# Changelog
All notable changes to `cache-mod` will be documented in this file.
The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
---
## [Unreleased]
### Added
### Changed
### Fixed
### Security
---
## [0.4.0] - 2026-05-20
### Added
- Public `TtlCache<K, V>` — bounded, thread-safe cache with per-entry time-to-live and lazy expiry. Each entry stamped with a deadline at insert time; expired entries are removed lazily on `get` / `contains_key` / `len`. On overflow the entry with the **soonest expiration** is evicted, which naturally prefers already-expired entries over live ones.
- `TtlCache::insert_with_ttl(&self, key, value, ttl)` — per-call TTL override that ignores the cache default for that one entry.
- Constructors `TtlCache::new(usize, Duration) -> Result<Self, CacheError>` and `TtlCache::with_capacity(NonZeroUsize, Duration) -> Self` mirroring `LruCache` / `LfuCache`.
- 13 integration tests covering: zero-capacity rejection, in-window get, lazy expiry through `get` / `contains_key` / `len`, per-call TTL override, soonest-expiry-first eviction, preference for already-expired entries over live ones, stale-as-absent on overwrite, live-update returning the old value, removal, clear, and `Send + Sync`. 4 new doctests on the type + both constructors + `insert_with_ttl`.
### Changed
- Crate-level docs in `src/lib.rs` updated to list `LruCache`, `LfuCache`, and `TtlCache` as the shipped reference implementations; trajectory clarified to point TinyLFU and `SizedCache` at 0.5.0.
- `Cargo.toml`: version `0.3.0` → `0.4.0`.
### Fixed
### Security
---
## [0.3.0] - 2026-05-20
### Added
- Public `LfuCache<K, V>` — bounded, thread-safe Least-Frequently-Used cache. Each entry carries a counter that increments on every `get` / `insert` of an already-present key. On overflow, the entry with the lowest counter is evicted; ties are broken in favour of the least-recently-accessed entry. Same `&self`-everywhere shape as `LruCache`: `Send + Sync`, poison-tolerant `Mutex`, no new dependencies.
- Constructors `LfuCache::new(usize) -> Result<Self, CacheError>` and `LfuCache::with_capacity(NonZeroUsize) -> Self` mirroring `LruCache`.
- Eight integration tests covering counter increments, LRU tie-break, `contains_key` non-promotion, replacement, removal, clear, capacity preservation, and `Send + Sync`.
### Changed
- Crate-level docs in `src/lib.rs` updated to list `LruCache` and `LfuCache` as the shipped reference implementations.
- `Cargo.toml`: version `0.2.0` → `0.3.0`.
### Fixed
### Security
---
## [0.2.0] - 2026-05-20
### Added
- Public `Cache<K, V>` trait — the common contract every cache type in this crate implements. Operations: `get`, `insert`, `remove`, `contains_key`, `len`, `is_empty`, `clear`, `capacity`. All methods take `&self` so instances are usable across threads and `.await` points without external locking.
- Public `LruCache<K, V>` — reference Least-Recently-Used implementation backed by a `Mutex<{ HashMap, VecDeque }>`. Bounded capacity; inserts past capacity evict the least-recently-accessed entry. `get` and `insert` promote to MRU; `contains_key` deliberately does not (query-only).
- Public `CacheError` enum (`#[non_exhaustive]`) with `InvalidCapacity` variant. `std::error::Error` impl gated on the `std` feature.
- Constructors `LruCache::new(usize) -> Result<Self, CacheError>` and `LruCache::with_capacity(NonZeroUsize) -> Self` (infallible).
- Integration tests covering insert/get, replacement, LRU eviction order, `contains_key` non-promotion, removal, clear, capacity reporting, `Send + Sync`, and error display.
### Changed
- `Cargo.toml`: version `0.1.0` → `0.2.0`; `edition` lowered from `2024` to `2021` so the declared MSRV of Rust 1.75 is actually buildable (edition 2024 requires Rust 1.85+). Scaffold-stage oversight surfaced by the 0.1.0 CI run.
- CI: removed the unused `actions/setup-node@v5` step (cache-mod is a pure Rust crate; Node was only present for the JS-action runtime).
- CI: switched dependency caching from `actions/cache@v4` to `Swatinem/rust-cache@v2`, aligning with the rest of the crate family and yielding Rust-aware cache keys.
- `rustfmt.toml`: `edition` synced to `2021` to match `Cargo.toml`.
- Added `.gitattributes` enforcing `eol=lf` across the tree so Windows CI runners (which default to `core.autocrlf=true`) don't trip rustfmt's `newline_style = "Unix"` setting.
- Stripped UTF-8 BOMs from every scaffold-generated text file (`Cargo.toml`, `README.md`, `CHANGELOG.md`, `REPS.md`, `clippy.toml`, `rustfmt.toml`, `.gitignore`, `.editorconfig`). Cargo tolerates a leading BOM, but the `Swatinem/rust-cache@v2` TOML parser does not — it was logging `Error parsing Cargo.toml manifest, fallback to caching entire file` on every run and losing per-package cache scoping.
### Fixed
- CI: resolved the baseline failures from the 0.1.0 scaffold run (manifest parse error on the MSRV row, "Incorrect newline style" on Windows, Node 20 deprecation warning on the cache action). Fix was deferred from 0.1.0 per release policy.
### Security
- CI: added `FORCE_JAVASCRIPT_ACTIONS_TO_NODE24=true` at the workflow level to opt every JavaScript action into the Node.js 24 runtime ahead of the June 2, 2026 forced migration.
---
## [0.1.0] - 2026-05-18
### Added
- Initial scaffold and repository bootstrap.
- REPS compliance baseline.
- CI for Linux/macOS/Windows on stable and MSRV (1.75).
[Unreleased]: https://github.com/jamesgober/cache-mod/compare/v0.4.0...HEAD
[0.4.0]: https://github.com/jamesgober/cache-mod/releases/tag/v0.4.0
[0.3.0]: https://github.com/jamesgober/cache-mod/releases/tag/v0.3.0
[0.2.0]: https://github.com/jamesgober/cache-mod/releases/tag/v0.2.0
[0.1.0]: https://github.com/jamesgober/cache-mod/releases/tag/v0.1.0