Crate cache_mod 

cache-mod

HIGH-PERFORMANCE IN-PROCESS CACHING

Multiple eviction policies (LRU, LFU, TinyLFU, TTL, size-bounded). Async-safe, lock-minimized internals. Typed key-value API. No external store dependency.

Status

Stable. As of 1.0.0 the public API surface is frozen under strict SemVer — see docs/STABILITY.md for the full enumeration. Five reference cache implementations sit behind a common Cache trait: LruCache (Least-Recently-Used), LfuCache (Least-Frequently-Used), TtlCache (Time-To-Live, lazy expiry), TinyLfuCache (Count-Min Sketch admission filter + LRU main), and SizedCache (byte-bound capacity). Internals are arena-backed and sharded for concurrent throughput; the public surface does not depend on either choice and will not change as those internals evolve in the 1.x line.

Guarantees

• No unsafe. This crate contains zero unsafe blocks. Every cache operation goes through safe abstractions only.
• No panic!, no unwrap, no expect. The library code never calls any of these macros / methods on shipping paths. Where a non-panicking unreachable!() appears, it documents an invariant the caller is responsible for upholding inside pub(crate) arena helpers; every public method is panic-free given valid arguments. clippy::unwrap_used and clippy::expect_used are denied at the crate level.
• No background threads. Every cache type uses lazy bookkeeping — eviction, expiry, and sketch aging run on the call-site thread that triggered them. No std::thread::spawn happens inside the crate.
• No required runtime. The crate has no async runtime dependency. &self everywhere lets you share cache instances across .await points if you do use one.
• Send + Sync. Every cache type is Send + Sync when K: Send + Sync and V: Send + Sync.

Quick start

use cache_mod::{Cache, LruCache};

let cache: LruCache<&'static str, u32> = LruCache::new(64).expect("capacity > 0");

cache.insert("requests", 1);
cache.insert("errors", 0);

assert_eq!(cache.get(&"requests"), Some(1));
assert_eq!(cache.len(), 2);

License

Dual-licensed under Apache-2.0 OR MIT.

Structs

LfuCachestd

A bounded, thread-safe LFU cache.

LruCachestd

A bounded, thread-safe LRU cache.

SizedCachestd

A cache bounded by total byte-weight rather than entry count.

TinyLfuCachestd

A bounded, thread-safe cache with admission control.

TtlCachestd

A bounded, thread-safe cache with per-entry time-to-live.

Enums

CacheError

Errors produced by cache-mod.

Constants

VERSION

Crate version string, populated by Cargo at build time.

Traits

Cache

The common read / write / evict contract every cache type in this crate implements.