HistoryRPC(requestId: req.requestId, response: resp)
await conn.writeLp(rpc.encode().buffer)
ws.handler = handler
ws.codec = WakuStoreCodec
proc init*(T: type WakuStore,
peerManager: PeerManager,
rng: ref rand.HmacDrbgContext,
store: MessageStore,
wakuSwap: WakuSwap = nil,
retentionPolicy=none(MessageRetentionPolicy)): T =
let ws = WakuStore(
rng: rng,
peerManager: peerManager,
store: store,
wakuSwap: wakuSwap,
retentionPolicy: retentionPolicy
)
ws.initProtocolHandler()
return ws
proc init*(T: type WakuStore,
peerManager: PeerManager,
rng: ref rand.HmacDrbgContext,
wakuSwap: WakuSwap = nil,
retentionPolicy=none(MessageRetentionPolicy)): T =
let store = StoreQueueRef.new()
WakuStore.init(peerManager, rng, store, wakuSwap, retentionPolicy)
proc isValidMessage(msg: WakuMessage): bool =
if msg.timestamp == 0:
return true
let
now = getNanosecondTime(getTime().toUnixFloat())
lowerBound = now - MaxMessageTimestampVariance
upperBound = now + MaxMessageTimestampVariance
return lowerBound <= msg.timestamp and msg.timestamp <= upperBound
proc handleMessage*(w: WakuStore, pubsubTopic: string, msg: WakuMessage) =
if w.store.isNil():
# Messages should not be stored
return
if msg.ephemeral:
# The message is ephemeral, should not be stored
return
if not isValidMessage(msg):
waku_store_errors.inc(labelValues = [invalidMessage])
return
let insertStartTime = getTime().toUnixFloat()
block:
let
msgDigest = computeDigest(msg)
msgReceivedTime = if msg.timestamp > 0: msg.timestamp
else: getNanosecondTime(getTime().toUnixFloat())
trace "handling message", pubsubTopic=pubsubTopic, contentTopic=msg.contentTopic, timestamp=msg.timestamp, digest=msgDigest
let putStoreRes = w.store.put(pubsubTopic, msg, msgDigest, msgReceivedTime)
if putStoreRes.isErr():
debug "failed to insert message into the store", err=putStoreRes.error
waku_store_errors.inc(labelValues = [insertFailure])
return
let insertDuration = getTime().toUnixFloat() - insertStartTime
waku_store_insert_duration_seconds.observe(insertDuration)
## CLIENT
# TODO: This should probably be an add function and append the peer to an array
proc setPeer*(ws: WakuStore, peer: RemotePeerInfo) =
ws.peerManager.addPeer(peer, WakuStoreCodec)
waku_store_peers.inc()
proc query(w: WakuStore, req: HistoryQuery, peer: RemotePeerInfo): Future[WakuStoreResult[HistoryResponse]] {.async, gcsafe.} =
let connOpt = await w.peerManager.dialPeer(peer, WakuStoreCodec)
if connOpt.isNone():
waku_store_errors.inc(labelValues = [dialFailure])
return err(dialFailure)
let connection = connOpt.get()
let rpc = HistoryRPC(requestId: generateRequestId(w.rng), query: req)
await connection.writeLP(rpc.encode().buffer)
var message = await connOpt.get().readLp(MaxRpcSize.int)
let response = HistoryRPC.init(message)
if response.isErr():
error "failed to decode response"
waku_store_errors.inc(labelValues = [decodeRpcFailure])
return err(decodeRpcFailure)
waku_store_messages.set(response.value.response.messages.len.int64, labelValues = ["retrieved"])
return ok(response.value.response)
proc query*(w: WakuStore, req: HistoryQuery): Future[WakuStoreResult[HistoryResponse]] {.async, gcsafe.} =
# TODO: We need to be more stratigic about which peers we dial. Right now we just set one on the service.
# Ideally depending on the query and our set of peers we take a subset of ideal peers.
# This will require us to check for various factors such as:
# - which topics they track
# - latency?
# - default store peer?
let peerOpt = w.peerManager.selectPeer(WakuStoreCodec)
if peerOpt.isNone():
error "no suitable remote peers"
waku_store_errors.inc(labelValues = [peerNotFoundFailure])
return err(peerNotFoundFailure)
return await w.query(req, peerOpt.get())
## 21/WAKU2-FAULT-TOLERANT-STORE
const StoreResumeTimeWindowOffset: Timestamp = getNanosecondTime(20) ## Adjust the time window with an offset of 20 seconds
proc queryFromWithPaging*(w: WakuStore, query: HistoryQuery, peer: RemotePeerInfo): Future[WakuStoreResult[seq[WakuMessage]]] {.async, gcsafe.} =
## A thin wrapper for query. Sends the query to the given peer. when the query has a valid pagingInfo,
## it retrieves the historical messages in pages.
## Returns all the fetched messages, if error occurs, returns an error string
# Make a copy of the query
var req = query
var messageList: seq[WakuMessage] = @[]
# Fetch the history in pages
while true:
let res = await w.query(req, peer)
if res.isErr():
return err(res.error)
let response = res.get()
messageList.add(response.messages)
# Check whether it is the last page
if response.pagingInfo.pageSize == 0:
break
# Update paging cursor
req.pagingInfo.cursor = response.pagingInfo.cursor
return ok(messageList)
proc queryLoop(w: WakuStore, req: HistoryQuery, candidateList: seq[RemotePeerInfo]): Future[WakuStoreResult[seq[WakuMessage]]] {.async, gcsafe.} =
## Loops through the peers candidate list in order and sends the query to each
##
## Once all responses have been received, the retrieved messages are consolidated into one deduplicated list.
## if no messages have been retrieved, the returned future will resolve into a result holding an empty seq.
let queriesList = candidateList.mapIt(w.queryFromWithPaging(req, it))
await allFutures(queriesList)
let messagesList = queriesList
.map(proc (fut: Future[WakuStoreResult[seq[WakuMessage]]]): seq[WakuMessage] =
# These futures have been awaited before using allFutures(). Call completed() just as a sanity check.
if not fut.completed() or fut.read().isErr():
return @[]
fut.read().value
)
.concat()
.deduplicate()
if messagesList.len == 0:
return err("failed to resolve the query")
return ok(messagesList)
proc resume*(w: WakuStore,
peerList: Option[seq[RemotePeerInfo]] = none(seq[RemotePeerInfo]),
pageSize: uint64 = DefaultPageSize,
pubsubTopic = DefaultTopic): Future[WakuStoreResult[uint64]] {.async, gcsafe.} =
## resume proc retrieves the history of waku messages published on the default waku pubsub topic since the last time the waku store node has been online
## messages are stored in the store node's messages field and in the message db
## the offline time window is measured as the difference between the current time and the timestamp of the most recent persisted waku message
## an offset of 20 second is added to the time window to count for nodes asynchrony
## peerList indicates the list of peers to query from.
## The history is fetched from all available peers in this list and then consolidated into one deduplicated list.
## Such candidates should be found through a discovery method (to be developed).
## if no peerList is passed, one of the peers in the underlying peer manager unit of the store protocol is picked randomly to fetch the history from.
## The history gets fetched successfully if the dialed peer has been online during the queried time window.
## the resume proc returns the number of retrieved messages if no error occurs, otherwise returns the error string
# If store has not been provided, don't even try
if w.store.isNil():
return err("store not provided (nil)")
# NOTE: Original implementation is based on the message's sender timestamp. At the moment
# of writing, the sqlite store implementation returns the last message's receiver
# timestamp.
# lastSeenTime = lastSeenItem.get().msg.timestamp
let
lastSeenTime = w.store.getNewestMessageTimestamp().get(Timestamp(0))
now = getNanosecondTime(getTime().toUnixFloat())
debug "resuming with offline time window", lastSeenTime=lastSeenTime, currentTime=now
let
queryEndTime = now + StoreResumeTimeWindowOffset
queryStartTime = max(lastSeenTime - StoreResumeTimeWindowOffset, 0)
let req = HistoryQuery(
pubsubTopic: pubsubTopic,
startTime: queryStartTime,
endTime: queryEndTime,
pagingInfo: PagingInfo(
direction:PagingDirection.FORWARD,
pageSize: pageSize
)
)
var res: WakuStoreResult[seq[WakuMessage]]
if peerList.isSome():
debug "trying the candidate list to fetch the history"
res = await w.queryLoop(req, peerList.get())
else:
debug "no candidate list is provided, selecting a random peer"
# if no peerList is set then query from one of the peers stored in the peer manager
let peerOpt = w.peerManager.selectPeer(WakuStoreCodec)
if peerOpt.isNone():
warn "no suitable remote peers"
waku_store_errors.inc(labelValues = [peerNotFoundFailure])
return err("no suitable remote peers")
debug "a peer is selected from peer manager"
res = await w.queryFromWithPaging(req, peerOpt.get())
if res.isErr():
debug "failed to resume the history"
return err("failed to resume the history")
# Save the retrieved messages in the store
var added: uint = 0
for msg in res.get():
let putStoreRes = w.store.put(pubsubTopic, msg)
if putStoreRes.isErr():
warn "failed to insert resumed message into store", error=putStoreRes.error
continue
added.inc()
return ok(added)
## EXPERIMENTAL
# NOTE: Experimental, maybe incorporate as part of query call
proc queryWithAccounting*(ws: WakuStore, req: HistoryQuery): Future[WakuStoreResult[HistoryResponse]] {.async, gcsafe.} =
let peerOpt = ws.peerManager.selectPeer(WakuStoreCodec)
if peerOpt.isNone():
error "no suitable remote peers"
waku_store_errors.inc(labelValues = [peerNotFoundFailure])
return err(peerNotFoundFailure)
let res = await ws.query(req, peerOpt.get())
if res.isErr():
return err(res.error)
let response = res.get()
# Perform accounting operation. Assumes wakuSwap protocol is mounted
ws.wakuSwap.debit(peerOpt.get().peerId, response.messages.len)
return ok(response)