Config Manager

A thread-safe configuration manager for Rust applications that loads and caches JSON configuration files.

Features

• Thread-safe caching: Configurations are loaded once and cached for subsequent accesses
• Concurrent access: Safe for use across multiple threads with RwLock synchronization
• Type-safe retrieval: Supports deserializing configuration values into Rust types
• JSON-based: Configuration files are stored in JSON format

Usage

Basic Usage

1. Create a JSON configuration file in the configs/ directory (e.g., configs/app.json):

{
  "db_host": "localhost",
  "db_port": 5432,
  "debug_mode": true
}

2. Use the configuration in your Rust code:

use config_ro::Config;

let config = Config::new("app");
let db_host: String = config.get("db_host").unwrap();
let db_port: u16 = config.get("db_port").unwrap();
let debug_mode: bool = config.get("debug_mode").unwrap();

Advanced Usage

// Create multiple configuration instances
let app_config = Config::new("app");
let db_config = Config::new("database");

// Get nested values (if your JSON has nested objects)
let nested_value = app_config.get::<String>("nested.key").unwrap();

// Handle missing values
match app_config.get::<String>("optional_key") {
    Some(value) => println!("Got value: {}", value),
    None => println!("Using default value"),
}

API Reference

Config::new(name: &str) -> Config

Creates a new configuration instance for the given name. The configuration is loaded from configs/{name}.json if not already cached.

config.get<T: DeserializeOwned>(key: &str) -> Option<T>

Retrieves a configuration value by key, attempting to deserialize it into type T.

Thread Safety

The configuration manager is designed for concurrent access:

• Configuration loading is synchronized
• Multiple threads can read configurations simultaneously
• Configuration updates are exclusive (blocking other accesses during write)

Example Configuration File

{
  "app_name": "My Application",
  "version": "1.0.0",
  "database": {
    "host": "db.example.com",
    "port": 5432,
    "credentials": {
      "username": "admin",
      "password": "secret"
    }
  },
  "features": {
    "experimental": true,
    "logging": "verbose"
  }
}

Contributing

Contributions are welcome! Please open an issue or submit a PR for:

• New features
• Performance improvements
• Bug fixes

License

Dual-licensed under MIT or Apache 2.0 at your option.