nim-libp2p/libp2p/protocols/pubsub/pubsubpeer.nim

231 lines
7.4 KiB
Nim

## Nim-LibP2P
## Copyright (c) 2019 Status Research & Development GmbH
## Licensed under either of
## * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
## * MIT license ([LICENSE-MIT](LICENSE-MIT))
## at your option.
## This file may not be copied, modified, or distributed except according to
## those terms.
import options, hashes, strutils, tables, hashes
import chronos, chronicles, nimcrypto/sha2, metrics
import rpc/[messages, message, protobuf],
timedcache,
../../peerid,
../../peerinfo,
../../stream/connection,
../../crypto/crypto,
../../protobuf/minprotobuf,
../../utility
logScope:
topics = "pubsubpeer"
declareCounter(libp2p_pubsub_sent_messages, "number of messages sent", labels = ["id", "topic"])
declareCounter(libp2p_pubsub_received_messages, "number of messages received", labels = ["id", "topic"])
declareCounter(libp2p_pubsub_skipped_received_messages, "number of received skipped messages", labels = ["id"])
declareCounter(libp2p_pubsub_skipped_sent_messages, "number of sent skipped messages", labels = ["id"])
type
PubSubObserver* = ref object
onRecv*: proc(peer: PubSubPeer; msgs: var RPCMsg) {.gcsafe, raises: [Defect].}
onSend*: proc(peer: PubSubPeer; msgs: var RPCMsg) {.gcsafe, raises: [Defect].}
PubSubPeer* = ref object of RootObj
proto*: string # the protocol that this peer joined from
sendConn: Connection
peerInfo*: PeerInfo
handler*: RPCHandler
sentRpcCache: TimedCache[string] # cache for already sent messages
recvdRpcCache: TimedCache[string] # cache for already received messages
onConnect*: AsyncEvent
observers*: ref seq[PubSubObserver] # ref as in smart_ptr
RPCHandler* = proc(peer: PubSubPeer, msg: seq[RPCMsg]): Future[void] {.gcsafe.}
func hash*(p: PubSubPeer): Hash =
# int is either 32/64, so intptr basically, pubsubpeer is a ref
cast[pointer](p).hash
func `==`*(a, b: PubSubPeer): bool =
# override equiality to support both nil and peerInfo comparisons
# this in the future will allow us to recycle refs
let
aptr = cast[pointer](a)
bptr = cast[pointer](b)
if aptr == nil:
if bptr == nil:
true
else:
false
elif bptr == nil:
false
else:
if a.peerInfo == nil:
if b.peerInfo == nil:
true
else:
false
else:
if b.peerInfo == nil:
false
else:
a.peerInfo.id == b.peerInfo.id
proc id*(p: PubSubPeer): string = p.peerInfo.id
proc connected*(p: PubSubPeer): bool =
not(isNil(p.sendConn))
proc `conn=`*(p: PubSubPeer, conn: Connection) =
if not(isNil(conn)):
trace "attaching send connection for peer", peer = p.id
p.sendConn = conn
p.onConnect.fire()
proc conn*(p: PubSubPeer): Connection =
p.sendConn
proc recvObservers(p: PubSubPeer, msg: var RPCMsg) =
# trigger hooks
if not(isNil(p.observers)) and p.observers[].len > 0:
for obs in p.observers[]:
if not(isNil(obs)): # TODO: should never be nil, but...
obs.onRecv(p, msg)
proc sendObservers(p: PubSubPeer, msg: var RPCMsg) =
# trigger hooks
if not(isNil(p.observers)) and p.observers[].len > 0:
for obs in p.observers[]:
if not(isNil(obs)): # TODO: should never be nil, but...
obs.onSend(p, msg)
proc handle*(p: PubSubPeer, conn: Connection) {.async.} =
trace "handling pubsub rpc", peer = p.id, closed = conn.closed
try:
try:
while not conn.closed:
trace "waiting for data", peer = p.id, closed = conn.closed
let data = await conn.readLp(64 * 1024)
let digest = $(sha256.digest(data))
trace "read data from peer", peer = p.id, data = data.shortLog
if digest in p.recvdRpcCache:
libp2p_pubsub_skipped_received_messages.inc(labelValues = [p.id])
trace "message already received, skipping", peer = p.id
continue
var rmsg = decodeRpcMsg(data)
if rmsg.isErr():
notice "failed to decode msg from peer", peer = p.id
break
var msg = rmsg.get()
trace "decoded msg from peer", peer = p.id, msg = msg.shortLog
# trigger hooks
p.recvObservers(msg)
for m in msg.messages:
for t in m.topicIDs:
# metrics
libp2p_pubsub_received_messages.inc(labelValues = [p.id, t])
await p.handler(p, @[msg])
p.recvdRpcCache.put(digest)
finally:
trace "exiting pubsub peer read loop", peer = p.id
await conn.close()
except CancelledError as exc:
raise exc
except CatchableError as exc:
trace "Exception occurred in PubSubPeer.handle", exc = exc.msg
raise exc
proc send*(p: PubSubPeer, msgs: seq[RPCMsg]) {.async.} =
logScope:
peer = p.id
msgs = $msgs
for m in msgs.items:
trace "sending msgs to peer", toPeer = p.id, msgs = $msgs
# trigger send hooks
var mm = m # hooks can modify the message
p.sendObservers(mm)
let encoded = encodeRpcMsg(mm)
if encoded.len <= 0:
trace "empty message, skipping", peer = p.id
return
let digest = $(sha256.digest(encoded))
if digest in p.sentRpcCache:
trace "message already sent to peer, skipping", peer = p.id
libp2p_pubsub_skipped_sent_messages.inc(labelValues = [p.id])
continue
try:
trace "about to send message", peer = p.id,
encoded = digest
if p.connected: # this can happen if the remote disconnected
trace "sending encoded msgs to peer", peer = p.id,
encoded = encoded.shortLog
await p.sendConn.writeLp(encoded)
p.sentRpcCache.put(digest)
for m in msgs:
for mm in m.messages:
for t in mm.topicIDs:
# metrics
libp2p_pubsub_sent_messages.inc(labelValues = [p.id, t])
except CatchableError as exc:
trace "unable to send to remote", exc = exc.msg
if not(isNil(p.sendConn)):
await p.sendConn.close()
p.sendConn = nil
p.onConnect.clear()
raise exc
proc sendMsg*(p: PubSubPeer,
peerId: PeerID,
topic: string,
data: seq[byte],
seqno: uint64,
sign: bool): Future[void] {.gcsafe.} =
p.send(@[RPCMsg(messages: @[Message.init(p.peerInfo, data, topic, seqno, sign)])])
proc sendGraft*(p: PubSubPeer, topics: seq[string]) {.async.} =
try:
for topic in topics:
trace "sending graft msg to peer", peer = p.id, topicID = topic
await p.send(@[RPCMsg(control: some(ControlMessage(graft: @[ControlGraft(topicID: topic)])))])
except CancelledError as exc:
raise exc
except CatchableError as exc:
trace "Could not send graft", msg = exc.msg
proc sendPrune*(p: PubSubPeer, topics: seq[string]) {.async.} =
try:
for topic in topics:
trace "sending prune msg to peer", peer = p.id, topicID = topic
await p.send(@[RPCMsg(control: some(ControlMessage(prune: @[ControlPrune(topicID: topic)])))])
except CancelledError as exc:
raise exc
except CatchableError as exc:
trace "Could not send prune", msg = exc.msg
proc `$`*(p: PubSubPeer): string =
p.id
proc newPubSubPeer*(peerInfo: PeerInfo,
proto: string): PubSubPeer =
new result
result.proto = proto
result.peerInfo = peerInfo
result.sentRpcCache = newTimedCache[string](2.minutes)
result.recvdRpcCache = newTimedCache[string](2.minutes)
result.onConnect = newAsyncEvent()