| commit | 5a1343cb14b731f2146d8b8acbffa78d89860d2a | [log] [tgz] |
|---|---|---|
| author | Martin Kustermann <kustermann@google.com> | Fri Feb 14 03:51:04 2025 -0800 |
| committer | dart-internal-monorepo <dart-internal-monorepo@dart-ci-internal.iam.gserviceaccount.com> | Fri Feb 14 03:52:46 2025 -0800 |
| tree | f606993ecb080eb8bcd7d1c5e156848cb1e3a66f | |
| parent | ff102d6da184e856063a96c62c2b6da3994fc4f3 [diff] |
[dart2wasm] Avoid repeatedly allocating strings for the same json object keys Most jsons have ascii strings as keys in json objects and very often those keys are highly repetitive. In previous CLs we started to compute the hash of the json object keys eagerly, even before allocating the string. We can take advantage of this now by using consulting a fixed-size interning cache. The cost of this cache is * Memory: It has max 512 entries and only contains one byte strings used as keys in json (keys are usually very small). * Lookup: Bitmask and lookup in array, length comparison (fails often if keys are not the same), plus byte comparison (may often suceeed) * Insert: Simply store into an array. The benefit is that we are very likely to allocate a lot less string objects for the keys. This will make data fit better in caches, will make string equality checks (in map lookups) more often hit the fast case (pointer equality) and reduce GC pressure. Change-Id: Id8ed3a972a267dd0201383f8f51ed82758bc0e63 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/409680 Reviewed-by: Ömer Ağacan <omersa@google.com> Commit-Queue: Martin Kustermann <kustermann@google.com> https://dart.googlesource.com/sdk/+/4c6326353796ed628b916624264d1bacf0339064
Monorepo is:
With depot_tools installed and on your path, create a directory for your monorepo checkout and run these commands to create a gclient solution in that directory:
mkdir monorepo cd monorepo gclient config --unmanaged https://dart.googlesource.com/monorepo gclient sync -D
This gives you a checkout in the monorepo directory that contains:
monorepo/ DEPS - the DEPS used for this gclient checkout commits.json - the pinned commits for Dart, flutter/engine, and flutter/flutter tools/ - scripts used to create monorepo DEPS engine/src/ - the flutter/buildroot repo flutter/ - the flutter/engine repo out/ - the build directory, where Flutter engine builds are created third_party/ - Flutter dependencies checked out by DEPS dart/ - the Dart SDK checkout. third_party - Dart dependencies, also used by Flutter flutter/ - the flutter/flutter repo
Flutter's instructions for building the engine are at Compiling the engine
They can be followed closely, with a few changes:
goma_ctl ensure_start is sufficient.Example build commands that work on linux:
MONOREPO_PATH=$PWD if [[ ! $PATH =~ (^|:)$MONOREPO_PATH/flutter/bin(:|$) ]]; then PATH=$MONOREPO_PATH/flutter/bin:$PATH fi export GOMA_DIR=$(dirname $(command -v gclient))/.cipd_bin goma_ctl ensure_start pushd engine/src flutter/tools/gn --goma --no-prebuilt-dart-sdk --unoptimized --full-dart-sdk autoninja -C out/host_debug_unopt popd
The Flutter commands used to build and run apps will use the locally built Flutter engine and Dart SDK, instead of the one downloaded by the Flutter tool, if the --local-engine option is provided.
For example, to build and run the Flutter spinning square sample on the web platform,
MONOREPO_PATH=$PWD cd flutter/examples/layers flutter --local-engine=host_debug_unopt \ -d chrome run widgets/spinning_square.dart cd $MONOREPO_PATH
To build for desktop, specify the desktop platform device in flutter run as -d macos or -d linux or -d windows. You may also need to run the command
flutter create --platforms=windows,macos,linux
on existing apps, such as sample apps. New apps created with flutter create already include these support files. Details of desktop support are at Desktop Support for Flutter
Tests in the Flutter source tree can be run with the flutter test command, run in the directory of a package containing tests. For example:
MONOREPO_PATH=$PWD cd flutter/packages/flutter flutter test --local-engine=host_debug_unopt cd $MONOREPO_PATH
Please file an issue or email the dart-engprod team with any problems with or questions about using monorepo.
We will update this documentation to address them.
flutter commands may download the engine and Dart SDK files for the configured channel, even though they will be using the local engine and its SDK.gclient sync needs to be run in an administrator session, because some installed dependencies create symlinks.