Michael Richards
1cd8b28cfe
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>
The frontend_server package is used by both the flutter command line tool and the frontend_server_client package (used by webdev and package:test).
API Stability
Changes to the command line API or behavior should be tested against the follwing test suites (in addition to normal HHH testing):
- flutter_tools: https://github.com/flutter/flutter/tree/master/packages/flutter_tools
- frontend_server_client: https://github.com/dart-lang/webdev/tree/master/frontend_server_client
Otherwise these changes will need to be carefully coordinated with the flutter tooling and frontend_server_client teams.
This API stability does not cover any of the source code APIs.
Stable subset
- The frontend_server kernel compilation and expression evaluation for kernel should be considered "stable".
- The frontend_server JavaScript compilation is semi-stable, but clients should anticipate coordinated breaking changes in the future.
- The frontend_server JavaScript expression evaluation is experimental and is expected to change significantly from Dec 2020 through the end of 2021.
- Specific flags like the --flutter-widget-cache may be added for experimentation and should not be considered stable.