Redis Client for V

This module provides a Redis client implementation in V that supports the Redis Serialization Protocol (RESP) with a type-safe interface for common Redis commands.

Features

• Type-Safe Commands: Auto-detects value types at compile time
• Pipeline Support: Group commands for batch execution
• Connection Pooling: Efficient resource management
• RESP Protocol Support: Full Redis Serialization Protocol implementation
• Memory Efficient: Pre-allocated buffers for minimal allocations

Quick Start

module main

import db.redis

fn main() {
    // Connect to Redis
    mut db := redis.connect(redis.Config{
        host: 'localhost'
        port: 6379
    })!

    // Set and get values
    db.set('name', 'Alice')!
    name := db.get[string]('name')!
    println('Name: ${name}') // Output: Name: Alice

    // Integer operations
    db.set('counter', 42)!
    db.incr('counter')!
    counter := db.get[int]('counter')!
    println('Counter: ${counter}') // Output: Counter: 43

    // Clean up
    db.close()!
}

Supported Commands

Key Operations

// Set value
db.set('key', 'value')!
db.set('number', 42)!
db.set('binary', []u8{len: 4, init: 0})!

// Get value
str_value := db.get[string]('key')!
int_value := db.get[int]('number')!
bin_value := db.get[[]u8]('binary')!

// Delete key
db.del('key')!

// Set expiration
db.expire('key', 60)!  // 60 seconds

Hash Operations

// Set hash fields
db.hset('user:1', {
    'name': 'Bob',
    'age': 30,
})!

// Get single field
name := db.hget[string]('user:1', 'name')!

// Get all fields
user_data := db.hgetall[string]('user:1')!
println(user_data)  // Output: {'name': 'Bob', 'age': '30'}

Pipeline Operations

// Start pipeline
db.pipeline_start()

// Queue commands
db.incr('counter')
db.set('name', 'Charlie')
db.get[string]('name')

// Execute and get responses
responses := db.pipeline_execute()!
for resp in responses {
    println(resp)
}

Custom Commands

// Run raw commands
resp := db.cmd('SET', 'custom', 'value')!
result := db.cmd('GET', 'custom')!

// Complex commands
db.cmd('HSET', 'user:2', 'field1', 'value1', 'field2', '42')!

Error Handling

All functions return ! types and will return detailed errors for:

• Connection issues
• Protocol violations
• Type mismatches
• Redis error responses
• Timeout conditions

result := db.get[string]('nonexistent') or {
    println('Key not found')
    return
}

Connection Management

config := redis.Config{
    host: 'redis.server'
    port: 6379
    version: 2  // RESP2 protocol
}

mut db := redis.connect(config)!
defer {
    db.close() or { eprintln('Error closing connection: $err') }
}

Performance Tips

1. Reuse Connections: Maintain connections instead of creating new ones
2. Use Pipelines: Batch commands for high-throughput operations
3. Prefer Integers: Use numeric types for counters and metrics
4. Specify Types: Always specify return types for get operations

fn connect(config Config) !DB

connect establishes a connection to a Redis server

type RedisValue = string | i64 | bool | f32 | f64 | []u8 | RedisNull | []RedisValue

RedisValue represents all possible RESP (Redis Serialization Protocol) data types

struct Config {
pub mut:
	host    string = '127.0.0.1' // Redis server host
	port    u16    = 6379        // Redis server port
	version int    = 2           // RESP protocol version (default: v2)
}

Configuration options for Redis connection

struct DB {
pub mut:
	version int // RESP protocol version
mut:
	conn &net.TcpConn = unsafe { nil } // TCP connection to Redis

	// Pre-allocated buffers to reduce memory allocations
	cmd_buf            []u8 // Buffer for building commands
	resp_buf           []u8 // Buffer for reading responses
	pipeline_mode      bool
	pipeline_buffer    []u8
	pipeline_cmd_count int
}

DB represents a Redis database connection

fn (mut db DB) close() !

close terminates the connection to Redis server

fn (mut db DB) ping() !string

ping sends a PING command to verify server responsiveness

fn (mut db DB) del(key string) !i64

del deletes a key

fn (mut db DB) set[T](key string, value T) !string

set stores a key-value` pair in Redis. Supported value types: number, string, []u8

fn (mut db DB) get[T](key string) !T

get retrieves the value of a key. Supported return types: string, int, []u8

fn (mut db DB) incr(key string) !i64

incr increments the integer value of a key by 1

fn (mut db DB) decr(key string) !i64

decr decrements the integer value of a key by 1

fn (mut db DB) hset[T](key string, m map[string]T) !int

hset sets multiple key-value pairs in a hash. Supported value types: string, int, []u8

fn (mut db DB) hget[T](key string, m_key string) !T

hget retrieves the value of a hash field. Supported return types: string, int, []u8

fn (mut db DB) hgetall[T](key string) !map[string]T

hgetall retrieves all fields and values of a hash. Supported value types: string, int, []u8

fn (mut db DB) expire(key string, seconds int) !bool

expire sets a key's time to live in seconds

fn (mut db DB) cmd(cmd ...string) !RedisValue

cmd sends a custom command to Redis server for example: db.cmd('SET', 'key', 'value')!

fn (mut db DB) pipeline_start()

pipeline_start start a new pipeline

fn (mut db DB) pipeline_execute() ![]RedisValue

pipeline_execute executes the cmds in pipeline at once and retrieves all responses

struct RedisNull {}

RedisNull represents the Redis NULL type