Parcel Watcher enables applications to monitor filesystem changes in real time, facilitating efficient build processes and live development workflows. It's a native C++ module, offering significantly better performance than JavaScript-based alternatives. The core problem it solves is providing a performant and reliable mechanism for detecting file system modifications without constantly polling the directory. It leverages platform-specific APIs like FSEvents, Watchman, inotify, and others for optimal performance.
Notable for its native C++ implementation, offering superior performance and reduced overhead compared to JavaScript-based solutions. It supports a wide range of platforms including macOS, Linux, Windows, and FreeBSD. The library emphasizes efficiency through throttling and coalescing of events, preventing performance bottlenecks during large-scale file system operations. Designed with a flexible architecture that enables customization via backend selection and an extensive set of options.
- Realtime Notifications: Provides instant updates on file and directory changes.
- Cross-Platform Support: Functional on macOS, Linux, Windows, and FreeBSD.
- High Performance: Native C++ implementation ensures minimal overhead.
- Flexible Backends: Supports various filesystem event APIs (FSEvents, Watchman, inotify, etc.).
- Configurable Filtering: Allows ignoring specific files or directories using glob patterns.
- Historical Queries: Enables retrieving events since a specific snapshot.
- WASM Fallback: A WebAssembly version available for environments without native support.
The project is actively maintained with recent commits and a responsive issue tracker. Documentation is comprehensive and includes detailed explanations of the API and options. A significant number of projects, including Parcel 2, are actively using it, indicating a stable and reliable implementation. The community contribution is active which ensures it will remain supported for a long time.
This project is beneficial for developers requiring real-time monitoring of filesystem changes for tasks like live reloading, automated builds, and dependency management. It's particularly valuable for projects that benefit from fast and reliable file system event handling, offering a substantial improvement over less efficient approaches. It replaces manual file system scanning and polling with a responsive event-driven approach.