base/libs/qdecoder/qQueue.c File Reference

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include "qDecoder.h"
#include "qInternal.h"

Include dependency graph for qQueue.c:

Go to the source code of this file.

FunctionsTitleTestFour
bool	qQueueClear (Q_QUEUE *queue)
int	qQueueInit (Q_QUEUE *queue, void *datamem, size_t datamemsize, size_t objsize)
bool	qQueuePopFirst (Q_QUEUE *queue, void *object)
bool	qQueuePopLast (Q_QUEUE *queue, void *object)
bool	qQueuePush (Q_QUEUE *queue, const void *object)
size_t	qQueueSize (int max, size_t objsize)
bool	qQueueStatus (Q_QUEUE *queue, int *used, int *max)

---

Detailed Description

Circular-Queue Data Structure API

This implementation is designed to use statically allocated(fixed-size) memory for flexibilities. So you can use this queue with in shared-memory architecture to communicate with other processors.

   ----[Sample codes]----
   struct myobj {
     int integer;
     char string[255+1];
   };

   int main(void) {
     // allocate objects data memory
     size_t memsize = qQueueSize(10, sizeof(struct myobj));
     void *datamem = malloc(memsize);

     // for static data memory use can use this way
     // char datamem[NNN];

     // initialize queue
     Q_QUEUE queue;
     if(qQueueInit(&queue, datamem, memsize, sizeof(struct myobj)) == 0) {
       printf("Can't initialize queue.\n");
       return -1;
     }

     // push object
     int i;
     for(i = 1; ; i++) {
       // set sample object
       struct myobj obj;
       obj.integer = i;
       sprintf(obj.string, "hello world %d", i);

       // push object
       if(qQueuePush(&queue, &obj) == false) break;

       // print debug info
       printf("Push     : %d, %s\n", obj.integer, obj.string);
     }

     // pop object from head & tail
     while(true) {
       struct myobj pop;
       if(qQueuePopFirst(&queue, &pop) == false) break;
       printf("PopFirst : %d, %s\n", pop.integer, pop.string);

       if(qQueuePopLast(&queue, &pop) == false) break;
       printf("PopLast  : %d, %s\n", pop.integer, pop.string);
     }
     return 0;
   }

   ----[Results]----
   Push     : 1, hello world 1
   Push     : 2, hello world 2
   Push     : 3, hello world 3
   Push     : 4, hello world 4
   Push     : 5, hello world 5
   Push     : 6, hello world 6
   Push     : 7, hello world 7
   Push     : 8, hello world 8
   Push     : 9, hello world 9
   Push     : 10, hello world 10
   PopFirst : 1, hello world 1
   PopLast  : 10, hello world 10
   PopFirst : 2, hello world 2
   PopLast  : 9, hello world 9
   PopFirst : 3, hello world 3
   PopLast  : 8, hello world 8
   PopFirst : 4, hello world 4
   PopLast  : 7, hello world 7
   PopFirst : 5, hello world 5
   PopLast  : 6, hello world 6

Definition in file qQueue.c.