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

77 lines
2.4 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, sets, hashes, strutils
import chronos, chronicles
import rpcmsg,
timedcache,
../../peer,
../../peerinfo,
../../connection,
../../crypto/crypto,
../../protobuf/minprotobuf
logScope:
topic = "PubSubPeer"
type
PubSubPeer* = ref object of RootObj
id*: string # base58 peer id string
peerInfo*: PeerInfo
conn*: Connection
handler*: RPCHandler
topics*: seq[string]
seen: TimedCache[string] # list of messages forwarded to peers
RPCHandler* = proc(peer: PubSubPeer, msg: seq[RPCMsg]): Future[void] {.gcsafe.}
proc handle*(p: PubSubPeer) {.async, gcsafe.} =
trace "handling pubsub rpc", peer = p.id
try:
while not p.conn.closed:
let data = await p.conn.readLp()
trace "Read data from peer", peer = p.id, data = data.toHex()
if data.toHex() in p.seen:
trace "Message already received, skipping", peer = p.id
continue
let msg = decodeRpcMsg(data)
trace "Decoded msg from peer", peer = p.id, msg = msg
await p.handler(p, @[msg])
except:
error "An exception occured while processing pubsub rpc requests", exc = getCurrentExceptionMsg()
finally:
trace "closing connection to pubsub peer", peer = p.id
await p.conn.close()
proc send*(p: PubSubPeer, msgs: seq[RPCMsg]) {.async, gcsafe.} =
for m in msgs:
trace "sending msgs to peer", peer = p.id, msgs = msgs
let encoded = encodeRpcMsg(m)
if encoded.buffer.len <= 0:
trace "empty message, skipping", peer = p.id
return
let encodedHex = encoded.buffer.toHex()
if encodedHex in p.seen:
trace "message already sent to peer, skipping", peer = p.id
continue
trace "sending encoded msgs to peer", peer = p.id, encoded = encodedHex
await p.conn.writeLp(encoded.buffer)
p.seen.put(encodedHex)
proc newPubSubPeer*(conn: Connection, handler: RPCHandler): PubSubPeer =
new result
result.handler = handler
result.conn = conn
result.peerInfo = conn.peerInfo
result.id = conn.peerInfo.peerId.get().pretty()
result.seen = newTimedCache[string]()