Struct Config 

pub struct Config {
    pub database_url: String,
    pub max_concurrent_jobs: usize,
    pub tick_rate_ms: u64,
    pub max_retry_attempts: i32,
    pub retry_interval_ms: i64,
}

Application-wide configuration loaded from environment variables.

The struct fields correspond to specific environment variables. Some fields have default values specified by helper functions (e.g. default_max_concurrent_jobs).

Fields

• database_url: Required. Must be present in the environment as DATABASE_URL.
• max_concurrent_jobs: Optional. Defaults to 4 if not set.
• tick_rate_ms: Optional. Defaults to 1000 if not set.
• max_retry_attempts: Optional. Defaults to 3 if not set.
• retry_interval_ms: Optional. Defaults to 300_000 (5 minutes) if not set.

Example

// Loading from environment:
// 1. Optionally load .env file
// 2. Read config variables (DATABASE_URL is required)

// let cfg = Config::from_env();
// println!("Loaded config: {:?}", cfg);

Fields

database_url: String

The URL for your database connection. Must be set via DATABASE_URL.

max_concurrent_jobs: usize

Maximum number of concurrent jobs the application will handle. Defaults to 4 if not present in the environment.

tick_rate_ms: u64

Interval in milliseconds at which some recurring task or loop should tick. Defaults to 1000 if not set.

max_retry_attempts: i32

Number of retry attempts for a failed operation. Defaults to 3.

retry_interval_ms: i64

Interval in milliseconds between retries. Defaults to 300_000 (5 minutes).

Implementations

impl Config

pub fn init() -> Result<(), Box<dyn Error>>

Initializes and sets the global Config once using environment variables.

This function loads a .env file (if present) and then constructs a Config from the environment using envy::from_env. It attempts to store the resulting Config in the global static GLOBAL_CONFIG.

If the global config is already set, an error is returned.

Errors

Returns an error if:

• Any required environment variable is missing (e.g. DATABASE_URL),
• or if the config has already been set and you tried to set it again.

Example

// Typically called early in the program:
// Config::init().expect("Failed to initialize config");

pub fn from_env() -> Self

Constructs a new Config from environment variables without setting the global.

This function will:

1. Load a .env file if present,
2. Parse environment variables into a Config.

Panics

Panics if any required variable (e.g. DATABASE_URL) is missing or invalid.

Example

let cfg = Config::from_env(); // Panics if required variables are missing
println!("{:?}", cfg);

pub fn get_config() -> &'static Config

Returns a reference to the globally stored Config.

If the global config has not been set yet, this function will call Config::from_env to populate it for the first time.

Example

// Ensure it's initialized once, typically at startup:
// Config::init().ok();

// Retrieve the config anywhere else in the code:
let cfg = Config::get_config();
println!("Current DB URL: {}", cfg.database_url);

Trait Implementations

impl Debug for Config

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Config

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.