nginx双向链表ngx_queue_t

一、介绍

ngx_queue_t是nginx中实现的双向链表，在要用到双向链表的自定义结构体中将ngx_queue_t嵌入到自定义结构体中即可。还有一个特点是ngx_queue_t不涉及到内存分配。

二、例子

下面的源码是将《深入理解nginx》第7章关于ngx_queue_t的源码整合起来。Makefile则是参考http://blog.csdn.net/livelylittlefish/article/details/6586946。

#include

#include "ngx_config.h"

#include "ngx_conf_file.h"

#include "nginx.h"

#include "ngx_core.h"

#include "ngx_string.h"

#include "ngx_palloc.h"

#include "ngx_queue.h"

volatile ngx_cycle_t  *ngx_cycle;

void ngx_log_error_core(ngx_uint_t level,ngx_log_t *log, ngx_err_t err,

           const char *fmt, ...)

{

}

typedef struct {

       u_char*str;

       ngx_queue_tqEle;

       intnum;

}TestNode;

ngx_int_t compTestNode(const ngx_queue_t*a, const ngx_queue_t *b)

{

       TestNode*aNode = ngx_queue_data(a, TestNode, qEle);

       TestNode*bNode = ngx_queue_data(b, TestNode, qEle);

       returnaNode->num > bNode->num;

}

int main()

{

       ngx_queue_tqueueContainer;

       ngx_queue_init(&queueContainer);

       inti = 0;

       TestNodenode[5];

      

       for(; i

              node[i].num= i;

       }

      

       ngx_queue_insert_tail(&queueContainer,&node[0].qEle);

       ngx_queue_insert_head(&queueContainer,&node[1].qEle);

       ngx_queue_insert_tail(&queueContainer,&node[2].qEle);

       ngx_queue_insert_after(&queueContainer,&node[3].qEle);

       ngx_queue_insert_tail(&queueContainer,&node[4].qEle);

      

       ngx_queue_t*q;

       for(q = ngx_queue_head(&queueContainer);

              q!= ngx_queue_sentinel(&queueContainer);

              q= ngx_queue_next(q)) {

              TestNode*eleNode = ngx_queue_data(q, TestNode, qEle);

              printf("%d ",eleNode->num);

       }

      

       printf("*****sort***** ");

      

       ngx_queue_sort(&queueContainer,compTestNode);

       for(q = ngx_queue_head(&queueContainer);

              q!= ngx_queue_sentinel(&queueContainer);

              q= ngx_queue_next(q)) {

              TestNode*eleNode = ngx_queue_data(q, TestNode, qEle);

              printf("%d ",eleNode->num);

       }

             

       return0;

}

Makefile

CXX = gcc

CXXFLAGS += -g -Wall -Wextra

NGX_ROOT = /usr/src/nginx-1.0.4

TARGETS = test_queue

TARGETS_C_FILE = $(TARGETS).c

CLEANUP = rm -f $(TARGETS) *.o

all: $(TARGETS)

clean:

       $(CLEANUP)

CORE_INCS = -I.

       -I$(NGX_ROOT)/src/core

       -I$(NGX_ROOT)/src/event

       -I$(NGX_ROOT)/src/event/modules

       -I$(NGX_ROOT)/src/os/unix

       -I$(NGX_ROOT)/objs

NGX_PALLOC =$(NGX_ROOT)/objs/src/core/ngx_palloc.o

NGX_STRING =$(NGX_ROOT)/objs/src/core/ngx_string.o

NGX_ALLOC = $(NGX_ROOT)/objs/src/os/unix/ngx_alloc.o

NGX_QUEUE =$(NGX_ROOT)/objs/src/core/ngx_queue.o

$(TARGETS): $(TARGETS_C_FILE)

       $(CXX)$(CXXFLAGS) $(CORE_INCS) $(NGX_PALLOC) $(NGX_STRING) $(NGX_ALLOC) $(NGX_QUEUE)$^ -o $@

三、总结

1、一个链表通过链表头标识，不包含用户自定义的相关数据。

以上就介绍了nginx双向链表ngx_queue_t，包括了方面的内容，希望对PHP教程有兴趣的朋友有所帮助。