bytes: add Buffer.Available and Buffer.AvailableBuffer #53685
Description
Hi!
I propose to introduce a new method to bytes.Buffer:
// Extend grows buffer by n bytes, moves write position at the end of
// just grown data and return a part of buffer what extended the
// previous content.
func (b *Buffer) Extend(n int) []byte {
b.Grow(n)
l := len(b.buf)
b.buf = b.buf[:l + n]
return b.buf[l:]
}Rationale.
Grow combined with Write is nice, but some APIs, binary.PutUvarint for instance, works with slices of bytes. This means memory copying will be needed in order to write uvarint-encoded data. Lots of memory copies in my case where I have manual serialization for some data structures.
I guess this method would be handy in cases like mine, where I would:
- Extend buffer by the length of the serialized data.
- Will serialize right into the returned slice.