# File Service for Angel3

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Angel service that persists data to a file on disk, stored as a JSON list. It uses a simple mutex to prevent race conditions, and caches contents in memory until changes are made.

The file will be created on read/write, if it does not already exist.

This package is useful in development, as it prevents you from having to install an external database to run your server.

When running a multi-threaded server, there is no guarantee that file operations will be mutually excluded. Thus, try to only use this one a single-threaded server if possible, or one with very low load.

While not necessarily *slow*, this package makes no promises about performance.

## Usage

```dart
configureServer(Angel app) async {
  // Just like a normal service
  app.use(
    '/api/todos',
    JsonFileService(
      const LocalFileSystem().file('todos_db.json')
    ),
  );
}
```