kevy-embedded

In-process Redis-compatible key–value store — kevy without the network.

use kevy_embedded::{Store, Config};

let s = Store::open(Config::default())?;
s.set(b"greeting", b"hello")?;
assert_eq!(s.get(b"greeting")?, Some(b"hello".to_vec()));

When to use

• Embedded cache — replace lru::LruCache / moka with a fully Redis-semantic LRU (or LFU) that speaks all 5 data types.
• Embedded persistent store — opt into AOF + snapshot via Config::with_persist("./data"). Restart-safe out of the box.
• WASM / single-threaded apps — use Config::with_ttl_reaper_manual() and call Store::tick() from your own event loop. Full WASM walkthrough (browser / WASI / Cloudflare Workers): ../../docs/wasm.md.

When NOT to use

• You want a TCP-reachable Redis server → use the kevy crate's serve(...) entry point instead. kevy runs the full thread-per-core reactor + cross-shard routing.
• You need cross-process concurrency → kevy-embedded is single-process (one mutex). For multi-process, the network layer is the contract.

Persistence

with_persist(dir) enables both snapshot (dump-0.rdb) and AOF (aof-0.aof). On open the snapshot loads first, then the AOF replays — so a fresh process picks up exactly where the previous one left off. AOF auto-appends on every write; fsync policy follows Config::with_appendfsync(...):

Store::rewrite_aof() runs the equivalent of BGREWRITEAOF — rebuilds a compact AOF from current in-memory state and atomically swaps it in. v1.0 is synchronous (blocks the calling thread); v1.x will incrementalise.

Eviction

Set a hard memory ceiling via Config::with_max_memory(bytes) plus an EvictionPolicy (all 8 Redis policies — NoEviction / AllKeysLru / AllKeysLfu / AllKeysRandom / VolatileLru / VolatileLfu / VolatileRandom / VolatileTtl). LRU/LFU approximation matches Redis (24-bit clock + sample-based selection with maxmemory-samples = 5).

Examples

• examples/embedded.rs — minimal CRUD.
• examples/embedded-cache.rs — hard-cap LRU cache.

Dependencies

Zero crates.io dependencies. Only kevy-store (keyspace) + kevy-persist (snapshot / AOF). The whole network layer (kevy-rt, kevy-sys, kevy-uring) is intentionally NOT pulled in, so kevy-embedded compiles for any target kevy-store + kevy-persist compile for — including wasm32-unknown-unknown and wasm32-wasip1.