import std/[tables, heapqueue] import chronos type PeerType* = enum Incoming, Outgoing PeerFlags = enum Acquired, DeleteOnRelease EventType = enum NotEmptyEvent, NotFullEvent PeerStatus* = enum Success, ## Peer was successfully added to PeerPool. DuplicateError, ## Peer is already present in PeerPool. NoSpaceError, ## There no space for the peer in PeerPool. LowScoreError, ## Peer has too low score. DeadPeerError ## Peer is already dead. PeerItem[T] = object data: T peerType: PeerType flags: set[PeerFlags] index: int PeerIndex = object data: int cmp: proc(a, b: PeerIndex): bool {.closure, gcsafe.} PeerScoreCheckCallback*[T] = proc(peer: T): bool {.gcsafe, raises: [Defect].} PeerCounterCallback* = proc() {.gcsafe, raises: [Defect].} PeerPool*[A, B] = ref object incNotEmptyEvent*: AsyncEvent outNotEmptyEvent*: AsyncEvent incNotFullEvent*: AsyncEvent outNotFullEvent*: AsyncEvent incQueue: HeapQueue[PeerIndex] outQueue: HeapQueue[PeerIndex] registry: Table[B, PeerIndex] storage: seq[PeerItem[A]] cmp: proc(a, b: PeerIndex): bool {.closure, gcsafe.} scoreCheck: PeerScoreCheckCallback[A] peerCounter: PeerCounterCallback maxPeersCount: int maxIncPeersCount: int maxOutPeersCount: int curIncPeersCount: int curOutPeersCount: int acqIncPeersCount: int acqOutPeersCount: int PeerPoolError* = object of CatchableError proc `<`*(a, b: PeerIndex): bool = ## PeerIndex ``a`` holds reference to ``cmp()`` procedure which has captured ## PeerPool instance. a.cmp(b, a) proc fireNotEmptyEvent[A, B](pool: PeerPool[A, B], item: PeerItem[A]) {.inline.} = case item.peerType: of PeerType.Incoming: pool.incNotEmptyEvent.fire() of PeerType.Outgoing: pool.outNotEmptyEvent.fire() proc fireNotFullEvent[A, B](pool: PeerPool[A, B], item: PeerItem[A]) {.inline.} = case item.peerType: of PeerType.Incoming: pool.incNotFullEvent.fire() of PeerType.Outgoing: pool.outNotFullEvent.fire() iterator pairs*[A, B](pool: PeerPool[A, B]): (B, A) = for peerId, peerIdx in pool.registry: yield (peerId, pool.storage[peerIdx.data].data) template incomingEvent(eventType: EventType): AsyncEvent = case eventType of EventType.NotEmptyEvent: pool.incNotEmptyEvent of EventType.NotFullEvent: pool.incNotFullEvent template outgoingEvent(eventType: EventType): AsyncEvent = case eventType of EventType.NotEmptyEvent: pool.outNotEmptyEvent of EventType.NotFullEvent: pool.outNotFullEvent proc waitForEvent[A, B](pool: PeerPool[A, B], eventType: EventType, filter: set[PeerType]) {.async.} = if filter == {PeerType.Incoming, PeerType.Outgoing} or filter == {}: var fut1 = incomingEvent(eventType).wait() var fut2 = outgoingEvent(eventType).wait() try: discard await one(fut1, fut2) if fut1.finished: if not(fut2.finished): fut2.cancel() incomingEvent(eventType).clear() else: if not(fut1.finished): fut1.cancel() outgoingEvent(eventType).clear() except CancelledError as exc: if not(fut1.finished): fut1.cancel() if not(fut2.finished): fut2.cancel() raise exc elif PeerType.Incoming in filter: await incomingEvent(eventType).wait() incomingEvent(eventType).clear() elif PeerType.Outgoing in filter: await outgoingEvent(eventType).wait() outgoingEvent(eventType).clear() proc waitNotEmptyEvent[A, B](pool: PeerPool[A, B], filter: set[PeerType]): Future[void] = pool.waitForEvent(EventType.NotEmptyEvent, filter) proc waitNotFullEvent[A, B](pool: PeerPool[A, B], filter: set[PeerType]): Future[void] = pool.waitForEvent(EventType.NotFullEvent, filter) proc newPeerPool*[A, B](maxPeers = -1, maxIncomingPeers = -1, maxOutgoingPeers = -1, scoreCheckCb: PeerScoreCheckCallback[A] = nil, peerCounterCb: PeerCounterCallback = nil): PeerPool[A, B] = ## Create new PeerPool. ## ## ``maxPeers`` - maximum number of peers allowed. All the peers which ## exceeds this number will be rejected (``addPeer()`` procedure will return ## ``false``). By default this number is infinite. ## ## ``maxIncomingPeers`` - maximum number of incoming peers allowed. All the ## incoming peers exceeds this number will be rejected. By default this ## number is infinite. ## ## ``maxOutgoingPeers`` - maximum number of outgoing peers allowed. All the ## outgoing peers exceeds this number will be rejected. By default this ## number if infinite. ## ## ``scoreCheckCb`` - callback which will be called for all released peers. ## If callback procedure returns ``false`` peer will be removed from ## PeerPool. ## ## ``peerCountCb`` - callback to be called when number of peers in PeerPool ## has been changed. ## ## Please note, that if ``maxPeers`` is positive non-zero value, then equation ## ``maxPeers >= maxIncomingPeers + maxOutgoingPeers`` must be ``true``. var res = PeerPool[A, B]() if maxPeers != -1: doAssert(maxPeers >= maxIncomingPeers + maxOutgoingPeers) res.maxPeersCount = if maxPeers < 0: high(int) else: maxPeers res.maxIncPeersCount = if maxIncomingPeers < 0: high(int) else: maxIncomingPeers res.maxOutPeersCount = if maxOutgoingPeers < 0: high(int) else: maxOutgoingPeers res.incNotEmptyEvent = newAsyncEvent() res.outNotEmptyEvent = newAsyncEvent() res.incNotFullEvent = newAsyncEvent() res.outNotFullEvent = newAsyncEvent() res.incQueue = initHeapQueue[PeerIndex]() res.outQueue = initHeapQueue[PeerIndex]() res.registry = initTable[B, PeerIndex]() res.scoreCheck = scoreCheckCb res.peerCounter = peerCounterCb res.storage = newSeq[PeerItem[A]]() proc peerCmp(a, b: PeerIndex): bool {.closure, gcsafe.} = let p1 = res.storage[a.data].data let p2 = res.storage[b.data].data p1 < p2 res.cmp = peerCmp res proc len*[A, B](pool: PeerPool[A, B]): int = ## Returns number of registered peers in PeerPool ``pool``. This number ## includes all the peers (acquired and available). len(pool.registry) proc lenCurrent*[A, B](pool: PeerPool[A, B], filter = {PeerType.Incoming, PeerType.Outgoing}): int {.inline.} = ## Returns number of registered peers in PeerPool ``pool`` which satisfies ## filter ``filter``. (if PeerType.Incoming in filter: pool.curIncPeersCount else: 0) + (if PeerType.Outgoing in filter: pool.curOutPeersCount else: 0) proc lenAvailable*[A, B](pool: PeerPool[A, B], filter = {PeerType.Incoming, PeerType.Outgoing}): int {.inline.} = ## Returns number of available peers in PeerPool ``pool`` which satisfies ## filter ``filter``. (if PeerType.Incoming in filter: len(pool.incQueue) else: 0) + (if PeerType.Outgoing in filter: len(pool.outQueue) else: 0) proc lenAcquired*[A, B](pool: PeerPool[A, B], filter = {PeerType.Incoming, PeerType.Outgoing}): int {.inline.} = ## Returns number of acquired peers in PeerPool ``pool`` which satisifies ## filter ``filter``. (if PeerType.Incoming in filter: pool.acqIncPeersCount else: 0) + (if PeerType.Outgoing in filter: pool.acqOutPeersCount else: 0) proc lenSpace*[A, B](pool: PeerPool[A, B], filter = {PeerType.Incoming, PeerType.Outgoing}): int {.inline.} = ## Returns number of available space for peers in PeerPool ``pool`` which ## satisfies filter ``filter``. let curPeersCount = pool.curIncPeersCount + pool.curOutPeersCount let totalSpace = pool.maxPeersCount - curPeersCount let incoming = min(totalSpace, pool.maxIncPeersCount - pool.curIncPeersCount) let outgoing = min(totalSpace, pool.maxOutPeersCount - pool.curOutPeersCount) if filter == {PeerType.Incoming, PeerType.Outgoing}: # To avoid overflow check we need to check by ourself. if uint64(incoming) + uint64(outgoing) > uint64(high(int)): min(totalSpace, high(int)) else: min(totalSpace, incoming + outgoing) elif PeerType.Incoming in filter: incoming else: outgoing proc shortLogAvailable*[A, B](pool: PeerPool[A, B]): string = $len(pool.incQueue) & "/" & $len(pool.outQueue) proc shortLogAcquired*[A, B](pool: PeerPool[A, B]): string = $pool.acqIncPeersCount & "/" & $pool.acqOutPeersCount proc shortLogSpace*[A, B](pool: PeerPool[A, B]): string = $pool.lenSpace({PeerType.Incoming}) & "/" & $pool.lenSpace({PeerType.Outgoing}) proc shortLogCurrent*[A, B](pool: PeerPool[A, B]): string = $pool.curIncPeersCount & "/" & $pool.curOutPeersCount proc checkPeerScore[A, B](pool: PeerPool[A, B], peer: A): bool {.inline.} = ## Returns ``true`` if peer passing score check. if not(isNil(pool.scoreCheck)): pool.scoreCheck(peer) else: true proc peerCountChanged[A, B](pool: PeerPool[A, B]) {.inline.} = ## Call callback when number of peers changed. if not(isNil(pool.peerCounter)): pool.peerCounter() proc deletePeer*[A, B](pool: PeerPool[A, B], peer: A, force = false): bool = ## Remove ``peer`` from PeerPool ``pool``. ## ## Deletion occurs immediately only if peer is available, otherwise it will ## be deleted only when peer will be released. You can change this behavior ## with ``force`` option. mixin getKey let key = getKey(peer) if pool.registry.hasKey(key): let pindex = pool.registry[key].data var item = addr(pool.storage[pindex]) if (PeerFlags.Acquired in item[].flags): if not(force): item[].flags.incl(PeerFlags.DeleteOnRelease) else: if item[].peerType == PeerType.Incoming: dec(pool.curIncPeersCount) dec(pool.acqIncPeersCount) elif item[].peerType == PeerType.Outgoing: dec(pool.curOutPeersCount) dec(pool.acqOutPeersCount) # Indicate that we have an empty space pool.fireNotFullEvent(item[]) # Cleanup storage with default item, and removing key from hashtable. pool.storage[pindex] = PeerItem[A]() pool.registry.del(key) pool.peerCountChanged() else: if item[].peerType == PeerType.Incoming: # If peer is available, then its copy present in heapqueue, so we need # to remove it. for i in 0 ..< len(pool.incQueue): if pool.incQueue[i].data == pindex: pool.incQueue.del(i) break dec(pool.curIncPeersCount) elif item[].peerType == PeerType.Outgoing: # If peer is available, then its copy present in heapqueue, so we need # to remove it. for i in 0 ..< len(pool.outQueue): if pool.outQueue[i].data == pindex: pool.outQueue.del(i) break dec(pool.curOutPeersCount) # Indicate that we have an empty space pool.fireNotFullEvent(item[]) # Cleanup storage with default item, and removing key from hashtable. pool.storage[pindex] = PeerItem[A]() pool.registry.del(key) pool.peerCountChanged() true else: false proc addPeerImpl[A, B](pool: PeerPool[A, B], peer: A, peerKey: B, peerType: PeerType) = proc onPeerClosed(udata: pointer) {.gcsafe.} = discard pool.deletePeer(peer) let item = PeerItem[A](data: peer, peerType: peerType, index: len(pool.storage)) pool.storage.add(item) var pitem = addr(pool.storage[^1]) let pindex = PeerIndex(data: item.index, cmp: pool.cmp) pool.registry[peerKey] = pindex pitem[].data.getFuture().addCallback(onPeerClosed) if peerType == PeerType.Incoming: inc(pool.curIncPeersCount) pool.incQueue.push(pindex) pool.incNotEmptyEvent.fire() elif peerType == PeerType.Outgoing: inc(pool.curOutPeersCount) pool.outQueue.push(pindex) pool.outNotEmptyEvent.fire() pool.peerCountChanged() proc checkPeer*[A, B](pool: PeerPool[A, B], peer: A): PeerStatus {.inline.} = ## Checks if peer could be added to PeerPool, e.g. it has: ## ## * Positive value of peer's score - (PeerStatus.LowScoreError) ## * Peer's key is not present in PeerPool - (PeerStatus.DuplicateError) ## * Peer's lifetime future is not finished yet - (PeerStatus.DeadPeerError) ## ## If peer could be added to PeerPool procedure returns (PeerStatus.Success) mixin getKey, getFuture if not(pool.checkPeerScore(peer)): PeerStatus.LowScoreError else: let peerKey = getKey(peer) if not(pool.registry.hasKey(peerKey)): if not(peer.getFuture().finished): PeerStatus.Success else: PeerStatus.DeadPeerError else: PeerStatus.DuplicateError proc addPeerNoWait*[A, B](pool: PeerPool[A, B], peer: A, peerType: PeerType): PeerStatus = ## Add peer ``peer`` of type ``peerType`` to PeerPool ``pool``. ## ## Procedure returns ``PeerStatus`` ## * if ``peer`` is already closed - (PeerStatus.DeadPeerError) ## * if ``pool`` already has peer ``peer`` - (PeerStatus.DuplicateError) ## * if ``pool`` currently has a maximum of peers. ## (PeerStatus.NoSpaceError) ## * if ``pool`` currently has a maximum of `Incoming` or `Outgoing` peers. ## (PeerStatus.NoSpaceError) ## ## Procedure returns (PeerStatus.Success) on success. mixin getKey, getFuture let res = pool.checkPeer(peer) if res != PeerStatus.Success: res else: let peerKey = peer.getKey() case peerType: of PeerType.Incoming: if pool.lenSpace({PeerType.Incoming}) > 0: pool.addPeerImpl(peer, peerKey, peerType) PeerStatus.Success else: PeerStatus.NoSpaceError of PeerType.Outgoing: if pool.lenSpace({PeerType.Outgoing}) > 0: pool.addPeerImpl(peer, peerKey, peerType) PeerStatus.Success else: PeerStatus.NoSpaceError proc getPeerSpaceMask[A, B](pool: PeerPool[A, B], peerType: PeerType): set[PeerType] {.inline.} = ## This procedure returns set of events which you need to wait to get empty ## space for peer type ``peerType``. This set can be used for call to ## ``waitNotFullEvent()``. case peerType: of PeerType.Incoming: if pool.maxIncPeersCount >= pool.maxPeersCount: # If maximum number of `incoming` peers is only limited by # maximum number of peers, then we could wait for both events. # It means that we do not care about what peer will left pool. {PeerType.Incoming, PeerType.Outgoing} else: # Otherwise we could wait only for `incoming` event {PeerType.Incoming} of PeerType.Outgoing: if pool.maxOutPeersCount >= pool.maxPeersCount: # If maximum number of `outgoing` peers is only limited by # maximum number of peers, then we could wait for both events. # It means that we do not care about what peer will left pool. {PeerType.Incoming, PeerType.Outgoing} else: # Otherwise we could wait only for `outgoing` event {PeerType.Outgoing} proc waitForEmptySpace*[A, B](pool: PeerPool[A, B], peerType: PeerType) {.async.} = ## This procedure will block until ``pool`` will have an empty space for peer ## of type ``peerType``. let mask = pool.getPeerSpaceMask(peerType) while pool.lenSpace({peerType}) == 0: await pool.waitNotFullEvent(mask) proc addPeer*[A, B](pool: PeerPool[A, B], peer: A, peerType: PeerType): Future[PeerStatus] {.async.} = ## Add peer ``peer`` of type ``peerType`` to PeerPool ``pool``. ## ## This procedure will wait for an empty space in PeerPool ``pool``, if ## PeerPool ``pool`` is full. ## ## Procedure returns ``PeerStatus`` ## * if ``peer`` is already closed - (PeerStatus.DeadPeerError) ## * if ``pool`` already has peer ``peer`` - (PeerStatus.DuplicateError) ## ## Procedure returns (PeerStatus.Success) on success. mixin getKey let res = block: let res1 = pool.checkPeer(peer) if res1 != PeerStatus.Success: res1 else: let mask = pool.getPeerSpaceMask(peerType) # We going to block here until ``pool`` will not have free space, # for our type of peer. while pool.lenSpace({peerType}) == 0: await pool.waitNotFullEvent(mask) # Because we could wait for a long time we need to check peer one more # time to avoid race condition. let res2 = pool.checkPeer(peer) if res2 == PeerStatus.Success: let peerKey = peer.getKey() pool.addPeerImpl(peer, peerKey, peerType) PeerStatus.Success else: res2 return res proc acquireItemImpl[A, B](pool: PeerPool[A, B], filter: set[PeerType]): A {.inline.} = doAssert((len(pool.outQueue) > 0) or (len(pool.incQueue) > 0)) let pindex = if filter == {PeerType.Incoming, PeerType.Outgoing}: if len(pool.outQueue) > 0 and len(pool.incQueue) > 0: # Don't think `<` is actually `<` here. if pool.incQueue[0] < pool.outQueue[0]: inc(pool.acqIncPeersCount) let item = pool.incQueue.pop() item.data else: inc(pool.acqOutPeersCount) let item = pool.outQueue.pop() item.data else: if len(pool.outQueue) > 0: inc(pool.acqOutPeersCount) let item = pool.outQueue.pop() item.data else: inc(pool.acqIncPeersCount) let item = pool.incQueue.pop() item.data else: if PeerType.Outgoing in filter: inc(pool.acqOutPeersCount) let item = pool.outQueue.pop() item.data else: inc(pool.acqIncPeersCount) let item = pool.incQueue.pop() item.data var pitem = addr(pool.storage[pindex]) doAssert(PeerFlags.Acquired notin pitem[].flags) pitem[].flags.incl(PeerFlags.Acquired) pitem[].data proc acquire*[A, B](pool: PeerPool[A, B], filter = {PeerType.Incoming, PeerType.Outgoing}): Future[A] {.async.} = ## Acquire peer from PeerPool ``pool``, which match the filter ``filter``. mixin getKey doAssert(filter != {}, "Filter must not be empty") while true: if pool.lenAvailable(filter) == 0: await pool.waitNotEmptyEvent(filter) else: return pool.acquireItemImpl(filter) proc acquireNoWait*[A, B](pool: PeerPool[A, B], filter = {PeerType.Incoming, PeerType.Outgoing}): A = doAssert(filter != {}, "Filter must not be empty") if pool.lenAvailable(filter) < 1: raise newException(PeerPoolError, "Not enough peers in pool") pool.acquireItemImpl(filter) proc release*[A, B](pool: PeerPool[A, B], peer: A) = ## Release peer ``peer`` back to PeerPool ``pool`` mixin getKey let key = getKey(peer) var titem = pool.registry.getOrDefault(key, PeerIndex(data: -1)) if titem.data >= 0: let pindex = titem.data var item = addr(pool.storage[pindex]) if PeerFlags.Acquired in item[].flags: if not(pool.checkPeerScore(peer)): item[].flags.incl(DeleteOnRelease) if PeerFlags.DeleteOnRelease in item[].flags: # We do not care about result here because peer is present in registry # and has all proper flags set. discard pool.deletePeer(peer, force = true) else: item[].flags.excl(PeerFlags.Acquired) case item[].peerType of PeerType.Incoming: pool.incQueue.push(titem) dec(pool.acqIncPeersCount) of PeerType.Outgoing: pool.outQueue.push(titem) dec(pool.acqOutPeersCount) pool.fireNotEmptyEvent(item[]) proc release*[A, B](pool: PeerPool[A, B], peers: openarray[A]) {.inline.} = ## Release array of peers ``peers`` back to PeerPool ``pool``. for item in peers: pool.release(item) proc acquire*[A, B](pool: PeerPool[A, B], number: int, filter = {PeerType.Incoming, PeerType.Outgoing}): Future[seq[A]] {.async.} = ## Acquire ``number`` number of peers from PeerPool ``pool``, which match the ## filter ``filter``. doAssert(filter != {}, "Filter must not be empty") var peers = newSeq[A]() try: if number > 0: while true: if len(peers) >= number: break if pool.lenAvailable(filter) == 0: await pool.waitNotEmptyEvent(filter) else: peers.add(pool.acquireItemImpl(filter)) except CancelledError as exc: # If we got cancelled, we need to return all the acquired peers back to # pool. for item in peers: pool.release(item) peers.setLen(0) raise exc return peers proc acquireNoWait*[A, B](pool: PeerPool[A, B], number: int, filter = {PeerType.Incoming, PeerType.Outgoing}): seq[A] = ## Acquire ``number`` number of peers from PeerPool ``pool``, which match the ## filter ``filter``. doAssert(filter != {}, "Filter must not be empty") var peers = newSeq[A]() if pool.lenAvailable(filter) < number: raise newException(PeerPoolError, "Not enough peers in pool") for i in 0 ..< number: peers.add(pool.acquireItemImpl(filter)) return peers proc acquireIncomingPeer*[A, B](pool: PeerPool[A, B]): Future[A] {.inline.} = ## Acquire single incoming peer from PeerPool ``pool``. pool.acquire({PeerType.Incoming}) proc acquireOutgoingPeer*[A, B](pool: PeerPool[A, B]): Future[A] {.inline.} = ## Acquire single outgoing peer from PeerPool ``pool``. pool.acquire({PeerType.Outgoing}) proc acquireIncomingPeers*[A, B](pool: PeerPool[A, B], number: int): Future[seq[A]] {.inline.} = ## Acquire ``number`` number of incoming peers from PeerPool ``pool``. pool.acquire(number, {PeerType.Incoming}) proc acquireOutgoingPeers*[A, B](pool: PeerPool[A, B], number: int): Future[seq[A]] {.inline.} = ## Acquire ``number`` number of outgoing peers from PeerPool ``pool``. pool.acquire(number, {PeerType.Outgoing}) iterator peers*[A, B](pool: PeerPool[A, B], filter = {PeerType.Incoming, PeerType.Outgoing}): A = ## Iterate over sorted list of peers. ## ## All peers will be sorted by equation `>`(Peer1, Peer2), so biggest values ## will be first. var sorted = initHeapQueue[PeerIndex]() for i in 0 ..< len(pool.storage): if pool.storage[i].peerType in filter: sorted.push(PeerIndex(data: i, cmp: pool.cmp)) while len(sorted) > 0: let pindex = sorted.pop().data yield pool.storage[pindex].data iterator availablePeers*[A, B](pool: PeerPool[A, B], filter = {PeerType.Incoming, PeerType.Outgoing}): A = ## Iterate over sorted list of available peers. ## ## All peers will be sorted by equation `>`(Peer1, Peer2), so biggest values ## will be first. var sorted = initHeapQueue[PeerIndex]() for i in 0 ..< len(pool.storage): if (PeerFlags.Acquired notin pool.storage[i].flags) and (pool.storage[i].peerType in filter): sorted.push(PeerIndex(data: i, cmp: pool.cmp)) while len(sorted) > 0: let pindex = sorted.pop().data yield pool.storage[pindex].data iterator acquiredPeers*[A, B](pool: PeerPool[A, B], filter = {PeerType.Incoming, PeerType.Outgoing}): A = ## Iterate over sorted list of acquired (non-available) peers. ## ## All peers will be sorted by equation `>`(Peer1, Peer2), so biggest values ## will be first. var sorted = initHeapQueue[PeerIndex]() for i in 0 ..< len(pool.storage): if (PeerFlags.Acquired in pool.storage[i].flags) and (pool.storage[i].peerType in filter): sorted.push(PeerIndex(data: i, cmp: pool.cmp)) while len(sorted) > 0: let pindex = sorted.pop().data yield pool.storage[pindex].data proc `[]`*[A, B](pool: PeerPool[A, B], key: B): A {.inline.} = ## Retrieve peer with key ``key`` from PeerPool ``pool``. let pindex = pool.registry[key] pool.storage[pindex.data] proc `[]`*[A, B](pool: var PeerPool[A, B], key: B): var A {.inline.} = ## Retrieve peer with key ``key`` from PeerPool ``pool``. let pindex = pool.registry[key] pool.storage[pindex.data].data proc hasPeer*[A, B](pool: PeerPool[A, B], key: B): bool {.inline.} = ## Returns ``true`` if peer with ``key`` present in PeerPool ``pool``. pool.registry.hasKey(key) proc getOrDefault*[A, B](pool: PeerPool[A, B], key: B): A {.inline.} = ## Retrieves the peer from PeerPool ``pool`` using key ``key``. If peer is ## not present, default initialization value for type ``A`` is returned ## (e.g. 0 for any integer type). let pindex = pool.registry.getOrDefault(key, PeerIndex(data: -1)) if pindex.data >= 0: pool.storage[pindex.data].data else: A() proc getOrDefault*[A, B](pool: PeerPool[A, B], key: B, default: A): A {.inline.} = ## Retrieves the peer from PeerPool ``pool`` using key ``key``. If peer is ## not present, default value ``default`` is returned. let pindex = pool.registry.getOrDefault(key, PeerIndex(data: -1)) if pindex.data >= 0: pool.storage[pindex.data].data else: default proc clear*[A, B](pool: PeerPool[A, B]) = ## Performs PeerPool's ``pool`` storage and counters reset. pool.incQueue.clear() pool.outQueue.clear() pool.registry.clear() for i in 0 ..< len(pool.storage): 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() proc setScoreCheck*[A, B](pool: PeerPool[A, B], scoreCheckCb: PeerScoreCheckCallback[A]) = ## Add ScoreCheck callback. pool.scoreCheck = scoreCheckCb proc setPeerCounter*[A, B](pool: PeerPool[A, B], peerCounterCb: PeerCounterCallback) = ## Add PeerCounter callback. pool.peerCounter = peerCounterCb