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dart / sdk / c2bdda63f58cc76379d01475bcd8e915bb93969a
commitc2bdda63f58cc76379d01475bcd8e915bb93969a[log] [tgz]
authorBrian Quinlan <bquinlan@google.com>Mon Mar 13 22:39:13 2023 +0000
committerCommit Queue <dart-scoped@luci-project-accounts.iam.gserviceaccount.com>Mon Mar 13 22:39:13 2023 +0000
tree5f4d2d09f10589e996189d8d1a585147be50ef45
parentdde0acbd83b5a0de1daaee8d27cc75e8ca9ceb4a [diff]
[io] Improve the performance of the IOSink returned by `openWrite` by writing eagerly and accumulating small writes.

Benchmarks (benchmarks/FileIOSink/dart/FileIOSink.dart):

 @before:

  FileIOSink.Add.ManySmall(RunTime): 2341597.0 us.
  FileIOSink.Add.OneLarge(RunTime): 111.06925927974774 us.
  FileIOSink.Add.AlternatingAddSize(RunTime): 105.65958788898234 us.

 @after

  FileIOSink.Add.ManySmall(RunTime): 5007.1125 us.
  FileIOSink.Add.OneLarge(RunTime): 98.23492468475541 us.
  FileIOSink.Add.AlternatingAddSize(RunTime): 91.77411527720551 us.

So the relative performance changes are:

 FileIOSink.Add.ManySmall(RunTime): 0.00213x (MUCH faster)
 FileIOSink.Add.OneLarge(RunTime): 0.884x (slight faster - noise?)
 FileIOSink.Add.AlternatingAddSize(RunTime): 0.868x (slightly faster - noise?)

https://golem.corp.goog/Revision?repository=dart&revision=102771&patch=17842

Change-Id: Ic73f33299a570096dd05f254982f556767559966
Bug:https://github.com/dart-lang/sdk/issues/32874
Tested: unit tests
CoreLibraryReviewExempt: Performance-only fix for file writes in the VM.
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/285420
Commit-Queue: Brian Quinlan <bquinlan@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
6 files changed
tree: 5f4d2d09f10589e996189d8d1a585147be50ef45
  1. .dart_tool/
  2. .github/
  3. benchmarks/
  4. build/
  5. docs/
  6. pkg/
  7. runtime/
  8. samples/
  9. sdk/
  10. tests/
  11. third_party/
  12. tools/
  13. utils/
  14. .clang-format
  15. .gitattributes
  16. .gitconfig
  17. .gitignore
  18. .gn
  19. .mailmap
  20. .style.yapf
  21. .vpython
  22. AUTHORS
  23. BUILD.gn
  24. CHANGELOG.md
  25. codereview.settings
  26. CONTRIBUTING.md
  27. DEPS
  28. LICENSE
  29. OWNERS
  30. PATENT_GRANT
  31. PRESUBMIT.py
  32. README.dart-sdk
  33. README.md
  34. sdk_args.gni
  35. SECURITY.md
  36. WATCHLISTS
README.md

Dart

A client-optimized language for fast apps on any platform

Dart is:

  • Optimized for UI: Develop with a programming language specialized around the needs of user interface creation.

  • Productive: Make changes iteratively: use hot reload to see the result instantly in your running app.

  • Fast on all platforms: Compile to ARM & x64 machine code for mobile, desktop, and backend. Or compile to JavaScript for the web.

Dart's flexible compiler technology lets you run Dart code in different ways, depending on your target platform and goals:

  • Dart Native: For programs targeting devices (mobile, desktop, server, and more), Dart Native includes both a Dart VM with JIT (just-in-time) compilation and an AOT (ahead-of-time) compiler for producing machine code.

  • Dart Web: For programs targeting the web, Dart Web includes both a development time compiler (dartdevc) and a production time compiler (dart2js).

Dart platforms illustration

License & patents

Dart is free and open source.

See LICENSE and PATENT_GRANT.

Using Dart

Visit dart.dev to learn more about the language, tools, and to find codelabs.

Browse pub.dev for more packages and libraries contributed by the community and the Dart team.

Our API reference documentation is published at api.dart.dev, based on the stable release. (We also publish docs from our beta and dev channels, as well as from the primary development branch).

Building Dart

If you want to build Dart yourself, here is a guide to getting the source, preparing your machine to build the SDK, and building.

There are more documents on our wiki.

Contributing to Dart

The easiest way to contribute to Dart is to file issues.

You can also contribute patches, as described in Contributing.