本文主要是介绍nginx0.1.0之http模块初始化源码分析,希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!
http模块的初始化类似event模块,初始化的起点在解析到http指令的时候。对应的处理函数是ngx_http_block,因为该函数比较长,所以我们分段解析。第一部分先解析http模块的pre_conf、create_main_conf函数的实现。
static char *ngx_http_block(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{char *rv;ngx_uint_t mi, m, s, l, p, a, n;ngx_uint_t port_found, addr_found, virtual_names;ngx_conf_t pcf;ngx_array_t in_ports;ngx_listening_t *ls;ngx_http_listen_t *lscf;ngx_http_module_t *module;ngx_http_handler_pt *h;ngx_http_conf_ctx_t *ctx;ngx_http_in_port_t *in_port, *inport;ngx_http_in_addr_t *in_addr, *inaddr;ngx_http_server_name_t *s_name, *name;ngx_http_core_srv_conf_t **cscfp, *cscf;ngx_http_core_loc_conf_t *clcf;ngx_http_core_main_conf_t *cmcf;
#if (WIN32)ngx_iocp_conf_t *iocpcf;
#endif/* the main http context */ngx_test_null(ctx,ngx_pcalloc(cf->pool, sizeof(ngx_http_conf_ctx_t)),NGX_CONF_ERROR);// 创建一个ngx_http_conf_ctx_t结构体挂载到cycle的ctx中*(ngx_http_conf_ctx_t **) conf = ctx;/* count the number of the http modules and set up their indices */ngx_http_max_module = 0;// 遍历所有的nginx模块,筛选出http模块for (m = 0; ngx_modules[m]; m++) {if (ngx_modules[m]->type != NGX_HTTP_MODULE) {continue;}// 标记该模块在http中的索引,位置ngx_modules[m]->ctx_index = ngx_http_max_module++;}// 根据http的模块数,分配一个数组,分别由下面三个字段指向/* the main http main_conf, it's the same in the all http contexts */ngx_test_null(ctx->main_conf,ngx_pcalloc(cf->pool, sizeof(void *) * ngx_http_max_module),NGX_CONF_ERROR);/* the http null srv_conf, it's used to merge the server{}s' srv_conf's */ngx_test_null(ctx->srv_conf,ngx_pcalloc(cf->pool, sizeof(void *) * ngx_http_max_module),NGX_CONF_ERROR);/* the http null loc_conf, it's used to merge the server{}s' loc_conf's */ngx_test_null(ctx->loc_conf,ngx_pcalloc(cf->pool, sizeof(void *) * ngx_http_max_module),NGX_CONF_ERROR);/* create the main_conf, srv_conf and loc_conf in all http modules */for (m = 0; ngx_modules[m]; m++) {if (ngx_modules[m]->type != NGX_HTTP_MODULE) {continue;}// http模块的上下文,是ngx_http_module_t结构体module = ngx_modules[m]->ctx;mi = ngx_modules[m]->ctx_index;// 解析http配置前执行的钩子if (module->pre_conf) {if (module->pre_conf(cf) != NGX_OK) {return NGX_CONF_ERROR;}}// 创建一个ngx_http_core_main_conf_t结构体,挂到main_conf数组相应的位置if (module->create_main_conf) {ngx_test_null(ctx->main_conf[mi], module->create_main_conf(cf),NGX_CONF_ERROR);}// 创建一个ngx_http_core_srv_conf_t结构体,挂到srv_conf数组相应的位置if (module->create_srv_conf) {ngx_test_null(ctx->srv_conf[mi], module->create_srv_conf(cf), NGX_CONF_ERROR);}// 创建一个ngx_http_core_loc_conf_s 结构体,挂到loc_conf数组相应的位置if (module->create_loc_conf) {ngx_test_null(ctx->loc_conf[mi], module->create_loc_conf(cf),NGX_CONF_ERROR);}}...
}
下面我们看一下各个http模块的这些钩子函数都做了些什么。
1 pre_conf钩子
log模块
其他模块都是基于log模块的ngx_http_log_fmt_ops变量进行的。
ngx_http_log_op_name_t ngx_http_log_fmt_ops[] = {{ ngx_string("addr"), INET_ADDRSTRLEN - 1, ngx_http_log_addr },{ ngx_string("conn"), NGX_INT32_LEN, ngx_http_log_connection },{ ngx_string("pipe"), 1, ngx_http_log_pipe },{ ngx_string("time"), sizeof("28/Sep/1970:12:00:00") - 1,ngx_http_log_time },{ ngx_string("msec"), TIME_T_LEN + 4, ngx_http_log_msec },{ ngx_string("request"), 0, ngx_http_log_request },{ ngx_string("status"), 3, ngx_http_log_status },{ ngx_string("length"), NGX_OFF_T_LEN, ngx_http_log_length },{ ngx_string("apache_length"), NGX_OFF_T_LEN, ngx_http_log_apache_length },{ ngx_string("i"), NGX_HTTP_LOG_ARG, ngx_http_log_header_in },{ ngx_string("o"), NGX_HTTP_LOG_ARG, ngx_http_log_header_out },{ ngx_null_string, 0, NULL }
};static ngx_int_t ngx_http_log_pre_conf(ngx_conf_t *cf)
{ngx_http_log_op_name_t *op;for (op = ngx_http_log_fmt_ops; op->name.len; op++) { /* void */ }op->op = NULL;return NGX_OK;
}
gzip模块
static ngx_http_log_op_name_t ngx_http_gzip_log_fmt_ops[] = {{ ngx_string("gzip_ratio"), NGX_INT32_LEN + 3, ngx_http_gzip_log_ratio },{ ngx_null_string, 0, NULL }
};static ngx_int_t ngx_http_gzip_pre_conf(ngx_conf_t *cf)
{ngx_http_log_op_name_t *op;/*找到第一个没有名字的项,即最后一项,然后把op置空,为了防止下面一个for循环的时候op->op为空,不会导致死循环,因为执行完该函数后,op->op是下一个pre_conf函数执行时,ngx_http_log_fmt_ops数组的最后一个被判断的op->op*/for (op = ngx_http_gzip_log_fmt_ops; op->name.len; op++) { /* void */ }op->op = NULL;op = ngx_http_log_fmt_ops;/*找到最后一个op有值但是没有名字的项,这里其实是一个巧妙的设计,因为op有值但是没有名字的项,op->op指向的是一个ngx_http_log_op_name_t数组,然后op继续指向该数组第一个元素,继续迭代*/for (op = ngx_http_log_fmt_ops; op->op; op++) {if (op->name.len == 0) {op = (ngx_http_log_op_name_t *) op->op;}}/*每个模块中的ngx_http_log_op_name_t数组最后一个元素都是空的,然后在这给op->op赋值,op->op指向的数组的最后一个元素也是空项,以此类推*/op->op = (ngx_http_log_op_pt) ngx_http_gzip_log_fmt_ops;return NGX_OK;
}
userid模块
static ngx_http_log_op_name_t ngx_http_userid_log_fmt_ops[] = {{ ngx_string("uid_got"), 0, ngx_http_userid_log_uid_got },{ ngx_string("uid_set"), 0, ngx_http_userid_log_uid_set },{ ngx_null_string, 0, NULL }
};
static ngx_int_t ngx_http_userid_pre_conf(ngx_conf_t *cf)
{ngx_http_log_op_name_t *op;for (op = ngx_http_userid_log_fmt_ops; op->name.len; op++) { /* void */ }op->op = NULL;op = ngx_http_log_fmt_ops;for (op = ngx_http_log_fmt_ops; op->op; op++) {if (op->name.len == 0) {op = (ngx_http_log_op_name_t *) op->op;}}op->op = (ngx_http_log_op_pt) ngx_http_userid_log_fmt_ops;return NGX_OK;
}
各模块不一一列举,各模块的pre_conf函数执行完后内存视图是如下。
2 create_main_conf钩子
1 http_core模块
static void *ngx_http_core_create_main_conf(ngx_conf_t *cf)
{ngx_http_core_main_conf_t *cmcf;ngx_test_null(cmcf,ngx_pcalloc(cf->pool, sizeof(ngx_http_core_main_conf_t)),NGX_CONF_ERROR);ngx_init_array(cmcf->servers, cf->pool,5, sizeof(ngx_http_core_srv_conf_t *),NGX_CONF_ERROR);return cmcf;
}
2 charset_filter模块
static void *ngx_http_charset_create_main_conf(ngx_conf_t *cf)
{ngx_http_charset_main_conf_t *mcf;if (!(mcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_charset_main_conf_t)))) {return NGX_CONF_ERROR;}ngx_init_array(mcf->charsets, cf->pool, 5, sizeof(ngx_http_charset_t),NGX_CONF_ERROR);ngx_init_array(mcf->tables, cf->pool, 10, sizeof(ngx_http_charset_tables_t),NGX_CONF_ERROR);return mcf;
}
3 log模块
static void *ngx_http_log_create_main_conf(ngx_conf_t *cf)
{ngx_http_log_main_conf_t *conf;char *rc;ngx_str_t *value;if (!(conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_log_main_conf_t)))) {return NGX_CONF_ERROR;}ngx_init_array(conf->formats, cf->pool, 5, sizeof(ngx_http_log_fmt_t),NGX_CONF_ERROR);cf->args->nelts = 0;// 设置参数,在ngx_http_log_set_format里使用if (!(value = ngx_push_array(cf->args))) {return NGX_CONF_ERROR;}if (!(value = ngx_push_array(cf->args))) {return NGX_CONF_ERROR;}value->len = sizeof("combined") - 1;value->data = (u_char *) "combined";if (!(value = ngx_push_array(cf->args))) {return NGX_CONF_ERROR;}*value = ngx_http_combined_fmt;rc = ngx_http_log_set_format(cf, NULL, conf);if (rc != NGX_CONF_OK) {return NULL;}return conf;
}
执行完create_main_conf后的内存视图如下。
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