queue

package module
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 Go to latest Published: Feb 27, 2025 License: MIT Imports: 14 Imported by: 0

README

Queue

CodeQL Run Tests codecov

Queue is a Golang library for spawning and managing a Goroutine pool, allowing you to create multiple workers based on the CPU capacity of the machine.

Features

  • Supports Circular buffer queues.
  • Supports NSQ (a real-time distributed messaging platform) as a backend.
  • Supports NATS (connective technology for adaptive edge and distributed systems) as a backend.
  • Supports Redis Pub/Sub as a backend.
  • Supports Redis Streams as a backend.
  • Supports RabbitMQ as a backend.

Queue Scenario

A simple queue service using a ring buffer as the default backend.

queue01

Easily switch the queue service to use NSQ, NATS, or Redis.

queue02

Supports multiple producers and consumers.

queue03

Requirements

Go version 1.22 or above

Installation

Install the stable version:

go get github.com/blazium-engine/go-queue

Install the latest version:

go get github.com/blazium-engine/go-queue@master

Usage

Basic Usage of Pool (using the Task function)

By calling the QueueTask() method, tasks are scheduled to be executed by workers (goroutines) in the pool.

package main

import (
  "context"
  "fmt"
  "time"

  "github.com/blazium-engine/go-queue"
)

func main() {
  taskN := 100
  rets := make(chan string, taskN)

  // initial queue pool
  q := queue.NewPool(5)
  // shutdown the service and notify all the worker
  // wait all jobs are complete.
  defer q.Release()

  // assign tasks in queue
  for i := 0; i < taskN; i++ {
    go func(i int) {
      if err := q.QueueTask(func(ctx context.Context) error {
        rets <- fmt.Sprintf("Hi Gopher, handle the job: %02d", +i)
        return nil
      }); err != nil {
        panic(err)
      }
    }(i)
  }

  // wait until all tasks done
  for i := 0; i < taskN; i++ {
    fmt.Println("message:", <-rets)
    time.Sleep(20 * time.Millisecond)
  }
}
Basic Usage of Pool (using a message queue)

Define a new message struct and implement the Bytes() function to encode the message. Use the WithFn function to handle the message from the queue.

package main

import (
  "context"
  "encoding/json"
  "fmt"
  "log"
  "time"

  "github.com/blazium-engine/go-queue"
  "github.com/blazium-engine/go-queue/core"
)

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)

  // initial queue pool
  q := queue.NewPool(5, queue.WithFn(func(ctx context.Context, m core.TaskMessage) error {
    var v job
    if err := json.Unmarshal(m.Payload(), &v); err != nil {
      return err
    }

    rets <- "Hi, " + v.Name + ", " + v.Message
    return nil
  }))
  // shutdown the service and notify all the worker
  // wait all jobs are complete.
  defer q.Release()

  // assign tasks in queue
  for i := 0; i < taskN; i++ {
    go func(i int) {
      if err := q.Queue(&job{
        Name:    "Gopher",
        Message: fmt.Sprintf("handle the job: %d", i+1),
      }); err != nil {
        log.Println(err)
      }
    }(i)
  }

  // wait until all tasks done
  for i := 0; i < taskN; i++ {
    fmt.Println("message:", <-rets)
    time.Sleep(50 * time.Millisecond)
  }
}

Using NSQ as a Queue

Refer to the NSQ documentation.

package main

import (
  "context"
  "encoding/json"
  "fmt"
  "log"
  "time"

  "github.com/golang-queue/nsq"
  "github.com/blazium-engine/go-queue"
  "github.com/blazium-engine/go-queue/core"
)

type job struct {
  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 := 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 core.TaskMessage) error {
      var v job
      if err := json.Unmarshal(m.Payload(), &v); err != nil {
        return err
      }

      rets <- v.Message
      return nil
    }),
  )

  // define the queue
  q := queue.NewPool(
    5,
    queue.WithWorker(w),
  )

  // assign tasks in queue
  for i := 0; i < taskN; i++ {
    go func(i int) {
      q.Queue(&job{
        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.Release()
}

Using NATS as a Queue

Refer to the NATS documentation.

package main

import (
  "context"
  "encoding/json"
  "fmt"
  "log"
  "time"

  "github.com/golang-queue/nats"
  "github.com/blazium-engine/go-queue"
  "github.com/blazium-engine/go-queue/core"
)

type job struct {
  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 := nats.NewWorker(
    nats.WithAddr("127.0.0.1:4222"),
    nats.WithSubj("example"),
    nats.WithQueue("foobar"),
    nats.WithRunFunc(func(ctx context.Context, m core.TaskMessage) error {
      var v job
      if err := json.Unmarshal(m.Payload(), &v); err != nil {
        return err
      }

      rets <- v.Message
      return nil
    }),
  )

  // define the queue
  q, err := queue.NewQueue(
    queue.WithWorkerCount(10),
    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{
        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.Release()
}

Using Redis (Pub/Sub) as a Queue

Refer to the Redis documentation.

package main

import (
  "context"
  "encoding/json"
  "fmt"
  "log"
  "time"

  "github.com/blazium-engine/go-queue"
  "github.com/blazium-engine/go-queue/core"
  "github.com/golang-queue/redisdb"
)

type job struct {
  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 := redisdb.NewWorker(
    redisdb.WithAddr("127.0.0.1:6379"),
    redisdb.WithChannel("foobar"),
    redisdb.WithRunFunc(func(ctx context.Context, m core.TaskMessage) error {
      var v job
      if err := json.Unmarshal(m.Payload(), &v); err != nil {
        return err
      }

      rets <- v.Message
      return nil
    }),
  )

  // define the queue
  q, err := queue.NewQueue(
    queue.WithWorkerCount(10),
    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{
        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.Release()
}

Documentation

Index

Examples

Constants

This section is empty.

Variables

View Source 
var (
	// ErrNoTaskInQueue there is nothing in the queue
	ErrNoTaskInQueue = errors.New("golang-queue: no task in queue")
	// ErrQueueHasBeenClosed the current queue is closed
	ErrQueueHasBeenClosed = errors.New("golang-queue: queue has been closed")
	// ErrMaxCapacity Maximum size limit reached
	ErrMaxCapacity = errors.New("golang-queue: maximum size limit reached")
)
View Source 
var ErrMissingWorker = errors.New("missing worker module")

ErrMissingWorker missing define worker

View Source 
var ErrQueueShutdown = errors.New("queue has been closed and released")

ErrQueueShutdown the queue is released and closed.

Functions

This section is empty.

Types

type Logger 

type Logger interface {
	Infof(format string, args ...interface{})
	Errorf(format string, args ...interface{})
	Fatalf(format string, args ...interface{})
	Info(args ...interface{})
	Error(args ...interface{})
	Fatal(args ...interface{})
}

Logger interface is used throughout gorush

func NewEmptyLogger 

func NewEmptyLogger() Logger

NewEmptyLogger for simple logger.

Example 
l := NewEmptyLogger()
l.Info("test")
l.Infof("test")
l.Error("test")
l.Errorf("test")
l.Fatal("test")
l.Fatalf("test")

func NewLogger 

func NewLogger() Logger

NewLogger for simple logger.

type Metric 

type Metric interface {
	IncBusyWorker()
	DecBusyWorker()
	BusyWorkers() int64
	SuccessTasks() uint64
	FailureTasks() uint64
	SubmittedTasks() uint64
	CompletedTasks() uint64
	IncSuccessTask()
	IncFailureTask()
	IncSubmittedTask()
}

Metric interface

func NewMetric 

func NewMetric() Metric

NewMetric for default metric structure

type Option 

type Option interface {
	// contains filtered or unexported methods
}

An Option configures a mutex.

func WithAfterFn 

func WithAfterFn(afterFn func()) Option

WithAfterFn set callback function after job done

func WithFn 

func WithFn(fn func(context.Context, core.TaskMessage) error) Option

WithFn set custom job function

func WithLogger 

func WithLogger(l Logger) Option

WithLogger set custom logger

func WithMetric 

func WithMetric(m Metric) Option

WithMetric set custom Metric

func WithQueueSize 

func WithQueueSize(num int) Option

WithQueueSize set worker count

func WithWorker 

func WithWorker(w core.Worker) Option

WithWorker set custom worker

func WithWorkerCount 

func WithWorkerCount(num int64) Option

WithWorkerCount set worker count

type OptionFunc 

type OptionFunc func(*Options)

OptionFunc is a function that configures a queue.

type Options 

type Options struct {
	// contains filtered or unexported fields
}

Options for custom args in Queue

func NewOptions 

func NewOptions(opts ...Option) *Options

NewOptions initialize the default value for the options

type Queue 

type Queue struct {
	sync.Mutex
	// contains filtered or unexported fields
}

A Queue is a message queue.

func NewPool 

func NewPool(size int64, opts ...Option) *Queue

NewPool initializes a new pool

Example (QueueTask) 
taskN := 7
rets := make(chan int, taskN)
// allocate a pool with 5 goroutines to deal with those tasks
p := queue.NewPool(5)
// don't forget to release the pool in the end
defer p.Release()

// assign tasks to asynchronous goroutine pool
for i := 0; i < taskN; i++ {
	idx := i
	if err := p.QueueTask(func(context.Context) error {
		// sleep and return the index
		time.Sleep(20 * time.Millisecond)
		rets <- idx
		return nil
	}); err != nil {
		log.Println(err)
	}
}

// wait until all tasks done
for i := 0; i < taskN; i++ {
	fmt.Println("index:", <-rets)
}

Output:
index: 3
index: 0
index: 2
index: 4
index: 5
index: 6
index: 1
Example (QueueTaskTimeout) 
taskN := 7
rets := make(chan int, taskN)
resps := make(chan error, 1)
// allocate a pool with 5 goroutines to deal with those tasks
q := queue.NewPool(5)
// don't forget to release the pool in the end
defer q.Release()

// assign tasks to asynchronous goroutine pool
for i := 0; i < taskN; i++ {
	idx := i
	if err := q.QueueTask(func(ctx context.Context) error {
		// panic job
		if idx == 5 {
			panic("system error")
		}
		// timeout job
		if idx == 6 {
			time.Sleep(105 * time.Millisecond)
		}
		select {
		case <-ctx.Done():
			resps <- ctx.Err()
		default:
		}

		rets <- idx
		return nil
	}, job.AllowOption{
		Timeout: job.Time(100 * time.Millisecond),
	}); err != nil {
		log.Println(err)
	}
}

// wait until all tasks done
for i := 0; i < taskN-1; i++ {
	fmt.Println("index:", <-rets)
}
close(resps)
for e := range resps {
	fmt.Println(e.Error())
}

fmt.Println("success task count:", q.SuccessTasks())
fmt.Println("failure task count:", q.FailureTasks())
fmt.Println("submitted task count:", q.SubmittedTasks())

Output:
index: 3
index: 0
index: 2
index: 4
index: 6
index: 1
context deadline exceeded
success task count: 5
failure task count: 2
submitted task count: 7

func NewQueue 

func NewQueue(opts ...Option) (*Queue, error)

NewQueue returns a Queue.

func (*Queue) BusyWorkers 

func (q *Queue) BusyWorkers() int64

BusyWorkers returns the numbers of workers in the running process.

func (*Queue) CompletedTasks 

func (q *Queue) CompletedTasks() uint64

CompletedTasks returns the numbers of completed tasks.

func (*Queue) FailureTasks 

func (q *Queue) FailureTasks() uint64

BusyWorkers returns the numbers of failure tasks.

func (*Queue) Queue 

func (q *Queue) Queue(message core.QueuedMessage, opts ...job.AllowOption) error

Queue to queue single job with binary

func (*Queue) QueueTask 

func (q *Queue) QueueTask(task job.TaskFunc, opts ...job.AllowOption) error

QueueTask to queue single task

func (*Queue) Release 

func (q *Queue) Release()

Release for graceful shutdown.

func (*Queue) Shutdown 

func (q *Queue) Shutdown()

Shutdown stops all queues.

func (*Queue) Start 

func (q *Queue) Start()

Start to enable all worker

func (*Queue) SubmittedTasks 

func (q *Queue) SubmittedTasks() uint64

BusyWorkers returns the numbers of submitted tasks.

func (*Queue) SuccessTasks 

func (q *Queue) SuccessTasks() uint64

BusyWorkers returns the numbers of success tasks.

func (*Queue) UpdateWorkerCount 

func (q *Queue) UpdateWorkerCount(num int64)

UpdateWorkerCount to update worker number dynamically.

func (*Queue) Wait 

func (q *Queue) Wait()

Wait all process

type Ring 

type Ring struct {
	sync.Mutex
	// contains filtered or unexported fields
}

Ring represents a simple queue using a buffer channel.

func NewRing 

func NewRing(opts ...Option) *Ring

NewRing creates a new Ring instance with the provided options. It initializes the task queue with a default size of 2, sets the capacity based on the provided options, and configures the logger and run function. The function returns a pointer to the newly created Ring instance.

Parameters: 

opts - A variadic list of Option functions to configure the Ring instance.

Returns: 

*Ring - A pointer to the newly created Ring instance.

func (*Ring) Queue 

func (s *Ring) Queue(task core.TaskMessage) error

Queue adds a task to the ring buffer queue. It returns an error if the queue is shut down or has reached its maximum capacity.

func (*Ring) Request 

func (s *Ring) Request() (core.TaskMessage, error)

Request retrieves the next task message from the ring queue. If the queue has been stopped and is empty, it signals the exit channel and returns an error indicating the queue has been closed. If the queue is empty but not stopped, it returns an error indicating there are no tasks in the queue. If a task is successfully retrieved, it is removed from the queue, and the queue may be resized if it is less than half full. Returns the task message and nil on success, or an error if the queue is empty or has been closed.

func (*Ring) Run 

func (s *Ring) Run(ctx context.Context, task core.TaskMessage) error

Run executes a new task using the provided context and task message. It calls the runFunc function, which is responsible for processing the task. The context allows for cancellation and timeout control of the task execution.

func (*Ring) Shutdown 

func (s *Ring) Shutdown() error

Shutdown gracefully shuts down the worker. It sets the stopFlag to indicate that the queue is shutting down and prevents new tasks from being added. If the queue is already shut down, it returns ErrQueueShutdown. It waits for all tasks to be processed before completing the shutdown.

Source Files

View all Source files

Directories

Path Synopsis
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