Capis
A Redis-compatible in-memory key-value store, written from scratch in Java with java.nio and RESP. I built it to understand how Redis works by implementing it, not reading about it.
- Works with redis-cli: 35+ commands and 5 data types
- Transactions (MULTI/EXEC), pipelining and TTL expiry
- Hand-written LRU and LFU eviction
- Single-threaded, non-blocking server; about 65K requests per second for GET and SET on a 2nd-gen Intel Core i3


