一 、与请求相关

读取请求body

ngx_http_read_client_request_body 作用 : 用于读取请求体 位置： ngx_http_request_body.c

/** * 读取请求体， post_handler是回调函数，当body全部读取完成之后，会调用该函数 */ ngx_int_t ngx_http_read_client_request_body(ngx_http_request_t *r, ngx_http_client_body_handler_pt post_handler) { size_t preread; ssize_t size; ngx_int_t rc; ngx_buf_t *b; ngx_chain_t out; ngx_http_request_body_t *rb; ngx_http_core_loc_conf_t *clcf; r->main->count++; // 请求没有请求体、主动放弃了请求体，没有分配body的buffer，则直接调用post_handler指向的回调方法 if (r != r->main || r->request_body || r->discard_body) { r->request_body_no_buffering = 0; post_handler(r); return NGX_OK; } if (ngx_http_test_expect(r) != NGX_OK) { rc = NGX_HTTP_INTERNAL_SERVER_ERROR; goto done; } // 申请内存用于存放request body rb = ngx_pcalloc(r->pool, sizeof(ngx_http_request_body_t)); if (rb == NULL) { rc = NGX_HTTP_INTERNAL_SERVER_ERROR; goto done; } /* * set by ngx_pcalloc(): * * rb->bufs = NULL; * rb->buf = NULL; * rb->free = NULL; * rb->busy = NULL; * rb->chunked = NULL; */ rb->rest = -1; rb->post_handler = post_handler; r->request_body = rb; // 检查请求的header里的content-length字段，如果没有或者是小于零，则不读取body，直接调用post_handler回调方法 if (r->headers_in.content_length_n < 0 && !r->headers_in.chunked) { r->request_body_no_buffering = 0; post_handler(r); return NGX_OK; } #if (NGX_HTTP_V2) if (r->stream) { rc = ngx_http_v2_read_request_body(r); goto done; } #endif // 如果header部分比较小(client_header_buffer_size)，则再读取完header的时候，可能已经读取到了一部分的body内容 preread = r->header_in->last - r->header_in->pos; if (preread) { /* there is the pre-read part of the request body */ ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http client request body preread %uz", preread); out.buf = r->header_in; out.next = NULL; rc = ngx_http_request_body_filter(r, &out); if (rc != NGX_OK) { goto done; } r->request_length += preread - (r->header_in->last - r->header_in->pos); if (!r->headers_in.chunked && rb->rest > 0 && rb->rest <= (off_t) (r->header_in->end - r->header_in->last)) { /* the whole request body may be placed in r->header_in */ b = ngx_calloc_buf(r->pool); if (b == NULL) { rc = NGX_HTTP_INTERNAL_SERVER_ERROR; goto done; } b->temporary = 1; b->start = r->header_in->pos; b->pos = r->header_in->pos; b->last = r->header_in->last; b->end = r->header_in->end; rb->buf = b; r->read_event_handler = ngx_http_read_client_request_body_handler; r->write_event_handler = ngx_http_request_empty_handler; rc = ngx_http_do_read_client_request_body(r); goto done; } } else { /* set rb->rest */ if (ngx_http_request_body_filter(r, NULL) != NGX_OK) { rc = NGX_HTTP_INTERNAL_SERVER_ERROR; goto done; } } if (rb->rest == 0) { /* the whole request body was pre-read */ r->request_body_no_buffering = 0; post_handler(r); return NGX_OK; } if (rb->rest < 0) { ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0, "negative request body rest"); rc = NGX_HTTP_INTERNAL_SERVER_ERROR; goto done; } clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module); size = clcf->client_body_buffer_size; size += size >> 2; /* TODO: honor r->request_body_in_single_buf */ if (!r->headers_in.chunked && rb->rest < size) { size = (ssize_t) rb->rest; if (r->request_body_in_single_buf) { size += preread; } } else { size = clcf->client_body_buffer_size; } rb->buf = ngx_create_temp_buf(r->pool, size); if (rb->buf == NULL) { rc = NGX_HTTP_INTERNAL_SERVER_ERROR; goto done; } r->read_event_handler = ngx_http_read_client_request_body_handler; r->write_event_handler = ngx_http_request_empty_handler; rc = ngx_http_do_read_client_request_body(r); done: if (r->request_body_no_buffering && (rc == NGX_OK || rc == NGX_AGAIN)) { if (rc == NGX_OK) { r->request_body_no_buffering = 0; } else { /* rc == NGX_AGAIN */ r->reading_body = 1; } r->read_event_handler = ngx_http_block_reading; post_handler(r); } if (rc >= NGX_HTTP_SPECIAL_RESPONSE) { r->main->count--; } return rc; }

发送HTTP头部给客户端

ngx_http_send_header

发送响应包体给客户端

ngx_http_output_filter

作用: 发送HTTP响应的包体内容 位置: ngx_http_core_module.c 原型： ngx_int_t ngx_http_output_filter(ngx_http_request_t *r, ngx_chain_t *in) { ngx_int_t rc; ngx_connection_t *c; c = r->connection; ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0, "http output filter \"%V?%V\"", &r->uri, &r->args); rc = ngx_http_top_body_filter(r, in); if (rc == NGX_ERROR) { /* NGX_ERROR may be returned by any filter */ c->error = 1; } return rc; }

二、conf相关

ngx_http_conf_get_module_main_conf

示例： ngx_http_core_main_conf_t *cmcf; cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module);

ngx_http_get_module_loc_conf

示例: ngx_http_hello_loc_conf_t* my_conf; my_conf = ngx_http_get_module_loc_conf(r, ngx_http_hello_module);

三、 log记录相关

ngx_log_error

示例1 ： ngx_log_error(NGX_LOG_EMERG, r->connection->log, 0, "this is a test!");