golang/go

x/text/unicode/norm: reduce init-time memory usage

Open

#26,752 opened on Aug 1, 2018

View on GitHub
 (7 comments) (0 reactions) (0 assignees)Go (19,008 forks)batch import
NeedsFixPerformancehelp wanted

Repository metrics

Stars
 (133,883 stars)
PR merge metrics
 (No merged PRs in 30d)

Description

The golang.org/x/text/unicode/norm package allocs 21.47kB in its init function, regardless of whether the package is ever used.

We should do it lazily, as done in e.g. https://go-review.googlesource.com/c/net/+/127275 and https://go-review.googlesource.com/c/go/+/127075

This would help people who explicitly import it (or import it via golang.org/x/net/http2), as then the std-vendored copy would not need to also allocate the 20KB.

Perhaps some of those tables should be const strings, too, so the linker can put it in read-only sections. Then we can slice into it at runtime to get integers out.

/cc @mpvl

Contributor guide

Research direction
Implement lazy initialization of the norm package's tables by following patterns in https://go review.googlesource.com/c/net/+/127275 and https://go review.googlesource.com/c/go/+/127075. Also consider converting some tables to const strings to allow linker placement in read only sections.
Tech stack
go
Domain
backend
Issue type
Performance
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Go
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40