cleanup unused code

dial_queue.go

@@ -1,360 +0,0 @@
-package dht
-
-import (
-	"context"
-	"math"
-	"sync"
-	"time"
-
-	"github.com/libp2p/go-libp2p-core/peer"
-	queue "github.com/libp2p/go-libp2p-peerstore/queue"
-)
-
-const (
-	// DefaultDialQueueMinParallelism is the default value for the minimum number of worker dial goroutines that will
-	// be alive at any time.
-	DefaultDialQueueMinParallelism = 6
-	// DefaultDialQueueMaxParallelism is the default value for the maximum number of worker dial goroutines that can
-	// be alive at any time.
-	DefaultDialQueueMaxParallelism = 20
-	// DefaultDialQueueMaxIdle is the default value for the period that a worker dial goroutine waits before signalling
-	// a worker pool downscaling.
-	DefaultDialQueueMaxIdle = 5 * time.Second
-	// DefaultDialQueueScalingMutePeriod is the default value for the amount of time to ignore further worker pool
-	// scaling events, after one is processed. Its role is to reduce jitter.
-	DefaultDialQueueScalingMutePeriod = 1 * time.Second
-	// DefaultDialQueueScalingFactor is the default factor by which the current number of workers will be multiplied
-	// or divided when upscaling and downscaling events occur, respectively.
-	DefaultDialQueueScalingFactor = 1.5
-)
-
-type dialQueue struct {
-	*dqParams
-
-	nWorkers  uint
-	out       *queue.ChanQueue
-	startOnce sync.Once
-
-	waitingCh chan waitingCh
-	dieCh     chan struct{}
-	growCh    chan struct{}
-	shrinkCh  chan struct{}
-}
-
-type dqParams struct {
-	ctx    context.Context
-	target string
-	dialFn func(context.Context, peer.ID) error
-	in     *queue.ChanQueue
-	config dqConfig
-}
-
-type dqConfig struct {
-	// minParallelism is the minimum number of worker dial goroutines that will be alive at any time.
-	minParallelism uint
-	// maxParallelism is the maximum number of worker dial goroutines that can be alive at any time.
-	maxParallelism uint
-	// scalingFactor is the factor by which the current number of workers will be multiplied or divided when upscaling
-	// and downscaling events occur, respectively.
-	scalingFactor float64
-	// mutePeriod is the amount of time to ignore further worker pool scaling events, after one is processed.
-	// Its role is to reduce jitter.
-	mutePeriod time.Duration
-	// maxIdle is the period that a worker dial goroutine waits before signalling a worker pool downscaling.
-	maxIdle time.Duration
-}
-
-// dqDefaultConfig returns the default configuration for dial queues. See const documentation to learn the default values.
-func dqDefaultConfig() dqConfig {
-	return dqConfig{
-		minParallelism: DefaultDialQueueMinParallelism,
-		maxParallelism: DefaultDialQueueMaxParallelism,
-		scalingFactor:  DefaultDialQueueScalingFactor,
-		maxIdle:        DefaultDialQueueMaxIdle,
-		mutePeriod:     DefaultDialQueueScalingMutePeriod,
-	}
-}
-
-type waitingCh struct {
-	ch chan<- peer.ID
-	ts time.Time
-}
-
-// newDialQueue returns an _unstarted_ adaptive dial queue that spawns a dynamically sized set of goroutines to
-// preemptively stage dials for later handoff to the DHT protocol for RPC. It identifies backpressure on both
-// ends (dial consumers and dial producers), and takes compensating action by adjusting the worker pool. To
-// activate the dial queue, call Start().
-//
-// Why? Dialing is expensive. It's orders of magnitude slower than running an RPC on an already-established
-// connection, as it requires establishing a TCP connection, multistream handshake, crypto handshake, mux handshake,
-// and protocol negotiation.
-//
-// We start with config.minParallelism number of workers, and scale up and down based on demand and supply of
-// dialled peers.
-//
-// The following events trigger scaling:
-// - we scale up when we can't immediately return a successful dial to a new consumer.
-// - we scale down when we've been idle for a while waiting for new dial attempts.
-// - we scale down when we complete a dial and realise nobody was waiting for it.
-//
-// Dialler throttling (e.g. FD limit exceeded) is a concern, as we can easily spin up more workers to compensate, and
-// end up adding fuel to the fire. Since we have no deterministic way to detect this for now, we hard-limit concurrency
-// to config.maxParallelism.
-func newDialQueue(params *dqParams) (*dialQueue, error) {
-	dq := &dialQueue{
-		dqParams:  params,
-		out:       queue.NewChanQueue(params.ctx, queue.NewXORDistancePQ(params.target)),
-		growCh:    make(chan struct{}, 1),
-		shrinkCh:  make(chan struct{}, 1),
-		waitingCh: make(chan waitingCh),
-		dieCh:     make(chan struct{}, params.config.maxParallelism),
-	}
-
-	return dq, nil
-}
-
-// Start initiates action on this dial queue. It should only be called once; subsequent calls are ignored.
-func (dq *dialQueue) Start() {
-	dq.startOnce.Do(func() {
-		go dq.control()
-	})
-}
-
-func (dq *dialQueue) control() {
-	var (
-		dialled        <-chan peer.ID
-		waiting        []waitingCh
-		lastScalingEvt = time.Now()
-	)
-
-	defer func() {
-		for _, w := range waiting {
-			close(w.ch)
-		}
-		waiting = nil
-	}()
-
-	// start workers
-
-	tgt := int(dq.dqParams.config.minParallelism)
-	for i := 0; i < tgt; i++ {
-		go dq.worker()
-	}
-	dq.nWorkers = uint(tgt)
-
-	// control workers
-
-	for {
-		// First process any backlog of dial jobs and waiters -- making progress is the priority.
-		// This block is copied below; couldn't find a more concise way of doing this.
-		select {
-		case <-dq.ctx.Done():
-			return
-		case w := <-dq.waitingCh:
-			waiting = append(waiting, w)
-			dialled = dq.out.DeqChan
-			continue // onto the top.
-		case p, ok := <-dialled:
-			if !ok {
-				return // we're done if the ChanQueue is closed, which happens when the context is closed.
-			}
-			w := waiting[0]
-			logger.Debugf("delivering dialled peer to DHT; took %dms.", time.Since(w.ts)/time.Millisecond)
-			w.ch <- p
-			close(w.ch)
-			waiting = waiting[1:]
-			if len(waiting) == 0 {
-				// no more waiters, so stop consuming dialled jobs.
-				dialled = nil
-			}
-			continue // onto the top.
-		default:
-			// there's nothing to process, so proceed onto the main select block.
-		}
-
-		select {
-		case <-dq.ctx.Done():
-			return
-		case w := <-dq.waitingCh:
-			waiting = append(waiting, w)
-			dialled = dq.out.DeqChan
-		case p, ok := <-dialled:
-			if !ok {
-				return // we're done if the ChanQueue is closed, which happens when the context is closed.
-			}
-			w := waiting[0]
-			logger.Debugf("delivering dialled peer to DHT; took %dms.", time.Since(w.ts)/time.Millisecond)
-			w.ch <- p
-			close(w.ch)
-			waiting = waiting[1:]
-			if len(waiting) == 0 {
-				// no more waiters, so stop consuming dialled jobs.
-				dialled = nil
-			}
-		case <-dq.growCh:
-			if time.Since(lastScalingEvt) < dq.config.mutePeriod {
-				continue
-			}
-			dq.grow()
-			lastScalingEvt = time.Now()
-		case <-dq.shrinkCh:
-			if time.Since(lastScalingEvt) < dq.config.mutePeriod {
-				continue
-			}
-			dq.shrink()
-			lastScalingEvt = time.Now()
-		}
-	}
-}
-
-func (dq *dialQueue) Consume() <-chan peer.ID {
-	ch := make(chan peer.ID, 1)
-
-	select {
-	case p, ok := <-dq.out.DeqChan:
-		// short circuit and return a dialled peer if it's immediately available, or abort if DeqChan is closed.
-		if ok {
-			ch <- p
-		}
-		close(ch)
-		return ch
-	case <-dq.ctx.Done():
-		// return a closed channel with no value if we're done.
-		close(ch)
-		return ch
-	default:
-	}
-
-	// we have no finished dials to return, trigger a scale up.
-	select {
-	case dq.growCh <- struct{}{}:
-	default:
-	}
-
-	// park the channel until a dialled peer becomes available.
-	select {
-	case dq.waitingCh <- waitingCh{ch, time.Now()}:
-		// all good
-	case <-dq.ctx.Done():
-		// return a closed channel with no value if we're done.
-		close(ch)
-	}
-	return ch
-}
-
-func (dq *dialQueue) grow() {
-	// no mutex needed as this is only called from the (single-threaded) control loop.
-	defer func(prev uint) {
-		if prev == dq.nWorkers {
-			return
-		}
-		logger.Debugf("grew dial worker pool: %d => %d", prev, dq.nWorkers)
-	}(dq.nWorkers)
-
-	if dq.nWorkers == dq.config.maxParallelism {
-		return
-	}
-	// choosing not to worry about uint wrapping beyond max value.
-	target := uint(math.Floor(float64(dq.nWorkers) * dq.config.scalingFactor))
-	if target > dq.config.maxParallelism {
-		target = dq.config.maxParallelism
-	}
-	for ; dq.nWorkers < target; dq.nWorkers++ {
-		go dq.worker()
-	}
-}
-
-func (dq *dialQueue) shrink() {
-	// no mutex needed as this is only called from the (single-threaded) control loop.
-	defer func(prev uint) {
-		if prev == dq.nWorkers {
-			return
-		}
-		logger.Debugf("shrunk dial worker pool: %d => %d", prev, dq.nWorkers)
-	}(dq.nWorkers)
-
-	if dq.nWorkers == dq.config.minParallelism {
-		return
-	}
-	target := uint(math.Floor(float64(dq.nWorkers) / dq.config.scalingFactor))
-	if target < dq.config.minParallelism {
-		target = dq.config.minParallelism
-	}
-	// send as many die signals as workers we have to prune.
-	for ; dq.nWorkers > target; dq.nWorkers-- {
-		select {
-		case dq.dieCh <- struct{}{}:
-		default:
-			logger.Debugf("too many die signals queued up.")
-		}
-	}
-}
-
-func (dq *dialQueue) worker() {
-	// This idle timer tracks if the environment is slow. If we're waiting to long to acquire a peer to dial,
-	// it means that the DHT query is progressing slow and we should shrink the worker pool.
-	idleTimer := time.NewTimer(24 * time.Hour) // placeholder init value which will be overridden immediately.
-	defer idleTimer.Stop()
-	for {
-		// trap exit signals first.
-		select {
-		case <-dq.ctx.Done():
-			return
-		case <-dq.dieCh:
-			return
-		default:
-		}
-
-		idleTimer.Stop()
-		select {
-		case <-idleTimer.C:
-		default:
-			// NOTE: There is a slight race here. We could be in the
-			// middle of firing the timer and not read anything from the channel.
-			//
-			// However, that's not really a huge issue. We'll think
-			// we're idle but that's fine.
-		}
-		idleTimer.Reset(dq.config.maxIdle)
-
-		select {
-		case <-dq.dieCh:
-			return
-		case <-dq.ctx.Done():
-			return
-		case <-idleTimer.C:
-			// no new dial requests during our idle period; time to scale down.
-		case p, ok := <-dq.in.DeqChan:
-			if !ok {
-				return
-			}
-
-			t := time.Now()
-			if err := dq.dialFn(dq.ctx, p); err != nil {
-				logger.Debugf("discarding dialled peer because of error: %v", err)
-				continue
-			}
-			logger.Debugf("dialling %v took %dms (as observed by the dht subsystem).", p, time.Since(t)/time.Millisecond)
-			waiting := len(dq.waitingCh)
-
-			// by the time we're done dialling, it's possible that the context is closed, in which case there will
-			// be nobody listening on dq.out.EnqChan and we could block forever.
-			select {
-			case dq.out.EnqChan <- p:
-			case <-dq.ctx.Done():
-				return
-			}
-			if waiting > 0 {
-				// we have somebody to deliver this value to, so no need to shrink.
-				continue
-			}
-		}
-
-		// scaling down; control only arrives here if the idle timer fires, or if there are no goroutines
-		// waiting for the value we just produced.
-		select {
-		case dq.shrinkCh <- struct{}{}:
-		default:
-		}
-	}
-}

dial_queue_test.go

@@ -1,247 +0,0 @@
-package dht
-
-import (
-	"context"
-	"sync"
-	"sync/atomic"
-	"testing"
-	"time"
-
-	"github.com/libp2p/go-libp2p-core/peer"
-	queue "github.com/libp2p/go-libp2p-peerstore/queue"
-)
-
-func TestDialQueueGrowsOnSlowDials(t *testing.T) {
-	in := queue.NewChanQueue(context.Background(), queue.NewXORDistancePQ("test"))
-	hang := make(chan struct{})
-
-	var cnt int32
-	dialFn := func(ctx context.Context, p peer.ID) error {
-		atomic.AddInt32(&cnt, 1)
-		<-hang
-		return nil
-	}
-
-	// Enqueue 20 jobs.
-	for i := 0; i < 20; i++ {
-		in.EnqChan <- peer.ID(i)
-	}
-
-	// remove the mute period to grow faster.
-	config := dqDefaultConfig()
-	config.maxIdle = 10 * time.Minute
-	config.mutePeriod = 0
-	dq, err := newDialQueue(&dqParams{
-		ctx:    context.Background(),
-		target: "test",
-		in:     in,
-		dialFn: dialFn,
-		config: config,
-	})
-	if err != nil {
-		t.Error("unexpected error when constructing the dial queue", err)
-	}
-
-	dq.Start()
-
-	for i := 0; i < 4; i++ {
-		_ = dq.Consume()
-		time.Sleep(100 * time.Millisecond)
-	}
-
-	for i := 0; i < 20; i++ {
-		if atomic.LoadInt32(&cnt) > int32(DefaultDialQueueMinParallelism) {
-			return
-		}
-		time.Sleep(100 * time.Millisecond)
-	}
-
-	t.Errorf("expected 19 concurrent dials, got %d", atomic.LoadInt32(&cnt))
-
-}
-
-func TestDialQueueShrinksWithNoConsumers(t *testing.T) {
-	// reduce interference from the other shrink path.
-
-	in := queue.NewChanQueue(context.Background(), queue.NewXORDistancePQ("test"))
-	hang := make(chan struct{})
-
-	wg := new(sync.WaitGroup)
-	wg.Add(13)
-	dialFn := func(ctx context.Context, p peer.ID) error {
-		wg.Done()
-		<-hang
-		return nil
-	}
-
-	config := dqDefaultConfig()
-	config.maxIdle = 10 * time.Minute
-	config.mutePeriod = 0
-	dq, err := newDialQueue(&dqParams{
-		ctx:    context.Background(),
-		target: "test",
-		in:     in,
-		dialFn: dialFn,
-		config: config,
-	})
-	if err != nil {
-		t.Error("unexpected error when constructing the dial queue", err)
-	}
-
-	dq.Start()
-
-	// acquire 3 consumers, everytime we acquire a consumer, we will grow the pool because no dial job is completed
-	// and immediately returnable.
-	for i := 0; i < 3; i++ {
-		_ = dq.Consume()
-	}
-
-	// Enqueue 13 jobs, one per worker we'll grow to.
-	for i := 0; i < 13; i++ {
-		in.EnqChan <- peer.ID(i)
-	}
-
-	waitForWg(t, wg, 2*time.Second)
-
-	// Release a few dialFn, but not all of them because downscaling happens when workers detect there are no
-	// consumers to consume their values. So the other three will be these witnesses.
-	for i := 0; i < 3; i++ {
-		hang <- struct{}{}
-	}
-
-	// allow enough time for signalling and dispatching values to outstanding consumers.
-	time.Sleep(1 * time.Second)
-
-	// unblock the rest.
-	for i := 0; i < 10; i++ {
-		hang <- struct{}{}
-	}
-
-	wg = new(sync.WaitGroup)
-	// we should now only have 6 workers, because all the shrink events will have been honoured.
-	wg.Add(6)
-
-	// enqueue more jobs.
-	for i := 0; i < 6; i++ {
-		in.EnqChan <- peer.ID(i)
-	}
-
-	// let's check we have 6 workers hanging.
-	waitForWg(t, wg, 2*time.Second)
-}
-
-// Inactivity = workers are idle because the DHT query is progressing slow and is producing too few peers to dial.
-func TestDialQueueShrinksWithWhenIdle(t *testing.T) {
-	in := queue.NewChanQueue(context.Background(), queue.NewXORDistancePQ("test"))
-	hang := make(chan struct{})
-
-	var wg sync.WaitGroup
-	wg.Add(13)
-	dialFn := func(ctx context.Context, p peer.ID) error {
-		wg.Done()
-		<-hang
-		return nil
-	}
-
-	// Enqueue 13 jobs.
-	for i := 0; i < 13; i++ {
-		in.EnqChan <- peer.ID(i)
-	}
-
-	config := dqDefaultConfig()
-	config.maxIdle = 1 * time.Second
-	config.mutePeriod = 0
-	dq, err := newDialQueue(&dqParams{
-		ctx:    context.Background(),
-		target: "test",
-		in:     in,
-		dialFn: dialFn,
-		config: config,
-	})
-	if err != nil {
-		t.Error("unexpected error when constructing the dial queue", err)
-	}
-
-	dq.Start()
-
-	// keep up to speed with backlog by releasing the dial function every time we acquire a channel.
-	for i := 0; i < 13; i++ {
-		ch := dq.Consume()
-		hang <- struct{}{}
-		<-ch
-		time.Sleep(100 * time.Millisecond)
-	}
-
-	// wait for MaxIdlePeriod.
-	time.Sleep(1500 * time.Millisecond)
-
-	// we should now only have 6 workers, because all the shrink events will have been honoured.
-	wg.Add(6)
-
-	// enqueue more jobs
-	for i := 0; i < 10; i++ {
-		in.EnqChan <- peer.ID(i)
-	}
-
-	// let's check we have 6 workers hanging.
-	waitForWg(t, &wg, 2*time.Second)
-}
-
-func TestDialQueueMutePeriodHonored(t *testing.T) {
-	in := queue.NewChanQueue(context.Background(), queue.NewXORDistancePQ("test"))
-	hang := make(chan struct{})
-	var wg sync.WaitGroup
-	wg.Add(6)
-	dialFn := func(ctx context.Context, p peer.ID) error {
-		wg.Done()
-		<-hang
-		return nil
-	}
-
-	// Enqueue a bunch of jobs.
-	for i := 0; i < 20; i++ {
-		in.EnqChan <- peer.ID(i)
-	}
-
-	config := dqDefaultConfig()
-	config.mutePeriod = 2 * time.Second
-	dq, err := newDialQueue(&dqParams{
-		ctx:    context.Background(),
-		target: "test",
-		in:     in,
-		dialFn: dialFn,
-		config: config,
-	})
-	if err != nil {
-		t.Error("unexpected error when constructing the dial queue", err)
-	}
-
-	dq.Start()
-
-	// pick up three consumers.
-	for i := 0; i < 3; i++ {
-		_ = dq.Consume()
-		time.Sleep(100 * time.Millisecond)
-	}
-
-	time.Sleep(500 * time.Millisecond)
-
-	// we'll only have 6 workers because the grow signals have been ignored.
-	waitForWg(t, &wg, 2*time.Second)
-}
-
-func waitForWg(t *testing.T, wg *sync.WaitGroup, wait time.Duration) {
-	t.Helper()
-
-	done := make(chan struct{})
-	go func() {
-		defer close(done)
-		wg.Wait()
-	}()
-
-	select {
-	case <-time.After(wait):
-		t.Error("timeout while waiting for WaitGroup")
-	case <-done:
-	}
-}

kpeerset/kpeerset.go

@@ -68,91 +68,3 @@ func (ph *peerMetricHeap) Pop() interface{} {
 	ph.data = old[0 : n-1]
 	return item
 }
-
-/*
-// KPeerSet implements heap.Interface and PeerQueue
-type KPeerSet struct {
-	kvalue int
-
-	// from is the Key this PQ measures against
-	from ks.Key
-
-	// heap is a heap of peerDistance items
-	heap peerMetricHeap
-
-	lock sync.RWMutex
-}
-
-func (pq *KPeerSet) Len() int {
-	pq.lock.RLock()
-	defer pq.lock.RUnlock()
-
-	return len(pq.heap)
-}
-
-func (pq *KPeerSet) Check(p peer.ID) bool {
-	pq.lock.RLock()
-	defer pq.lock.RUnlock()
-
-	if pq.heap.Len() < pq.kvalue {
-		return true
-	}
-
-	distance := ks.XORKeySpace.Key([]byte(p)).Distance(pq.from)
-	return distance.Cmp(pq.heap[0].metric) != -1
-}
-
-func (pq *KPeerSet) Add(p peer.ID) (bool, peer.ID) {
-	pq.lock.Lock()
-	defer pq.lock.Unlock()
-
-	distance := ks.XORKeySpace.Key([]byte(p)).Distance(pq.from)
-
-	var replacedPeer peer.ID
-	if pq.heap.Len() >= pq.kvalue {
-		// If we're not closer than the worst peer, drop this.
-		if distance.Cmp(pq.heap[0].metric) != -1 {
-			return false, replacedPeer
-		}
-		// Replacing something, remove it.
-		replacedPeer = heap.Pop(&pq.heap).(*peerMetric).peer
-	}
-
-	heap.Push(&pq.heap, &peerMetric{
-		peer:   p,
-		metric: distance,
-	})
-	return true, replacedPeer
-}
-
-func (pq *KPeerSet) Remove(id peer.ID) {
-	pq.lock.Lock()
-	defer pq.lock.Unlock()
-
-	for i, pm := range pq.heap {
-		if pm.peer == id {
-			heap.Remove(&pq.heap, i)
-			return
-		}
-	}
-}
-
-func (pq *KPeerSet) Peers() []peer.ID {
-	pq.lock.RLock()
-	defer pq.lock.RUnlock()
-
-	ret := make([]peer.ID, len(pq.heap))
-	for _, pm := range pq.heap {
-		ret = append(ret, pm.peer)
-	}
-	return ret
-}
-
-func New(kvalue int, from string) *KPeerSet {
-	return &KPeerSet{
-		from:   ks.XORKeySpace.Key([]byte(from)),
-		kvalue: kvalue,
-		heap:   make([]*peerMetric, 0, kvalue),
-	}
-}
-*/

kpeerset/metrics.go

@@ -26,45 +26,6 @@ func (p peerLatencyMetricList) Less(i, j int) bool {
 func (p peerLatencyMetricList) Swap(i, j int)           { p[i], p[j] = p[j], p[i] }
 func (p peerLatencyMetricList) GetPeerID(i int) peer.ID { return p[i].peer }
 
-func less(pm1, pm2 *peerLatencyMetric) bool {
-	p1Connectedness, p2Connectedness := pm1.connectedness, pm2.connectedness
-	p1Latency, p2Latency := pm1.latency, pm2.latency
-
-	// Compare latency assuming that connected is lower latency than unconnected
-	if p1Connectedness == network.Connected {
-		if p2Connectedness == network.Connected {
-			return p1Latency < p2Latency
-		}
-		return true
-	}
-	if p2Connectedness == network.Connected {
-		return false
-	}
-
-	// Compare latency assuming recent connection is lower latency than older connection.
-	// TODO: This assumption largely stems from our latency library showing peers we know nothing about as
-	// having zero latency
-	if p1Connectedness == network.CanConnect {
-		if p2Connectedness == network.CanConnect {
-			return p1Latency > p2Latency
-		}
-		return true
-	}
-	if p2Connectedness == network.CanConnect {
-		return false
-	}
-
-	// Check if either peer has proven to be unconnectable, if so rank them low
-	if p1Connectedness == network.CannotConnect && p2Connectedness != network.CannotConnect {
-		return false
-	}
-	if p2Connectedness == network.CannotConnect && p1Connectedness != network.CannotConnect {
-		return true
-	}
-
-	return pm1.metric.Cmp(pm2.metric) == -1
-}
-
 func calculationLess(pm1, pm2 peerLatencyMetric) bool {
 	return calc(pm1).Cmp(calc(pm2)) == -1
 }
@@ -110,54 +71,3 @@ func PeersSortedByLatency(peers []IPeerMetric, net network.Network, metrics peer
 	sort.Sort(lst)
 	return lst
 }
-
-func SortByLatency(net network.Network, metrics peerstore.Metrics) func(peers []*peerMetric) []peer.ID {
-	return func(peers []*peerMetric) []peer.ID {
-		metricLst := NewPeerMetricList(peers, func(p1, p2 *peerMetric) bool {
-			p1Connectedness := net.Connectedness(p1.peer)
-			p2Connectedness := net.Connectedness(p2.peer)
-
-			// Compare latency assuming that connected is lower latency than unconnected
-			if p1Connectedness == network.Connected {
-				if p2Connectedness == network.Connected {
-					return metrics.LatencyEWMA(p1.peer) > metrics.LatencyEWMA(p2.peer)
-				}
-				return true
-			}
-			if p2Connectedness == network.Connected {
-				return false
-			}
-
-			// Compare latency assuming recent connection is lower latency than older connection.
-			// TODO: This assumption largely stems from our latency library showing peers we know nothing about as
-			// having zero latency
-			if p1Connectedness == network.CanConnect {
-				if p2Connectedness == network.CanConnect {
-					return metrics.LatencyEWMA(p1.peer) > metrics.LatencyEWMA(p2.peer)
-				}
-				return true
-			}
-			if p2Connectedness == network.CanConnect {
-				return false
-			}
-
-			// Check if either peer has proven to be unconnectable, if so rank them low
-			if p1Connectedness == network.CannotConnect && p2Connectedness != network.CannotConnect {
-				return false
-			}
-			if p2Connectedness == network.CannotConnect && p1Connectedness != network.CannotConnect {
-				return true
-			}
-
-			return p1.metric.Cmp(p2.metric) == -1
-		})
-
-		sort.Stable(metricLst)
-		peerLst := make([]peer.ID, metricLst.Len())
-		for i := range peerLst {
-			peerLst[i] = metricLst.GetPeerID(i)
-		}
-
-		return peerLst
-	}
-}

kpeerset/sorted_peerset.go

@@ -14,34 +14,6 @@ type SortablePeers interface {
 	GetPeerID(i int) peer.ID
 }
 
-type comparer func(id1, id2 *peerMetric) bool
-
-type peerMetricList struct {
-	data []*peerMetric
-	cmp  comparer
-}
-
-func (pm peerMetricList) Len() int { return len(pm.data) }
-
-func (pm peerMetricList) Less(i, j int) bool {
-	return pm.cmp(pm.data[i], pm.data[j])
-}
-
-func (pm peerMetricList) Swap(i, j int) {
-	pm.data[i], pm.data[j] = pm.data[j], pm.data[i]
-}
-
-func (pm peerMetricList) GetPeerID(i int) peer.ID {
-	return pm.data[i].peer
-}
-
-func NewPeerMetricList(peers []*peerMetric, cmp func(p1, p2 *peerMetric) bool) peerMetricList {
-	return peerMetricList{
-		data: peers,
-		cmp:  cmp,
-	}
-}
-
 func NewSortedPeerset(kvalue int, from string, sortPeers func([]IPeerMetric) SortablePeers) *SortedPeerset {
 	fromKey := ks.XORKeySpace.Key([]byte(from))
 

query.go

@@ -15,10 +15,10 @@ import (
 // ErrNoPeersQueried is returned when we failed to connect to any peers.
 var ErrNoPeersQueried = errors.New("failed to query any peers")
 
-type qfn func(context.Context, peer.ID) ([]*peer.AddrInfo, error)
+type queryFn func(context.Context, peer.ID) ([]*peer.AddrInfo, error)
-type sfn func(*kpeerset.SortedPeerset) bool
+type stopFn func(*kpeerset.SortedPeerset) bool
 
-type qu struct {
+type query struct {
 	ctx    context.Context
 	cancel context.CancelFunc
 
@@ -26,11 +26,11 @@ type qu struct {
 
 	localPeers           *kpeerset.SortedPeerset
 	globallyQueriedPeers *peer.Set
-	queryFn              qfn
+	queryFn              queryFn
-	stopFn               sfn
+	stopFn               stopFn
 }
 
-func (dht *IpfsDHT) runDisjointQueries(ctx context.Context, d int, target string, queryFn qfn, stopFn sfn) ([]*qu, error) {
+func (dht *IpfsDHT) runDisjointQueries(ctx context.Context, d int, target string, queryFn queryFn, stopFn stopFn) ([]*query, error) {
 	queryCtx, cancelQuery := context.WithCancel(ctx)
 
 	numQueriesComplete := 0
@@ -49,11 +49,11 @@ func (dht *IpfsDHT) runDisjointQueries(ctx context.Context, d int, target string
 		seedPeers[i], seedPeers[j] = seedPeers[j], seedPeers[i]
 	})
 
-	queries := make([]*qu, d)
+	queries := make([]*query, d)
 
 	peersQueried := peer.NewSet()
 	for i := 0; i < d; i++ {
-		query := &qu{
+		query := &query{
 			ctx:                  queryCtx,
 			cancel:               cancelQuery,
 			dht:                  dht,
@@ -98,7 +98,7 @@ func (dht *IpfsDHT) sortPeers(peers []kpeerset.IPeerMetric) kpeerset.SortablePee
 	return kpeerset.PeersSortedByLatency(peers, dht.host.Network(), dht.peerstore)
 }
 
-func strictParallelismQuery(q *qu) {
+func strictParallelismQuery(q *query) {
 	/*
 		start with K closest peers (some queried already some not)
 		take best alpha (sorted by some metric)
@@ -150,7 +150,7 @@ func strictParallelismQuery(q *qu) {
 	}
 }
 
-func simpleQuery(q *qu) {
+func simpleQuery(q *query) {
 	/*
 		start with K closest peers (some queried already some not)
 		take best alpha (sorted by some metric)
@@ -210,7 +210,7 @@ func simpleQuery(q *qu) {
 	}
 }
 
-func boundedDialQuery(q *qu) {
+func boundedDialQuery(q *query) {
 	/*
 		start with K closest peers (some queried already some not)
 		take best alpha (sorted by some metric)
@@ -268,7 +268,7 @@ type queryResult struct {
 	foundCloserPeer bool
 }
 
-func (q *qu) queryPeer(ctx context.Context, p peer.ID) *queryResult {
+func (q *query) queryPeer(ctx context.Context, p peer.ID) *queryResult {
 	dialCtx, queryCtx := ctx, ctx
 
 	if err := q.dht.dialPeer(dialCtx, p); err != nil {

routing.go

@@ -320,9 +320,9 @@ func (dht *IpfsDHT) updatePeerValues(ctx context.Context, key string, val []byte
 	}
 }
 
-func (dht *IpfsDHT) getValues(ctx context.Context, key string, stopQuery chan struct{}) (<-chan RecvdVal, <-chan []*qu) {
+func (dht *IpfsDHT) getValues(ctx context.Context, key string, stopQuery chan struct{}) (<-chan RecvdVal, <-chan []*query) {
 	valCh := make(chan RecvdVal, 1)
-	queriesCh := make(chan []*qu, 1)
+	queriesCh := make(chan []*query, 1)
 
 	if rec, err := dht.getLocal(key); rec != nil && err == nil {
 		select {