mirror of
https://github.com/octoleo/syncthing.git
synced 2024-12-23 03:18:59 +00:00
143 lines
2.8 KiB
Go
143 lines
2.8 KiB
Go
package protocol
|
|
|
|
import (
|
|
"errors"
|
|
"io"
|
|
"sync/atomic"
|
|
|
|
"github.com/calmh/syncthing/buffers"
|
|
)
|
|
|
|
func pad(l int) int {
|
|
d := l % 4
|
|
if d == 0 {
|
|
return 0
|
|
}
|
|
return 4 - d
|
|
}
|
|
|
|
var padBytes = []byte{0, 0, 0}
|
|
|
|
type marshalWriter struct {
|
|
w io.Writer
|
|
tot uint64
|
|
err error
|
|
b [8]byte
|
|
}
|
|
|
|
// We will never encode nor expect to decode blobs larger than 10 MB. Check
|
|
// inserted to protect against attempting to allocate arbitrary amounts of
|
|
// memory when reading a corrupt message.
|
|
const maxBytesFieldLength = 10 * 1 << 20
|
|
|
|
var ErrFieldLengthExceeded = errors.New("Raw bytes field size exceeds limit")
|
|
|
|
func (w *marshalWriter) writeString(s string) {
|
|
w.writeBytes([]byte(s))
|
|
}
|
|
|
|
func (w *marshalWriter) writeBytes(bs []byte) {
|
|
if w.err != nil {
|
|
return
|
|
}
|
|
if len(bs) > maxBytesFieldLength {
|
|
w.err = ErrFieldLengthExceeded
|
|
return
|
|
}
|
|
w.writeUint32(uint32(len(bs)))
|
|
if w.err != nil {
|
|
return
|
|
}
|
|
_, w.err = w.w.Write(bs)
|
|
if p := pad(len(bs)); w.err == nil && p > 0 {
|
|
_, w.err = w.w.Write(padBytes[:p])
|
|
}
|
|
atomic.AddUint64(&w.tot, uint64(len(bs)+pad(len(bs))))
|
|
}
|
|
|
|
func (w *marshalWriter) writeUint32(v uint32) {
|
|
if w.err != nil {
|
|
return
|
|
}
|
|
w.b[0] = byte(v >> 24)
|
|
w.b[1] = byte(v >> 16)
|
|
w.b[2] = byte(v >> 8)
|
|
w.b[3] = byte(v)
|
|
_, w.err = w.w.Write(w.b[:4])
|
|
atomic.AddUint64(&w.tot, 4)
|
|
}
|
|
|
|
func (w *marshalWriter) writeUint64(v uint64) {
|
|
if w.err != nil {
|
|
return
|
|
}
|
|
w.b[0] = byte(v >> 56)
|
|
w.b[1] = byte(v >> 48)
|
|
w.b[2] = byte(v >> 40)
|
|
w.b[3] = byte(v >> 32)
|
|
w.b[4] = byte(v >> 24)
|
|
w.b[5] = byte(v >> 16)
|
|
w.b[6] = byte(v >> 8)
|
|
w.b[7] = byte(v)
|
|
_, w.err = w.w.Write(w.b[:8])
|
|
atomic.AddUint64(&w.tot, 8)
|
|
}
|
|
|
|
func (w *marshalWriter) getTot() uint64 {
|
|
return atomic.LoadUint64(&w.tot)
|
|
}
|
|
|
|
type marshalReader struct {
|
|
r io.Reader
|
|
tot uint64
|
|
err error
|
|
b [8]byte
|
|
}
|
|
|
|
func (r *marshalReader) readString() string {
|
|
bs := r.readBytes()
|
|
defer buffers.Put(bs)
|
|
return string(bs)
|
|
}
|
|
|
|
func (r *marshalReader) readBytes() []byte {
|
|
if r.err != nil {
|
|
return nil
|
|
}
|
|
l := int(r.readUint32())
|
|
if r.err != nil {
|
|
return nil
|
|
}
|
|
if l > maxBytesFieldLength {
|
|
r.err = ErrFieldLengthExceeded
|
|
return nil
|
|
}
|
|
b := buffers.Get(l + pad(l))
|
|
_, r.err = io.ReadFull(r.r, b)
|
|
atomic.AddUint64(&r.tot, uint64(l+pad(l)))
|
|
return b[:l]
|
|
}
|
|
|
|
func (r *marshalReader) readUint32() uint32 {
|
|
if r.err != nil {
|
|
return 0
|
|
}
|
|
_, r.err = io.ReadFull(r.r, r.b[:4])
|
|
atomic.AddUint64(&r.tot, 8)
|
|
return uint32(r.b[3]) | uint32(r.b[2])<<8 | uint32(r.b[1])<<16 | uint32(r.b[0])<<24
|
|
}
|
|
|
|
func (r *marshalReader) readUint64() uint64 {
|
|
if r.err != nil {
|
|
return 0
|
|
}
|
|
_, r.err = io.ReadFull(r.r, r.b[:8])
|
|
atomic.AddUint64(&r.tot, 8)
|
|
return uint64(r.b[7]) | uint64(r.b[6])<<8 | uint64(r.b[5])<<16 | uint64(r.b[4])<<24 |
|
|
uint64(r.b[3])<<32 | uint64(r.b[2])<<40 | uint64(r.b[1])<<48 | uint64(r.b[0])<<56
|
|
}
|
|
|
|
func (r *marshalReader) getTot() uint64 {
|
|
return atomic.LoadUint64(&r.tot)
|
|
}
|