ibrcommon/ibrcommon/net/tcpstream.cpp

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/*
 * tcpstream.cpp
 *
 *  Created on: 29.07.2009
 *      Author: morgenro
 */

#include "ibrcommon/config.h"
#include "ibrcommon/Logger.h"
#include "ibrcommon/net/tcpstream.h"
#include "ibrcommon/thread/MutexLock.h"
#include <netinet/in.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/tcp.h>
#include <errno.h>
#include <signal.h>
#include <fcntl.h>
#include <string.h>

namespace ibrcommon
{
        tcpstream::tcpstream(int socket) :
                iostream(this), errmsg(ERROR_NONE), _socket(socket), in_buf_(new char[BUFF_SIZE]), out_buf_(new char[BUFF_SIZE]), _nonblocking(false), _timeout(0)
        {
                // create a pipe for interruption
                if (pipe(_interrupt_pipe_read) < 0)
                {
                        printf ("Error %d creating pipe\n", errno);
                        exit (-1);
                }

                // create a pipe for interruption
                if (pipe(_interrupt_pipe_write) < 0)
                {
                        printf ("Error %d creating pipe\n", errno);
                        exit (-1);
                }

                // set the pipe to non-blocking
                vsocket::set_non_blocking(_interrupt_pipe_read[0]);
                vsocket::set_non_blocking(_interrupt_pipe_read[1]);
                vsocket::set_non_blocking(_interrupt_pipe_write[0]);
                vsocket::set_non_blocking(_interrupt_pipe_write[1]);

                // Initialize get pointer.  This should be zero so that underflow is called upon first read.
                setg(0, 0, 0);
                setp(out_buf_, out_buf_ + BUFF_SIZE - 1);
        }

        tcpstream::~tcpstream()
        {
                delete[] in_buf_;
                delete[] out_buf_;

                // finally, close the socket
                close();
        }

        string tcpstream::getAddress() const
        {
                struct ::sockaddr_in sa;
                int iLen = sizeof(sa);

                getpeername(_socket, (sockaddr*) &sa, (socklen_t*) &iLen);
                return inet_ntoa(sa.sin_addr);
        }

        int tcpstream::getPort() const
        {
                struct ::sockaddr_in sa;
                int iLen = sizeof(sa);

                getpeername(_socket, (sockaddr*) &sa, (socklen_t*) &iLen);
                return ntohs(sa.sin_port);
        }

        void tcpstream::interrupt()
        {
                ::write(_interrupt_pipe_read[1], "i", 1);
                ::write(_interrupt_pipe_write[1], "i", 1);
        }

        void tcpstream::close(bool errorcheck)
        {
                static ibrcommon::Mutex close_lock;
                ibrcommon::MutexLock l(close_lock);

                if (_socket == -1)
                {
                        if (errorcheck) throw ConnectionClosedException();
                        return;
                }

                int sock = _socket;
                _socket = -1;

                // unblock all socket operations
                interrupt();

                if ((::close(sock) == -1) && errorcheck)
                {
                        throw ConnectionClosedException();
                }
        }

        int tcpstream::sync()
        {
                int ret = std::char_traits<char>::eq_int_type(this->overflow(
                                std::char_traits<char>::eof()), std::char_traits<char>::eof()) ? -1
                                : 0;

                return ret;
        }

        int tcpstream::select(int int_pipe, bool &read, bool &write, bool &error, int timeout) throw (select_exception)
        {
                // return if the stream was closed
                if (_socket == -1)
                {
                        throw select_exception(select_exception::SELECT_CLOSED);
                }

                if (!_nonblocking)
                {
                        // set the tcp socket to non-blocking
                        vsocket::set_non_blocking(_socket);
                        
                        // do not set this mode again
                        _nonblocking = true;
                }

                int high_fd = _socket;

                fd_set fds_read, fds_write, fds_error;
                fd_set *fdsp_write = NULL, *fdsp_error = NULL;

                FD_ZERO(&fds_read);
                FD_ZERO(&fds_write);
                FD_ZERO(&fds_error);

                if (read)
                {
                        FD_SET(_socket, &fds_read);
                }

                if (write)
                {
                        FD_SET(_socket, &fds_write);
                        fdsp_write = &fds_write;
                }

                if (error)
                {
                        FD_SET(_socket, &fds_error);
                        fdsp_error = &fds_error;
                }

                read = false;
                write = false;
                error = false;

                // socket for the self-pipe trick
                FD_SET(int_pipe, &fds_read);
                if (high_fd < int_pipe) high_fd = int_pipe;

                int res = 0;

                // set timeout
                struct timeval tv;
                tv.tv_sec = timeout;
                tv.tv_usec = 0;

                bool _continue = true;
                while (_continue)
                {
                        if (timeout > 0)
                        {
                                res = ::select(high_fd + 1, &fds_read, fdsp_write, fdsp_error, &tv);
                        }
                        else
                        {
                                res = ::select(high_fd + 1, &fds_read, fdsp_write, fdsp_error, NULL);
                        }

                        // check for select error
                        if (res < 0)
                        {
                                throw select_exception(select_exception::SELECT_ERROR);
                        }

                        // check for timeout
                        if (res == 0)
                        {
                                throw select_exception(select_exception::SELECT_TIMEOUT);
                        }

                        if (FD_ISSET(int_pipe, &fds_read))
                        {
                                IBRCOMMON_LOGGER_DEBUG(25) << "unblocked by self-pipe-trick" << IBRCOMMON_LOGGER_ENDL;

                                // this was an interrupt with the self-pipe-trick
                                char buf[2];
                                ::read(int_pipe, buf, 2);
                        }

                        // return if the stream was closed
                        if (_socket == -1)
                        {
                                throw select_exception(select_exception::SELECT_CLOSED);
                        }

                        if (FD_ISSET(_socket, &fds_read))
                        {
                                read = true;
                                _continue = false;
                        }

                        if (FD_ISSET(_socket, &fds_write))
                        {
                                write = true;
                                _continue = false;
                        }

                        if (FD_ISSET(_socket, &fds_error))
                        {
                                error = true;
                                _continue = false;
                        }
                }

                return res;
        }

        int tcpstream::overflow(int c)
        {
                char *ibegin = out_buf_;
                char *iend = pptr();

                // mark the buffer as free
                setp(out_buf_, out_buf_ + BUFF_SIZE - 1);

                if (!std::char_traits<char>::eq_int_type(c, std::char_traits<char>::eof()))
                {
                        *iend++ = std::char_traits<char>::to_char_type(c);
                }

                // if there is nothing to send, just return
                if ((iend - ibegin) == 0)
                {
                        IBRCOMMON_LOGGER_DEBUG(90) << "tcpstream::overflow() nothing to sent" << IBRCOMMON_LOGGER_ENDL;
                        return std::char_traits<char>::not_eof(c);
                }

                bool read = false, write = true, error = false;
                select(_interrupt_pipe_write[0], read, write, error);

                // bytes to send
                size_t bytes = (iend - ibegin);

                // send the data
                ssize_t ret = ::send(_socket, out_buf_, (iend - ibegin), MSG_NOSIGNAL);

                if (ret < 0)
                {
                        switch (errno)
                        {
                        case EPIPE:
                                // connection has been reset
                                errmsg = ERROR_EPIPE;
                                break;

                        case ECONNRESET:
                                // Connection reset by peer
                                errmsg = ERROR_RESET;
                                break;

                        case EAGAIN:
                                // sent failed but we should retry again
                                return overflow(c);

                        default:
                                errmsg = ERROR_WRITE;
                        }

                        // failure
                        close();
                        std::stringstream ss; ss << "<tcpstream> send() in tcpstream failed: " << errno;
                        throw ConnectionClosedException(ss.str());
                }
                else
                {
                        // check how many bytes are sent
                        if ((size_t)ret < bytes)
                        {
                                // we did not sent all bytes
                                char *resched_begin = ibegin + ret;
                                char *resched_end = iend;

                                // bytes left to send
                                size_t bytes_left = resched_end - resched_begin;

                                // move the data to the begin of the buffer
                                ::memcpy(ibegin, resched_begin, bytes_left);

                                // new free buffer
                                char *buffer_begin = ibegin + bytes_left;

                                // mark the buffer as free
                                setp(buffer_begin, out_buf_ + BUFF_SIZE - 1);
                        }
                }

                return std::char_traits<char>::not_eof(c);
        }

        int tcpstream::underflow()
        {
                try {
                        bool read = true;
                        bool write = false;
                        bool error = false;

                        select(_interrupt_pipe_read[0], read, write, error, _timeout);

                        // read some bytes
                        int bytes = ::recv(_socket, in_buf_, BUFF_SIZE, 0);

                        // end of stream
                        if (bytes == 0)
                        {
                                errmsg = ERROR_CLOSED;
                                close();
                                IBRCOMMON_LOGGER_DEBUG(40) << "<tcpstream> recv() returned zero: " << errno << IBRCOMMON_LOGGER_ENDL;
                                return std::char_traits<char>::eof();
                        }
                        else if (bytes < 0)
                        {
                                switch (errno)
                                {
                                case EPIPE:
                                        // connection has been reset
                                        errmsg = ERROR_EPIPE;
                                        break;

                                default:
                                        errmsg = ERROR_READ;
                                }

                                close();
                                IBRCOMMON_LOGGER_DEBUG(40) << "<tcpstream> recv() failed: " << errno << IBRCOMMON_LOGGER_ENDL;
                                return std::char_traits<char>::eof();
                        }

                        // Since the input buffer content is now valid (or is new)
                        // the get pointer should be initialized (or reset).
                        setg(in_buf_, in_buf_, in_buf_ + bytes);

                        return std::char_traits<char>::not_eof(in_buf_[0]);
                } catch (const select_exception &ex) {
                        return std::char_traits<char>::eof();
                }
        }

        void tcpstream::setTimeout(unsigned int value)
        {
                _timeout = value;
        }

        void tcpstream::enableKeepalive()
        {
                /* Set the option active */
                int optval = 1;
                if(setsockopt(_socket, SOL_SOCKET, SO_KEEPALIVE, &optval, sizeof(optval)) < 0) {
                        throw ibrcommon::vsocket_exception("<tcpstream> can not activate keepalives");
                }
        }

        void tcpstream::enableLinger(int l)
        {
                // set linger option to the socket
                struct linger linger;

                linger.l_onoff = 1;
                linger.l_linger = l;
                ::setsockopt(_socket, SOL_SOCKET, SO_LINGER, &linger, sizeof(linger));
        }

        void tcpstream::enableNoDelay()
        {
                int set = 1;
                ::setsockopt(_socket, IPPROTO_TCP, TCP_NODELAY, (char *)&set, sizeof(set));
        }

}