Key features include:

• Optimized Interpreter: PrimJS introduces a template interpreter leveraging stack caching and register optimizations, significantly enhancing performance.
• Seamless Object Model Integration: The engine's object model integrates efficiently with the Lynx object model, reducing data communication overhead and improving rendering performance.
• Advanced Memory Management: Utilizing a Garbage Collector (GC) instead of QuickJS's Reference Counting, PrimJS offers better performance, improved memory analyzability, and reduced risk of memory leaks.
• Comprehensive Debugging Support: Full implementation of the Chrome DevTools Protocol (CDP) enables seamless integration with Chrome Debugger for enhanced debugging capabilities.
• WebAssembly Support: Initial WebAssembly support for module loading, instantiation, and basic JavaScript-to-WASM interoperability.

Performance

For detailed performance benchmarks, please refer to performance comparison document. The benchmark results show that PrimJS outperforms QuickJS by approximately 28% in overall score (3735 vs 2904) on the Octane Benchmark suite. We are continuously working on performance optimizations.

Quick Start

Dependencies

1. Clone the repository:

   git clone git@github.com:lynx-family/primjs.git
   

2. Install dependencies:

   cd primjs
   source tools/envsetup.sh
   hab sync .
   

Building on Linux and macOS

PrimJS uses gn and ninja for building. Follow these steps to generate the qjs binary:

gn gen out/Default
ninja -C out/Default qjs_exe

PrimJS snapshot, compatible memory management, and tracing GC are enabled by default only for arm64 targets with pre-generated embedded.S files. Currently, these targets are Android, iOS, and macOS. The features remain disabled on Linux, other platforms without embedded.S, and non-arm64 targets.

To explicitly target arm64 (on macOS, this also enables these features by default):

gn gen out/Default --args='target_cpu="arm64"'
ninja -C out/Default -j32 qjs_exe

Release Build

For a release build, set the is_debug = false argument during configuration.

Running PrimJS

The primary binary is qjs, located at out/Default/qjs. Use it to run JavaScript files:

./out/Default/qjs test.js

Running Tests

Run the following steps from the root directory to build and execute unit tests:

Build Unit Tests

python3 tools/ci/check_test_build.py

Run Unit Tests

python3 tools/ci/check_test_run.py

How to Contribute

Code of Conduct

We are devoted to ensuring a positive, inclusive, and safe environment for all contributors. Please find our Code of Conduct for detailed information.

Contributing Guide

We welcome you to join and become a member of Lynx Authors. It's people like you that make this project great.

Please refer to lynx contributing guide for details.

Open Source Roadmap

Discussions

Large discussions and proposals are discussed in Github Discussions

License

PrimJS is Apache licensed, as found in the LICENSE file.