从前面截断缓冲区

Question

The bytes.Buffer object has a Truncate(n int) method to discard all but the first n bytes.

I'd need the exact inverse of that - keeping the last n bytes.

I could do the following

b := buf.Bytes()
buf.Reset()
buf.Write(b[offset:])

but I'm not sure if this will re-use the slice efficiently.

Are there better options?

Answer 1

There are two alternatives:

• The solution you give, which allows the first 'offset' bytes to be reused.
• Create a bytes.NewBuffer(b[offset:]) and use that. This will not allow the first 'offset' bytes to be collected until you're done with the new buffer, but it avoids the cost of copying.