SRPCHttpServer中不支持自定url映射方法

[rayinengineer]

像BRPC的服务框架，支持自定义url的映射，如

if (server.AddService(&queue_svc,
                      brpc::SERVER_DOESNT_OWN_SERVICE,
                      "/v1/queue/start   => start,"
                      "/v1/queue/stop    => stop,"
                      "/v1/queue/stats/* => get_stats") != 0) {
    LOG(ERROR) << "Fail to add queue_svc";
    return -1;
}

目前这边修改了一个

srpc/src/rpc_client.h 中增加两个模板特例

static inline void __set_request_uri_by_uri(const ParsedURI *uri,std::string& request_uri)
{
	if (uri->path && uri->path[0])
		request_uri = uri->path;
	else
		return;

	if (uri->query && uri->query[0])
	{
		request_uri += "?";
		request_uri += uri->query;
	}
}

template<>
inline void RPCClient<RPCTYPESRPCHttp>::task_init(COMPLEXTASK *task) const
{
	__task_init(task);
	std::string header_host;

	if (this->has_addr_info)
		header_host += this->params.host + ":" + std::to_string(this->params.port);
	else
		__set_host_by_uri(task->get_current_uri(), this->params.is_ssl, header_host);

	task->get_req()->set_header_pair("Host", header_host.c_str());

	std::string request_uri;
	__set_request_uri_by_uri(task->get_current_uri(),request_uri);
	if (!request_uri.empty())
	{
		task->get_req()->set_request_uri(request_uri);
	}
}

template<>
inline void RPCClient<RPCTYPEThriftHttp>::task_init(COMPLEXTASK *task) const
{
	__task_init(task);
	std::string header_host;

	if (this->has_addr_info)
		header_host += this->params.host + ":" + std::to_string(this->params.port);
	else
		__set_host_by_uri(task->get_current_uri(), this->params.is_ssl, header_host);

	task->get_req()->set_header_pair("Host", header_host.c_str());

	std::string request_uri;
	__set_request_uri_by_uri(task->get_current_uri(),request_uri);
	if (!request_uri.empty())
	{
		task->get_req()->set_request_uri(request_uri);
	}
}

srpc/src/message/rpc_message_srpc.cc

bool SRPCHttpRequest::serialize_meta()
{
	if (this->buf->size() > 0x7FFFFFFF)
		return false;

	RPCMeta *meta = static_cast<RPCMeta *>(this->meta);
	int data_type = meta->data_type();
	int compress_type = meta->compress_type();

	set_http_version("HTTP/1.1");
	set_method("POST");
	
	if (NULL == get_request_uri())
	{
		set_request_uri("/" + meta->mutable_request()->service_name() +
						"/" + meta->mutable_request()->method_name());
	}
	
	...
	
}

srpc/src/rpc_server.h中增加该接口，该接口比add_service多了一个原来的路径映射到service 方法，如"Test/abc => Echo,Test/cde => Echo2"

int add_service(RPCService *service, const std::string& mapping);

template<class RPCTYPE>
inline int RPCServer<RPCTYPE>::add_service(RPCService* service,const std::string& mapping)
{
	size_t pos = 0;
	size_t equalPos;
	while ((equalPos = mapping.find("=>", pos)) != std::string::npos) 
	{
		size_t nextKeyPos = mapping.find(',', equalPos);
		if (nextKeyPos == std::string::npos) {
			nextKeyPos = mapping.length();
        	}
		if (equalPos - pos > 0 && nextKeyPos - equalPos - 2 > 0)//key value
        	{
			std::string key = mapping.substr(pos, equalPos - pos);
            		std::string value = "/" + service->get_name() +
							"/" + mapping.substr(equalPos + 2, nextKeyPos - equalPos - 2);
			this->path_map.emplace(key,value);
		}
		pos = nextKeyPos + 1;
	}

	return add_service(service);
}

增加特例实现，因为get_request_uri、set_request_uri只有在HTTP请求中才能获取到

template<>
void RPCServer<RPCTYPESRPCHttp>::server_process(NETWORKTASK *task) const
{
	auto *req = task->get_req();
	auto *resp = task->get_resp();
	int status_code;

	const auto it = this->path_map.find(req->get_request_uri());
	if (it != this->path_map.cend())
	{
		req->set_request_uri(it->second);
	}

	if (!req->deserialize_meta())
		status_code = RPCStatusMetaError;
	else
	{
		auto *server_task = static_cast<TASK *>(task);
		RPCModuleData *task_data = server_task->mutable_module_data();
		req->get_meta_module_data(*task_data);

		RPCTYPESRPCHttp::server_reply_init(req, resp);
		auto *service = this->find_service(req->get_service_name());

		if (!service)
			status_code = RPCStatusServiceNotFound;
		else
		{
			auto *rpc = service->find_method(req->get_method_name());

			if (!rpc)
				status_code = RPCStatusMethodNotFound;
			else
			{
				for (auto *module : this->modules)
				{
					if (module)
						module->server_task_begin(server_task, *task_data);
				}

				status_code = req->decompress();
				if (status_code == RPCStatusOK)
					status_code = (*rpc)(server_task->worker);
			}
		}

		SERIES *series = static_cast<SERIES *>(series_of(task));
		series->set_module_data(task_data);
	}

	resp->set_status_code(status_code);
}

[rayinengineer]

上述的srpc/src/rpc_client.h 中可以自定义url，如果有，就使用自定义的，如果没有就采用默认的；

struct srpc::RPCClientParams params = srpc::RPC_CLIENT_PARAMS_DEFAULT;
params.url = "http://127.0.0.1:1415/Test/Echo";
Example::SRPCHttpClient client(&params);

srpc/src/rpc_server.h中加url映射,调用方式：

server.add_service(&impl,"/Test/Echo=>Echo," "/Test/xxx=>Test");

[Barenboim]

感谢感谢！我们看一下。也可以发PR讨论。

[holmes1412]

@rayinengineer hi，感谢你提的这个需求，感觉非常合理呀~ 参考了下其他rpc系统的trans coding做法，没有统一的规范，所以我们当前使用了json来表达。比如：

SRPCHttpServer server;
ExampleServiceImpl impl;
server.add_service(&impl, "{ \"/test/echo\": \"Echo\"," "\"/no/method/for/test\": \"Test\" }");

麻烦有空了看看这个格式是否方便呢？