Limiter

A static rate limiter used to control the frequency of operations.

Installation

import "github.com/leoheung/go-patterns/parallel/limiter"

API Reference

Create a Limiter

// Create a limiter with a specific interval
// 100ms interval = 10 operations per second
lim := limiter.NewStaticLimiter(100 * time.Millisecond)

Wait for Token

// Blocking call: waits until the next token is available
lim.GrantNextToken()

Control

// Change the limiting interval at runtime
lim.Reset(200 * time.Millisecond)

// Stop the underlying ticker to release resources
lim.Stop()

Complete Example

package main

import (
    "fmt"
    "time"
    "github.com/leoheung/go-patterns/parallel/limiter"
)

func main() {
    // Create a limiter: 1 operation per 200ms (5 ops/sec)
    lim := limiter.NewStaticLimiter(200 * time.Millisecond)
    defer lim.Stop()

    for i := 0; i < 5; i++ {
        start := time.Now()

        // Wait for token
        lim.GrantNextToken()

        // Perform operation
        fmt.Printf("Operation %d at %v (elapsed: %v)\n",
            i+1, time.Now().Format("15:04:05.000"),
            time.Since(start))
    }
}

Features

• Precise Timing: Built on time.Ticker for accurate interval control.
• Thread-safe: Safe for concurrent access from multiple goroutines.
• Dynamic Configuration: Supports updating the rate on the fly using Reset.
• Resource Management: Includes a Stop method to clean up background tickers.