#include <sstream>
#include <iostream>
+#include <algorithm>
#include "socket_handler.hxx"
#include "t2n_exception.hxx"
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)
{
/// by the connection class you are using.
void socket_handler::close()
{
+ LOGSTREAM(debug,"close connection");
// graceful shutdown
shutdown(sock,SHUT_RDWR);
::close(sock);
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
0: return instantly
+ @param[out] usec_timeout_remaining microseconds from the timeout that were not used
*/
bool socket_handler::data_waiting(long long usec_timeout,long long* usec_timeout_remaining)
{
@param[in,out] usec_timeout wait until new data is found, max timeout usecs.
-1: wait endless
0: return instantly
+ @param[out] usec_timeout_remaining microseconds from the timeout that were not used
*/
-bool socket_handler::fill_buffer(std::string& buffer, long long usec_timeout, long long *timeout_remaining)
+bool socket_handler::fill_buffer(std::string& buffer, long long usec_timeout, long long *usec_timeout_remaining)
{
// fast path for timeout==0
- if (usec_timeout==0 || data_waiting(usec_timeout,timeout_remaining))
+ if (usec_timeout==0 || data_waiting(usec_timeout,usec_timeout_remaining))
return fill_buffer(buffer);
else
return false;
char socket_buffer[recv_buffer_size];
int nbytes = read (sock, socket_buffer, recv_buffer_size);
+
if (nbytes < 0)
{
if (errno == EAGAIN)
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
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;
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));
}
+
}
git://developer.intra2net.com / libt2n / blobdiff