ngx array 相关结构

typedef struct {
    void        *elts;      /* 数组元素起始地址 */
    ngx_uint_t   nelts;     /* 已使用的数组元素个数 */
    size_t       size;      /* 数组元素大小 */
    ngx_uint_t   nalloc;    /* 数组元素个数 */
    ngx_pool_t  *pool;      /* 分配数组内存的内存池 */
} ngx_array_t;

1.实例

#include <stdio.h>
#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_array.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, ...)
{
}

void dump_pool(ngx_pool_t *pool);
void dump_array(ngx_array_t *array);


int
main(int argc, char *argv[])
{
    // 创建 pool, 并初始化
    ngx_log_t *log = NULL;
    ngx_pool_t *pool;
    ngx_array_t *array, *array1;
    ngx_str_t *str;

    printf("size of pool: %lu\n", sizeof(ngx_pool_t));
    printf("size of array: %lu\n", sizeof(ngx_array_t));
    printf("size of str: %lu\n", sizeof(ngx_str_t));
    printf("size of pool_large: %lu\n", sizeof(ngx_pool_large_t));
    printf("size of pool_data: %lu\n", sizeof(ngx_pool_data_t));

    pool = ngx_create_pool(1024, log);
    dump_pool(pool);

    // 创建 array
    array = ngx_array_create(pool, 10, 100);    // 5个30大小元素
    dump_array(array);
    dump_pool(pool);

    str = (ngx_str_t *)ngx_array_push(array);
    printf("%p\n", str);
    ngx_str_set(str, "bei jing");
    str = (ngx_str_t *)ngx_array_push(array);
    printf("%p\n", str);
    ngx_str_set(str, "shang hai");
        dump_array(array);
    dump_pool(pool);

    // 创建 array
    array1 = ngx_array_create(pool, 9, 100);

    dump_array(array1);
    dump_pool(pool);


    // 销毁 pool
    ngx_destroy_pool(pool);

    return 0;
}

void
dump_pool(ngx_pool_t *pool)
{
    printf("\x1b[32m > dump pool: \x1b[0m\n");

    printf("%10s : %-p\n", "d", &(pool->d));
    printf("%10s : %-p\n", "d->last", pool->d.last);
    printf("%10s : %-p\n", "d->end", pool->d.end);
    printf("%10s : %-p\n\n", "d->next", pool->d.next);
    printf("%10s : %-lu\n", "d->failed", pool->d.failed);
    
    if (pool->d.next) {
        printf("next: \n");
        dump_pool(pool->d.next);
        printf("------------------------------------\n");
    }
    
    printf("%10s : %-lu\n", "max", pool->max);
    printf("%10s : %-p\n", "current", pool->current);
    printf("%10s : %-p\n", "chain", pool->chain);
    printf("%10s : %-p\n", "large", pool->large);
    printf("%10s : %-p\n", "cleanup", pool->cleanup);
    printf("%10s : %-p\n", "log", pool->log);

    return;
}

void
dump_array(ngx_array_t *array)
{
    ngx_uint_t i;
    ngx_str_t *str;

    printf("\x1b[32m > dump array: \x1b[0m\n");

    printf("%10s : %-p\n", "elts", array->elts);
    printf("%10s : %-lu\n", "nelts", array->nelts);
    printf("%10s : %-lu\n", "size", array->size);
    printf("%10s : %-lu\n", "nalloc", array->nalloc);
    printf("%10s : %-p\n", "pool", array->pool);

    for (i = 0; i < (array->nelts); i++) {
        str = (ngx_str_t *)((u_char *)array->elts + i * array->size);
        printf("%10s<%lu.%-p>", str->data, i, str);
    }
    printf("\n");

    return;
}

2.执行

gcc -c -O -pipe -O -W -Wall -Wpointer-arith -Wno-unused-parameter -Wunused-function -Wunused-variable -Wunused-value -Werror -g  -I ../../objs/  -I ../os/unix/  -I../core/  -I /usr/local/opt/pcre/include/  -I../event/  -I../os/  ./t_ngx_array.c

gcc -o ./t_ngx_array ./t_ngx_array.o ../../objs/src/core/ngx_string.o ../../objs/src/os/unix/ngx_alloc.o  ../../objs/src/core/ngx_palloc.o  ../../objs/src/core/ngx_array.o 

3.结果

size of pool: 80
size of array: 40
size of str: 16
size of pool_large: 16
size of pool_data: 32
 > dump pool: 
         d : 0x7fef0b002000
   d->last : 0x7fef0b002050
    d->end : 0x7fef0b002400
   d->next : 0x0

 d->failed : 0
       max : 944
   current : 0x7fef0b002000
     chain : 0x0
     large : 0x0
   cleanup : 0x0
       log : 0x0
 > dump array: 
      elts : 0x7fef0ac02820
     nelts : 0
      size : 100
    nalloc : 10
      pool : 0x7fef0b002000

 > dump pool: 
         d : 0x7fef0b002000
   d->last : 0x7fef0b002088
    d->end : 0x7fef0b002400
   d->next : 0x0

 d->failed : 0
       max : 944
   current : 0x7fef0b002000
     chain : 0x0
     large : 0x7fef0b002078
   cleanup : 0x0
       log : 0x0
0x7fef0ac02820
0x7fef0ac02884
 > dump array: 
      elts : 0x7fef0ac02820
     nelts : 2
      size : 100
    nalloc : 10
      pool : 0x7fef0b002000
  bei jing<0.0x7fef0ac02820> shang hai<1.0x7fef0ac02884>
 > dump pool: 
         d : 0x7fef0b002000
   d->last : 0x7fef0b002088
    d->end : 0x7fef0b002400
   d->next : 0x0

 d->failed : 0
       max : 944
   current : 0x7fef0b002000
     chain : 0x0
     large : 0x7fef0b002078
   cleanup : 0x0
       log : 0x0
 > dump array: 
      elts : 0x7fef0b002420
     nelts : 0
      size : 100
    nalloc : 9
      pool : 0x7fef0b002000

 > dump pool: 
         d : 0x7fef0b002000
   d->last : 0x7fef0b0020b0
    d->end : 0x7fef0b002400
   d->next : 0x7fef0b002400

 d->failed : 0
next: 
 > dump pool: 
         d : 0x7fef0b002400
   d->last : 0x7fef0b0027a4
    d->end : 0x7fef0b002800
   d->next : 0x0

 d->failed : 0
       max : 0
   current : 0x0
     chain : 0x0
     large : 0x0
   cleanup : 0x0
       log : 0x0
------------------------------------
       max : 944
   current : 0x7fef0b002000
     chain : 0x0
     large : 0x7fef0b002078
   cleanup : 0x0
       log : 0x0