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Add buffered reader

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9seconds
2018-07-03 10:10:00 +03:00
parent 5f54a235d2
commit 586ffab01b
4 changed files with 100 additions and 114 deletions
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mtproto/wrappers/frame.go
+42 -61
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@@ -22,11 +22,11 @@ const (
var frameRWCPadding = [4]byte{0x04, 0x00, 0x00, 0x00}
type FrameRWC struct {
conn wrappers.ReadWriteCloserWithAddr
wrappers.BufferedReader
conn wrappers.ReadWriteCloserWithAddr
readSeqNo int32
writeSeqNo int32
readBuf *bytes.Buffer
}
func (f *FrameRWC) Write(buf []byte) (int, error) {
@@ -54,51 +54,49 @@ func (f *FrameRWC) Write(buf []byte) (int, error) {
}
func (f *FrameRWC) Read(p []byte) (int, error) {
if f.readBuf.Len() > 0 {
return f.flush(p)
}
return f.BufferedRead(p, func() error {
buf := &bytes.Buffer{}
for {
buf.Reset()
if _, err := io.CopyN(buf, f.conn, 4); err != nil {
return errors.Annotate(err, "Cannot read frame padding")
}
if !bytes.Equal(buf.Bytes(), frameRWCPadding[:]) {
break
}
}
messageLength := binary.LittleEndian.Uint32(buf.Bytes())
if messageLength%4 != 0 || messageLength < frameRWCMinMessageLength || messageLength > frameRWCMaxMessageLength {
return errors.Errorf("Incorrect frame message length %d", messageLength)
}
sum := crc32.NewIEEE()
sum.Write(buf.Bytes())
buf := &bytes.Buffer{}
for {
buf.Reset()
if _, err := io.CopyN(buf, f.conn, 4); err != nil {
return 0, errors.Annotate(err, "Cannot read frame padding")
buf.Grow(int(messageLength) - 4) // -4 because we already read the first number
if _, err := io.CopyN(buf, f.conn, int64(messageLength)-4); err != nil {
return errors.Annotate(err, "Cannot read the message frame")
}
if !bytes.Equal(buf.Bytes(), frameRWCPadding[:]) {
break
sum.Write(buf.Bytes())
var seqNo int32
binary.Read(buf, binary.LittleEndian, seqNo)
if seqNo != f.readSeqNo {
return errors.Errorf("Unexpected sequence number %d (wait for %d)", seqNo, f.readSeqNo)
}
}
f.readSeqNo++
messageLength := binary.LittleEndian.Uint32(buf.Bytes())
if messageLength%4 != 0 || messageLength < frameRWCMinMessageLength || messageLength > frameRWCMaxMessageLength {
return 0, errors.Errorf("Incorrect frame message length %d", messageLength)
}
sum := crc32.NewIEEE()
sum.Write(buf.Bytes())
data := buf.Bytes()[:int(messageLength)-4-4-4]
checksum := binary.LittleEndian.Uint32(buf.Bytes()[int(messageLength)-4-4-4:])
if checksum != sum.Sum32() {
return errors.Errorf("CRC32 checksum mismatch. Wait for %d, got %d", sum.Sum32(), checksum)
buf.Reset()
buf.Grow(int(messageLength) - 4) // -4 because we already read the first number
if _, err := io.CopyN(buf, f.conn, int64(messageLength)-4); err != nil {
return 0, errors.Annotate(err, "Cannot read the message frame")
}
sum.Write(buf.Bytes())
}
f.Buffer.Write(data)
var seqNo int32
binary.Read(buf, binary.LittleEndian, seqNo)
if seqNo != f.readSeqNo {
return 0, errors.Errorf("Unexpected sequence number %d (wait for %d)", seqNo, f.readSeqNo)
}
f.readSeqNo++
data := buf.Bytes()[:int(messageLength)-4-4-4]
checksum := binary.LittleEndian.Uint32(buf.Bytes()[int(messageLength)-4-4-4:])
if checksum != sum.Sum32() {
return 0, errors.Errorf("CRC32 checksum mismatch. Wait for %d, got %d", sum.Sum32(), checksum)
}
f.readBuf.Write(data)
return f.flush(p)
return nil
})
}
func (f *FrameRWC) Close() error {
@@ -109,28 +107,11 @@ func (f *FrameRWC) Addr() *net.TCPAddr {
return f.conn.Addr()
}
func (f *FrameRWC) flush(p []byte) (int, error) {
sizeToRead := len(p)
if f.readBuf.Len() < sizeToRead {
sizeToRead = f.readBuf.Len()
}
data := f.readBuf.Bytes()
copy(p, data[:sizeToRead])
if sizeToRead == f.readBuf.Len() {
f.readBuf.Reset()
} else {
f.readBuf = bytes.NewBuffer(data[sizeToRead:])
}
return sizeToRead, nil
}
func NewFrameRWC(conn wrappers.ReadWriteCloserWithAddr, seqNo int32) wrappers.ReadWriteCloserWithAddr {
return &FrameRWC{
conn: conn,
readSeqNo: seqNo,
writeSeqNo: seqNo,
readBuf: &bytes.Buffer{},
BufferedReader: wrappers.NewBufferedReader(),
conn: conn,
readSeqNo: seqNo,
writeSeqNo: seqNo,
}
}