自己的队列通用函数库

在glib里面一般都有一套现成的可以用的队列，链表函数可以用，mplayer,ffmpeg等开源软件里面也有相应的实现，我们在写程序时也经常要用到这样的功能，可以借鉴里面的实现方法，实现自己的库函数，减少程序的依赖性。下面是我常用的自己的库，大多是借鉴mplayer里面的思路.
/*packet_queue.h*/
#ifndef _PACKET_QUEUE_H_
#define _PACKET_QUEUE_H_

#include

typedef struct packet_stream_st{
    int len;
    unsigned char *buffer;
    struct packet_stream_st *next;
}packet_stream_t;

typedef struct {
    int packs;
    packet_stream_t *first;
    packet_stream_t *last;
}queue_stream_t;

packet_stream_t* new_packet_stream(int len);
void free_packet_stream(packet_stream_t* ps);
queue_stream_t* new_queue_stream();
void free_queue_stream(queue_stream_t* qs);
void qs_add_packet(queue_stream_t* qs, packet_stream_t* ps);
packet_stream_t* qs_get_packet(queue_stream_t* qs);

#endif

/*packet_queue.c*/
#include
#include "packet_queue.h"

packet_stream_t* new_packet_stream(int len)
{
    packet_stream_t* ps = (packet_stream_t*)malloc(sizeof(packet_stream_t));
    ps->next = NULL;
    ps->buffer = (unsigned char *)malloc(len);
    ps->len = len;
    return ps;
}

void free_packet_stream(packet_stream_t* ps)
{
    if(ps){
        if(ps->buffer) {free(ps->buffer); ps->buffer=NULL;}
        free(ps);
        ps = NULL;
    }
}

queue_stream_t* new_queue_stream()
{
    queue_stream_t *qs = (queue_stream_t*)malloc(sizeof(queue_stream_t));
    qs->packs = 0;
    qs->first = qs->last = NULL;
    return qs;
}

static void qs_free_packs(queue_stream_t* qs)
{
    packet_stream_t* ps = qs->first;
    while(ps){
        packet_stream_t* pn = ps->next;
        free_packet_stream(ps);
        ps = pn;
    }
    qs->packs = 0;
    qs->first = qs->last = NULL;
}

void free_queue_stream(queue_stream_t* qs)
{
    qs_free_packs(qs);
    free(qs);
}

void qs_add_packet(queue_stream_t* qs, packet_stream_t* ps)
{
    ++qs->packs;
    if(qs->last){
        qs->last->next = ps;
            qs->last = ps;     
    }else{
        qs->first = qs->last = ps;
    }
}

packet_stream_t* qs_get_packet(queue_stream_t* qs)
{
    if(qs->packs){
        packet_stream_t* ps = qs->first;
        qs->first = ps->next;
        if(!qs->first) qs->last = NULL;
        --qs->packs;
        return ps;
    }

    return NULL;
}   

/*usage: main.c*/
#include
#include
#include "packet_queue.h"

int main()
{
    int i;
    queue_stream_t * qs = new_queue_stream();
    for(i=0; i<10; i++){
        packet_stream_t *ps = new_packet_stream(32);
        strcpy(ps->buffer,"Hello World!");
        printf("===current adding queue len:%d=====\n",qs->packs);
        qs_add_packet(qs, ps);
    }
    for(i=0; i<20; i++){
        packet_stream_t *ps = qs_get_packet(qs);
        if(ps){
            printf("===current reading queue len:%d=====\n",qs->packs);
            printf("packet:%s\n",ps->buffer);
        }
    }
    free_queue_stream(qs);
    return 0;
}

/*Makefile*/
TARGET=test_queue

CROSS_COMPILE    =
CC              = $(CROSS_COMPILE)gcc
LD              = $(CROSS_COMPILE)ld
STRIP           = $(CROSS_COMPILE)strip

SRC=${wildcard *.c lib/*.c}
OBJS=${SRC:%.c=%.o}
NAME=${SRC:%.c=%}
DEPS=$(SRC:%.c=.dep/%.d)

CFLAGS= -g -Wall -Iinclude -Llib
LDFLAGS=

.PHONY: dep  all


all :  $(OBJS)
    $(CC) -o $(TARGET) $(OBJS) $(LDFLAGS)


%.o: %.c
    ${CC} ${CFLAGS} -c $< -o $@

clean:
    rm -rf .dep .tmp .src.mk $(TARGET) $(OBJS)