status-go/vendor/github.com/lucas-clemente/quic-go/streams_map_incoming_uni.go

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2022-04-01 16:16:46 +00:00
// This file was automatically generated by genny.
// Any changes will be lost if this file is regenerated.
// see https://github.com/cheekybits/genny
package quic
import (
"context"
"sync"
"github.com/lucas-clemente/quic-go/internal/protocol"
"github.com/lucas-clemente/quic-go/internal/wire"
)
// When a stream is deleted before it was accepted, we can't delete it from the map immediately.
// We need to wait until the application accepts it, and delete it then.
type receiveStreamIEntry struct {
stream receiveStreamI
shouldDelete bool
}
type incomingUniStreamsMap struct {
mutex sync.RWMutex
newStreamChan chan struct{}
streams map[protocol.StreamNum]receiveStreamIEntry
nextStreamToAccept protocol.StreamNum // the next stream that will be returned by AcceptStream()
nextStreamToOpen protocol.StreamNum // the highest stream that the peer opened
maxStream protocol.StreamNum // the highest stream that the peer is allowed to open
maxNumStreams uint64 // maximum number of streams
newStream func(protocol.StreamNum) receiveStreamI
queueMaxStreamID func(*wire.MaxStreamsFrame)
closeErr error
}
func newIncomingUniStreamsMap(
newStream func(protocol.StreamNum) receiveStreamI,
maxStreams uint64,
queueControlFrame func(wire.Frame),
) *incomingUniStreamsMap {
return &incomingUniStreamsMap{
newStreamChan: make(chan struct{}, 1),
streams: make(map[protocol.StreamNum]receiveStreamIEntry),
maxStream: protocol.StreamNum(maxStreams),
maxNumStreams: maxStreams,
newStream: newStream,
nextStreamToOpen: 1,
nextStreamToAccept: 1,
queueMaxStreamID: func(f *wire.MaxStreamsFrame) { queueControlFrame(f) },
}
}
func (m *incomingUniStreamsMap) AcceptStream(ctx context.Context) (receiveStreamI, error) {
// drain the newStreamChan, so we don't check the map twice if the stream doesn't exist
select {
case <-m.newStreamChan:
default:
}
m.mutex.Lock()
var num protocol.StreamNum
var entry receiveStreamIEntry
for {
num = m.nextStreamToAccept
if m.closeErr != nil {
m.mutex.Unlock()
return nil, m.closeErr
}
var ok bool
entry, ok = m.streams[num]
if ok {
break
}
m.mutex.Unlock()
select {
case <-ctx.Done():
return nil, ctx.Err()
case <-m.newStreamChan:
}
m.mutex.Lock()
}
m.nextStreamToAccept++
// If this stream was completed before being accepted, we can delete it now.
if entry.shouldDelete {
if err := m.deleteStream(num); err != nil {
m.mutex.Unlock()
return nil, err
}
}
m.mutex.Unlock()
return entry.stream, nil
}
func (m *incomingUniStreamsMap) GetOrOpenStream(num protocol.StreamNum) (receiveStreamI, error) {
m.mutex.RLock()
if num > m.maxStream {
m.mutex.RUnlock()
return nil, streamError{
message: "peer tried to open stream %d (current limit: %d)",
nums: []protocol.StreamNum{num, m.maxStream},
}
}
// if the num is smaller than the highest we accepted
// * this stream exists in the map, and we can return it, or
// * this stream was already closed, then we can return the nil
if num < m.nextStreamToOpen {
var s receiveStreamI
// If the stream was already queued for deletion, and is just waiting to be accepted, don't return it.
if entry, ok := m.streams[num]; ok && !entry.shouldDelete {
s = entry.stream
}
m.mutex.RUnlock()
return s, nil
}
m.mutex.RUnlock()
m.mutex.Lock()
// no need to check the two error conditions from above again
// * maxStream can only increase, so if the id was valid before, it definitely is valid now
// * highestStream is only modified by this function
for newNum := m.nextStreamToOpen; newNum <= num; newNum++ {
m.streams[newNum] = receiveStreamIEntry{stream: m.newStream(newNum)}
select {
case m.newStreamChan <- struct{}{}:
default:
}
}
m.nextStreamToOpen = num + 1
entry := m.streams[num]
m.mutex.Unlock()
return entry.stream, nil
}
func (m *incomingUniStreamsMap) DeleteStream(num protocol.StreamNum) error {
m.mutex.Lock()
defer m.mutex.Unlock()
return m.deleteStream(num)
}
func (m *incomingUniStreamsMap) deleteStream(num protocol.StreamNum) error {
if _, ok := m.streams[num]; !ok {
return streamError{
message: "tried to delete unknown incoming stream %d",
nums: []protocol.StreamNum{num},
}
}
// Don't delete this stream yet, if it was not yet accepted.
// Just save it to streamsToDelete map, to make sure it is deleted as soon as it gets accepted.
if num >= m.nextStreamToAccept {
entry, ok := m.streams[num]
if ok && entry.shouldDelete {
return streamError{
message: "tried to delete incoming stream %d multiple times",
nums: []protocol.StreamNum{num},
}
}
entry.shouldDelete = true
m.streams[num] = entry // can't assign to struct in map, so we need to reassign
return nil
}
delete(m.streams, num)
// queue a MAX_STREAM_ID frame, giving the peer the option to open a new stream
if m.maxNumStreams > uint64(len(m.streams)) {
maxStream := m.nextStreamToOpen + protocol.StreamNum(m.maxNumStreams-uint64(len(m.streams))) - 1
// Never send a value larger than protocol.MaxStreamCount.
if maxStream <= protocol.MaxStreamCount {
m.maxStream = maxStream
m.queueMaxStreamID(&wire.MaxStreamsFrame{
Type: protocol.StreamTypeUni,
MaxStreamNum: m.maxStream,
})
}
}
return nil
}
func (m *incomingUniStreamsMap) CloseWithError(err error) {
m.mutex.Lock()
m.closeErr = err
for _, entry := range m.streams {
entry.stream.closeForShutdown(err)
}
m.mutex.Unlock()
close(m.newStreamChan)
}