puper / goqueue Goto Github PK

Golang channel can not support infinite size, I use it as a replacement.

It is very very very similar to the Queue of Python, as a practice...

NOTE: Maybe a lots of BUGs in the code...

go get github.com/Damnever/goqueue

Just for example, I use Queue.Get(true, 0) and Queue.PutNoWait(value) more and often, but channel can not do that...

package main

import "github.com/Damnever/goqueue"
import "fmt"

func main() {
	queue := goqueue.NewQueue(0)

	worker := func(queue *goqueue.Queue) {
        for {
		    e, err := queue.Get(true, 0)
		    if err != nil {
			    fmt.Println("Unexpect Error: %v\n", err)
		    }
            num := e.Value.(int)
            fmt.Printf("-> %v\n", num)
		    queue.TaskDone()
            if num % 3 == 0 {
                for i := num + 1; i < num + 3; i ++ {
                     queue.PutNoWait(i)
                }
            }
        }
	}

    for i := 0; i <= 27; i += 3 {
		queue.PutNoWait(i)
    }

    for i := 0; i < 5; i++ {
        go worker(queue)
    }

    queue.WaitAllComplete()
	fmt.Println("All task done!!!")
}

• NewQueue(maxSize int) *Queue

  Create a Queue. If maxSize is zero, return a Queue with infinite size.

Queue Methods:

• (queue *Queue) Size() int

  Return the Queue size.

• (queue *Queue) IsEmpty() bool

  Return true if Queue is empty, return false otherwise.

• (queue *Queue) IsFull() bool

  Return true if Queue is full(as long as maxSize is not zero), return false otherwise.

• (queue *Queue) Get(block bool, timeout float64) (*list.Element, error)

  If block is false, return (&list.Element{Value: ...}, nil) immediately if Queue is not empty, return (&list.Element{}, EmptyQueueError) otherwise.

  If block is true and timeout is zero, wait until an element available.

  If block is true and timeout greater than zero, return immediately if an element available before timeout, return EmptyQueueError if no element is available within timeout.

• (queue *Queue) GetNoWait() (*list.Element, error)

  Same as Get with block=false.

• (queue *Queue) Put(value interface{}, block bool, timeout float64) (*list.Element, error)

  If maxSize is zero, put value into Queue immediately.

  If maxSize is not zero: (1) If block is false, put value into Queue immediately and return (&list.Element{Value: ...}, nil) if Queue is not full, return (&list.Element{}, FullQueueError) otherwise. (2) If block is true and timeout is zero, wait until free slot available. (3) If block is true and timeout greater than zero, put value into Queue and return immediately if a slot available before timeout, return EmptyQueueError if no free slot is available within timeout.

• (queue *Queue) PutNoWait(value interface{}) (*list.Element, error)

  Same as Put with block=false.

• (queue *Queue) TaskDone()

  If you use WaitAllComplete method, you must call this method after you invoked Get/GetNoWait to indicate a formerly enqueue task is done.

  If you called this method more times than number of elements in Queue, then an error will panic...

• (queue *Queue) WaitAllComplete()

  Blocks until all elements in the Queue have been gotten and processed.

Errors:

• type EmptyQueueError struct{}

• type FullQueueError struct{}