telebit/mplexer/decoder.go

72 lines
1.6 KiB
Go

package telebit
import (
"encoding/hex"
"fmt"
"io"
"log"
)
// Decoder handles a Reader stream containing mplexy-encoded clients
type Decoder struct {
in io.Reader
bufferSize int
}
// NewDecoder returns an initialized Decoder
func NewDecoder(rin io.Reader) *Decoder {
return &Decoder{
in: rin,
bufferSize: defaultBufferSize,
}
}
// Decode will call WriteMessage as often as addressable data exists,
// reading up to bufferSize (default 8192) at a time
// (header + data, though headers are often sent separately from data).
func (d *Decoder) Decode(out Router) error {
p := NewParser(out)
rx := make(chan []byte)
rxErr := make(chan error)
go func() {
for {
b := make([]byte, d.bufferSize)
n, err := d.in.Read(b)
log.Println("[debug] [decoder] [srv] Tunnel read", n, string(b[:n]))
if n > 0 {
rx <- b[:n]
}
if nil != err {
fmt.Println("[debug] [decoder] [srv] Tunnel read err", err)
rxErr <- err
return
}
}
}()
for {
select {
case b := <-rx:
n, err := p.Write(b)
fmt.Println("[debug] [decoder] [srv] Tunnel write", n, len(b), hex.EncodeToString(b))
// TODO BUG: handle when 'n' bytes written is less than len(b)
if nil != err {
fmt.Println("[debug] [decoder] [srv] Tunnel write error")
// an error to write represents an unrecoverable error,
// not just a downstream client error
//d.in.Close()
return err
}
case err := <-rxErr:
//d.in.Close()
if io.EOF == err {
// it can be assumed that err will close though, right
return nil
}
return err
}
}
}