aboutsummaryrefslogtreecommitdiff
path: root/src/strings/builder.go
AgeCommit message (Collapse)Author
2025-05-19strings,bytes: add internal docs about perennial noCopy questionsAlan Donovan
Updates #26462 Updates #25907 Updates #47276 Updates #48398 Change-Id: Ic64fc8d0c284f6e5aa383a8d417fa5768dcd7925 Reviewed-on: https://go-review.googlesource.com/c/go/+/674096 Auto-Submit: Alan Donovan <adonovan@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2024-07-22cmd/compile: don't inline runtime functions in -d=checkptr buildCherry Mui
Runtime functions, e.g. internal/abi.NoEscape, should not be instrumented with checkptr. But if they are inlined into a checkptr-enabled function, they will be instrumented, and may result in a check failure. Let the compiler not inline runtime functions into checkptr- enabled functions. Also undo the change in the strings package in CL 598295, as the compiler handles it now. Fixes #68511. Updates #68415. Change-Id: I78eb380855ac9dd53c1a1a628ec0da75c3e5a1a0 Reviewed-on: https://go-review.googlesource.com/c/go/+/599435 LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com> Reviewed-by: Keith Randall <khr@google.com>
2024-07-15strings: re-introduce noescape wrapperCuong Manh Le
CL 573955 added internal/abi:NoEscape function, and use it in strings builder copyCheck code. However, internal/abi is a runtime package, which can not be built with -d=checkptr flag yet. This causes incorrect inlining decision, since NoEscape must not be inlined when -d=checkptr is used. Fixing this by re-introducing noescape wrapper. Fixes #68415 Change-Id: I776cab4c9e9e4b3e58162dcce6ec025cb366bdee Reviewed-on: https://go-review.googlesource.com/c/go/+/598295 Reviewed-by: Michael Knyszek <mknyszek@google.com> Reviewed-by: Jorropo <jorropo.pgm@gmail.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Keith Randall <khr@google.com> Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2024-04-17internal/abi: define EmptyInterface, TypeOf, and NoEscapeMichael Anthony Knyszek
This change defines two commonly-defined functions and a commonly-defined type in internal/abi to try and deduplicate some definitions. This is motivated by a follow-up CL which will want access to TypeOf in yet another package. There still exist duplicate definitions of all three of these things in the runtime, and this CL doesn't try to handle that yet. There are far too many uses in the runtime to handle manually in a way that feels comfortable; automated refactoring will help. For #62483. Change-Id: I02fc64a28f11af618f6071f94d27f45c135fa8ac Reviewed-on: https://go-review.googlesource.com/c/go/+/573955 Auto-Submit: Michael Knyszek <mknyszek@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: David Chase <drchase@google.com>
2024-02-19strings: make use of sizeclasses in (*Builder).GrowMateusz Poliwczak
Fixes #64833 Change-Id: Ice3f5dfab65f5525bc7a6f57ddeaabda8d64dfa3 GitHub-Last-Rev: 38f1d6c19d8ec29ae5645ce677839a301f798df3 GitHub-Pull-Request: golang/go#64835 Reviewed-on: https://go-review.googlesource.com/c/go/+/552135 Reviewed-by: Keith Randall <khr@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: Keith Randall <khr@golang.org> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2023-10-13bytes,strings: add available godoc linkcui fliter
Change-Id: Id9706a783d3321e3706eeee102286522e7968efd Reviewed-on: https://go-review.googlesource.com/c/go/+/534775 Reviewed-by: Ian Lance Taylor <iant@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com> Auto-Submit: Ian Lance Taylor <iant@google.com>
2023-02-27bytes, strings: avoid unnecessary zero initializationJoe Tsai
Add bytealg.MakeNoZero that specially allocates a []byte without zeroing it. It assumes the caller will populate every byte. From within the bytes and strings packages, we can use bytealg.MakeNoZero in a way where our logic ensures that the entire slice is overwritten such that uninitialized bytes are never leaked to the end user. We use bytealg.MakeNoZero from within the following functions: * bytes.Join * bytes.Repeat * bytes.ToUpper * bytes.ToLower * strings.Builder.Grow The optimization in strings.Builder transitively benefits the following: * strings.Join * strings.Map * strings.Repeat * strings.ToUpper * strings.ToLower * strings.ToValidUTF8 * strings.Replace * any user logic that depends on strings.Builder This optimization is especially notable on large buffers that do not fit in the CPU cache, such that the cost of runtime.memclr and runtime.memmove are non-trivial since they are both limited by the relatively slow speed of physical RAM. Performance: RepeatLarge/256/1 66.0ns ± 3% 64.5ns ± 1% ~ (p=0.095 n=5+5) RepeatLarge/256/16 55.4ns ± 5% 53.1ns ± 3% -4.17% (p=0.016 n=5+5) RepeatLarge/512/1 95.5ns ± 7% 87.1ns ± 2% -8.78% (p=0.008 n=5+5) RepeatLarge/512/16 84.4ns ± 9% 76.2ns ± 5% -9.73% (p=0.016 n=5+5) RepeatLarge/1024/1 161ns ± 4% 144ns ± 7% -10.45% (p=0.016 n=5+5) RepeatLarge/1024/16 148ns ± 3% 141ns ± 5% ~ (p=0.095 n=5+5) RepeatLarge/2048/1 296ns ± 7% 288ns ± 5% ~ (p=0.841 n=5+5) RepeatLarge/2048/16 298ns ± 8% 281ns ± 5% ~ (p=0.151 n=5+5) RepeatLarge/4096/1 593ns ± 8% 539ns ± 8% -8.99% (p=0.032 n=5+5) RepeatLarge/4096/16 568ns ±12% 526ns ± 7% ~ (p=0.056 n=5+5) RepeatLarge/8192/1 1.15µs ± 8% 1.08µs ±12% ~ (p=0.095 n=5+5) RepeatLarge/8192/16 1.12µs ± 4% 1.07µs ± 7% ~ (p=0.310 n=5+5) RepeatLarge/8192/4097 1.77ns ± 1% 1.76ns ± 2% ~ (p=0.310 n=5+5) RepeatLarge/16384/1 2.06µs ± 7% 1.94µs ± 5% ~ (p=0.222 n=5+5) RepeatLarge/16384/16 2.02µs ± 4% 1.92µs ± 6% ~ (p=0.095 n=5+5) RepeatLarge/16384/4097 1.50µs ±15% 1.44µs ±11% ~ (p=0.802 n=5+5) RepeatLarge/32768/1 3.90µs ± 8% 3.65µs ±11% ~ (p=0.151 n=5+5) RepeatLarge/32768/16 3.92µs ±14% 3.68µs ±12% ~ (p=0.222 n=5+5) RepeatLarge/32768/4097 3.71µs ± 5% 3.43µs ± 4% -7.54% (p=0.032 n=5+5) RepeatLarge/65536/1 7.47µs ± 8% 6.88µs ± 9% ~ (p=0.056 n=5+5) RepeatLarge/65536/16 7.29µs ± 4% 6.74µs ± 6% -7.60% (p=0.016 n=5+5) RepeatLarge/65536/4097 7.90µs ±11% 6.34µs ± 5% -19.81% (p=0.008 n=5+5) RepeatLarge/131072/1 17.0µs ±18% 14.1µs ± 6% -17.32% (p=0.008 n=5+5) RepeatLarge/131072/16 15.2µs ± 2% 16.2µs ±17% ~ (p=0.151 n=5+5) RepeatLarge/131072/4097 15.7µs ± 6% 14.8µs ±11% ~ (p=0.095 n=5+5) RepeatLarge/262144/1 30.4µs ± 5% 31.4µs ±13% ~ (p=0.548 n=5+5) RepeatLarge/262144/16 30.1µs ± 4% 30.7µs ±11% ~ (p=1.000 n=5+5) RepeatLarge/262144/4097 31.2µs ± 7% 32.7µs ±13% ~ (p=0.310 n=5+5) RepeatLarge/524288/1 67.5µs ± 9% 63.7µs ± 3% ~ (p=0.095 n=5+5) RepeatLarge/524288/16 67.2µs ± 5% 62.9µs ± 6% ~ (p=0.151 n=5+5) RepeatLarge/524288/4097 65.5µs ± 4% 65.2µs ±18% ~ (p=0.548 n=5+5) RepeatLarge/1048576/1 141µs ± 6% 137µs ±14% ~ (p=0.421 n=5+5) RepeatLarge/1048576/16 140µs ± 2% 134µs ±11% ~ (p=0.222 n=5+5) RepeatLarge/1048576/4097 141µs ± 3% 134µs ±10% ~ (p=0.151 n=5+5) RepeatLarge/2097152/1 258µs ± 2% 271µs ±10% ~ (p=0.222 n=5+5) RepeatLarge/2097152/16 263µs ± 6% 273µs ± 9% ~ (p=0.151 n=5+5) RepeatLarge/2097152/4097 270µs ± 2% 277µs ± 6% ~ (p=0.690 n=5+5) RepeatLarge/4194304/1 684µs ± 3% 467µs ± 6% -31.69% (p=0.008 n=5+5) RepeatLarge/4194304/16 682µs ± 1% 471µs ± 7% -30.91% (p=0.008 n=5+5) RepeatLarge/4194304/4097 685µs ± 2% 465µs ±20% -32.12% (p=0.008 n=5+5) RepeatLarge/8388608/1 1.50ms ± 1% 1.16ms ± 8% -22.63% (p=0.008 n=5+5) RepeatLarge/8388608/16 1.50ms ± 2% 1.22ms ±17% -18.49% (p=0.008 n=5+5) RepeatLarge/8388608/4097 1.51ms ± 7% 1.33ms ±11% -11.56% (p=0.008 n=5+5) RepeatLarge/16777216/1 3.48ms ± 4% 2.66ms ±13% -23.76% (p=0.008 n=5+5) RepeatLarge/16777216/16 3.37ms ± 3% 2.57ms ±13% -23.72% (p=0.008 n=5+5) RepeatLarge/16777216/4097 3.38ms ± 9% 2.50ms ±11% -26.16% (p=0.008 n=5+5) RepeatLarge/33554432/1 7.74ms ± 1% 4.70ms ±19% -39.31% (p=0.016 n=4+5) RepeatLarge/33554432/16 7.90ms ± 4% 4.78ms ± 9% -39.50% (p=0.008 n=5+5) RepeatLarge/33554432/4097 7.80ms ± 2% 4.86ms ±11% -37.60% (p=0.008 n=5+5) RepeatLarge/67108864/1 16.4ms ± 3% 9.7ms ±15% -41.29% (p=0.008 n=5+5) RepeatLarge/67108864/16 16.5ms ± 1% 9.9ms ±15% -39.83% (p=0.008 n=5+5) RepeatLarge/67108864/4097 16.5ms ± 1% 11.0ms ±18% -32.95% (p=0.008 n=5+5) RepeatLarge/134217728/1 35.2ms ±12% 19.2ms ±10% -45.58% (p=0.008 n=5+5) RepeatLarge/134217728/16 34.6ms ± 6% 19.3ms ± 7% -44.07% (p=0.008 n=5+5) RepeatLarge/134217728/4097 33.2ms ± 2% 19.3ms ±14% -41.79% (p=0.008 n=5+5) RepeatLarge/268435456/1 70.9ms ± 2% 36.2ms ± 5% -48.87% (p=0.008 n=5+5) RepeatLarge/268435456/16 77.4ms ± 7% 36.1ms ± 8% -53.33% (p=0.008 n=5+5) RepeatLarge/268435456/4097 75.8ms ± 4% 37.0ms ± 4% -51.15% (p=0.008 n=5+5) RepeatLarge/536870912/1 163ms ±14% 77ms ± 9% -52.94% (p=0.008 n=5+5) RepeatLarge/536870912/16 156ms ± 4% 76ms ± 6% -51.42% (p=0.008 n=5+5) RepeatLarge/536870912/4097 151ms ± 2% 76ms ± 6% -49.64% (p=0.008 n=5+5) RepeatLarge/1073741824/1 293ms ± 5% 149ms ± 8% -49.18% (p=0.008 n=5+5) RepeatLarge/1073741824/16 308ms ± 9% 150ms ± 8% -51.19% (p=0.008 n=5+5) RepeatLarge/1073741824/4097 299ms ± 5% 151ms ± 6% -49.51% (p=0.008 n=5+5) Updates #57153 Change-Id: I024553b7e676d6da6408278109ac1fa8def0a802 Reviewed-on: https://go-review.googlesource.com/c/go/+/456336 Reviewed-by: Dmitri Shuralyov <dmitshur@google.com> Reviewed-by: Ian Lance Taylor <iant@google.com> Run-TryBot: Joseph Tsai <joetsai@digital-static.net> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
2022-09-07strings: simplify code using unsafe.StringDatacuiweixie
Updates #54854 Change-Id: I93396dc92bd2decba895f2d059e1aeffcd22312c Reviewed-on: https://go-review.googlesource.com/c/go/+/428158 Run-TryBot: Bryan Mills <bcmills@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Auto-Submit: Bryan Mills <bcmills@google.com> Reviewed-by: Bryan Mills <bcmills@google.com> Reviewed-by: Robert Griesemer <gri@google.com>
2022-08-23strings: rely on utf8.AppendRuneJoe Tsai
This is both simpler and more performant. Change-Id: I66ef8e49c059a722932392ee3ecfb951d9b8e121 Reviewed-on: https://go-review.googlesource.com/c/go/+/412339 TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: David Chase <drchase@google.com> Run-TryBot: Joseph Tsai <joetsai@digital-static.net> Auto-Submit: Joseph Tsai <joetsai@digital-static.net> Reviewed-by: Ian Lance Taylor <iant@google.com>
2022-04-05all: separate doc comment from //go: directivesRuss Cox
A future change to gofmt will rewrite // Doc comment. //go:foo to // Doc comment. // //go:foo Apply that change preemptively to all comments (not necessarily just doc comments). For #51082. Change-Id: Iffe0285418d1e79d34526af3520b415a12203ca9 Reviewed-on: https://go-review.googlesource.com/c/go/+/384260 Trust: Russ Cox <rsc@golang.org> Run-TryBot: Russ Cox <rsc@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gopher Robot <gobot@golang.org>
2022-02-19strings: fix typo in commentGeorge Looshch
Remove unnecessary whitespace in noescape comment Fixes #50634 Change-Id: I1c8d16c020b05678577d349470fac7e7ab8a10b7 Reviewed-on: https://go-review.googlesource.com/c/go/+/378815 Reviewed-by: Ian Lance Taylor <iant@golang.org> Trust: Dmitri Shuralyov <dmitshur@golang.org>
2021-02-24bufio, bytes, strings: handle negative runes in WriteRuneDavid Benjamin
Updates #43254 Change-Id: I7d4bf3b99cc36ca2156af5bb01a1c595419d1d3c Reviewed-on: https://go-review.googlesource.com/c/go/+/280492 Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com> Reviewed-by: Rob Pike <r@golang.org> Trust: Emmanuel Odeke <emmanuel@orijtech.com> Run-TryBot: Emmanuel Odeke <emmanuel@orijtech.com> TryBot-Result: Go Bot <gobot@golang.org>
2019-10-17cmd/compile: add -d=checkptr to validate unsafe.Pointer rulesMatthew Dempsky
This CL adds -d=checkptr as a compile-time option for adding instrumentation to check that Go code is following unsafe.Pointer safety rules dynamically. In particular, it currently checks two things: 1. When converting unsafe.Pointer to *T, make sure the resulting pointer is aligned appropriately for T. 2. When performing pointer arithmetic, if the result points to a Go heap object, make sure we can find an unsafe.Pointer-typed operand that pointed into the same object. These checks are currently disabled for the runtime, and can also be disabled through a new //go:nocheckptr annotation. The latter is necessary for functions like strings.noescape, which intentionally violate safety rules to workaround escape analysis limitations. Fixes #22218. Change-Id: If5a51273881d93048f74bcff10a3275c9c91da6a Reviewed-on: https://go-review.googlesource.com/c/go/+/162237 Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2018-08-20strings: add Builder.CapDaniel Martí
To report the capacity of the underlying buffer. The method mirrors bytes.Buffer.Cap. The method can be useful to know whether or not calling write or grow methods will result in an allocation, or to know how much memory has been allocated so far. Fixes #26269. Change-Id: I391db45ae825011566b594836991e28135369a78 Reviewed-on: https://go-review.googlesource.com/122835 Run-TryBot: Daniel Martí <mvdan@mvdan.cc> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-01-09strings: prevent copyCheck from forcing Builder to escape and allocateBrad Fitzpatrick
All credit and blame goes to Ian for this suggestion, copied from the runtime. Fixes #23382 Updates #7921 Change-Id: I3d5a9ee4ab730c87e0f3feff3e7fceff9bcf9e18 Reviewed-on: https://go-review.googlesource.com/86976 Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-12-11strings: fix two Builder bugs allowing mutation of strings, remove ReadFromBrad Fitzpatrick
The Builder's ReadFrom method allows the underlying unsafe slice to escape, and for callers to subsequently modify memory that had been unsafely converted into an immutable string. In the original proposal for Builder (#18990), I'd noted there should be no Read methods: > There would be no Reset or Bytes or Truncate or Read methods. > Nothing that could mutate the []byte once it was unsafely converted > to a string. And in my prototype (https://golang.org/cl/37767), I handled ReadFrom properly, but when https://golang.org/cl/74931 arrived, I missed that it had a ReadFrom method and approved it. Because we're so close to the Go 1.10 release, just remove the ReadFrom method rather than think about possible fixes. It has marginal utility in a Builder anyway. Also, fix a separate bug that also allowed mutation of a slice's backing array after it had been converted into a slice by disallowing copies of the Builder by value. Updates #18990 Fixes #23083 Fixes #23084 Change-Id: Id1f860f8a4f5f88b32213cf85108ebc609acb95f Reviewed-on: https://go-review.googlesource.com/83255 Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-12-08strings: delete unused constantCaleb Spare
Change-Id: I235c5bc7ce598047eccc1518984dd27f568046a2 Reviewed-on: https://go-review.googlesource.com/82776 Run-TryBot: Caleb Spare <cespare@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-11-06strings: add BuilderCaleb Spare
This is like a write-only subset of bytes.Buffer with an allocation-free String method. Fixes #18990. Change-Id: Icdf7240f4309a52924dc3af04a39ecd737a210f4 Reviewed-on: https://go-review.googlesource.com/74931 Run-TryBot: Caleb Spare <cespare@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
generated by cgit v1.3 (git 2.53.0) at 2026-04-15 21:01:43 +0000