[队列]简单的队列操作

本文摘抄于《C嵌入式编程设计模式》

1. 头文件部分：Queue.h

#ifndef __QUEUE_H_
#define __QUEUE_H_

#define QUEUE_SIZE     10

/* class queue */
typedef struct Queue queue;
struct Queue
{
    int buffer[QUEUE_SIZE];
    int head;
    int size;
    int tail;
    int (*isFull)(Queue *const me);
    int (*isEmpty)(Queue *const me);
    int (*getSize)(Queue *const me);
    void (*insert)(Queue *const me, int k);
    int (*remove)(Queue *const me);    
};

/* Constructors and destructors */
void Queue_init(Queue *const me, int (*isFull)(Queue *const me),
                int (*isEmpty)(Queue *const me),
                int (*getSize)(Queue *const me),
                void (*insert)(Queue *const me, int k),
                int (*remove)(Queue *const me));
void Queue_Cleanup(Queue *const me);
/* Operaters */
int Queue_isFull(Queue *const me);
int Queue_isEmpty(Queue *const me);
int Queue_getSize(Queue *const me);
void Queue_insert(Queue *const me, int k);s
int Queue_remove(Queue *const);

Queue *Queue_Create(void);
void Queue_Destroy(Queue *const me);

#endif

2. 源文件实现部分：queue.c

#include <stdio.h>
#include <stdlib.h>
#include "Queue.h"

/* init struct */
void Queue_init(Queue *const me, int (*isFullFunction)(Queue *const me),
                int (*isEmptyFunction)(Queue *const me),
                int (*getSizeFunction)(Queue *const me),
                void (*insertFunction)(Queue *const me, int k),
                int (*removeFunction)(Queue *const me))
{
    me->head = 0;
    me->size = 0;
    me->tail = 0;

    me->isFull = isFullFunction;
    me->isEmpty = isEmptyFunction;
    me->getSize = getSizeFunction;
    me->insert = insertFunction;
    me->remove = removeFunction;
}
/* operation clean up */
void Queue_Cleanup(Queue * const me)
{
    //TODO:
}
/* operation is Full */
int Queue_isFull(Queue * const me)
{
    return (me->head+1)%QUEUE_SIZE == me->tail;
}
/* operation isEmpty */
int Queue_isEmpty(Queue * const me)
{
    return (me->head == me->tail);
}
/* operation getSize */
int Queue_getSize(Queue * const me)
{
    return me->size;
}    
/* operation insert */
void Queue_insert(Queue * const me,int k)
{
    if(!me->isFull(me))
    {
        me->buffer[me->head] = k;
        me->head = (me->head+1)%QUEUE_SIZE;
        ++me->size;
    }
}
/* operation remove */
int Queue_remove(Queue *const me)
{
    int value = -9999;
    if(!me->isEmpty(me))
    {
        value = me->buffer[me->tail];
        me->tail = (me->tail+1)%QUEUE_SIZE;
        --me->size;
    }
    return value;
}
/* queue create */
Queue *Queue_Create(void)
{
    Queue *me = (Queue*)malloc(sizeof(Queue));
    if(me!=NULL)
    {
        Queue_init(me,Queue_isFull,Queue_isEmpty,Queue_getSize,Queue_insert,Queue_remove);
    }
    return me;
}
/* queue remove */
void Queue_remove(Queue *const me)
{
    if(me!= NULL)
    {
        Queue_Cleanup(me);
    }
    free(me);
}

　3. 队列测试代码：TestQueue.c

#include <stdio.h>
#include <stdlib.h>
#include "Queue.h"

int main(void)
{
    int j,k,h,t;

    /* test normal queue */
    Queue *myQ;
    myQ = Queue_Create();
    k = 1000;

    for(j = 0; j < QUEUE_SIZE; j++)
    {
        h = myQ->head;
        myQ->insert(myQ, k);
        printf("inserting %d at position %d, size=%d
", k--, h, myQ->getSize(myQ));
    }
    printf("Inserting %d elements
", myQ->getSize(myQ));
    for(j = 0;j < QUEUE_SIZE; j++)
    {
        t = myQ->tail;
        k = myQ->getSize(myQ);
        printf("Removing %d at position %d, size=%d
", k, t, myQ->getSize(myQ));        
    }

    printf("last item removed %d
", k);
    printf("Current queue size %d
", myQ->getSize(myQ));
    puts("Queue test program");
    
    return EXIT_SUCCESS;