Files
quic-go/stream.go
2016-04-25 14:59:26 +02:00

138 lines
3.2 KiB
Go

package quic
import (
"fmt"
"github.com/lucas-clemente/quic-go/frames"
"github.com/lucas-clemente/quic-go/protocol"
"github.com/lucas-clemente/quic-go/utils"
)
// A Stream assembles the data from StreamFrames and provides a super-convenient Read-Interface
type Stream struct {
Session *Session
StreamID protocol.StreamID
StreamFrames chan *frames.StreamFrame
CurrentFrame *frames.StreamFrame
ReadPosInFrame int
WriteOffset uint64
ReadOffset uint64
frameQueue []*frames.StreamFrame // TODO: replace with heap
}
// NewStream creates a new Stream
func NewStream(session *Session, StreamID protocol.StreamID) *Stream {
return &Stream{
Session: session,
StreamID: StreamID,
StreamFrames: make(chan *frames.StreamFrame, 8), // ToDo: add config option for this number
}
}
// Read reads data
func (s *Stream) Read(p []byte) (int, error) {
bytesRead := 0
for bytesRead < len(p) {
if s.CurrentFrame == nil {
s.CurrentFrame = s.getNextFrameInOrder(bytesRead == 0)
if s.CurrentFrame == nil {
return bytesRead, nil
}
s.ReadPosInFrame = 0
}
m := utils.Min(len(p)-bytesRead, len(s.CurrentFrame.Data)-s.ReadPosInFrame)
copy(p[bytesRead:], s.CurrentFrame.Data[s.ReadPosInFrame:])
s.ReadPosInFrame += m
bytesRead += m
s.ReadOffset += uint64(m)
if s.ReadPosInFrame >= len(s.CurrentFrame.Data) {
s.CurrentFrame = nil
}
}
return bytesRead, nil
}
func (s *Stream) getNextFrameInOrder(wait bool) *frames.StreamFrame {
// First, check the queue
for i, f := range s.frameQueue {
if f.Offset == s.ReadOffset {
// Move last element into position i
s.frameQueue[i] = s.frameQueue[len(s.frameQueue)-1]
s.frameQueue = s.frameQueue[:len(s.frameQueue)-1]
return f
}
}
// TODO: Handle error and break while(true) loop
for {
var nextFrameFromChannel *frames.StreamFrame
if wait {
nextFrameFromChannel = <-s.StreamFrames
} else {
select {
case nextFrameFromChannel = <-s.StreamFrames:
default:
return nil
}
}
if nextFrameFromChannel.Offset == s.ReadOffset {
return nextFrameFromChannel
}
// Discard if we already know it
if nextFrameFromChannel.Offset < s.ReadOffset {
continue
}
// Append to queue
s.frameQueue = append(s.frameQueue, nextFrameFromChannel)
}
}
// ReadByte implements io.ByteReader
func (s *Stream) ReadByte() (byte, error) {
// TODO: Optimize
p := make([]byte, 1)
n, err := s.Read(p)
if err != nil {
return 0, err
}
if n != 1 {
panic("Stream: should have returned error")
}
return p[0], nil
}
func (s *Stream) Write(p []byte) (int, error) {
data := make([]byte, len(p))
copy(data, p)
err := s.Session.QueueFrame(&frames.StreamFrame{
StreamID: s.StreamID,
Offset: s.WriteOffset,
Data: data,
})
if err != nil {
return 0, err
}
s.WriteOffset += uint64(len(p))
return len(p), nil
}
// Close imlpements io.Closer
func (s *Stream) Close() error {
fmt.Printf("Closing stream %d\n", s.StreamID)
return s.Session.QueueFrame(&frames.StreamFrame{
StreamID: s.StreamID,
Offset: s.WriteOffset,
FinBit: true,
})
}
// AddStreamFrame adds a new stream frame
func (s *Stream) AddStreamFrame(frame *frames.StreamFrame) error {
s.StreamFrames <- frame
return nil
}