Zedis

A Redis-compatible in-memory data store written in Zig, designed for learning and experimentation. Zedis implements the core Redis protocol and data structures with a focus on simplicity, performance, and thread safety.

Made for learning purposes. Not intended for production use.

Features

• Redis Protocol Compatibility: Supports the Redis Serialization Protocol (RESP)locks
• Multiple Data Types: String and integer value storage with automatic type conversion
• Core Commands: Essential Redis commands including GET, SET, INCR, DECR, DEL, EXISTS, and TYPE
• High Performance: Written in Zig for optimal performance and memory safety
• Connection Management: Handles multiple concurrent client connections
• Disk persistence (RDB): Point-in-time snapshots of your dataset.
• Memory Management: No memory allocation during command execution.
• Pub/Sub: Decoupled communication between services. (latest feature) 🎉

Roadmap

Add RDB snapshots
Implement pub/sub functionality
Implement key expiration
Background job for key expiration
Add tests to key expiration
Implement AOF (Append Only File) logging
Implement more Redis commands
Add support for lists and sets
Add configuration file support
Add clustering support
Performance benchmarking suite

Quick Start

Prerequisites

• Zig (minimum version 0.15.1)

Building and Running

# Clone the repository
git clone https://github.com/barddoo/zedis.git
cd zedis

# Build the project
zig build

# Run the server
zig build run

The server will start on 127.0.0.1:6379 by default.

Testing with Redis CLI

You can test Zedis using the standard redis-cli or any Redis client:

# Connect to Zedis
redis-cli -h 127.0.0.1 -p 6379

# Try some commands
127.0.0.1:6379> SET mykey "Hello, Zedis!"
OK
127.0.0.1:6379> GET mykey
"Hello, Zedis!"
127.0.0.1:6379> INCR counter
(integer) 1
127.0.0.1:6379> TYPE mykey
string

Development

Project Structure

The codebase follows Zig conventions with clear separation of concerns:

• Type-safe operations with compile-time guarantees
• Explicit error handling throughout
• Memory safety without garbage collection
• Modular design for easy extension
• Comprehensive logging for debugging

Memory Management

All memory allocations are handled during the initialization phase. No dynamic memory allocation occurs during command execution, ensuring high performance and predictability. Hugely inspired by this article.

Building for Development

# Build in debug mode (default)
zig build -Doptimize=Debug

# Build optimized release
zig build -Doptimize=ReleaseFast

# Run tests (when available)
zig build test

Adding New Commands

1. Implement the command handler in the appropriate file under src/commands/
2. Register the command in the command registry
3. Add tests for the new functionality

Example:

pub fn myCommand(client: *Client, args: []const Value) !void {
    // Command implementation
    try client.writeSimpleString("OK");
}

Code Style

• Follow Zig's standard formatting (zig fmt)
• Add comprehensive error handling
• Include documentation comments for public APIs
• Write tests for new functionality

Contact

• GitHub: @barddoo
• Project Link: https://github.com/barddoo/zedis

Thanks

• Inspired by Redis and Zig