mini-redis

Redis‑style data store focused on network programming, data structures, and low‑level systems code. It implements a TCP server and client and an in‑memory key/value engine (strings and sorted sets). It also includes a binary protocol, timers for key expiration, and a thread pool for background deletes.

Build and run

# Clone
git clone https://github.com/cmunoz-g/mini-redis.git
cd mini-redis

# Build
make

# Run server
./mini-redis <port>

# Run client
./mini-redis-client <port>

Usage

Supported commands:

• set <key> <value>
• get <key>
• del <key>
• keys
• zadd <key> <score> <member>
• zrem <key> <member>
• zscore <key> <member>
• zquery <key> <score> <name> <offset> <limit>
• expire <key> <ttl_ms>
• quit / exit

Implementation details

• Server loop: builds pollfd set, computes timer deadline, accepts new connections, processes readable/writable sockets, applies expirations.
• Connections: each Conn tracks readiness flags, in/out buffers, and idle/read/write timestamps. Buffers support append/consume.
• Request path: handle_read assembles frames; handle_request parses length‑prefixed payloads, validates command/arity, dispatches do_request. Replies are serialized (response_begin/end).
• Protocol: outer frame: 32‑bit big‑endian length. Payload: tag + type‑specific body (nil/str/int/dbl/arr/err/close).
• Database: intrusive key storage via Entry nodes; strings stored inline, ZSET backed by an AVL tree.
• TTL: Expirations are processed in the event loop.
• Thread pool: workers block on a condition variable, pop tasks and execute. Used to background delete entries to speed up performance.

Notes

• Protocol format is custom and not Redis RESP.
• Command interface is intentionally minimal, building a full Redis command set is not the scope of this project.