nginx的helloworld模块的helloworld

nginx--->config文件---->module--->command[]<----->函数----->handler
                          |           |
                         ctx等        位置等

自己加的注释
ngx_http_hello_world_module.c
———————–
#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>
#include <ngx_buf.h>
static  char *ngx_http_hello_world(ngx_conf_t *cf ,ngx_command_t *cmd,void *conf);
//*cf 指向ngx_conf_t 结构体指针，从指令后面传过来的参数
//*cmd 指向当前结构体ngx_command_t 的指针(互相指)
//*conf指向自定义模块配置结构体的指针
static ngx_command_t ngx_http_hello_world_commands[]={
{
ngx_string(“hello_world”),//指令名称，nginx.conf中使用
NGX_HTTP_LOC_CONF|NGX_CONF_NOARGS,  //注释1
ngx_http_hello_world,//回调函数 ，上面定义的带三个参数
0,//保持的值放的位置：全局，server，location
0,//指令的值保存的位置
NULL //一般都为NULL
},
ngx_null_command  //读入ngx_null_command 指令后停止
};
static u_char ngx_hello_world[]=”hello world”;
//ngx_http_<module name>_module_ctx用于创建和合并三个配置
//参考http/ngx_http_config.h 
static ngx_http_module_t ngx_http_hello_world_module_ctx={
NULL,//preconfiguration
NULL,//postconfiguration
NULL,//create main configuration
NULL,//init main configuration
NULL,//create server configuration
NULL,//merge server configuration
NULL,//create location configuration
NULL //merge localtion configuration
};
//nginx进程，线程相关，ngx_http_<module name>_module
//这个模块的定义是把数据处理关联到特定模块的关键
ngx_module_t ngx_http_hello_world_module={
NGX_MODULE_V1,
&ngx_http_hello_world_module_ctx,//module context
ngx_http_hello_world_commands,  //module directives
NGX_HTTP_MODULE,         //module type
NULL, //init master
NULL, //init module
NULL, //init process
NULL, //init thread
NULL, //exit thread
NULL, //exit process
NULL, //exit master
NGX_MODULE_V1_PADDING
};
static ngx_int_t ngx_http_hello_world_handler(ngx_http_request_t *r)
{
ngx_buf_t *b;
ngx_chain_t out;

r->headers_out.content_type.len =sizeof(“text/plain”)-1;
r->headers_out.content_type.data=(u_char *) “text/plain”;

b=ngx_pcalloc(r->pool,sizeof(ngx_buf_t));

out.buf=b;
out.next=NULL;

b->pos=ngx_hello_world;
b->last=ngx_hello_world+sizeof(ngx_hello_world);
b->memory=1;
b->last_buf=1;

r->headers_out.status=NGX_HTTP_OK;
r->headers_out.content_length_n=sizeof(ngx_hello_world);
ngx_http_send_header(r);

return ngx_http_output_filter(r,&out);
}
//回调函数，1获得location中的“核心”结构体，2为他分配个处理函数
static char *ngx_http_hello_world(ngx_conf_t *cf,ngx_command_t *cmd,void *conf)
{
ngx_http_core_loc_conf_t *clcf;

clcf=ngx_http_conf_get_module_loc_conf(cf,ngx_http_core_module);
clcf->handler=ngx_http_hello_world_handler;
return NGX_CONF_OK;
}
—————————
config:

ngx_addon_name=ngx_http_hello_world_module
HTTP_MODULES="$HTTP_MODULES ngx_http_hello_world_module"
NGX_ADDON_SRCS="$NGX_ADDON_SRCS $ngx_addon_dir/ngx_http_hello_world_module.c"
CORE_LIBS="$CORE_LIBS -lpcre"

在objs/下生成Makefile之后
修改

CC =    gcc -g

配置nginx.conf
location /hello {
hello_world;
}
启动nginx
curl http://localhost/hello
然后hello world出来了，牛b了

注释1：
NGX_HTTP_MAIN_CONF  指令出现在全局位置部分是合法的
NGX_HTTP_SRV_CONF   指令出现在server主机配置部分是合法的
NGX_HTTP_LOC_CONF   指令出现在Location配置部分是合法的
NGX_HTTP_UPS_CONF   指令出现在upstream配置部分是合法的
NGX_CONF_NOARGS     指令没有参数
NGX_CONF_TAKE1      指令读一个参数
。。。。。
NGX_CONF_TAKE7      指令读7个参数
NGX_CONF_FLAG       指令读一个布尔型数据
NGX_CONF_1MORE      指令至少读一个参数
NGX_CONF_2MORE      指令至少读2个参数

————-调试——–
gdb -d /opt/nginxtest/nginx/sbin/ nginx 10540
l就能看代码了

———-ltrace 和strace————-
strace -T -c -p 10700
curl localhost/hello
ctl+c 看epoll调用次数

[root@red54apple sbin]# strace -T -c -p 10700
Process 10700 attached - interrupt to quit
Process 10700 detached
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
100.00    0.000060          60         1           write
  0.00    0.000000           0         1           close
  0.00    0.000000           0         1           ioctl
  0.00    0.000000           0         1           writev
  0.00    0.000000           0         1           accept
  0.00    0.000000           0         3         1 recvfrom
  0.00    0.000000           0         1           setsockopt
  0.00    0.000000           0         3           epoll_wait
  0.00    0.000000           0         1           epoll_ctl
------ ----------- ----------- --------- --------- ----------------
100.00    0.000060                    13         1 total
[root@red54apple sbin]# ldconfig -p |grep mysql

[root@red54apple sbin]# ltrace -p 10700
__errno_location()                                                                                           = 0x2b8699230640
gettimeofday(0x7fff5219a250, NULL)                                                                           = 0
localtime_r(0x7fff5219a1b8, 0x7fff5219a2a0, 84, 0, 0x6c7d27)                                                 = 0x7fff5219a2a0
epoll_wait(8, 0xa607610, 512, 0xffffffff, 0x6c8b48
)                                                          = 1
gettimeofday(0x7fff5219a250, NULL)                                                                           = 0
localtime_r(0x7fff5219a1b8, 0x7fff5219a2a0, 84, 0, 0x6c7d45)                                                 = 0x7fff5219a2a0
accept(6, 0x7fff5219a250, 0x7fff5219a2c0, 0xa621250, 0x6c8b62)                                               = 3
memset(0x2b869943c180, '00', 184)                                                                          = 0x2b869943c180
memset(0xa621320, '00', 104)                                                                               = 0xa621320
memset(0xa63b330, '00', 104)                                                                               = 0xa63b330
posix_memalign(0x7fff5219a1b0, 16, 256, 0xa63b330, 104)                                                      = 0
ioctl(3, 21537, 0x7fff5219a1fc)                                                                              = 0
epoll_ctl(8, 1, 3, 0x7fff5219a160, 0xa613718)                                                                = 0
epoll_wait(8, 0xa607610, 512, 60000, 0xa613718)                                                              = 1
gettimeofday(0x7fff5219a250, NULL)                                                                           = 0
malloc(1256)                                                                                                 = 0xa608e20
posix_memalign(0x7fff5219a170, 16, 256, 256, 3)                                                              = 0
malloc(1024)                                                                                                 = 0xa609310
posix_memalign(0x7fff5219a240, 16, 4096, 144, 3)                                                             = 0
recv(3, 0xa609310, 1024, 0, 3)                                                                               = 158
strncmp("penSSL/0.9.8b zlib/1.2.3 libidn/"..., "pera", 4)                                                    = -4
strncmp("SL/0.9.8b zlib/1.2.3 libidn/0.6."..., "afari/", 6)                                                  = -14
strncmp("L/0.9.8b zlib/1.2.3 libidn/0.6.5", "afari/", 6)                                                     = -21
writev(3, 0x7fff52199650, 2, 0x7fff52199650, 0xa60a1cd)                                                      = 159
write(4, "127.0.0.1 - - [29/Nov/2011:15:21"..., 170)                                                         = 170
free(0xa609720)                                                                                              = <void>
free(0xa608e20)                                                                                              = <void>
free(0xa609310)                                                                                              = <void>
setsockopt(3, 6, 1, 0x7fff52199fe4, 4)                                                                       = 0
malloc(1024)                                                                                                 = 0xa608e20
__errno_location()                                                                                           = 0x2b8699230640
recv(3, 0xa608e20, 1024, 0, 3)                                                                               = 0
close(3)                                                                                                     = 0
free(0xa608e20)                                                                                              = <void>
free(0xa613680)                                                                                              = <void>
free(0xa5fe390)                                                                                              = <void>
epoll_wait(8, 0xa607610, 512, 0xffffffff, 0

 <unfinished ...>
[root@red54apple sbin]#

然后就该看这个了
http://www.evanmiller.org/nginx-modules-guide.html

顺便统计下代码行数
find . -name “*.c” |xargs cat|wc -l
find . -name “*.c” |xargs cat|grep -v ^$|wc -l
8万有效代码，精读吧，恩，好的

更多需要参考
http://search.cpan.org/~agent/
http://agentzh.org/#Presentations
agentzh.blogspot.com
zhangyichun那个大牛
微薄叫agentzh
http://www.codinglabs.org/html/intro-of-nginx-module-development.html
echo模块
http://openresty.org/
多模块的开发

视频和ppt
http://agentzh.org/misc/slides/perl-lz-apps/#26

upstream main_db {
       drizzle_server 127.0.0.1:3306
           user=monty password=some_pass dbname=test
           protocol=mysql;

       drizzle_keepalive max=10 overflow=reject
           mode=single;
   }

location /mysql {
       set_unescape_uri $sql $arg_sql;
       set_unescape_uri $backend $arg_backend;

       drizzle_query $sql;
       drizzle_pass $backend;
   }