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caddy/vendor/github.com/lucas-clemente/quic-go/streams_map_legacy.go
2018-03-25 22:37:41 -06:00

277 lines
7.9 KiB
Go

package quic
import (
"errors"
"fmt"
"sync"
"github.com/lucas-clemente/quic-go/internal/handshake"
"github.com/lucas-clemente/quic-go/internal/protocol"
"github.com/lucas-clemente/quic-go/internal/utils"
"github.com/lucas-clemente/quic-go/internal/wire"
"github.com/lucas-clemente/quic-go/qerr"
)
type streamsMapLegacy struct {
mutex sync.RWMutex
perspective protocol.Perspective
streams map[protocol.StreamID]streamI
nextStreamToOpen protocol.StreamID // StreamID of the next Stream that will be returned by OpenStream()
highestStreamOpenedByPeer protocol.StreamID
nextStreamOrErrCond sync.Cond
openStreamOrErrCond sync.Cond
closeErr error
nextStreamToAccept protocol.StreamID
newStream func(protocol.StreamID) streamI
numOutgoingStreams uint32
numIncomingStreams uint32
maxIncomingStreams uint32
maxOutgoingStreams uint32
}
var _ streamManager = &streamsMapLegacy{}
var errMapAccess = errors.New("streamsMap: Error accessing the streams map")
func newStreamsMapLegacy(newStream func(protocol.StreamID) streamI, maxStreams int, pers protocol.Perspective) streamManager {
// add some tolerance to the maximum incoming streams value
maxIncomingStreams := utils.MaxUint32(
uint32(maxStreams)+protocol.MaxStreamsMinimumIncrement,
uint32(float64(maxStreams)*float64(protocol.MaxStreamsMultiplier)),
)
sm := streamsMapLegacy{
perspective: pers,
streams: make(map[protocol.StreamID]streamI),
newStream: newStream,
maxIncomingStreams: maxIncomingStreams,
}
sm.nextStreamOrErrCond.L = &sm.mutex
sm.openStreamOrErrCond.L = &sm.mutex
nextServerInitiatedStream := protocol.StreamID(2)
nextClientInitiatedStream := protocol.StreamID(3)
if pers == protocol.PerspectiveServer {
sm.highestStreamOpenedByPeer = 1
}
if pers == protocol.PerspectiveServer {
sm.nextStreamToOpen = nextServerInitiatedStream
sm.nextStreamToAccept = nextClientInitiatedStream
} else {
sm.nextStreamToOpen = nextClientInitiatedStream
sm.nextStreamToAccept = nextServerInitiatedStream
}
return &sm
}
// getStreamPerspective says which side should initiate a stream
func (m *streamsMapLegacy) streamInitiatedBy(id protocol.StreamID) protocol.Perspective {
if id%2 == 0 {
return protocol.PerspectiveServer
}
return protocol.PerspectiveClient
}
func (m *streamsMapLegacy) GetOrOpenReceiveStream(id protocol.StreamID) (receiveStreamI, error) {
// every bidirectional stream is also a receive stream
return m.getOrOpenStream(id)
}
func (m *streamsMapLegacy) GetOrOpenSendStream(id protocol.StreamID) (sendStreamI, error) {
// every bidirectional stream is also a send stream
return m.getOrOpenStream(id)
}
// getOrOpenStream either returns an existing stream, a newly opened stream, or nil if a stream with the provided ID is already closed.
// Newly opened streams should only originate from the client. To open a stream from the server, OpenStream should be used.
func (m *streamsMapLegacy) getOrOpenStream(id protocol.StreamID) (streamI, error) {
m.mutex.RLock()
s, ok := m.streams[id]
m.mutex.RUnlock()
if ok {
return s, nil
}
// ... we don't have an existing stream
m.mutex.Lock()
defer m.mutex.Unlock()
// We need to check whether another invocation has already created a stream (between RUnlock() and Lock()).
s, ok = m.streams[id]
if ok {
return s, nil
}
if m.perspective == m.streamInitiatedBy(id) {
if id <= m.nextStreamToOpen { // this is a stream opened by us. Must have been closed already
return nil, nil
}
return nil, qerr.Error(qerr.InvalidStreamID, fmt.Sprintf("peer attempted to open stream %d", id))
}
if id <= m.highestStreamOpenedByPeer { // this is a peer-initiated stream that doesn't exist anymore. Must have been closed already
return nil, nil
}
for sid := m.highestStreamOpenedByPeer + 2; sid <= id; sid += 2 {
if _, err := m.openRemoteStream(sid); err != nil {
return nil, err
}
}
m.nextStreamOrErrCond.Broadcast()
return m.streams[id], nil
}
func (m *streamsMapLegacy) openRemoteStream(id protocol.StreamID) (streamI, error) {
if m.numIncomingStreams >= m.maxIncomingStreams {
return nil, qerr.TooManyOpenStreams
}
// maxNewStreamIDDelta is the maximum difference between and a newly opened Stream and the highest StreamID that a client has ever opened
// note that the number of streams is half this value, since the client can only open streams with open StreamID
maxStreamIDDelta := protocol.StreamID(4 * m.maxIncomingStreams)
if id+maxStreamIDDelta < m.highestStreamOpenedByPeer {
return nil, qerr.Error(qerr.InvalidStreamID, fmt.Sprintf("attempted to open stream %d, which is a lot smaller than the highest opened stream, %d", id, m.highestStreamOpenedByPeer))
}
m.numIncomingStreams++
if id > m.highestStreamOpenedByPeer {
m.highestStreamOpenedByPeer = id
}
s := m.newStream(id)
return s, m.putStream(s)
}
func (m *streamsMapLegacy) openStreamImpl() (streamI, error) {
if m.numOutgoingStreams >= m.maxOutgoingStreams {
return nil, qerr.TooManyOpenStreams
}
m.numOutgoingStreams++
s := m.newStream(m.nextStreamToOpen)
m.nextStreamToOpen += 2
return s, m.putStream(s)
}
// OpenStream opens the next available stream
func (m *streamsMapLegacy) OpenStream() (Stream, error) {
m.mutex.Lock()
defer m.mutex.Unlock()
if m.closeErr != nil {
return nil, m.closeErr
}
return m.openStreamImpl()
}
func (m *streamsMapLegacy) OpenStreamSync() (Stream, error) {
m.mutex.Lock()
defer m.mutex.Unlock()
for {
if m.closeErr != nil {
return nil, m.closeErr
}
str, err := m.openStreamImpl()
if err == nil {
return str, err
}
if err != nil && err != qerr.TooManyOpenStreams {
return nil, err
}
m.openStreamOrErrCond.Wait()
}
}
func (m *streamsMapLegacy) OpenUniStream() (SendStream, error) {
return nil, errors.New("gQUIC doesn't support unidirectional streams")
}
func (m *streamsMapLegacy) OpenUniStreamSync() (SendStream, error) {
return nil, errors.New("gQUIC doesn't support unidirectional streams")
}
// AcceptStream returns the next stream opened by the peer
// it blocks until a new stream is opened
func (m *streamsMapLegacy) AcceptStream() (Stream, error) {
m.mutex.Lock()
defer m.mutex.Unlock()
var str streamI
for {
var ok bool
if m.closeErr != nil {
return nil, m.closeErr
}
str, ok = m.streams[m.nextStreamToAccept]
if ok {
break
}
m.nextStreamOrErrCond.Wait()
}
m.nextStreamToAccept += 2
return str, nil
}
func (m *streamsMapLegacy) AcceptUniStream() (ReceiveStream, error) {
return nil, errors.New("gQUIC doesn't support unidirectional streams")
}
func (m *streamsMapLegacy) DeleteStream(id protocol.StreamID) error {
m.mutex.Lock()
defer m.mutex.Unlock()
_, ok := m.streams[id]
if !ok {
return errMapAccess
}
delete(m.streams, id)
if m.streamInitiatedBy(id) == m.perspective {
m.numOutgoingStreams--
} else {
m.numIncomingStreams--
}
m.openStreamOrErrCond.Signal()
return nil
}
func (m *streamsMapLegacy) putStream(s streamI) error {
id := s.StreamID()
if _, ok := m.streams[id]; ok {
return fmt.Errorf("a stream with ID %d already exists", id)
}
m.streams[id] = s
return nil
}
func (m *streamsMapLegacy) CloseWithError(err error) {
m.mutex.Lock()
defer m.mutex.Unlock()
m.closeErr = err
m.nextStreamOrErrCond.Broadcast()
m.openStreamOrErrCond.Broadcast()
for _, s := range m.streams {
s.closeForShutdown(err)
}
}
// TODO(#952): this won't be needed when gQUIC supports stateless handshakes
func (m *streamsMapLegacy) UpdateLimits(params *handshake.TransportParameters) {
m.mutex.Lock()
m.maxOutgoingStreams = params.MaxStreams
for id, str := range m.streams {
str.handleMaxStreamDataFrame(&wire.MaxStreamDataFrame{
StreamID: id,
ByteOffset: params.StreamFlowControlWindow,
})
}
m.mutex.Unlock()
m.openStreamOrErrCond.Broadcast()
}
// should never be called, since MAX_STREAM_ID frames can only be unpacked for IETF QUIC
func (m *streamsMapLegacy) HandleMaxStreamIDFrame(f *wire.MaxStreamIDFrame) error {
return errors.New("gQUIC doesn't have MAX_STREAM_ID frames")
}