Merge pull request #48 from libp2p/fix-buffer-usage

don't reslice byte slices taking from the buffer

util.go

@@ -72,6 +72,9 @@ type segmentedBuffer struct {
  pending uint32
  len uint32
  bm sync.Mutex
+ // read position in b[0].
+ // We must not reslice any of the buffers in b, as we need to put them back into the pool.
+ readPos int
  b [][]byte
 }
 
@@ -135,13 +138,15 @@ func (s *segmentedBuffer) Read(b []byte) (int, error) {
  if len(s.b) == 0 {
  return 0, io.EOF
  }
- n := copy(b, s.b[0])
- if n == len(s.b[0]) {
+ data := s.b[0][s.readPos:]
+ n := copy(b, data)
+ if n == len(data) {
  pool.Put(s.b[0])
  s.b[0] = nil
  s.b = s.b[1:]
+ s.readPos = 0
  } else {
- s.b[0] = s.b[0][n:]
+ s.readPos += n
  }
  if n > 0 {
  s.len -= uint32(n)