Message Queues

Message queues ช่วยให้ระบบ communicate แบบ asynchronous

In-Memory Channel Queue

package main

import (
    "fmt"
    "sync"
    "time"
)

type Job struct {
    ID      int
    Payload string
}

type Queue struct {
    jobs chan Job
    wg   sync.WaitGroup
}

func NewQueue(size int) *Queue {
    return &Queue{
        jobs: make(chan Job, size),
    }
}

func (q *Queue) Push(job Job) {
    q.jobs <- job
}

func (q *Queue) StartWorkers(num int, handler func(Job)) {
    for i := 0; i < num; i++ {
        q.wg.Add(1)
        go func(workerID int) {
            defer q.wg.Done()
            for job := range q.jobs {
                fmt.Printf("Worker %d processing job %d\n", workerID, job.ID)
                handler(job)
            }
        }(i)
    }
}

func (q *Queue) Close() {
    close(q.jobs)
    q.wg.Wait()
}

func main() {
    queue := NewQueue(100)

    // Start workers
    queue.StartWorkers(3, func(job Job) {
        time.Sleep(100 * time.Millisecond)
        fmt.Printf("Completed job %d: %s\n", job.ID, job.Payload)
    })

    // Push jobs
    for i := 1; i <= 10; i++ {
        queue.Push(Job{ID: i, Payload: fmt.Sprintf("Task %d", i)})
    }

    // Wait for completion
    queue.Close()
    fmt.Println("All jobs completed!")
}