Crate easy_prefs

easy_prefs

A simple, safe, and performant preferences library for Rust applications.

Created by Ever Accountable – an app that helps people overcome compulsive porn use and become their best selves. Visit everaccountable.com for more details.

This library provides an intuitive API for managing preferences using a struct-like interface. Its key design goals are:

• Ease of Use: Read/write preferences as easily as struct fields.
• Safety: Uses temporary files for writes to prevent data corruption.
• Performance: Optimized for fast operations.
• Testability: Integrates seamlessly with unit tests.

Limitation: Not suited for large datasets. All data is held in memory, and the entire file is rewritten on save. For substantial data, use a database instead.

Single-Instance Constraint

The load() method enforces that only one instance of a preferences struct exists at a time, using a static atomic flag. This prevents data races in production but can cause issues in parallel test execution. Tests using load() are combined into a single test to avoid conflicts.

Error Handling

The load() function returns a Result with LoadError variants instead of panicking. Errors include existing instances, directory issues, or file operation failures. See load() for details.

Re-exports

pub use paste;

pub use toml;

pub use once_cell;

Macros

easy_prefs

Macro to define a preferences struct with file persistence.

Structs

TestEasyPreferencesUpdated

Updated test preferences for schema evolution.

Enums

LoadError

Errors that can occur when loading preferences.