go/api/next/53685.txt

pkg bytes, method (*Buffer) Available() int #53685
pkg bytes, method (*Buffer) AvailableBuffer() []uint8 #53685
bytes: add Buffer.Available and Buffer.AvailableBuffer This adds a new Buffer.AvailableBuffer method that returns an empty buffer with a possibly non-empty capacity for use with append-like APIs. The typical usage pattern is something like: b := bb.AvailableBuffer() b = appendValue(b, v) bb.Write(b) It allows logic combining append-like APIs with Buffer to avoid needing to allocate and manage buffers themselves and allows the append-like APIs to directly write into the Buffer. The Buffer.Write method uses the builtin copy function, which avoids copying bytes if the source and destination are identical. Thus, Buffer.Write is a constant-time call for this pattern. Performance: BenchmarkBufferAppendNoCopy 2.909 ns/op 5766942167.24 MB/s This benchmark should only be testing the cost of bookkeeping and never the copying of the input slice. Thus, the MB/s should be orders of magnitude faster than RAM. Fixes #53685 Change-Id: I0b41e54361339df309db8d03527689b123f99085 Reviewed-on: https://go-review.googlesource.com/c/go/+/474635 Run-TryBot: Joseph Tsai <joetsai@digital-static.net> Reviewed-by: Daniel Martí <mvdan@mvdan.cc> Reviewed-by: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Auto-Submit: Joseph Tsai <joetsai@digital-static.net> Reviewed-by: Ian Lance Taylor <iant@google.com> 2023-02-06 12:37:39 -07:00			`pkg bytes, method (*Buffer) Available() int #53685`
			`pkg bytes, method (*Buffer) AvailableBuffer() []uint8 #53685`