Queue
Queue is a Golang library for spawning and managing a Goroutine pool, Alloowing you to create multiple worker according to limit CPU number of machine.
Features
- Support buffered channel queue.
- Support NSQ (A realtime distributed messaging platform) as backend.
- Support NATS (Connective Technology for Adaptive Edge & Distributed Systems) as backend.
Installation
Install the stable version:
go get github.com/golang-queue/queue
Install the latest verison:
go get github.com/golang-queue/queue@master
Usage
The first step to create a new job as QueueMessage
interface:
type job struct {
Message string
}
func (j *job) Bytes() []byte {
b, err := json.Marshal(j)
if err != nil {
panic(err)
}
return b
}
The second step to create the new worker, use the buffered channel as an example.
// define the worker
w := simple.NewWorker(
simple.WithQueueNum(taskN),
simple.WithRunFunc(func(ctx context.Context, m queue.QueuedMessage) error {
v, ok := m.(*job)
if !ok {
if err := json.Unmarshal(m.Bytes(), &v); err != nil {
return err
}
}
rets <- v.Message
return nil
}),
)
or use the NSQ as backend, see the worker example:
// define the worker
w := nsq.NewWorker(
nsq.WithAddr("127.0.0.1:4150"),
nsq.WithTopic("example"),
nsq.WithChannel("foobar"),
// concurrent job number
nsq.WithMaxInFlight(10),
nsq.WithRunFunc(func(ctx context.Context, m queue.QueuedMessage) error {
v, ok := m.(*job)
if !ok {
if err := json.Unmarshal(m.Bytes(), &v); err != nil {
return err
}
}
rets <- v.Message
return nil
}),
)
or use the NATS as backend, see the worker example:
w := nats.NewWorker(
nats.WithAddr("127.0.0.1:4222"),
nats.WithSubj("example"),
nats.WithQueue("foobar"),
nats.WithRunFunc(func(ctx context.Context, m queue.QueuedMessage) error {
v, ok := m.(*job)
if !ok {
if err := json.Unmarshal(m.Bytes(), &v); err != nil {
return err
}
}
rets <- v.Message
return nil
}),
)
The third step to create a queue and initialize multiple workers, receive all job messages:
// define the queue
q, err := queue.NewQueue(
queue.WithWorkerCount(5),
queue.WithWorker(w),
)
if err != nil {
log.Fatal(err)
}
// start the five worker
q.Start()
// assign tasks in queue
for i := 0; i < taskN; i++ {
go func(i int) {
q.Queue(&job{
Name: "foobar",
Message: fmt.Sprintf("handle the job: %d", i+1),
})
}(i)
}
// wait until all tasks done
for i := 0; i < taskN; i++ {
fmt.Println("message:", <-rets)
time.Sleep(50 * time.Millisecond)
}
// shutdown the service and notify all the worker
q.Shutdown()
// wait all jobs are complete.
q.Wait()
Full example code as below or try it in playground.
package main
import (
"context"
"encoding/json"
"fmt"
"log"
"time"
"github.com/golang-queue/queue"
"github.com/golang-queue/queue/simple"
)
type job struct {
Name string
Message string
}
func (j *job) Bytes() []byte {
b, err := json.Marshal(j)
if err != nil {
panic(err)
}
return b
}
func main() {
taskN := 100
rets := make(chan string, taskN)
// define the worker
w := simple.NewWorker(
simple.WithQueueNum(taskN),
simple.WithRunFunc(func(ctx context.Context, m queue.QueuedMessage) error {
v, ok := m.(*job)
if !ok {
if err := json.Unmarshal(m.Bytes(), &v); err != nil {
return err
}
}
rets <- "Hi, " + v.Name + ", " + v.Message
return nil
}),
)
// define the queue
q, err := queue.NewQueue(
queue.WithWorkerCount(5),
queue.WithWorker(w),
)
if err != nil {
log.Fatal(err)
}
// start the five worker
q.Start()
// assign tasks in queue
for i := 0; i < taskN; i++ {
go func(i int) {
q.Queue(&job{
Name: "foobar",
Message: fmt.Sprintf("handle the job: %d", i+1),
})
}(i)
}
// wait until all tasks done
for i := 0; i < taskN; i++ {
fmt.Println("message:", <-rets)
time.Sleep(50 * time.Millisecond)
}
// shutdown the service and notify all the worker
q.Shutdown()
// wait all jobs are complete.
q.Wait()
}