| commit | 7defa796fec08ff4180eae3379da47019ad16019 | [log] [tgz] |
|---|---|---|
| author | Katharine Berry <ktbry@google.com> | Wed May 29 09:56:09 2019 -0700 |
| committer | Daniel Martí <mvdan@mvdan.cc> | Thu Oct 24 07:44:52 2019 +0000 |
| tree | 5957a21baa0a3a087d908d4a222f41df82fd713a | |
| parent | be03d4f470ed7887405ab93f751a8591aef9b6f9 [diff] |
cover: significantly improve the speed of cover.ParseProfiles ParseProfiles currently uses a regex to parse each line. This is not very fast, and can lead to ParseProfiles being excessively slow on certain pathological inputs. This change substantially improves the performance by parsing manually instead. On an input of about 3 GB of data containing about 36 million lines, the time spent in ParseProfiles drops from 72 seconds to 11 seconds, with actual string parsing time dropping from 61 seconds to 2 seconds. Since this change completely changes the parsing, it also adds some tests for ParseProfiles to help ensure the new parsing is correct. A benchmark for parseLine is also included. Here is a comparison of the old regex implementation versus the new manual one: name old time/op new time/op delta ParseLine-12 2.43µs ± 2% 0.05µs ± 8% -97.98% (p=0.000 n=10+9) name old speed new speed delta ParseLine-12 42.5MB/s ± 2% 2103.2MB/s ± 7% +4853.14% (p=0.000 n=10+9) Fixes golang/go#32211 Change-Id: If8f91ecbda776c08243de4e423de4eea55f0082b Reviewed-on: https://go-review.googlesource.com/c/tools/+/179377 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@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.