128 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			128 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C++
		
	
	
	
| // Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
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| // Distributed under the MIT License (http://opensource.org/licenses/MIT)
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| 
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| #pragma once
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| 
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| #ifdef _WIN32
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|     #error include tcp_client-windows.h instead
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| #endif
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| 
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| // tcp client helper
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| #include <spdlog/common.h>
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| #include <spdlog/details/os.h>
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| 
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| #include <arpa/inet.h>
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| #include <netdb.h>
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| #include <netinet/in.h>
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| #include <netinet/tcp.h>
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| #include <sys/socket.h>
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| #include <unistd.h>
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| 
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| #include <string>
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| 
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| namespace spdlog {
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| namespace details {
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| class tcp_client {
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|     int socket_ = -1;
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| 
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| public:
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|     bool is_connected() const { return socket_ != -1; }
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| 
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|     void close() {
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|         if (is_connected()) {
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|             ::close(socket_);
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|             socket_ = -1;
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|         }
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|     }
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| 
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|     int fd() const { return socket_; }
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| 
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|     ~tcp_client() { close(); }
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| 
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|     // try to connect or throw on failure
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|     void connect(const std::string &host, int port) {
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|         close();
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|         struct addrinfo hints {};
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|         memset(&hints, 0, sizeof(struct addrinfo));
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|         hints.ai_family = AF_UNSPEC;      // To work with IPv4, IPv6, and so on
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|         hints.ai_socktype = SOCK_STREAM;  // TCP
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|         hints.ai_flags = AI_NUMERICSERV;  // port passed as as numeric value
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|         hints.ai_protocol = 0;
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| 
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|         auto port_str = std::to_string(port);
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|         struct addrinfo *addrinfo_result;
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|         auto rv = ::getaddrinfo(host.c_str(), port_str.c_str(), &hints, &addrinfo_result);
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|         if (rv != 0) {
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|             throw_spdlog_ex(fmt_lib::format("::getaddrinfo failed: {}", gai_strerror(rv)));
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|         }
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| 
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|         // Try each address until we successfully connect(2).
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|         int last_errno = 0;
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|         for (auto *rp = addrinfo_result; rp != nullptr; rp = rp->ai_next) {
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| #if defined(SOCK_CLOEXEC)
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|             const int flags = SOCK_CLOEXEC;
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| #else
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|             const int flags = 0;
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| #endif
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|             socket_ = ::socket(rp->ai_family, rp->ai_socktype | flags, rp->ai_protocol);
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|             if (socket_ == -1) {
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|                 last_errno = errno;
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|                 continue;
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|             }
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|             rv = ::connect(socket_, rp->ai_addr, rp->ai_addrlen);
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|             if (rv == 0) {
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|                 break;
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|             }
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|             last_errno = errno;
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|             ::close(socket_);
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|             socket_ = -1;
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|         }
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|         ::freeaddrinfo(addrinfo_result);
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|         if (socket_ == -1) {
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|             throw_spdlog_ex("::connect failed", last_errno);
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|         }
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| 
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|         // set TCP_NODELAY
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|         int enable_flag = 1;
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|         ::setsockopt(socket_, IPPROTO_TCP, TCP_NODELAY, reinterpret_cast<char *>(&enable_flag),
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|                      sizeof(enable_flag));
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| 
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|         // prevent sigpipe on systems where MSG_NOSIGNAL is not available
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| #if defined(SO_NOSIGPIPE) && !defined(MSG_NOSIGNAL)
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|         ::setsockopt(socket_, SOL_SOCKET, SO_NOSIGPIPE, reinterpret_cast<char *>(&enable_flag),
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|                      sizeof(enable_flag));
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| #endif
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| 
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| #if !defined(SO_NOSIGPIPE) && !defined(MSG_NOSIGNAL)
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|     #error "tcp_sink would raise SIGPIPE since neither SO_NOSIGPIPE nor MSG_NOSIGNAL are available"
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| #endif
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|     }
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| 
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|     // Send exactly n_bytes of the given data.
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|     // On error close the connection and throw.
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|     void send(const char *data, size_t n_bytes) {
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|         size_t bytes_sent = 0;
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|         while (bytes_sent < n_bytes) {
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| #if defined(MSG_NOSIGNAL)
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|             const int send_flags = MSG_NOSIGNAL;
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| #else
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|             const int send_flags = 0;
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| #endif
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|             auto write_result =
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|                 ::send(socket_, data + bytes_sent, n_bytes - bytes_sent, send_flags);
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|             if (write_result < 0) {
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|                 close();
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|                 throw_spdlog_ex("write(2) failed", errno);
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|             }
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| 
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|             if (write_result == 0)  // (probably should not happen but in any case..)
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|             {
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|                 break;
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|             }
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|             bytes_sent += static_cast<size_t>(write_result);
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|         }
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|     }
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| };
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| }  // namespace details
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| }  // namespace spdlog
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