1 定义ngx_http_init_static_location_trees 函数 定义在 ./nginx-1.24.0/src/http/ngx_http.cstaticngx_int_tngx_http_init_static_location_trees(ngx_conf_t*cf,ngx_http_core_loc_conf_t*pclcf){ngx_queue_t*q,*locations;ngx_http_core_loc_conf_t*clcf;ngx_http_location_queue_t*lq;locationspclcf-locations;if(locationsNULL){returnNGX_OK;}if(ngx_queue_empty(locations)){returnNGX_OK;}for(qngx_queue_head(locations);q!ngx_queue_sentinel(locations);qngx_queue_next(q)){lq(ngx_http_location_queue_t*)q;clcflq-exact?lq-exact:lq-inclusive;if(ngx_http_init_static_location_trees(cf,clcf)!NGX_OK){returnNGX_ERROR;}}if(ngx_http_join_exact_locations(cf,locations)!NGX_OK){returnNGX_ERROR;}ngx_http_create_locations_list(locations,ngx_queue_head(locations));pclcf-static_locationsngx_http_create_locations_tree(cf,locations,0);if(pclcf-static_locationsNULL){returnNGX_ERROR;}returnNGX_OK;}ngx_http_init_static_location_trees 函数的主要作用是 在配置解析阶段递归地初始化静态 location 树static location trees 用于后续请求处理时快速匹配 location。2 详解1 函数签名staticngx_int_tngx_http_init_static_location_trees(ngx_conf_t*cf,ngx_http_core_loc_conf_t*pclcf)返回值 NGX_OK成功。 NGX_ERROR失败参数 ngx_conf_t *cf 指向配置解析上下文 ngx_http_core_loc_conf_t *pclcf 父级的 http_core_loc_conf_t 结构体指针。 它代表当前正在处理的作用域通常是一个 server 块或者是嵌套的 location 块。2 逻辑流程1 局部变量 2 locations 链表检查 3 遍历递归 4 合并 5 排序 6 构建二叉查找树 7 返回成功1 局部变量{ngx_queue_t*q,*locations;ngx_http_core_loc_conf_t*clcf;ngx_http_location_queue_t*lq;2 locations 链表检查locationspclcf-locations;if(locationsNULL){returnNGX_OK;}if(ngx_queue_empty(locations)){returnNGX_OK;}从父配置 pclcf 中获取其下属的 locations 链表ngx_queue_t 类型。 如果没有定义任何 location或者列表为空则直接返回成功NGX_OK无需构建树。3 遍历递归for(qngx_queue_head(locations);q!ngx_queue_sentinel(locations);qngx_queue_next(q)){lq(ngx_http_location_queue_t*)q;clcflq-exact?lq-exact:lq-inclusive;if(ngx_http_init_static_location_trees(cf,clcf)!NGX_OK){returnNGX_ERROR;}}遍历父 location 的所有直接子 location 并对每个子 location 递归地调用自身 以构建其内部的静态 location 树4 合并if(ngx_http_join_exact_locations(cf,locations)!NGX_OK){returnNGX_ERROR;}将同一层级内具有相同名称的精确匹配和前缀匹配 location 合并到同一个节点中5 排序ngx_http_create_locations_list(locations,ngx_queue_head(locations));6 构建二叉查找树pclcf-static_locationsngx_http_create_locations_tree(cf,locations,0);if(pclcf-static_locationsNULL){returnNGX_ERROR;}使用整理排序后的链表 来构建二叉查找树7 返回成功returnNGX_OK;}