diff options
Diffstat (limited to 'src/pkg/bytes/buffer.go')
| -rw-r--r-- | src/pkg/bytes/buffer.go | 18 |
1 files changed, 8 insertions, 10 deletions
diff --git a/src/pkg/bytes/buffer.go b/src/pkg/bytes/buffer.go index 9d58326a4f..ccddd95a49 100644 --- a/src/pkg/bytes/buffer.go +++ b/src/pkg/bytes/buffer.go @@ -139,21 +139,19 @@ func (b *Buffer) ReadFrom(r io.Reader) (n int64, err error) { b.Truncate(0) } for { - if cap(b.buf)-len(b.buf) < MinRead { - var newBuf []byte - // can we get space without allocation? - if b.off+cap(b.buf)-len(b.buf) >= MinRead { - // reuse beginning of buffer - newBuf = b.buf[0 : len(b.buf)-b.off] - } else { - // not enough space at end; put space on end - newBuf = makeSlice(2*(cap(b.buf)-b.off) + MinRead)[:len(b.buf)-b.off] + if free := cap(b.buf) - len(b.buf); free < MinRead { + // not enough space at end + newBuf := b.buf + if b.off+free < MinRead { + // not enough space using beginning of buffer; + // double buffer capacity + newBuf = makeSlice(2*cap(b.buf) + MinRead) if newBuf == nil { return n, ErrTooLarge } } copy(newBuf, b.buf[b.off:]) - b.buf = newBuf + b.buf = newBuf[:len(b.buf)-b.off] b.off = 0 } m, e := r.Read(b.buf[len(b.buf):cap(b.buf)]) |