// FindProvidersAsync returns a channel of providers for the given key
func (bsnet *impl) FindProvidersAsync(ctx context.Context, k key.Key, max int) <-chan peer.ID {
// Since routing queries are expensive, give bitswap the peers to which we
// have open connections. Note that this may cause issues if bitswap starts
// precisely tracking which peers provide certain keys. This optimization
// would be misleading. In the long run, this may not be the most
// appropriate place for this optimization, but it won't cause any harm in
// the short term.
connectedPeers := bsnet.host.Network().Peers()
out := make(chan peer.ID, len(connectedPeers)) // just enough buffer for these connectedPeers
for _, id := range connectedPeers {
if id == bsnet.host.ID() {
continue // ignore self as provider
}
out <- id
}
go func() {
defer close(out)
providers := bsnet.routing.FindProvidersAsync(ctx, k, max)
for info := range providers {
if info.ID == bsnet.host.ID() {
continue // ignore self as provider
}
bsnet.host.Peerstore().AddAddrs(info.ID, info.Addrs, peer.TempAddrTTL)
select {
case <-ctx.Done():
return
case out <- info.ID:
}
}
}()
return out
}
func GarbageCollectAsync(n *core.IpfsNode, ctx context.Context) (<-chan *KeyRemoved, error) {
keychan, err := n.Blockstore.AllKeysChan(ctx)
if err != nil {
return nil, err
}
output := make(chan *KeyRemoved)
go func() {
defer close(output)
for {
select {
case k, ok := <-keychan:
if !ok {
return
}
if !n.Pinning.IsPinned(k) {
err := n.Blockstore.DeleteBlock(k)
if err != nil {
log.Debugf("Error removing key from blockstore: %s", err)
continue
}
select {
case output <- &KeyRemoved{k}:
case <-ctx.Done():
}
}
case <-ctx.Done():
return
}
}
}()
return output, nil
}
// Subscribe returns a channel of blocks for the given |keys|. |blockChannel|
// is closed if the |ctx| times out or is cancelled, or after sending len(keys)
// blocks.
func (ps *impl) Subscribe(ctx context.Context, keys ...key.Key) <-chan *blocks.Block {
blocksCh := make(chan *blocks.Block, len(keys))
valuesCh := make(chan interface{}, len(keys)) // provide our own channel to control buffer, prevent blocking
if len(keys) == 0 {
close(blocksCh)
return blocksCh
}
ps.wrapped.AddSubOnceEach(valuesCh, toStrings(keys)...)
go func() {
defer close(blocksCh)
defer ps.wrapped.Unsub(valuesCh) // with a len(keys) buffer, this is an optimization
for {
select {
case <-ctx.Done():
return
case val, ok := <-valuesCh:
if !ok {
return
}
block, ok := val.(*blocks.Block)
if !ok {
return
}
select {
case <-ctx.Done():
return
case blocksCh <- block: // continue
}
}
}
}()
return blocksCh
}
// connects to providers for the given keys
func (bs *Bitswap) providerConnector(parent context.Context) {
defer log.Info("bitswap client worker shutting down...")
for {
log.Event(parent, "Bitswap.ProviderConnector.Loop")
select {
case req := <-bs.findKeys:
keys := req.keys
if len(keys) == 0 {
log.Warning("Received batch request for zero blocks")
continue
}
log.Event(parent, "Bitswap.ProviderConnector.Work", logging.LoggableMap{"Keys": keys})
// NB: Optimization. Assumes that providers of key[0] are likely to
// be able to provide for all keys. This currently holds true in most
// every situation. Later, this assumption may not hold as true.
child, cancel := context.WithTimeout(req.ctx, providerRequestTimeout)
providers := bs.network.FindProvidersAsync(child, keys[0], maxProvidersPerRequest)
for p := range providers {
go bs.network.ConnectTo(req.ctx, p)
}
cancel()
case <-parent.Done():
return
}
}
}
// FetchGraph asynchronously fetches all nodes that are children of the given
// node, and returns a channel that may be waited upon for the fetch to complete
func FetchGraph(ctx context.Context, root *Node, serv DAGService) chan struct{} {
log.Warning("Untested.")
var wg sync.WaitGroup
done := make(chan struct{})
for _, l := range root.Links {
wg.Add(1)
go func(lnk *Link) {
// Signal child is done on way out
defer wg.Done()
select {
case <-ctx.Done():
return
}
nd, err := lnk.GetNode(ctx, serv)
if err != nil {
log.Debug(err)
return
}
// Wait for children to finish
<-FetchGraph(ctx, nd, serv)
}(l)
}
go func() {
wg.Wait()
done <- struct{}{}
}()
return done
}
func (e *offlineExchange) GetBlocks(ctx context.Context, ks []key.Key) (<-chan *blocks.Block, error) {
out := make(chan *blocks.Block, 0)
go func() {
defer close(out)
var misses []key.Key
for _, k := range ks {
hit, err := e.bs.Get(k)
if err != nil {
misses = append(misses, k)
// a long line of misses should abort when context is cancelled.
select {
// TODO case send misses down channel
case <-ctx.Done():
return
default:
continue
}
}
select {
case out <- hit:
case <-ctx.Done():
return
}
}
}()
return out, nil
}
func (bs *Bitswap) rebroadcastWorker(parent context.Context) {
ctx, cancel := context.WithCancel(parent)
defer cancel()
broadcastSignal := time.NewTicker(rebroadcastDelay.Get())
defer broadcastSignal.Stop()
tick := time.NewTicker(10 * time.Second)
defer tick.Stop()
for {
log.Event(ctx, "Bitswap.Rebroadcast.idle")
select {
case <-tick.C:
n := bs.wm.wl.Len()
if n > 0 {
log.Debug(n, "keys in bitswap wantlist")
}
case <-broadcastSignal.C: // resend unfulfilled wantlist keys
log.Event(ctx, "Bitswap.Rebroadcast.active")
entries := bs.wm.wl.Entries()
if len(entries) > 0 {
bs.connectToProviders(ctx, entries)
}
case <-parent.Done():
return
}
}
}
func (ps *PingService) Ping(ctx context.Context, p peer.ID) (<-chan time.Duration, error) {
s, err := ps.Host.NewStream(ID, p)
if err != nil {
return nil, err
}
out := make(chan time.Duration)
go func() {
defer close(out)
for {
select {
case <-ctx.Done():
return
default:
t, err := ping(s)
if err != nil {
log.Debugf("ping error: %s", err)
return
}
select {
case out <- t:
case <-ctx.Done():
return
}
}
}
}()
return out, nil
}
func (cq *ChanQueue) process(ctx context.Context) {
// construct the channels here to be able to use them bidirectionally
enqChan := make(chan peer.ID)
deqChan := make(chan peer.ID)
cq.EnqChan = enqChan
cq.DeqChan = deqChan
go func() {
log.Debug("processing")
defer log.Debug("closed")
defer close(deqChan)
var next peer.ID
var item peer.ID
var more bool
for {
if cq.Queue.Len() == 0 {
// log.Debug("wait for enqueue")
select {
case next, more = <-enqChan:
if !more {
return
}
// log.Debug("got", next)
case <-ctx.Done():
return
}
} else {
next = cq.Queue.Dequeue()
// log.Debug("peek", next)
}
select {
case item, more = <-enqChan:
if !more {
if cq.Queue.Len() > 0 {
return // we're done done.
}
enqChan = nil // closed, so no use.
}
// log.Debug("got", item)
cq.Queue.Enqueue(item)
cq.Queue.Enqueue(next) // order may have changed.
next = ""
case deqChan <- next:
// log.Debug("dequeued", next)
next = ""
case <-ctx.Done():
return
}
}
}()
}
// Run is the main republisher loop
func (np *Republisher) Run(ctx context.Context) {
for {
select {
case <-np.Publish:
quick := time.After(np.TimeoutShort)
longer := time.After(np.TimeoutLong)
wait:
select {
case <-ctx.Done():
return
case <-np.Publish:
quick = time.After(np.TimeoutShort)
goto wait
case <-quick:
case <-longer:
}
log.Info("Publishing Changes!")
err := np.root.Publish(ctx)
if err != nil {
log.Error("republishRoot error: %s", err)
}
case <-ctx.Done():
return
}
}
}
func pingPeer(ctx context.Context, n *core.IpfsNode, pid peer.ID, numPings int) <-chan interface{} {
outChan := make(chan interface{})
go func() {
defer close(outChan)
if len(n.Peerstore.Addrs(pid)) == 0 {
// Make sure we can find the node in question
outChan <- &PingResult{
Text: fmt.Sprintf("Looking up peer %s", pid.Pretty()),
}
ctx, cancel := context.WithTimeout(ctx, kPingTimeout)
defer cancel()
p, err := n.Routing.FindPeer(ctx, pid)
if err != nil {
outChan <- &PingResult{Text: fmt.Sprintf("Peer lookup error: %s", err)}
return
}
n.Peerstore.AddAddrs(p.ID, p.Addrs, peer.TempAddrTTL)
}
outChan <- &PingResult{Text: fmt.Sprintf("PING %s.", pid.Pretty())}
ctx, cancel := context.WithTimeout(ctx, kPingTimeout*time.Duration(numPings))
defer cancel()
pings, err := n.Ping.Ping(ctx, pid)
if err != nil {
log.Debugf("Ping error: %s", err)
outChan <- &PingResult{Text: fmt.Sprintf("Ping error: %s", err)}
return
}
var done bool
var total time.Duration
for i := 0; i < numPings && !done; i++ {
select {
case <-ctx.Done():
done = true
break
case t, ok := <-pings:
if !ok {
done = true
break
}
outChan <- &PingResult{
Success: true,
Time: t,
}
total += t
time.Sleep(time.Second)
}
}
averagems := total.Seconds() * 1000 / float64(numPings)
outChan <- &PingResult{
Text: fmt.Sprintf("Average latency: %.2fms", averagems),
}
}()
return outChan
}
func (bs *Bitswap) taskWorker(ctx context.Context, id int) {
idmap := logging.LoggableMap{"ID": id}
defer log.Info("bitswap task worker shutting down...")
for {
log.Event(ctx, "Bitswap.TaskWorker.Loop", idmap)
select {
case nextEnvelope := <-bs.engine.Outbox():
select {
case envelope, ok := <-nextEnvelope:
if !ok {
continue
}
log.Event(ctx, "Bitswap.TaskWorker.Work", logging.LoggableMap{
"ID": id,
"Target": envelope.Peer.Pretty(),
"Block": envelope.Block.Multihash.B58String(),
})
bs.wm.SendBlock(ctx, envelope)
case <-ctx.Done():
return
}
case <-ctx.Done():
return
}
}
}
// GetBlocks returns a channel where the caller may receive blocks that
// correspond to the provided |keys|. Returns an error if BitSwap is unable to
// begin this request within the deadline enforced by the context.
//
// NB: Your request remains open until the context expires. To conserve
// resources, provide a context with a reasonably short deadline (ie. not one
// that lasts throughout the lifetime of the server)
func (bs *Bitswap) GetBlocks(ctx context.Context, keys []key.Key) (<-chan *blocks.Block, error) {
select {
case <-bs.process.Closing():
return nil, errors.New("bitswap is closed")
default:
}
promise := bs.notifications.Subscribe(ctx, keys...)
for _, k := range keys {
log.Event(ctx, "Bitswap.GetBlockRequest.Start", &k)
}
bs.wm.WantBlocks(keys)
req := &blockRequest{
keys: keys,
ctx: ctx,
}
select {
case bs.findKeys <- req:
return promise, nil
case <-ctx.Done():
return nil, ctx.Err()
}
}
func (bs *Bitswap) provideCollector(ctx context.Context) {
defer close(bs.provideKeys)
var toProvide []key.Key
var nextKey key.Key
var keysOut chan key.Key
for {
select {
case blk, ok := <-bs.newBlocks:
if !ok {
log.Debug("newBlocks channel closed")
return
}
if keysOut == nil {
nextKey = blk.Key()
keysOut = bs.provideKeys
} else {
toProvide = append(toProvide, blk.Key())
}
case keysOut <- nextKey:
if len(toProvide) > 0 {
nextKey = toProvide[0]
toProvide = toProvide[1:]
} else {
keysOut = nil
}
case <-ctx.Done():
return
}
}
}
// GetBlocks gets a list of blocks asynchronously and returns through
// the returned channel.
// NB: No guarantees are made about order.
func (s *BlockService) GetBlocks(ctx context.Context, ks []key.Key) <-chan *blocks.Block {
out := make(chan *blocks.Block, 0)
go func() {
defer close(out)
var misses []key.Key
for _, k := range ks {
hit, err := s.Blockstore.Get(k)
if err != nil {
misses = append(misses, k)
continue
}
log.Debug("Blockservice: Got data in datastore.")
select {
case out <- hit:
case <-ctx.Done():
return
}
}
rblocks, err := s.Exchange.GetBlocks(ctx, misses)
if err != nil {
log.Debugf("Error with GetBlocks: %s", err)
return
}
for b := range rblocks {
select {
case out <- b:
case <-ctx.Done():
return
}
}
}()
return out
}
// LogError logs the error to the owner of the context.
//
// If this context was created with ContextWithErrorLog, then this method
// passes the error to context creator over an unbuffered channel.
//
// If this context was created by other means, this method is a no-op.
func LogError(ctx context.Context, err error) {
v := ctx.Value(errLogKey)
errs, ok := v.(privateChanType)
if !ok {
return
}
errs <- err
}
func (pm *ProviderManager) AddProvider(ctx context.Context, k key.Key, val peer.ID) {
prov := &addProv{
k: k,
val: val,
}
select {
case pm.newprovs <- prov:
case <-ctx.Done():
}
}
func (d *Diagnostics) getDiagnosticFromPeer(ctx context.Context, p peer.ID, pmes *pb.Message) (<-chan *DiagInfo, error) {
s, err := d.host.NewStream(ProtocolDiag, p)
if err != nil {
return nil, err
}
cr := ctxio.NewReader(ctx, s) // ok to use. we defer close stream in this func
cw := ctxio.NewWriter(ctx, s) // ok to use. we defer close stream in this func
r := ggio.NewDelimitedReader(cr, inet.MessageSizeMax)
w := ggio.NewDelimitedWriter(cw)
start := time.Now()
if err := w.WriteMsg(pmes); err != nil {
return nil, err
}
out := make(chan *DiagInfo)
go func() {
defer func() {
close(out)
s.Close()
rtt := time.Since(start)
log.Infof("diagnostic request took: %s", rtt.String())
}()
for {
rpmes := new(pb.Message)
if err := r.ReadMsg(rpmes); err != nil {
log.Debugf("Error reading diagnostic from stream: %s", err)
return
}
if rpmes == nil {
log.Debug("Got no response back from diag request.")
return
}
di, err := decodeDiagJson(rpmes.GetData())
if err != nil {
log.Debug(err)
return
}
select {
case out <- di:
case <-ctx.Done():
return
}
}
}()
return out, nil
}
func (mq *msgQueue) runQueue(ctx context.Context) {
for {
select {
case <-mq.work: // there is work to be done
mq.doWork(ctx)
case <-mq.done:
return
case <-ctx.Done():
return
}
}
}
// Run runs the query at hand. pass in a list of peers to use first.
func (q *dhtQuery) Run(ctx context.Context, peers []peer.ID) (*dhtQueryResult, error) {
select {
case <-ctx.Done():
return nil, ctx.Err()
default:
}
ctx, cancel := context.WithCancel(ctx)
defer cancel()
runner := newQueryRunner(q)
return runner.Run(ctx, peers)
}
func (np *nodePromise) Get(ctx context.Context) (*Node, error) {
if np.cache != nil {
return np.cache, nil
}
select {
case blk := <-np.recv:
np.cache = blk
case <-np.ctx.Done():
return nil, np.ctx.Err()
case <-ctx.Done():
return nil, ctx.Err()
}
return np.cache, nil
}
// WithDeadlineFraction returns a Context with a fraction of the
// original context's timeout. This is useful in sequential pipelines
// of work, where one might try options and fall back to others
// depending on the time available, or failure to respond. For example:
//
// // getPicture returns a picture from our encrypted database
// // we have a pipeline of multiple steps. we need to:
// // - get the data from a database
// // - decrypt it
// // - apply many transforms
// //
// // we **know** that each step takes increasingly more time.
// // The transforms are much more expensive than decryption, and
// // decryption is more expensive than the database lookup.
// // If our database takes too long (i.e. >0.2 of available time),
// // there's no use in continuing.
// func getPicture(ctx context.Context, key string) ([]byte, error) {
// // fractional timeout contexts to the rescue!
//
// // try the database with 0.2 of remaining time.
// ctx1, _ := ctxext.WithDeadlineFraction(ctx, 0.2)
// val, err := db.Get(ctx1, key)
// if err != nil {
// return nil, err
// }
//
// // try decryption with 0.3 of remaining time.
// ctx2, _ := ctxext.WithDeadlineFraction(ctx, 0.3)
// if val, err = decryptor.Decrypt(ctx2, val); err != nil {
// return nil, err
// }
//
// // try transforms with all remaining time. hopefully it's enough!
// return transformer.Transform(ctx, val)
// }
//
//
func WithDeadlineFraction(ctx context.Context, fraction float64) (
context.Context, context.CancelFunc) {
d, found := ctx.Deadline()
if !found { // no deadline
return context.WithCancel(ctx)
}
left := d.Sub(time.Now())
if left < 0 { // already passed...
return context.WithCancel(ctx)
}
left = time.Duration(float64(left) * fraction)
return context.WithTimeout(ctx, left)
}
func (pm *ProviderManager) GetProviders(ctx context.Context, k key.Key) []peer.ID {
gp := &getProv{
k: k,
resp: make(chan []peer.ID, 1), // buffered to prevent sender from blocking
}
select {
case <-ctx.Done():
return nil
case pm.getprovs <- gp:
}
select {
case <-ctx.Done():
return nil
case peers := <-gp.resp:
return peers
}
}
func (c *client) FindProvidersAsync(ctx context.Context, k key.Key, max int) <-chan peer.PeerInfo {
out := make(chan peer.PeerInfo)
go func() {
defer close(out)
for i, p := range c.server.Providers(k) {
if max <= i {
return
}
select {
case out <- p:
case <-ctx.Done():
return
}
}
}()
return out
}
// GetNodes returns an array of 'NodeGetter' promises, with each corresponding
// to the key with the same index as the passed in keys
func (ds *dagService) GetNodes(ctx context.Context, keys []key.Key) []NodeGetter {
// Early out if no work to do
if len(keys) == 0 {
return nil
}
promises := make([]NodeGetter, len(keys))
sendChans := make([]chan<- *Node, len(keys))
for i := range keys {
promises[i], sendChans[i] = newNodePromise(ctx)
}
dedupedKeys := dedupeKeys(keys)
go func() {
ctx, cancel := context.WithCancel(ctx)
defer cancel()
blkchan := ds.Blocks.GetBlocks(ctx, dedupedKeys)
for count := 0; count < len(keys); {
select {
case blk, ok := <-blkchan:
if !ok {
return
}
nd, err := Decoded(blk.Data)
if err != nil {
// NB: can happen with improperly formatted input data
log.Debug("Got back bad block!")
return
}
is := FindLinks(keys, blk.Key(), 0)
for _, i := range is {
count++
sendChans[i] <- nd
}
case <-ctx.Done():
return
}
}
}()
return promises
}
// Bootstrap ensures the dht routing table remains healthy as peers come and go.
// it builds up a list of peers by requesting random peer IDs. The Bootstrap
// process will run a number of queries each time, and run every time signal fires.
// These parameters are configurable.
//
// As opposed to BootstrapWithConfig, Bootstrap satisfies the routing interface
func (dht *IpfsDHT) Bootstrap(ctx context.Context) error {
proc, err := dht.BootstrapWithConfig(DefaultBootstrapConfig)
if err != nil {
return err
}
// wait till ctx or dht.Context exits.
// we have to do it this way to satisfy the Routing interface (contexts)
go func() {
defer proc.Close()
select {
case <-ctx.Done():
case <-dht.Context().Done():
}
}()
return nil
}
// CloseAfterContext schedules the process to close after the given
// context is done. It is the equivalent of:
//
// func CloseAfterContext(p goprocess.Process, ctx context.Context) {
// go func() {
// <-ctx.Done()
// p.Close()
// }()
// }
//
func CloseAfterContext(p goprocess.Process, ctx context.Context) {
if p == nil {
panic("nil Process")
}
if ctx == nil {
panic("nil Context")
}
// context.Background(). if ctx.Done() is nil, it will never be done.
// we check for this to avoid wasting a goroutine forever.
if ctx.Done() == nil {
return
}
go func() {
<-ctx.Done()
p.Close()
}()
}
// FindProvidersAsync returns a channel of providers for the given key
func (nc *networkClient) FindProvidersAsync(ctx context.Context, k key.Key, max int) <-chan peer.ID {
// NB: this function duplicates the PeerInfo -> ID transformation in the
// bitswap network adapter. Not to worry. This network client will be
// deprecated once the ipfsnet.Mock is added. The code below is only
// temporary.
out := make(chan peer.ID)
go func() {
defer close(out)
providers := nc.routing.FindProvidersAsync(ctx, k, max)
for info := range providers {
select {
case <-ctx.Done():
case out <- info.ID:
}
}
}()
return out
}
func (e *Engine) taskWorker(ctx context.Context) {
defer close(e.outbox) // because taskWorker uses the channel exclusively
for {
oneTimeUse := make(chan *Envelope, 1) // buffer to prevent blocking
select {
case <-ctx.Done():
return
case e.outbox <- oneTimeUse:
}
// receiver is ready for an outoing envelope. let's prepare one. first,
// we must acquire a task from the PQ...
envelope, err := e.nextEnvelope(ctx)
if err != nil {
close(oneTimeUse)
return // ctx cancelled
}
oneTimeUse <- envelope // buffered. won't block
close(oneTimeUse)
}
}
func readMsgCtx(ctx context.Context, r msgio.Reader, p proto.Message) ([]byte, error) {
var msg []byte
// read in a goroutine so we can exit when our context is cancelled.
done := make(chan error)
go func() {
var err error
msg, err = r.ReadMsg()
select {
case done <- err:
case <-ctx.Done():
}
}()
select {
case <-ctx.Done():
return nil, ctx.Err()
case e := <-done:
if e != nil {
return nil, e
}
}
return msg, proto.Unmarshal(msg, p)
}
