RGW中request的处理流程是什么

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请求处理流程图

以civetweb为例

1. rgw_main.cc为整个radosgw服务的入口，main()函数中根据在ceph.conf的rgw frontends参数设置来选择不同的前端类型，之后执行相应的run()方法实现整个frontend服务的启动。注意这里会根据ceph.conf中rgw_enable_apis的设置，实现s3、swift、admin等多种类型的接口生成不同的handler，具体代码如下

 #src/rgw/rgw_main.cc get_str_list(g_conf->rgw_enable_apis, apis); #获取接口类型列表   map apis_map;   for (list::iterator li = apis.begin(); li != apis.end(); ++li) {     apis_map[*li] = true;   } ...   if (apis_map.count("s3") > 0 || s3website_enabled) {     if (! swift_at_root) {       rest.register_default_mgr(set_logging(new RGWRESTMgr_S3(s3website_enabled))); #设置S3接口默认handler为RGWRESTMgr_S3 ...   if (apis_map.count("swift") > 0) {     do_swift = true;     swift_init(g_ceph_context);     RGWRESTMgr_SWIFT* const swift_resource = new RGWRESTMgr_SWIFT;#设置swift接口默认handler为RGWRESTMgr_SWIFT     ...

2. 之后在对应的rgw_civetweb_fronted.cc中，根据之前介绍的civetweb启动流程，设置相应启动参数，之后使用mg_start()完成civetweb的启动。（注意参数中callback设置的是civetweb_callback）

 #src/rgw/rgw_civetweb_frontend.cc int RGWMongooseFrontend::run() {   char thread_pool_buf[32];   snprintf(thread_pool_buf, sizeof(thread_pool_buf), "%d",        (int)g_conf->rgw_thread_pool_size);   string port_str;   map conf_map = conf->get_config_map();   conf->get_val("port", "80", &port_str);   conf_map.erase("port");   std::replace(port_str.begin(), port_str.end(), '+', ',');   conf_map["listening_ports"] = port_str; #civetweb默认启动监听端口   set_conf_default(conf_map, "enable_keep_alive", "yes"); #keep_alive参数设置   set_conf_default(conf_map, "num_threads", thread_pool_buf); #默认threads设置   set_conf_default(conf_map, "decode_url", "no");   ...   struct mg_callbacks cb;   memset((void *)&cb, 0, sizeof(cb));   cb.begin_request = civetweb_callback; #回调函数设置   cb.log_message = rgw_civetweb_log_callback;   cb.log_access = rgw_civetweb_log_access_callback;   ctx = mg_start(&cb, &env, (const char **)&options); #启动服务   if (!ctx) {     return -EIO;   }   return 0; } /* RGWMongooseFrontend::run */

3. 经过上一步的设置，在civetweb_callback中每一个request请求都需要经过process_request()进行处理，注意每个request请求都会绑定一组RGWRados(负责底层Librados的数据读写)/RGWREST（对应request和Response的处理）/OpsLogSocket（日志消息记录）

#src/rgw/rgw_civetweb_frontend.ccstatic int civetweb_callback(struct mg_connection* conn) {struct mg_request_info* req_info = mg_get_request_info(conn);RGWMongooseEnv* pe = static_cast(req_info->user_data); {// hold a read lock over access to pe->store for reconfigurationRWLock::RLocker lock(pe->mutex);RGWRados* store = pe->store; RGWREST* rest = pe->rest; OpsLogSocket* olog = pe->olog; RGWRequest req(store->get_new_req_id());RGWMongoose client_io(conn);int ret = process_request(pe->store, rest, &req, &client_io, olog); #每个request请求绑定一组前面的RGWRados、RGWREST、OpsLogSocket ...

4. 之后调用rgw_process.cc中的process_request(),其中rest->get_handler根据请求的URL是否包含bucket、object信息，获取到对应的handler类型，之后调用handler->get_op(store)根据前面取得的handler对应request_method获取到最终的handler，之后触发handler对应的pre_exec()、execute()、complete()完整整个request请求的处理，代码如下:

 #src/rgw/rgw_process.cc int process_request(RGWRados* store, RGWREST* rest, RGWRequest* req,GWStreamIO* client_io, OpsLogSocket* olog) {int ret = 0; client_io->init(g_ceph_context); ... RGWHandler_REST *handler = rest->get_handler(store, s, client_io, &mgr,&init_error); #这里根据URL里面是否包含bucket、Object字段会进一步获取到对应的handler类型 if (init_error != 0) { abort_early(s, NULL, init_error, NULL); goto done; } dout(10) << "handler=" << typeid(*handler).name() << dendl; should_log = mgr->get_logging(); req->log_format(s, "getting op %d", s->op); op = handler->get_op(store); #这里根据request_method获取到最终处理request请求的handler类型 ... req->log(s, "pre-executing"); op->pre_exec(); #请求预处理 req->log(s, "executing"); op->execute(); #具体请求的具体实现 req->log(s, "completing"); op->complete(); #完成请求处理

 #src/rgw/rgw_process.cc RGWHandler_REST* RGWRESTMgr_S3::get_handler(struct req_state *s) {   bool is_s3website = enable_s3website && (s->prot_flags & RGW_REST_WEBSITE);   int ret =     RGWHandler_REST_S3::init_from_header(s,                     is_s3website ? RGW_FORMAT_HTML :                     RGW_FORMAT_XML, true);   if (ret < 0)     return NULL;   RGWHandler_REST* handler;   // TODO: Make this more readable   if (is_s3website) {     if (s->init_state.url_bucket.empty()) {       handler = new RGWHandler_REST_Service_S3Website;     } else if (s->object.empty()) {       handler = new RGWHandler_REST_Bucket_S3Website;     } else {       handler = new RGWHandler_REST_Obj_S3Website;     }   } else {     if (s->init_state.url_bucket.empty()) {         handler = new RGWHandler_REST_Service_S3; #bucket为空则切换到RGWHandler_REST_Service_S3     } else if (s->object.empty()) {         handler = new RGWHandler_REST_Bucket_S3; #obj为空则切换RGWHandler_REST_Bucket_S3     } else {         handler = new RGWHandler_REST_Obj_S3; #bucket和Object都不为空，则切换到RGWHandler_REST_Obj_S3     }   }   ldout(s->cct, 20) << __func__ << " handler=" << typeid(*handler).name()             << dendl;   return handler; }

 #src/rgw/rgw_rest.cc RGWOp* RGWHandler_REST::get_op(RGWRados* store) {   RGWOp *op;   switch (s->op)  #这里s对应一个req_state的结构体   { rest->op    case OP_GET:      op = op_get();      break;    case OP_PUT:      op = op_put();      break;    case OP_DELETE:      op = op_delete();      break;    case OP_HEAD:      op = op_head();      break;    case OP_POST:      op = op_post();      break;    case OP_COPY:      op = op_copy();      break;    case OP_OPTIONS:      op = op_options();      break;    default:      return NULL;   }   if (op) {     op->init(store, s, this);   }   return op; } /* get_op */

 结构体定义 struct req_state {   CephContext *cct;   RGWClientIO *cio;   RGWRequest *req; /// XXX: re-remove??   http_op op; #对应一个枚举类型，具体如下   RGWOpType op_type;   ...   enum http_op {   OP_GET,   OP_PUT,   OP_DELETE,   OP_HEAD,   OP_POST,   OP_COPY,   OP_OPTIONS,   OP_UNKNOWN, };

URL->handler过程

理解整个URL转换handler的过程，能够感觉request信息快速定位具体的op操作，方便debug，整个过程用下面一张图总结。

感谢各位的阅读，以上就是"RGW中request的处理流程是什么"的内容了，经过本文的学习后，相信大家对RGW中request的处理流程是什么这一问题有了更深刻的体会，具体使用情况还需要大家实践验证。这里是，小编将为大家推送更多相关知识点的文章，欢迎关注！