Redic

Redis server/client implementation in C from scratch with no dependencies

Running locally

• Make sure you have make and any C compiler installed on your system.
• Run git clone git@github.com:WinterCore/redic.git && cd redic
• To build the project, simply run make
• And finally, to run the server ./Redic (it will run on port 6969 by default, use --port 7000 to change it)

Interacting with the server

• You can use any Redis cli or you can just use redis-cli which comes bundled with Redis
• Don't forget to specify the port of Redic when running commands, eg: redis-cli -p 6969 SET foo bar

Running the tests

• The suite needs Deno. It builds and launches its own server, so don't start one first.
• Run deno task test

TODO

• TCP server with configurable port
• Concurrent client connections (one thread per client)
• RESP protocol parser (simple string, bulk string, array, integer, error, null)
• RESP serializer
• Actor pattern for data layer — single-threaded data store (septic tank) with lock-free reads/writes via message-passing (sewer channels + ring buffer)
• TTL stored per key with lazy expiry on access
• Inline command support (plain-text commands via telnet/netcat)
• Pipelining (handle multiple commands in a single read)
• Active expiry — background task that periodically sweeps expired keys
• Commands
  • PING [message]
  • SET key value [NX|XX] [GET] [EX|PX|EXAT|PXAT|KEEPTTL]
  • GET key
  • DEL key [key ...] (single key for now cuz command parser doesn't support variadic args)
  • TTL key
  • INFO
  • EXISTS key [key ...] (single key for now)
  • EXPIRE key seconds
  • INCR / DECR / INCRBY / DECRBY
  • APPEND key value
  • MGET key [key ...] / MSET key value [key value ...]
  • KEYS pattern
  • TYPE key
  • RENAME key newkey
  • Lists (LPUSH, RPUSH, LPOP, RPOP, LRANGE)
  • Hashes (HSET, HGET, HGETALL, HDEL)
  • Sets (SADD, SREM, SMEMBERS, SISMEMBER)
• AOF persistence — mutation routing, batched flushing, and fsync'd appends to data.aof are done; still need startup replay, torn-tail recovery, flush-on-shutdown, and compaction
• Replication — replica handshake (PING → REPLCONF → PSYNC), full resync on connect, partial resync via replication backlog after reconnect
• Transactions — MULTI / EXEC / DISCARD with WATCH for optimistic locking
• Pub/Sub — SUBSCRIBE / PUBLISH / UNSUBSCRIBE with fan-out to blocking subscribers