package swarm

import (
	
	
	
	
	

	
	

	ma 
)

type dialJob struct {
	addr    ma.Multiaddr
	peer    peer.ID
	ctx     context.Context
	resp    chan transport.DialUpdate
	timeout time.Duration
}

func ( *dialJob) () bool {
	return .ctx.Err() != nil
}

type dialLimiter struct {
	lk sync.Mutex

	fdConsuming int
	fdLimit     int
	waitingOnFd []*dialJob

	dialFunc dialfunc

	activePerPeer      map[peer.ID]int
	perPeerLimit       int
	waitingOnPeerLimit map[peer.ID][]*dialJob
}

type dialfunc func(context.Context, peer.ID, ma.Multiaddr, chan<- transport.DialUpdate) (transport.CapableConn, error)

func newDialLimiter( dialfunc) *dialLimiter {
	 := ConcurrentFdDials
	if  := os.Getenv("LIBP2P_SWARM_FD_LIMIT");  != "" {
		if ,  := strconv.ParseInt(, 10, 32);  == nil {
			 = int()
		}
	}
	return newDialLimiterWithParams(, , DefaultPerPeerRateLimit)
}

func newDialLimiterWithParams( dialfunc, ,  int) *dialLimiter {
	return &dialLimiter{
		fdLimit:            ,
		perPeerLimit:       ,
		waitingOnPeerLimit: make(map[peer.ID][]*dialJob),
		activePerPeer:      make(map[peer.ID]int),
		dialFunc:           ,
	}
}

// freeFDToken frees FD token and if there are any schedules another waiting dialJob
// in it's place
func ( *dialLimiter) () {
	log.Debugf("[limiter] freeing FD token; waiting: %d; consuming: %d", len(.waitingOnFd), .fdConsuming)
	.fdConsuming--

	for len(.waitingOnFd) > 0 {
		 := .waitingOnFd[0]
		.waitingOnFd[0] = nil // clear out memory
		.waitingOnFd = .waitingOnFd[1:]

		if len(.waitingOnFd) == 0 {
			// clear out memory.
			.waitingOnFd = nil
		}

		// Skip over canceled dials instead of queuing up a goroutine.
		if .cancelled() {
			.freePeerToken()
			continue
		}
		.fdConsuming++

		// we already have activePerPeer token at this point so we can just dial
		go .executeDial()
		return
	}
}

func ( *dialLimiter) ( *dialJob) {
	log.Debugf("[limiter] freeing peer token; peer %s; addr: %s; active for peer: %d; waiting on peer limit: %d",
		.peer, .addr, .activePerPeer[.peer], len(.waitingOnPeerLimit[.peer]))
	// release tokens in reverse order than we take them
	.activePerPeer[.peer]--
	if .activePerPeer[.peer] == 0 {
		delete(.activePerPeer, .peer)
	}

	 := .waitingOnPeerLimit[.peer]
	for len() > 0 {
		 := [0]
		[0] = nil // clear out memory
		 = [1:]

		if len() == 0 {
			delete(.waitingOnPeerLimit, .peer)
		} else {
			.waitingOnPeerLimit[.peer] = 
		}

		if .cancelled() {
			continue
		}

		.activePerPeer[.peer]++ // just kidding, we still want this token

		.addCheckFdLimit()
		return
	}
}

func ( *dialLimiter) ( *dialJob) {
	.lk.Lock()
	defer .lk.Unlock()
	if .shouldConsumeFd(.addr) {
		.freeFDToken()
	}

	.freePeerToken()
}

func ( *dialLimiter) ( ma.Multiaddr) bool {
	// we don't consume FD's for relay addresses for now as they will be consumed when the Relay Transport
	// actually dials the Relay server. That dial call will also pass through this limiter with
	// the address of the relay server i.e. non-relay address.
	,  := .ValueForProtocol(ma.P_CIRCUIT)

	 :=  == nil

	return ! && isFdConsumingAddr()
}

func ( *dialLimiter) ( *dialJob) {
	if .shouldConsumeFd(.addr) {
		if .fdConsuming >= .fdLimit {
			log.Debugf("[limiter] blocked dial waiting on FD token; peer: %s; addr: %s; consuming: %d; "+
				"limit: %d; waiting: %d", .peer, .addr, .fdConsuming, .fdLimit, len(.waitingOnFd))
			.waitingOnFd = append(.waitingOnFd, )
			return
		}

		log.Debugf("[limiter] taking FD token: peer: %s; addr: %s; prev consuming: %d",
			.peer, .addr, .fdConsuming)
		// take token
		.fdConsuming++
	}

	log.Debugf("[limiter] executing dial; peer: %s; addr: %s; FD consuming: %d; waiting: %d",
		.peer, .addr, .fdConsuming, len(.waitingOnFd))
	go .executeDial()
}

func ( *dialLimiter) ( *dialJob) {
	if .activePerPeer[.peer] >= .perPeerLimit {
		log.Debugf("[limiter] blocked dial waiting on peer limit; peer: %s; addr: %s; active: %d; "+
			"peer limit: %d; waiting: %d", .peer, .addr, .activePerPeer[.peer], .perPeerLimit,
			len(.waitingOnPeerLimit[.peer]))
		 := .waitingOnPeerLimit[.peer]
		.waitingOnPeerLimit[.peer] = append(, )
		return
	}
	.activePerPeer[.peer]++

	.addCheckFdLimit()
}

// AddDialJob tries to take the needed tokens for starting the given dial job.
// If it acquires all needed tokens, it immediately starts the dial, otherwise
// it will put it on the waitlist for the requested token.
func ( *dialLimiter) ( *dialJob) {
	.lk.Lock()
	defer .lk.Unlock()

	log.Debugf("[limiter] adding a dial job through limiter: %v", .addr)
	.addCheckPeerLimit()
}

func ( *dialLimiter) ( peer.ID) {
	.lk.Lock()
	defer .lk.Unlock()
	delete(.waitingOnPeerLimit, )
	log.Debugf("[limiter] clearing all peer dials: %v", )
	// NB: the waitingOnFd list doesn't need to be cleaned out here, we will
	// remove them as we encounter them because they are 'cancelled' at this
	// point
}

// executeDial calls the dialFunc, and reports the result through the response
// channel when finished. Once the response is sent it also releases all tokens
// it held during the dial.
func ( *dialLimiter) ( *dialJob) {
	defer .finishedDial()
	if .cancelled() {
		return
	}

	,  := context.WithTimeout(.ctx, .timeout)
	defer ()

	,  := .dialFunc(, .peer, .addr, .resp)
	 := transport.UpdateKindDialSuccessful
	if  != nil {
		 = transport.UpdateKindDialFailed
	}
	select {
	case .resp <- transport.DialUpdate{Kind: , Conn: , Addr: .addr, Err: }:
	case <-.ctx.Done():
		if  != nil {
			.Close()
		}
	}
}