go/src/bytes/buffer_test.go, branch fix-runtime-test-GOMAXPROCS

std: pass bytes.Buffer and strings.Builder by pointer

2025-05-19T16:13:04Z

This CL fixes a number of (all true positive) findings of vet's copylock analyzer patched to treat the Bu{ff,uild}er types as non-copyable after first use. This does require imposing an additional indirection between noder.writer and Encoder since the field is embedded by value but its constructor now returns a pointer. Updates golang/go#25907 Updates golang/go#47276 Change-Id: I0b4d77ac12bcecadf06a91709e695365da10766c Reviewed-on: https://go-review.googlesource.com/c/go/+/635339 Reviewed-by: Robert Findley Commit-Queue: Alan Donovan LUCI-TryBot-Result: Go LUCI Auto-Submit: Alan Donovan

all: omit unnecessary 0 in slice expression

2024-09-03T20:55:15Z

All changes are related to the code, except for the comments in src/regexp/syntax/parse.go and src/slices/slices.go. Change-Id: I73c5d3c54099749b62210aa7f3182c5eb84bb6a6 GitHub-Last-Rev: 794aa9b0539811d00e1cd42be1e8d9fe9afe0281 GitHub-Pull-Request: golang/go#69170 Reviewed-on: https://go-review.googlesource.com/c/go/+/609678 Reviewed-by: Dmitri Shuralyov LUCI-TryBot-Result: Go LUCI Reviewed-by: Ian Lance Taylor Auto-Submit: Ian Lance Taylor

bytes: skip TestNewBufferShallow if optimization is disabled

2024-04-26T13:31:36Z

TestNewBufferShallow should be skipped if optimization is disabled. It is currently failing on no-opt builders. Change-Id: Ib5e62022a56a4e5f158f247d69a6229d2cb4d99e Reviewed-on: https://go-review.googlesource.com/c/go/+/581915 Auto-Submit: Than McIntosh Reviewed-by: Than McIntosh Auto-Submit: Quim Muntal LUCI-TryBot-Result: Go LUCI Reviewed-by: Joedian Reid

bytes: add test to ensure shallow copy of NewBuffer does not allocate

2024-04-24T13:36:51Z

At present, there is no API to reset the underlying []byte of an existing Buffer struct, except to shallow copy the entire Buffer struct. Updates #67004 Change-Id: I08998f7a95ae5bde0897d86247d47f23cd784583 Reviewed-on: https://go-review.googlesource.com/c/go/+/581297 Auto-Submit: Joseph Tsai Reviewed-by: Joedian Reid TryBot-Result: Gopher Robot Reviewed-by: Keith Randall Run-TryBot: Joseph Tsai Reviewed-by: Keith Randall LUCI-TryBot-Result: Go LUCI

std: fix various nilness findings

2023-04-20T01:07:29Z

Found by running $ go run golang.org/x/tools/go/analysis/passes/nilness/cmd/nilness@latest std No actual bugs--other than one panic(nil)--but a few places where error nilness was unclear. Change-Id: Ia916ba30f46f29c1bcf928cc62280169b922463a Reviewed-on: https://go-review.googlesource.com/c/go/+/486675 Reviewed-by: Ian Lance Taylor Run-TryBot: Alan Donovan TryBot-Result: Gopher Robot Auto-Submit: Alan Donovan

bytes: add Buffer.Available and Buffer.AvailableBuffer

2023-03-13T17:03:14Z

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 Reviewed-by: Daniel Martí Reviewed-by: Cherry Mui TryBot-Result: Gopher Robot Auto-Submit: Joseph Tsai Reviewed-by: Ian Lance Taylor

bytes: rely on runtime.growslice for growing

2022-03-10T16:24:16Z

Rather than naively making a slice of capacity 2*c+n, rely on the append(..., make(...)) pattern to allocate a slice that aligns up to the closest size class. Performance: name old time/op new time/op delta BufferWriteBlock/N4096 3.03µs ± 6% 2.04µs ± 6% -32.60% (p=0.000 n=10+10) BufferWriteBlock/N65536 47.8µs ± 6% 28.1µs ± 2% -41.32% (p=0.000 n=9+8) BufferWriteBlock/N1048576 844µs ± 7% 510µs ± 5% -39.59% (p=0.000 n=8+9) name old alloc/op new alloc/op delta BufferWriteBlock/N4096 12.3kB ± 0% 7.2kB ± 0% -41.67% (p=0.000 n=10+10) BufferWriteBlock/N65536 258kB ± 0% 130kB ± 0% -49.60% (p=0.000 n=10+10) BufferWriteBlock/N1048576 4.19MB ± 0% 2.10MB ± 0% -49.98% (p=0.000 n=10+8) name old allocs/op new allocs/op delta BufferWriteBlock/N4096 3.00 ± 0% 3.00 ± 0% ~ (all equal) BufferWriteBlock/N65536 7.00 ± 0% 7.00 ± 0% ~ (all equal) BufferWriteBlock/N1048576 11.0 ± 0% 11.0 ± 0% ~ (all equal) The performance is faster since the growth rate is capped at 2x, while previously it could grow by amounts potentially much greater than 2x, leading to significant amounts of memory waste and extra copying. Credit goes to Martin Möhrmann for suggesting the append(b, make([]T, n)...) pattern. Fixes #42984 Updates #51462 Change-Id: I7b23f75dddbf53f8b8b93485bb1a1fff9649b96b Reviewed-on: https://go-review.googlesource.com/c/go/+/349994 Trust: Joseph Tsai Trust: Josh Bleecher Snyder Reviewed-by: Bryan Mills Reviewed-by: Ian Lance Taylor Reviewed-by: Josh Bleecher Snyder

bufio, bytes, strings: handle negative runes in WriteRune

2021-02-24T04:01:25Z

Updates #43254 Change-Id: I7d4bf3b99cc36ca2156af5bb01a1c595419d1d3c Reviewed-on: https://go-review.googlesource.com/c/go/+/280492 Reviewed-by: Emmanuel Odeke Reviewed-by: Rob Pike Trust: Emmanuel Odeke Run-TryBot: Emmanuel Odeke TryBot-Result: Go Bot

bytes: deflake TestGrow by using testing.AllocsPerRun

2020-02-26T18:40:56Z

Fixes #36695 Change-Id: I4392246015252018b49f321a5a839cc68cc611d7 GitHub-Last-Rev: c2fb1f7ddbe9b80059eed69f31781abe0a1db185 GitHub-Pull-Request: golang/go#36732 Reviewed-on: https://go-review.googlesource.com/c/go/+/216237 Reviewed-by: Bryan C. Mills Run-TryBot: Bryan C. Mills TryBot-Result: Gobot Gobot

bytes: clean up a test

2019-02-26T23:16:46Z

Change-Id: Iaa0e1721996b582bba9509c083755e1f125abb6b GitHub-Last-Rev: c9b13ec0cdc2b22aafa54706dc6df6113a11712b GitHub-Pull-Request: golang/go#29996 Reviewed-on: https://go-review.googlesource.com/c/160420 Run-TryBot: Brad Fitzpatrick TryBot-Result: Gobot Gobot Reviewed-by: Keith Randall