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/* Copyright (C) 2002-2005 RealVNC Ltd. All Rights Reserved.
* Copyright 2011 Pierre Ossman for Cendio AB
* Copyright 2017 Peter Astrand <astrand@cendio.se> for Cendio AB
*
* This is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this software; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
* USA.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <string.h>
#include <errno.h>
#ifdef _WIN32
#include <winsock2.h>
#undef errno
#define errno WSAGetLastError()
#include <os/winerrno.h>
#else
#include <sys/types.h>
#include <unistd.h>
#include <sys/time.h>
#include <sys/socket.h>
#endif
/* Old systems have select() in sys/time.h */
#ifdef HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif
#include <rdr/FdOutStream.h>
#include <rdr/Exception.h>
#include <rfb/util.h>
using namespace rdr;
enum { DEFAULT_BUF_SIZE = 16384 };
FdOutStream::FdOutStream(int fd_, bool blocking_, int timeoutms_, size_t bufSize_)
: fd(fd_), blocking(blocking_), timeoutms(timeoutms_),
bufSize(bufSize_ ? bufSize_ : DEFAULT_BUF_SIZE), offset(0)
{
ptr = start = sentUpTo = new U8[bufSize];
end = start + bufSize;
gettimeofday(&lastWrite, NULL);
}
FdOutStream::~FdOutStream()
{
try {
blocking = true;
flush();
} catch (Exception&) {
}
delete [] start;
}
void FdOutStream::setTimeout(int timeoutms_) {
timeoutms = timeoutms_;
}
void FdOutStream::setBlocking(bool blocking_) {
blocking = blocking_;
}
size_t FdOutStream::length()
{
return offset + ptr - sentUpTo;
}
int FdOutStream::bufferUsage()
{
return ptr - sentUpTo;
}
unsigned FdOutStream::getIdleTime()
{
return rfb::msSince(&lastWrite);
}
void FdOutStream::flush()
{
while (sentUpTo < ptr) {
size_t n = writeWithTimeout((const void*) sentUpTo,
ptr - sentUpTo,
blocking? timeoutms : 0);
// Timeout?
if (n == 0) {
// If non-blocking then we're done here
if (!blocking)
break;
throw TimedOut();
}
sentUpTo += n;
offset += n;
}
// Managed to flush everything?
if (sentUpTo == ptr)
ptr = sentUpTo = start;
}
size_t FdOutStream::overrun(size_t itemSize, size_t nItems)
{
if (itemSize > bufSize)
throw Exception("FdOutStream overrun: max itemSize exceeded");
// First try to get rid of the data we have
flush();
// Still not enough space?
if (itemSize > (size_t)(end - ptr)) {
// Can we shuffle things around?
// (don't do this if it gains us less than 25%)
if (((size_t)(sentUpTo - start) > bufSize / 4) &&
(itemSize < bufSize - (ptr - sentUpTo))) {
memmove(start, sentUpTo, ptr - sentUpTo);
ptr = start + (ptr - sentUpTo);
sentUpTo = start;
} else {
// Have to get rid of more data, so turn off non-blocking
// for a bit...
bool realBlocking;
realBlocking = blocking;
blocking = true;
flush();
blocking = realBlocking;
}
}
size_t nAvail;
nAvail = (end - ptr) / itemSize;
if (nAvail < nItems)
return nAvail;
return nItems;
}
//
// writeWithTimeout() writes up to the given length in bytes from the given
// buffer to the file descriptor. If there is a timeout set and that timeout
// expires, it throws a TimedOut exception. Otherwise it returns the number of
// bytes written. It never attempts to send() unless select() indicates that
// the fd is writable - this means it can be used on an fd which has been set
// non-blocking. It also has to cope with the annoying possibility of both
// select() and send() returning EINTR.
//
size_t FdOutStream::writeWithTimeout(const void* data, size_t length, int timeoutms)
{
int n;
do {
fd_set fds;
struct timeval tv;
struct timeval* tvp = &tv;
if (timeoutms != -1) {
tv.tv_sec = timeoutms / 1000;
tv.tv_usec = (timeoutms % 1000) * 1000;
} else {
tvp = NULL;
}
FD_ZERO(&fds);
FD_SET(fd, &fds);
n = select(fd+1, 0, &fds, 0, tvp);
} while (n < 0 && errno == EINTR);
if (n < 0)
throw SystemException("select", errno);
if (n == 0)
return 0;
do {
// select only guarantees that you can write SO_SNDLOWAT without
// blocking, which is normally 1. Use MSG_DONTWAIT to avoid
// blocking, when possible.
#ifndef MSG_DONTWAIT
n = ::send(fd, (const char*)data, length, 0);
#else
n = ::send(fd, (const char*)data, length, MSG_DONTWAIT);
#endif
} while (n < 0 && (errno == EINTR));
if (n < 0)
throw SystemException("write", errno);
gettimeofday(&lastWrite, NULL);
return n;
}
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