Queue

Header file

#include "mln_queue.h"

Module

queue

Functions/Macros

mln_queue_init

mln_queue_t *mln_queue_init(mln_uauto_t qlen, queue_free free_handler);

typedef void (*queue_free)(void *);

Description: Create a queue.

This queue is a fixed-length queue, so qlen is the length of the queue. free_handler is the release function, which is used to release the data in each member of the queue. If you don't need to release, just set NULL.

The parameter of the release function is the data structure pointer of each member of the queue.

Return value: return a queue pointer of type mln_queue_t on success, NULL on failure

mln_queue_destroy

void mln_queue_destroy(mln_queue_t *q);

Description: Destroy the queue.

When the queue is destroyed, the data of the queue members will be automatically released according to the setting of free_handler.

Return value: none

mln_queue_append

int mln_queue_append(mln_queue_t *q, void *data);

Description: Append data data to the end of queue q.

Return value: -1 if the queue is full, 0 if successful

mln_queue_get

void *mln_queue_get(mln_queue_t *q);

Description: Get the data of the leader of the team.

Return value: return the data pointer if successful, or NULL if the queue is empty

mln_queue_remove

void mln_queue_remove(mln_queue_t *q);

Description: Deletes the head element of the queue, but does not release resources.

Return value: none

mln_queue_search

void *mln_queue_search(mln_queue_t *q, mln_uauto_t index);

Description: Find and return the data of the index member starting from the head of the queue q, with the subscript starting from 0.

Return value: Returns the data pointer on success, otherwise NULL

mln_queue_free_index

void mln_queue_free_index(mln_queue_t *q, mln_uauto_t index);

Description: Release the member of the specified subscript index in the queue q, and release its data according to free_handler.

Return value: none

mln_queue_iterate

int mln_queue_iterate(mln_queue_t *q, queue_iterate_handler handler, void *udata);

typedef int (*queue_iterate_handler)(void *, void *);

Description: Iterate over each queue member.

udata is a custom structure pointer to assist traversal, and can be set to NULL if not required.

The two parameters of handler are: member data, udata.

Return value: 0 is returned when the traversal is completed, and -1 is returned when it is interrupted

mln_queue_empty

mln_queue_empty(q)

Description: Determine if queue q is an empty queue.

Return value: non-0 if empty, 0 otherwise

mln_queue_full

mln_queue_full(q)

Description: Determine if the queue is full.

Return value: non-0 if full, 0 otherwise

mln_queue_length

mln_queue_length(q)

Description: Get the total length of queue q.

Return value: unsigned integer length value

mln_queue_element

mln_queue_element(q)

Description: Get the current number of members in queue q.

Return value: unsigned integer value

Example

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

int main(int argc, char *argv[])
{
    int i = 10;
    mln_queue_t *q;

    q = mln_queue_init(10, NULL);
    if (q == NULL) {
        fprintf(stderr, "queue init failed.\n");
        return -1;
    }
    mln_queue_append(q, &i);
    printf("%d\n", *(int *)mln_queue_get(q));
    mln_queue_destroy(q);

    return 0;
}