Files
sdk/pkg
Michael Richards 1cd8b28cfe [frontend_server] This adds the ability for the frontend server to be a resident process, allowing it to live through invocations of the Dart CLI. This allows the CLI to utilize the frontend's incremental compilation mode and keep cached kernel files for better performance. This currently only supports VM targets.
When launched as a snapshot, the initial compile is slower than the existing pub approach because of a process start time of around 500 ms. When launched as a compiled executable, initial compile times are the same as the existing pub approach. Once launched, experimental results show times to produce a kernel file of at worst 1.5-2x faster than pub's solution and at best 10x faster than pub's solution. The typical workflow of making changes and recompiling results in an average of a 5x speedup with respect to pub's implementation.

Because compiler instances use a lot of memory, there is a limit on the number of active compilers that the resident server will keep alive, and will actively bring instances down when this limit is exceeded. If the user was previously compiling a given project during the lifespan of a ResidentFrontendServer and its compiler is taken down between requests, a new compiler instance will be allocated for the request. Performance is still between 1.5x-5x faster for this case when compared to pub's compile times.

Change-Id: If9ee1ecc71d660d34faf23381c764dc11d6a5902
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/252001
Reviewed-by: Siva Annamalai <asiva@google.com>
Reviewed-by: Jake Macdonald <jakemac@google.com>
Commit-Queue: Michael Richards <msrichards@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
2022-08-02 18:08:21 +00:00
..
2022-07-28 18:30:10 +00:00
2022-07-25 12:21:59 +00:00
2022-07-29 18:11:01 +00:00

Package validation

The packages in pkg/ are automatically validated on the LUCI CI bots. The validation is largely done by the tools/package_deps package; it can be tested locally via:

dart tools/package_deps/bin/package_deps.dart

Packages which are published

There are several packages developed in pkg/ which are published to pub. Validation of these packages is particularly important because the pub tools are not used for these packages during development; we get our dependency versions from the DEPS file. Its very easy for the dependencies specified in a package's pubspec file to get out of date wrt the packages and versions actually used.

In order to better ensure we're publishing correct packages, we validate some properties of the pubspec files on our CI system. These validations include:

  • that the dependencies listed in the pubspec are used in the package
  • that all the packages used by the source are listed in the pubspec
  • that we don't use relative path deps to pkg/ or third_party/ packages

Packages which are not published

For packages in pkg/ which we do not intend to be published, we put the following comment in the pubspec.yaml file:

# This package is not intended for consumption on pub.dev. DO NOT publish.
publish_to: none

These pubspecs are still validated by the package validation tool. The contents are more informational as the pubspecs for these packages are not consumed by the pub tool or ecosystem.

We validate:

  • that the dependencies listed in the pubspec are used in the package
  • that all the packages used by the source are listed in the pubspec
  • that a reference to a pkg/ package is done via a relative path dependency