| commit | e491bc5d86b3a914dcc604a186e9c1383152daf9 | [log] [tgz] |
|---|---|---|
| author | Jens Johansen <jensj@google.com> | Thu May 17 06:49:41 2018 +0000 |
| committer | commit-bot@chromium.org <commit-bot@chromium.org> | Thu May 17 06:49:41 2018 +0000 |
| tree | ef67730e4c8a0e51106fba245b3eef568c78fd60 | |
| parent | 8101ee0479d6628c70f63133bb8d875c447a50dc [diff] |
Allow to specify what dill file to initialize from This CL updates the frontend_server to allow specifying what dill file to initialize from. Normally, it tries to initialize from the same dill file as is the output. This is fine in many cases (e.g. flutter run always says it should output to build/app.dill): The first time it compiles everything, subsequent times (across restarts) it only recompiles what's needed. When running tests, however, the output is in a temporary directory, so it doesn't work across restarts. The startup time for tests is always rather high, because it always has to recompile everything. This CL updates the frontend_server to allow specifying what dill file to initialize from. Flutter can thus save the compiled test file in a centralized location (e.g. build/test.dill) and load from that across restarts. Plumbing this into flutter yields the following result, when running a single test (the one automatically created when creating a new flutter project): Before: ~5.5 seconds Now, first run: ~5.5 second (unchanged) Now, subsequent runs: ~3.4 seconds Approximate breakdown: Startup cost (e.g. if there's no test directory): ~ 800 ms Starting up the actual frontend server: ~150 ms Reading source from old dill, loading all relevant files and invalidating source: ~ 300 ms Compiling everything (or, rather, nothing as it's all from the dill at this point): ~ 650 ms Serializing: ~ 250 ms Copying files: ~ 50 ms Running the actual test: ~1100 ms Total: ~3300 ms `time flutter test --local-engine=host_debug --preview-dart-2` says ~3.4 seconds... To compare, --no-preview-dart-2 takes ~2.2 seconds, so dart2 still has a (significantly) higher startup cost. Moves the needle on https://github.com/flutter/flutter/issues/15767. Change-Id: I36a2d05bc76e0193d369df42eb3b9f08416dd78f Reviewed-on: https://dart-review.googlesource.com/51820 Reviewed-by: Kevin Millikin <kmillikin@google.com> Reviewed-by: Vyacheslav Egorov <vegorov@google.com> Commit-Queue: Jens Johansen <jensj@google.com>
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