docs-04-client.md

中文版

04 - RPC Client

• Each Client corresponds to one specific target/one specific cluster
• Each Client corresponds to one specific network communication protocol
• Each Client corresponds to one specific IDL

Sample

You can follow the detailed example below:

• Following the above example, the client is relatively simple and you can call the method directly.
• Use Example::XXXClient to create a client instance of some RPC. The IP+port or URL of the target is required.
• With the client instance, directly call the rpc function Echo. This is an asynchronous request, and the callback function will be invoked after the request is completed.
• For the usage of the RPC Context, please check RPC Context.

#include <stdio.h>
#include "example.srpc.h"
#include "workflow/WFFacilities.h"

using namespace srpc;

int main()
{
    Example::SRPCClient client("127.0.0.1", 1412);
    EchoRequest req;
    req.set_message("Hello!");
    req.set_name("SRPCClient");

    WFFacilities::WaitGroup wait_group(1);

    client.Echo(&req, [&wait_group](EchoResponse *response, RPCContext *ctx) {
        if (ctx->success())
            printf("%s\n", response->DebugString().c_str());
        else
            printf("status[%d] error[%d] errmsg:%s\n",
                    ctx->get_status_code(), ctx->get_error(), ctx->get_errmsg());
        wait_group.done();
    });

    wait_group.wait();
    return 0;
}

Client startup parameters

Client can be started directly by passing in ip, port, or through client startup parameters.

The above example:

Example::SRPCClient client("127.0.0.1", 1412);

is equivalent to:

struct RPCClientParams param = RPC_CLIENT_PARAMS_DEFAULT;
param.host = "127.0.0.1";
param.port = 1412;
Example::SRPCClient client(&param);

also equivalent to:

struct RPCClientParams param = RPC_CLIENT_PARAMS_DEFAULT;
param.url = "srpc://127.0.0.1:1412";
Example::SRPCClient client(&param);

Note that RPC_CLIENT_PARAMS_DEFAULT must be used to initialize the client's parameters, which contains a RPCTaskParams, including the default data_type, compress_type, retry_max and various timeouts. The specific struct can refer to rpc_options.h.