X-Git-Url: http://developer.intra2net.com/git/?p=libt2n;a=blobdiff_plain;f=src%2Fsocket_handler.cpp;h=532c7f87efd94906f51a862e0c306021105f70ca;hp=ed37e4d739e99088de339260913c6be6511afcb7;hb=c7857475c8b0f02cac3ce29a617a4d542fa59f37;hpb=45a2ebc9695c4d7be6548b7e0f800d117ae56a0b diff --git a/src/socket_handler.cpp b/src/socket_handler.cpp index ed37e4d..532c7f8 100644 --- a/src/socket_handler.cpp +++ b/src/socket_handler.cpp @@ -35,6 +35,7 @@ #include #include +#include #include "socket_handler.hxx" #include "t2n_exception.hxx" @@ -45,6 +46,16 @@ using namespace std; namespace libt2n { +socket_handler::socket_handler(int _sock, socket_type_value _socket_type) +: sock(_sock) +, recv_buffer_size( default_recv_buffer_size ) +, write_block_size( default_write_block_size ) +, write_timeout( default_write_timeout ) +, socket_type(_socket_type) +{ +} + + /// set options like fast reuse and keepalive every socket should have void socket_handler::set_socket_options(int sock) { @@ -96,6 +107,53 @@ bool socket_handler::is_closed() return !(r & O_ACCMODE); } + +/** + * @brief set a new size for the receive buffer. + * @param new_recv_buffer_size the new size for the receive buffer. + * + * The receive buffer determines the amount of data which is tried to read at once + * from the underlying socket. + * + * The value is normalized to be at least 512 bytes and at max 32K bytes. + */ +void socket_handler::set_recv_buffer_size(unsigned int new_recv_buffer_size) +{ + recv_buffer_size= std::max( 512u, std::min( 32u * 1024u, new_recv_buffer_size )); +} // + + +/** + * @brief set new size for the data chunks when writeing. + * @param new_write_block_size the new chunk size. + * + * The write block size determines the amount of data which is tried to write + * to the socket when data needs to be sended. + * Since writing data is done in a loop, this does not limit the amunt of data which can + * be written. + * + * The value is normalized to be at least 512 bytes and at max 32K bytes. + */ +void socket_handler::set_write_block_size(unsigned int new_write_block_size) +{ + write_block_size= std::max( 512u, std::min( 32u * 1024u, new_write_block_size )); +} // + + +/** + * @brief set new timeout for writing a block + * @param new_write_timeout the new timeout in usecs, -1: wait endless + * + * The write timeout determines the maximum amount of time that is waited + * between writing each block. If the timeout is exceeded, write will + * throw t2n_transfer_error + */ +void socket_handler::set_write_timeout(long long new_write_timeout) +{ + write_block_size=new_write_timeout; +} // + + /** @brief check if new data is waiting on the raw socket @param[in,out] usec_timeout wait until new data is found, max timeout usecs. -1: wait endless @@ -126,6 +184,7 @@ bool socket_handler::data_waiting(long long usec_timeout,long long* usec_timeout int ret=select (FD_SETSIZE, &active_fd_set, NULL, NULL, timeout_ptr); // return the timeout we did not use + // todo: this is linux specific according to man 2 select if (usec_timeout > 0 && usec_timeout_remaining != NULL) *usec_timeout_remaining=(tval.tv_sec*1000000)+tval.tv_usec; @@ -172,11 +231,7 @@ bool socket_handler::fill_buffer(std::string& buffer) try_again=true; } else - { - LOGSTREAM(error,"error reading from socket : " << strerror(errno)); - // TODO: exception? - return false; - } + EXCEPTIONSTREAM(error,t2n_transfer_error,"error reading from socket : " << strerror(errno)); } // End-of-file @@ -190,7 +245,7 @@ bool socket_handler::fill_buffer(std::string& buffer) // Data read -> store it if (nbytes > 0) { - buffer.assign(socket_buffer,nbytes); + buffer.append(socket_buffer,nbytes); LOGSTREAM(debug,nbytes << " bytes read"); } @@ -217,26 +272,21 @@ void socket_handler::socket_write(const std::string& data) write_size = data.size()-offset; int rtn; - while ((rtn=::write(sock, data.data()+offset, write_size)) && - rtn == -1 && (errno == EAGAIN || errno == EINTR)) + while ((rtn=::write(sock, data.data()+offset, write_size)) == -1 && + (errno == EAGAIN || errno == EINTR)) { - usleep (80000); + wait_ready_to_write(sock,write_timeout); LOGSTREAM(debug,"resuming write() call after EAGAIN or EINTR"); } if (rtn == -1) - { - LOGSTREAM(error,"write() returned " << strerror(errno)); - // TODO: exception? - return; - } + EXCEPTIONSTREAM(error,t2n_transfer_error,"write() returned " << strerror(errno)); else if (rtn != write_size) { - LOGSTREAM(error,"write() wrote " << rtn << " bytes, should have been " + LOGSTREAM(debug,"write() wrote " << rtn << " bytes, should have been " << write_size << " (complete: " << data.size() << ")"); - // TODO: exception? - return; + write_size = rtn; } offset += write_size; @@ -245,6 +295,51 @@ void socket_handler::socket_write(const std::string& data) LOGSTREAM(debug,"wrote " << data.size() << " bytes"); return; +} // eo socket_handler::socket_write(const std::string&) + +/// wait until the socket is ready to write again +void socket_handler::wait_ready_to_write(int socket, long long write_block_timeout) +{ + // prepare socket sets + fd_set write_set[1]; + fd_set except_set[1]; + FD_ZERO(write_set); + FD_ZERO(except_set); + FD_SET(socket, write_set); + FD_SET(socket, except_set); + + // prepare timeout struct + struct timeval tval; + struct timeval *timeout_ptr; + + if (write_block_timeout == -1) + timeout_ptr = NULL; + else + { + timeout_ptr = &tval; + + // convert timeout from long long usec to int sec + int usec + tval.tv_sec = write_block_timeout / 1000000; + tval.tv_usec = write_block_timeout % 1000000; + } + + // let's wait for the socket to become writable again... + int rtn; + while ((rtn=::select(socket+1, NULL, write_set, except_set, timeout_ptr)) ==-1 && errno == EINTR); + + if (rtn > 0 && (!FD_ISSET(socket,write_set)) && FD_ISSET(socket, except_set)) + { + // if we are selected but cannot write and have an exception + // we have serious trouble... + EXCEPTIONSTREAM(error,t2n_transfer_error,"exception on socket; cannot write any more."); + } + + if (rtn==0) + EXCEPTIONSTREAM(error,t2n_transfer_error,"timeout on select() for write"); + + if (rtn==-1) + EXCEPTIONSTREAM(error,t2n_transfer_error,"cannot select() for write: " << strerror(errno)); } + }