smart-sensor-example/random-sensor-ldmc/rpc_service.hpp

115 lines
3.8 KiB
C++

#pragma once
#include <iostream>
#include <string>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <cstring>
#include <map>
#include <functional>
template < typename T_RpcTag >
struct RpcService {
private:
uint32_t port;
std::map< T_RpcTag, std::function<void( char const * input, size_t input_len, int client_sock )> > handler;
public:
RpcService(uint32_t port) :port(port)
{}
template < typename F, typename Request, typename Response >
void register_handler(T_RpcTag tag, std::function<F(Request const&, Response&)> f) {
handler.emplace(
tag,
std::function([f]( char const * request_buffer, size_t len, int client_sock ) {
Request * request = (Request*) (request_buffer + sizeof(T_RpcTag));
Response response;
f( *request, response );
send(client_sock, (void const*)&response, sizeof(response), 0);
})
);
}
void handle_client(int client_sock) {
char request_buffer[1024];
ssize_t bytes_received;
// Receive data from client
bytes_received = recv(client_sock, request_buffer, sizeof(request_buffer), 0);
if (bytes_received == -1) {
std::cerr << "Failed to receive data" << std::endl;
return;
}
printf("received %lu bytes:\n", bytes_received);
for( size_t i = 0; i < bytes_received;)
{
printf("%4lx : ", i);
for( size_t col = 0; col < 8; ++col ) {
printf("%2x ", request_buffer[i++]);
}
printf("\n");
}
if (bytes_received >= sizeof(T_RpcTag) ) {
T_RpcTag * tag = (T_RpcTag*) request_buffer;
if( handler.contains(*tag) ){
(handler[*tag])( request_buffer, bytes_received, client_sock );
} else {
std::string response("invalid RPC");
send(client_sock, response.c_str(), response.length(), 0);
}
}
}
int run() {
int server_sock, client_sock;
struct sockaddr_in server_addr, client_addr;
socklen_t addr_len = sizeof(client_addr);
// Create socket
server_sock = socket(AF_INET, SOCK_STREAM, 0);
if (server_sock == -1) {
std::cerr << "Failed to create socket" << std::endl;
return 1;
}
// Set up server address
server_addr.sin_family = AF_INET;
server_addr.sin_addr.s_addr = INADDR_ANY;
server_addr.sin_port = htons(port);
// Bind socket to the address and port
if (bind(server_sock, (struct sockaddr*)&server_addr, sizeof(server_addr)) == -1) {
std::cerr << "Failed to bind socket" << std::endl;
return 1;
}
// Listen for incoming connections
if (listen(server_sock, 3) == -1) {
std::cerr << "Failed to listen on socket" << std::endl;
return 1;
}
std::cout << "Server listening on port " << port << "..." << std::endl;
// Accept and handle client connections
while (true) {
client_sock = accept(server_sock, (struct sockaddr*)&client_addr, &addr_len);
if (client_sock == -1) {
std::cerr << "Failed to accept connection" << std::endl;
continue;
}
std::cout << "Client connected!" << std::endl;
handle_client(client_sock);
// Close the client socket after handling the request
close(client_sock);
}
// Close the server socket
close(server_sock);
}
};