redjis

A Redis server implementation in Node.js, built from scratch. Speaks the RESP protocol, supports replication, persistence, pub/sub, streams, sorted sets, geo commands, and transactions.

Run

node app/main.js [--port 6379] [--dir /path] [--dbfilename dump.rdb] [--replicaof <host> <port>]

Connect with any standard Redis client or redis-cli.

Implemented

Core

• RESP protocol encoding and decoding
• PING, ECHO, INFO
• SET / GET with optional TTL (PX, EX) and key expiry
• KEYS with pattern matching
• TYPE, INCR, CONFIG GET

Lists

• RPUSH, LPUSH, LRANGE, LPOP, LLEN
• BLPOP — blocking pop with timeout, unblocks on new push

Streams

• XADD with auto-generated stream IDs (*, partial IDs)
• XRANGE, XREAD — both blocking and non-blocking reads

Sorted Sets — backed by a skip list

• ZADD, ZREM, ZRANK, ZRANGE, ZCARD, ZSCORE

Geo

• GEOADD, GEOPOS, GEODIST, GEOSEARCH

Pub/Sub

• SUBSCRIBE, UNSUBSCRIBE, PUBLISH
• Subscriber mode enforcement — commands outside the allowed set are rejected

Transactions

• MULTI, EXEC, DISCARD
• Commands queued and executed atomically; errors inside a transaction do not abort the whole batch

Replication

• Master/replica roles via --replicaof
• Handshake via REPLCONF and PSYNC
• Command propagation from master to all connected replicas
• WAIT — blocks until N replicas have acknowledged a given offset
• Replica offset tracking and REPLCONF GETACK handling

Persistence

• RDB file parsing on startup — loads keys and TTLs from an existing dump

Structure

app/
  main.js              entry point, command dispatch
  config.js            server config (port, role, dir, replication state)
  state/store.js       in-memory stores for strings, lists, streams, sorted sets
  handlers/            per-feature command handlers
  transcoder/          RESP encoder and decoder
  data_structures/     skip list, queue
  utils/               RDB parser, expiry logic, connection helpers