#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 )
+, socket_type(_socket_type)
+{
+}
+
+
/// set options like fast reuse and keepalive every socket should have
void socket_handler::set_socket_options(int 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 amound of data which is tried to write
+ * to the socket when data needs to be sended.
+ * Since writeing 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 check if new data is waiting on the raw socket
- @param usec_timeout wait until new data is found, max timeout usecs.
+ @param[in,out] usec_timeout wait until new data is found, max timeout usecs.
-1: wait endless
- NULL: no timeout
+ 0: return instantly
*/
-bool socket_handler::data_waiting(long long usec_timeout)
+bool socket_handler::data_waiting(long long usec_timeout,long long* usec_timeout_remaining)
{
// just our socket
fd_set active_fd_set;
{
timeout_ptr = &tval;
- // timeout von long long usec in int sec + int usec umrechnen
+ // convert timeout from long long usec to int sec + int usec
tval.tv_sec = usec_timeout / 1000000;
tval.tv_usec = usec_timeout % 1000000;
}
- if(select (FD_SETSIZE, &active_fd_set, NULL, NULL, timeout_ptr) > 0)
+ 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;
+
+ if (ret > 0)
return true;
else
return false;
/** @brief read data from the raw socket and copy it into the provided buffer
@param buffer the buffer where to append the new data
- @param usec_timeout wait until new data is found, max timeout usecs.
+ @param[in,out] usec_timeout wait until new data is found, max timeout usecs.
-1: wait endless
- NULL: no timeout
+ 0: return instantly
*/
-bool socket_handler::fill_buffer(std::string& buffer, long long usec_timeout)
+bool socket_handler::fill_buffer(std::string& buffer, long long usec_timeout, long long *timeout_remaining)
{
// fast path for timeout==0
- if (usec_timeout==0 || data_waiting(usec_timeout))
+ if (usec_timeout==0 || data_waiting(usec_timeout,timeout_remaining))
return fill_buffer(buffer);
else
return false;
// Data read -> store it
if (nbytes > 0)
{
- buffer.assign(socket_buffer,nbytes);
- LOGSTREAM(debug,nbytes << " read");
+ buffer.append(socket_buffer,nbytes);
+ LOGSTREAM(debug,nbytes << " bytes read");
}
// more data waiting -> recurse
while ((rtn=::write(sock, data.data()+offset, write_size)) &&
rtn == -1 && (errno == EAGAIN || errno == EINTR))
{
- usleep (80000);
+ fd_set write_set[1];
+ fd_set except_set[1];
+ FD_ZERO(write_set);
+ FD_ZERO(except_set);
+ FD_SET(sock, write_set);
+ FD_SET(sock, except_set);
+ // let's wait for the socket to become writable again...
+ //TODO: use a timeout here?
+ int n= ::select(sock+1, NULL, write_set, except_set, NULL);
+ if (n==1 && ! FD_ISSET(sock,write_set) && FD_ISSET(sock, except_set))
+ {
+ // if we are selected but cannot write and have an exception
+ // we have serious trouble...
+ LOGSTREAM(error,"exception on socket; cannot write any more.");
+ //TODO: exception?
+ return;
+ }
LOGSTREAM(debug,"resuming write() call after EAGAIN or EINTR");
}
}
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&)
}
git://developer.intra2net.com / libt2n / blobdiff