Atomhold

Thread-safe configuration store with atomic replacement, versioning, and flexible unload policies.

atomhold provides a robust, concurrent key-value store designed for managing configuration states in multi-threaded applications. It leverages RCU (Read-Copy-Update) semantics for wait-free reads and ensures atomic consistency for updates.

Features

• Wait-free Reads: Uses arc-swap to allow concurrent lock-free access to configuration entries.
• Atomic Updates: Ensures consistent snapshots during updates; readers never see partial states.
• Flexible Unload Policies:
  • Removable: Entries can be updated or removed freely.
  • Persistent: Entries are protected against accidental removal, ensuring critical configs remain available.
• Versioning: Automatically tracks version numbers and timestamps for every entry.
• Change Events: Optional integration with tokio to broadcast Loaded, Updated, Removed, or Retained events.
• Thread Safety: Fully thread-safe, requiring T: Clone + Send + Sync.

Usage Examples

Check the examples directory for runnable code:

• Basic Usage: examples/basic.rs - Demonstrates inserting, retrieving, and removing configurations with different unload policies.
• Event Broadcasting: examples/events.rs - Asynchronous event subscription example using tokio to react to configuration changes in real-time.

Installation

[dependencies]
atomhold = { version = "0.2", features = ["full"] }

Feature Flags

Feature	Description
events	Enable event broadcasting via tokio::sync::broadcast
full	All of the above

License

Released under the MIT License © 2026 Canmi