🚀 RediGo

A feature-rich Redis server implementation in Go, built as part of the CodeCrafters Redis challenge. This project implements the Redis Serialization Protocol (RESP) and supports a wide range of Redis commands and features.

🎯 Quick Start

# Pull and run from Docker Hub
docker pull seanxunx/redigo:latest
docker run -p 6379:6379 seanxunx/redigo:latest

# Connect with redis-cli
redis-cli -h localhost -p 6379

✨ Features

🔑 Data Structures

• Strings - Basic key-value operations with expiration support
• Lists - LPUSH, RPUSH, LPOP, LRANGE, LLEN, and blocking operations (BLPOP)
• Sorted Sets - ZADD, ZRANK, ZRANGE, ZCARD, ZSCORE, ZREM
• Streams - XADD, XRANGE, XREAD for event streaming
• Geospatial - GEOADD, GEOPOS, GEODIST, GEOSEARCH for location-based queries

🔄 Advanced Features

• Master-Slave Replication - Full replication support with PSYNC
• RDB Persistence - Load and save data from/to RDB files
• Transactions - MULTI, EXEC, DISCARD for atomic operations
• Pub/Sub - SUBSCRIBE, PUBLISH, UNSUBSCRIBE for messaging
• Blocking Operations - BLPOP with timeout support
• RESP Protocol - Full Redis Serialization Protocol implementation

📡 Supported Commands

Basic Commands

• PING - Test server connectivity
• ECHO - Echo the given string
• COMMAND - Get command info
• INFO - Server information
• CONFIG - Configuration management
• KEYS - Find keys matching pattern
• TYPE - Determine key type

String Commands

• SET - Set key to value with optional expiration (PX, EX)
• GET - Get value of key
• INCR - Increment key value

List Commands

• RPUSH - Push to right of list
• LPUSH - Push to left of list
• LPOP - Pop from left of list
• BLPOP - Blocking pop from left of list
• LRANGE - Get range of elements
• LLEN - Get list length

Sorted Set Commands

• ZADD - Add member with score
• ZRANK - Get member rank
• ZRANGE - Get range by index
• ZCARD - Get set cardinality
• ZSCORE - Get member score
• ZREM - Remove members

Stream Commands

• XADD - Add entry to stream
• XRANGE - Query range of entries
• XREAD - Read from streams (with blocking support)

Geospatial Commands

• GEOADD - Add location coordinates
• GEOPOS - Get position of members
• GEODIST - Get distance between members
• GEOSEARCH - Search by radius or box

Pub/Sub Commands

• SUBSCRIBE - Subscribe to channels
• PUBLISH - Publish message to channel
• UNSUBSCRIBE - Unsubscribe from channels

Transaction Commands

• MULTI - Start transaction
• EXEC - Execute transaction
• DISCARD - Discard transaction

Replication Commands

• REPLCONF - Replication configuration
• PSYNC - Synchronize with master
• WAIT - Wait for replication acknowledgment

🏗️ Project Structure

.
├── app/
│   ├── main.go           # Entry point
│   ├── server/           # TCP server and connection handling
│   │   ├── server.go     # Server implementation
│   │   ├── conn_handler.go # Command execution
│   │   └── parser.go     # RDB file parser
│   ├── resp/             # RESP protocol encoder/decoder
│   │   ├── encoder.go
│   │   ├── decoder.go
│   │   └── utils.go
│   ├── kv/               # Key-value store implementations
│   │   ├── kv.go         # Main store
│   │   ├── string.go     # String operations
│   │   ├── list.go       # List operations
│   │   ├── zset.go       # Sorted set operations
│   │   ├── stream.go     # Stream operations
│   │   ├── geo.go        # Geospatial operations
│   │   └── transaction.go # Transaction support
│   └── geospatial/       # Geospatial utilities
│       ├── geohash.go    # Geohash encoding
│       └── distance.go   # Distance calculations
├── Dockerfile
├── docker-compose.yml
├── go.mod
└── go.sum

🚀 Getting Started

Prerequisites

• Go 1.25.0 or higher
• Docker (optional)

Running Locally

# Run as master on default port 6379
go run ./app/main.go

# Run on custom port
go run ./app/main.go -port 6380

# Run as replica
go run ./app/main.go -port 6380 -replicaof "localhost 6379"

# Run with RDB persistence
go run ./app/main.go -dir /tmp/redis -dbfilename dump.rdb

🐳 Running with Docker

Using Pre-built Image from Docker Hub

# Pull the latest image
docker pull seanxunx/redigo:latest

# Run as master
docker run -p 6379:6379 seanxunx/redigo:latest

# Run with custom port
docker run -p 6380:6379 seanxunx/redigo:latest

# Run with volume for RDB persistence
docker run -p 6379:6379 -v $(pwd)/data:/data \
  seanxunx/redigo:latest -dir /data -dbfilename dump.rdb

# Using Docker Compose
docker-compose up -d

Building from Source

# Build locally
docker build -t redigo .
docker run -p 6379:6379 redigo

🔌 Connecting to the Server

# Using redis-cli
redis-cli -h localhost -p 6379

# Or using telnet
telnet localhost 6379

🎯 Usage Examples

# String operations
SET mykey "Hello World" PX 10000
GET mykey
INCR counter

# List operations
RPUSH mylist "item1" "item2" "item3"
LRANGE mylist 0 -1
LPOP mylist

# Sorted set operations
ZADD leaderboard 100 "player1" 200 "player2"
ZRANGE leaderboard 0 -1 WITHSCORES
ZRANK leaderboard "player1"

# Stream operations
XADD mystream * field1 value1 field2 value2
XRANGE mystream - +
XREAD STREAMS mystream 0-0

# Geospatial operations
GEOADD locations 13.361389 38.115556 "Palermo"
GEOADD locations 15.087269 37.502669 "Catania"
GEODIST locations "Palermo" "Catania" km
GEOSEARCH locations FROMLONLAT 15 37 BYRADIUS 200 km

# Pub/Sub
SUBSCRIBE news
PUBLISH news "Breaking news!"

# Transactions
MULTI
SET key1 value1
SET key2 value2
EXEC

🔧 Configuration Options

Flag	Description	Default
-port	Server port	6379
-replicaof	Master server address (host port)	"" (master mode)
-dir	Directory for RDB file	""
-dbfilename	RDB filename	""

🏛️ Architecture Highlights

• Concurrent-Safe - All operations use Go's sync primitives for thread safety
• RESP Protocol - Full implementation of Redis Serialization Protocol
• Non-Blocking I/O - Each connection handled in its own goroutine
• Master-Slave Replication - Command propagation with offset tracking
• Blocking Operations - Efficient blocking with Go channels and condition variables
• RDB Persistence - Binary format parsing with expiration support

📦 Docker Image

The project builds a minimal Docker image using multi-stage builds:

• Builder stage: Compiles the Go application
• Runtime stage: Uses scratch for minimal image size (~10MB)
• Publicly Available: seanxunx/redigo on Docker Hub

Pull the image:

docker pull seanxunx/redigo:latest

🛠️ Development

# Install dependencies
go mod download

# Build
go build -o redigo ./app/

# Run tests (if available)
go test ./...

🤝 Contributing

This is a learning project built for CodeCrafters. Feel free to fork and experiment!

📝 License

This project is open source and available for educational purposes.

🎓 Acknowledgments

Built as part of the CodeCrafters Redis Challenge - a hands-on way to learn how Redis works by building your own Redis server.

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Made with ❤️ and Go