148 lines
4.3 KiB
Nim
148 lines
4.3 KiB
Nim
# Nim-Libp2p
|
|
# Copyright (c) 2022 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.
|
|
|
|
when (NimMajor, NimMinor) < (1, 4):
|
|
{.push raises: [Defect].}
|
|
else:
|
|
{.push raises: [].}
|
|
|
|
## This module implements Pool of StreamTransport.
|
|
import chronos
|
|
|
|
const
|
|
DefaultPoolSize* = 8
|
|
## Default pool size
|
|
|
|
type
|
|
ConnectionFlags = enum
|
|
None, Busy
|
|
|
|
PoolItem = object
|
|
transp*: StreamTransport
|
|
flags*: set[ConnectionFlags]
|
|
|
|
PoolState = enum
|
|
Connecting, Connected, Closing, Closed
|
|
|
|
TransportPool* = ref object
|
|
## Transports pool object
|
|
transports: seq[PoolItem]
|
|
busyCount: int
|
|
state: PoolState
|
|
bufferSize: int
|
|
event: AsyncEvent
|
|
|
|
TransportPoolError* = object of AsyncError
|
|
|
|
proc waitAll[T](futs: seq[Future[T]]): Future[void] =
|
|
## Performs waiting for all Future[T].
|
|
var counter = len(futs)
|
|
var retFuture = newFuture[void]("connpool.waitAllConnections")
|
|
proc cb(udata: pointer) =
|
|
dec(counter)
|
|
if counter == 0:
|
|
retFuture.complete()
|
|
for fut in futs:
|
|
fut.addCallback(cb)
|
|
return retFuture
|
|
|
|
proc newPool*(address: TransportAddress, poolsize: int = DefaultPoolSize,
|
|
bufferSize = DefaultStreamBufferSize,
|
|
): Future[TransportPool] {.async.} =
|
|
## Establish pool of connections to address ``address`` with size
|
|
## ``poolsize``.
|
|
var pool = new TransportPool
|
|
pool.bufferSize = bufferSize
|
|
pool.transports = newSeq[PoolItem](poolsize)
|
|
var conns = newSeq[Future[StreamTransport]](poolsize)
|
|
pool.state = Connecting
|
|
for i in 0..<poolsize:
|
|
conns[i] = connect(address, bufferSize)
|
|
# Waiting for all connections to be established.
|
|
await waitAll(conns)
|
|
# Checking connections and preparing pool.
|
|
for i in 0..<poolsize:
|
|
if conns[i].failed:
|
|
raise conns[i].error
|
|
else:
|
|
let transp = conns[i].read()
|
|
let item = PoolItem(transp: transp)
|
|
pool.transports[i] = item
|
|
# Setup available connections event
|
|
pool.event = newAsyncEvent()
|
|
pool.state = Connected
|
|
result = pool
|
|
|
|
proc acquire*(pool: TransportPool): Future[StreamTransport] {.async.} =
|
|
## Acquire non-busy connection from pool ``pool``.
|
|
var transp: StreamTransport
|
|
if pool.state in {Connected}:
|
|
while true:
|
|
if pool.busyCount < len(pool.transports):
|
|
for conn in pool.transports.mitems():
|
|
if Busy notin conn.flags:
|
|
conn.flags.incl(Busy)
|
|
inc(pool.busyCount)
|
|
transp = conn.transp
|
|
break
|
|
else:
|
|
await pool.event.wait()
|
|
pool.event.clear()
|
|
|
|
if not isNil(transp):
|
|
break
|
|
else:
|
|
raise newException(TransportPoolError, "Pool is not ready!")
|
|
result = transp
|
|
|
|
proc release*(pool: TransportPool, transp: StreamTransport) =
|
|
## Release connection ``transp`` back to pool ``pool``.
|
|
if pool.state in {Connected, Closing}:
|
|
var found = false
|
|
for conn in pool.transports.mitems():
|
|
if conn.transp == transp:
|
|
conn.flags.excl(Busy)
|
|
dec(pool.busyCount)
|
|
pool.event.fire()
|
|
found = true
|
|
break
|
|
if not found:
|
|
raise newException(TransportPoolError, "Transport not bound to pool!")
|
|
else:
|
|
raise newException(TransportPoolError, "Pool is not ready!")
|
|
|
|
proc join*(pool: TransportPool) {.async.} =
|
|
## Waiting for all connection to become available.
|
|
if pool.state in {Connected, Closing}:
|
|
while true:
|
|
if pool.busyCount == 0:
|
|
break
|
|
else:
|
|
await pool.event.wait()
|
|
pool.event.clear()
|
|
elif pool.state == Connecting:
|
|
raise newException(TransportPoolError, "Pool is not ready!")
|
|
|
|
proc close*(pool: TransportPool) {.async.} =
|
|
## Closes transports pool ``pool`` and release all resources.
|
|
if pool.state == Connected:
|
|
pool.state = Closing
|
|
# Waiting for all transports to become available.
|
|
await pool.join()
|
|
# Closing all transports
|
|
var pending = newSeq[Future[void]](len(pool.transports))
|
|
for i in 0..<len(pool.transports):
|
|
let transp = pool.transports[i].transp
|
|
transp.close()
|
|
pending[i] = transp.join()
|
|
# Waiting for all transports to be closed
|
|
await waitAll(pending)
|
|
# Mark pool as `Closed`.
|
|
pool.state = Closed
|