| commit | cb2dda6eabdf9160e66ca7293897f984154a7f8b | [log] [tgz] |
|---|---|---|
| author | Dominik Honnef <dominik@honnef.co> | Wed Apr 10 15:47:02 2019 +0200 |
| committer | Dominik Honnef <dominik@honnef.co> | Wed Apr 24 03:11:03 2019 +0000 |
| tree | 231dc272118af71c6a943421cbdc39a3fc294f33 | |
| parent | f62e16ca4165a3ae6024315bdec53b340c447b6d [diff] |
go/packages: deduplicate file parsing When loading packages from source, many files are being parsed repeatedly, for example due to test variants. While the median number of times a file gets parsed is 2, it is significantly higher (up to 28 times) when parsing the standard library, because of test variant shenanigans. By caching file contents and their parsed representations we can cut down on processing time and garbage produced. When loading individual packages or 3rd party projects, the effect is rather small. However when loading the entire standard library, the effect is substantial. name old time/op new time/op delta Jaeger-8 2.95s ± 7% 2.84s ± 8% ~ (p=0.089 n=10+10) Std-8 4.96s ± 7% 4.23s ± 3% -14.62% (p=0.000 n=9+9) Strconv-8 892ms ±34% 877ms ±21% ~ (p=0.853 n=10+10) name old alloc/op new alloc/op delta Jaeger-8 1.22GB ± 0% 1.21GB ± 0% -0.84% (p=0.000 n=10+10) Std-8 2.57GB ± 0% 2.20GB ± 0% -14.61% (p=0.000 n=10+8) Strconv-8 201MB ± 1% 200MB ± 1% ~ (p=0.105 n=10+10) name old allocs/op new allocs/op delta Jaeger-8 12.7M ± 0% 12.4M ± 0% -1.82% (p=0.000 n=9+10) Std-8 26.4M ± 0% 17.3M ± 0% -34.62% (p=0.000 n=9+9) Strconv-8 1.94M ± 0% 1.91M ± 0% -1.50% (p=0.000 n=10+10) When loading std, peak RSS decreases from 1.96 GB to 1.57 GB. While we're here, we simplify our ParseFile implementation. The contract of ParseFile specifies that implementations must use src for parsing, and use filename only for display purposes. As such, we mustn't ever call it with a nil src, making the check for a nil src in our own implementation superfluous. Change-Id: I33daac20fc52ccdb3187a336633f712d01b71d86 Reviewed-on: https://go-review.googlesource.com/c/tools/+/171377 Run-TryBot: Ian Cottrell <iancottrell@google.com> Run-TryBot: Michael Matloob <matloob@golang.org> Reviewed-by: Michael Matloob <matloob@golang.org>
This subrepository holds the source for various packages and tools that support the Go programming language.
Some of the tools, godoc and vet for example, are included in binary Go distributions.
Others, including the Go guru and the test coverage tool, can be fetched with go get.
Packages include a type-checker for Go and an implementation of the Static Single Assignment form (SSA) representation for Go programs.
The easiest way to install is to run go get -u golang.org/x/tools/.... You can also manually git clone the repository to $GOPATH/src/golang.org/x/tools.
This repository uses Gerrit for code changes. To learn how to submit changes to this repository, see https://golang.org/doc/contribute.html.
The main issue tracker for the tools repository is located at https://github.com/golang/go/issues. Prefix your issue with “x/tools/(your subdir):” in the subject line, so it is easy to find.