478 lines
17 KiB
Nim
478 lines
17 KiB
Nim
import tables, heapqueue
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import chronos
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type
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PeerType* = enum
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None, Incoming, Outgoing
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PeerFlags = enum
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Acquired, DeleteOnRelease
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PeerItem[T] = object
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data: T
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peerType: PeerType
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flags: set[PeerFlags]
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index: int
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PeerIndex = object
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data: int
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cmp: proc(a, b: PeerIndex): bool {.closure, gcsafe.}
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PeerPool*[A, B] = ref object
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incNeEvent: AsyncEvent
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outNeEvent: AsyncEvent
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incQueue: HeapQueue[PeerIndex]
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outQueue: HeapQueue[PeerIndex]
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registry: Table[B, PeerIndex]
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storage: seq[PeerItem[A]]
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cmp: proc(a, b: PeerIndex): bool {.closure, gcsafe.}
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maxPeersCount: int
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maxIncPeersCount: int
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maxOutPeersCount: int
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curIncPeersCount: int
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curOutPeersCount: int
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acqIncPeersCount: int
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acqOutPeersCount: int
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proc `<`*(a, b: PeerIndex): bool =
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result = a.cmp(b, a)
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proc fireEvent[A, B](pool: PeerPool[A, B], item: PeerItem[A]) {.inline.} =
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if item.peerType == PeerType.Incoming:
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pool.incNeEvent.fire()
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elif item.peerType == PeerType.Outgoing:
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pool.outNeEvent.fire()
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proc waitEvent[A, B](pool: PeerPool[A, B],
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filter: set[PeerType]) {.async.} =
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if filter == {PeerType.Incoming, PeerType.Outgoing} or filter == {}:
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var fut1 = pool.incNeEvent.wait()
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var fut2 = pool.outNeEvent.wait()
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try:
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discard await one(fut1, fut2)
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if fut1.finished:
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if not(fut2.finished):
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fut2.cancel()
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pool.incNeEvent.clear()
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else:
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if not(fut1.finished):
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fut1.cancel()
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pool.outNeEvent.clear()
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except CancelledError:
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if not(fut1.finished):
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fut1.cancel()
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if not(fut2.finished):
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fut2.cancel()
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raise
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elif PeerType.Incoming in filter:
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await pool.incNeEvent.wait()
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pool.incNeEvent.clear()
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elif PeerType.Outgoing in filter:
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await pool.outNeEvent.wait()
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pool.outNeEvent.clear()
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template getItem[A, B](pool: PeerPool[A, B],
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filter: set[PeerType]): ptr PeerItem[A] =
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doAssert((len(pool.outQueue) > 0) or (len(pool.incQueue) > 0))
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var pindex: int
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if filter == {PeerType.Incoming, PeerType.Outgoing}:
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if len(pool.outQueue) > 0 and len(pool.incQueue) > 0:
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# Don't think `<` is actually `<` here.
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if pool.incQueue[0] < pool.outQueue[0]:
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inc(pool.acqIncPeersCount)
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pindex = pool.incQueue.pop().data
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else:
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inc(pool.acqOutPeersCount)
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pindex = pool.outQueue.pop().data
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else:
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if len(pool.outQueue) > 0:
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inc(pool.acqOutPeersCount)
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pindex = pool.outQueue.pop().data
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else:
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inc(pool.acqIncPeersCount)
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pindex = pool.incQueue.pop().data
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else:
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if PeerType.Outgoing in filter:
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inc(pool.acqOutPeersCount)
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pindex = pool.outQueue.pop().data
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elif PeerType.Incoming in filter:
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inc(pool.acqIncPeersCount)
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pindex = pool.incQueue.pop().data
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addr(pool.storage[pindex])
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proc newPeerPool*[A, B](maxPeers = -1,
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maxIncomingPeers = -1,
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maxOutgoingPeers = -1): PeerPool[A, B] =
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## Create new PeerPool.
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##
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## ``maxPeers`` - maximum number of peers allowed. All the peers which
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## exceeds this number will be rejected (``addPeer()`` procedure will return
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## ``false``). By default this number is infinite.
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##
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## ``maxIncomingPeers`` - maximum number of incoming peers allowed. All the
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## incoming peers exceeds this number will be rejected. By default this
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## number is infinite.
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##
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## ``maxOutgoingPeers`` - maximum number of outgoing peers allowed. All the
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## outgoing peers exceeds this number will be rejected. By default this
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## number if infinite.
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##
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## Please note, that if ``maxPeers`` is positive non-zero value, then equation
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## ``maxPeers >= maxIncomingPeers + maxOutgoingPeers`` must be ``true``.
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var res = PeerPool[A, B]()
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if maxPeers != -1:
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doAssert(maxPeers >= maxIncomingPeers + maxOutgoingPeers)
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res.maxPeersCount = if maxPeers < 0: high(int)
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else: maxPeers
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res.maxIncPeersCount = if maxIncomingPeers < 0: high(int)
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else: maxIncomingPeers
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res.maxOutPeersCount = if maxOutgoingPeers < 0: high(int)
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else: maxOutgoingPeers
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res.incNeEvent = newAsyncEvent()
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res.outNeEvent = newAsyncEvent()
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res.incQueue = initHeapQueue[PeerIndex]()
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res.outQueue = initHeapQueue[PeerIndex]()
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res.registry = initTable[B, PeerIndex]()
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res.storage = newSeq[PeerItem[A]]()
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proc peerCmp(a, b: PeerIndex): bool {.closure, gcsafe.} =
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let p1 = res.storage[a.data].data
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let p2 = res.storage[b.data].data
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result = p1 < p2
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res.cmp = peerCmp
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result = res
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proc len*[A, B](pool: PeerPool[A, B]): int =
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## Returns number of registered peers in PeerPool ``pool``. This number
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## includes all the peers (acquired and available).
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result = len(pool.registry)
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proc lenAvailable*[A, B](pool: PeerPool[A, B],
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filter = {PeerType.Incoming,
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PeerType.Outgoing}): int {.inline.} =
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## Returns number of available peers in PeerPool ``pool`` which satisfies
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## filter ``filter``.
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if PeerType.Incoming in filter:
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result = result + len(pool.incQueue)
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if PeerType.Outgoing in filter:
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result = result + len(pool.outQueue)
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proc lenAcquired*[A, B](pool: PeerPool[A, B],
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filter = {PeerType.Incoming,
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PeerType.Outgoing}): int {.inline.} =
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## Returns number of acquired peers in PeerPool ``pool`` which satisifies
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## filter ``filter``.
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if PeerType.Incoming in filter:
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result = result + pool.acqIncPeersCount
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if PeerType.Outgoing in filter:
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result = result + pool.acqOutPeersCount
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proc deletePeer*[A, B](pool: PeerPool[A, B], peer: A, force = false): bool =
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## Remove ``peer`` from PeerPool ``pool``.
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##
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## Deletion occurs immediately only if peer is available, otherwise it will
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## be deleted only when peer will be released. You can change this behavior
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## with ``force`` option.
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mixin getKey
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var key = getKey(peer)
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if pool.registry.hasKey(key):
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let pindex = pool.registry[key].data
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var item = addr(pool.storage[pindex])
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if (PeerFlags.Acquired in item[].flags):
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if not(force):
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item[].flags.incl(PeerFlags.DeleteOnRelease)
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else:
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if item[].peerType == PeerType.Incoming:
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dec(pool.curIncPeersCount)
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dec(pool.acqIncPeersCount)
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elif item[].peerType == PeerType.Outgoing:
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dec(pool.curOutPeersCount)
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dec(pool.acqOutPeersCount)
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# Cleanup storage with default item, and removing key from hashtable.
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pool.storage[pindex] = PeerItem[A]()
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pool.registry.del(key)
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else:
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if item[].peerType == PeerType.Incoming:
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# If peer is available, then its copy present in heapqueue, so we need
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# to remove it.
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for i in 0 ..< len(pool.incQueue):
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if pool.incQueue[i].data == pindex:
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pool.incQueue.del(i)
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break
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dec(pool.curIncPeersCount)
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elif item[].peerType == PeerType.Outgoing:
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# If peer is available, then its copy present in heapqueue, so we need
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# to remove it.
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for i in 0 ..< len(pool.outQueue):
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if pool.outQueue[i].data == pindex:
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pool.outQueue.del(i)
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break
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dec(pool.curOutPeersCount)
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# Cleanup storage with default item, and removing key from hashtable.
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pool.storage[pindex] = PeerItem[A]()
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pool.registry.del(key)
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result = true
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proc addPeer*[A, B](pool: PeerPool[A, B], peer: A, peerType: PeerType): bool =
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## Add peer ``peer`` of type ``peerType`` to PeerPool ``pool``.
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##
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## Returns ``true`` on success.
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mixin getKey, getFuture
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if len(pool.registry) >= pool.maxPeersCount:
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return false
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var item = PeerItem[A](data: peer, peerType: peerType,
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index: len(pool.storage))
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var key = getKey(peer)
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if not(pool.registry.hasKey(key)):
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pool.storage.add(item)
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var pitem = addr(pool.storage[^1])
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let pindex = PeerIndex(data: item.index, cmp: pool.cmp)
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pool.registry[key] = pindex
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proc onPeerClosed(udata: pointer) {.gcsafe.} =
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discard pool.deletePeer(peer)
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pitem[].data.getFuture().addCallback(onPeerClosed)
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if peerType == PeerType.Incoming:
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if pool.curIncPeersCount >= pool.maxIncPeersCount:
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return false
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else:
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inc(pool.curIncPeersCount)
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pool.incQueue.push(pindex)
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pool.incNeEvent.fire()
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elif peerType == PeerType.Outgoing:
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if pool.curOutPeersCount >= pool.maxOutPeersCount:
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return false
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else:
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inc(pool.curOutPeersCount)
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pool.outQueue.push(pindex)
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pool.outNeEvent.fire()
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result = true
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proc addIncomingPeer*[A, B](pool: PeerPool[A, B], peer: A): bool {.inline.} =
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## Add incoming peer ``peer`` to PeerPool ``pool``.
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##
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## Returns ``true`` on success.
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result = pool.addPeer(peer, PeerType.Incoming)
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proc addOutgoingPeer*[A, B](pool: PeerPool[A, B], peer: A): bool {.inline.} =
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## Add outgoing peer ``peer`` to PeerPool ``pool``.
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##
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## Returns ``true`` on success.
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result = pool.addPeer(peer, PeerType.Outgoing)
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proc acquire*[A, B](pool: PeerPool[A, B],
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filter = {PeerType.Incoming,
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PeerType.Outgoing}): Future[A] {.async.} =
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## Acquire peer from PeerPool ``pool``, which match the filter ``filter``.
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doAssert(filter != {}, "Filter must not be empty")
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while true:
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var count = 0
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if PeerType.Incoming in filter:
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count = count + len(pool.incQueue)
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if PeerType.Outgoing in filter:
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count = count + len(pool.outQueue)
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if count == 0:
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await pool.waitEvent(filter)
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else:
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var item = pool.getItem(filter)
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doAssert(PeerFlags.Acquired notin item[].flags)
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item[].flags.incl(PeerFlags.Acquired)
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result = item[].data
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break
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proc release*[A, B](pool: PeerPool[A, B], peer: A) =
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## Release peer ``peer`` back to PeerPool ``pool``
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mixin getKey
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var key = getKey(peer)
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var titem = pool.registry.getOrDefault(key, PeerIndex(data: -1))
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if titem.data >= 0:
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let pindex = titem.data
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var item = addr(pool.storage[pindex])
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if PeerFlags.Acquired in item[].flags:
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item[].flags.excl(PeerFlags.Acquired)
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if PeerFlags.DeleteOnRelease in item[].flags:
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if item[].peerType == PeerType.Incoming:
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dec(pool.curIncPeersCount)
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dec(pool.acqIncPeersCount)
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elif item[].peerType == PeerType.Outgoing:
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dec(pool.curOutPeersCount)
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dec(pool.acqOutPeersCount)
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pool.storage[pindex] = PeerItem[A]()
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pool.registry.del(key)
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else:
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if item[].peerType == PeerType.Incoming:
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pool.incQueue.push(titem)
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dec(pool.acqIncPeersCount)
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elif item[].peerType == PeerType.Outgoing:
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pool.outQueue.push(titem)
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dec(pool.acqOutPeersCount)
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pool.fireEvent(item[])
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proc release*[A, B](pool: PeerPool[A, B], peers: openarray[A]) {.inline.} =
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## Release array of peers ``peers`` back to PeerPool ``pool``.
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for item in peers:
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pool.release(item)
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proc acquire*[A, B](pool: PeerPool[A, B],
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number: int,
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filter = {PeerType.Incoming,
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PeerType.Outgoing}): Future[seq[A]] {.async.} =
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## Acquire ``number`` number of peers from PeerPool ``pool``, which match the
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## filter ``filter``.
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doAssert(filter != {}, "Filter must not be empty")
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var peers = newSeq[A]()
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try:
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if number > 0:
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while true:
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if len(peers) >= number:
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break
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var count = 0
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if PeerType.Incoming in filter:
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count = count + len(pool.incQueue)
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if PeerType.Outgoing in filter:
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count = count + len(pool.outQueue)
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if count == 0:
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await pool.waitEvent(filter)
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else:
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var item = pool.getItem(filter)
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doAssert(PeerFlags.Acquired notin item[].flags)
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item[].flags.incl(PeerFlags.Acquired)
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peers.add(item[].data)
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except CancelledError:
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# If we got cancelled, we need to return all the acquired peers back to
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# pool.
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for item in peers:
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pool.release(item)
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peers.setLen(0)
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raise
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result = peers
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proc acquireIncomingPeer*[A, B](pool: PeerPool[A, B]): Future[A] {.inline.} =
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## Acquire single incoming peer from PeerPool ``pool``.
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pool.acquire({PeerType.Incoming})
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proc acquireOutgoingPeer*[A, B](pool: PeerPool[A, B]): Future[A] {.inline.} =
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## Acquire single outgoing peer from PeerPool ``pool``.
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pool.acquire({PeerType.Outgoing})
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proc acquireIncomingPeers*[A, B](pool: PeerPool[A, B],
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number: int): Future[seq[A]] {.inline.} =
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## Acquire ``number`` number of incoming peers from PeerPool ``pool``.
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pool.acquire(number, {PeerType.Incoming})
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proc acquireOutgoingPeers*[A, B](pool: PeerPool[A, B],
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number: int): Future[seq[A]] {.inline.} =
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## Acquire ``number`` number of outgoing peers from PeerPool ``pool``.
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pool.acquire(number, {PeerType.Outgoing})
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iterator peers*[A, B](pool: PeerPool[A, B],
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filter = {PeerType.Incoming,
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PeerType.Outgoing}): A =
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## Iterate over sorted list of peers.
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##
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## All peers will be sorted by equation `>`(Peer1, Peer2), so biggest values
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## will be first.
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var sorted = initHeapQueue[PeerIndex]()
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for i in 0 ..< len(pool.storage):
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if pool.storage[i].peerType in filter:
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sorted.push(PeerIndex(data: i, cmp: pool.cmp))
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while len(sorted) > 0:
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let pindex = sorted.pop().data
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yield pool.storage[pindex].data
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iterator availablePeers*[A, B](pool: PeerPool[A, B],
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filter = {PeerType.Incoming,
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PeerType.Outgoing}): A =
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## Iterate over sorted list of available peers.
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##
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## All peers will be sorted by equation `>`(Peer1, Peer2), so biggest values
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## will be first.
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var sorted = initHeapQueue[PeerIndex]()
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for i in 0 ..< len(pool.storage):
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if (PeerFlags.Acquired notin pool.storage[i].flags) and
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(pool.storage[i].peerType in filter):
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sorted.push(PeerIndex(data: i, cmp: pool.cmp))
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while len(sorted) > 0:
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let pindex = sorted.pop().data
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yield pool.storage[pindex].data
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iterator acquiredPeers*[A, B](pool: PeerPool[A, B],
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filter = {PeerType.Incoming,
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PeerType.Outgoing}): A =
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## Iterate over sorted list of acquired (non-available) peers.
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##
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## All peers will be sorted by equation `>`(Peer1, Peer2), so biggest values
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## will be first.
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var sorted = initHeapQueue[PeerIndex]()
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for i in 0 ..< len(pool.storage):
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if (PeerFlags.Acquired in pool.storage[i].flags) and
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(pool.storage[i].peerType in filter):
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sorted.push(PeerIndex(data: i, cmp: pool.cmp))
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while len(sorted) > 0:
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let pindex = sorted.pop().data
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yield pool.storage[pindex].data
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proc `[]`*[A, B](pool: PeerPool[A, B], key: B): A {.inline.} =
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## Retrieve peer with key ``key`` from PeerPool ``pool``.
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let pindex = pool.registry[key]
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result = pool.storage[pindex.data]
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proc `[]`*[A, B](pool: var PeerPool[A, B], key: B): var A {.inline.} =
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## Retrieve peer with key ``key`` from PeerPool ``pool``.
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let pindex = pool.registry[key]
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result = pool.storage[pindex.data].data
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proc hasPeer*[A, B](pool: PeerPool[A, B], key: B): bool {.inline.} =
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## Returns ``true`` if peer with ``key`` present in PeerPool ``pool``.
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result = pool.registry.hasKey(key)
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proc getOrDefault*[A, B](pool: PeerPool[A, B], key: B): A {.inline.} =
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## Retrieves the peer from PeerPool ``pool`` using key ``key``. If peer is
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## not present, default initialization value for type ``A`` is returned
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## (e.g. 0 for any integer type).
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let pindex = pool.registry.getOrDefault(key, PeerIndex(data: -1))
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if pindex.data >= 0:
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result = pool.storage[pindex.data].data
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proc getOrDefault*[A, B](pool: PeerPool[A, B], key: B,
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default: A): A {.inline.} =
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## Retrieves the peer from PeerPool ``pool`` using key ``key``. If peer is
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## not present, default value ``default`` is returned.
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let pindex = pool.registry.getOrDefault(key, PeerIndex(data: -1))
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if pindex.data >= 0:
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result = pool.storage[pindex.data].data
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else:
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result = default
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proc clear*[A, B](pool: PeerPool[A, B]) =
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## Performs PeerPool's ``pool`` storage and counters reset.
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pool.incQueue.clear()
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pool.outQueue.clear()
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pool.registry.clear()
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for i in 0 ..< len(pool.storage):
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pool.storage[i] = PeerItem[A]()
|
|
pool.storage.setLen(0)
|
|
pool.curIncPeersCount = 0
|
|
pool.curOutPeersCount = 0
|
|
pool.acqIncPeersCount = 0
|
|
pool.acqOutPeersCount = 0
|
|
|
|
proc clearSafe*[A, B](pool: PeerPool[A, B]) {.async.} =
|
|
## Performs "safe" clear. Safe means that it first acquires all the peers
|
|
## in PeerPool, and only after that it will reset storage.
|
|
var acquired = newSeq[A]()
|
|
while len(pool.registry) > len(acquired):
|
|
var peers = await pool.acquire(len(pool.registry) - len(acquired))
|
|
for item in peers:
|
|
acquired.add(item)
|
|
pool.clear()
|