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/* Copyright (C) 2002-2005 RealVNC Ltd. All Rights Reserved.
*
* 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>
#include <sys/time.h>
#ifdef _WIN32
#include <winsock2.h>
#define close closesocket
#undef errno
#define errno WSAGetLastError()
#include <os/winerrno.h>
#else
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#endif
/* Old systems have select() in sys/time.h */
#ifdef HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif
#include <rdr/FdInStream.h>
#include <rdr/Exception.h>
using namespace rdr;
enum { DEFAULT_BUF_SIZE = 8192 };
FdInStream::FdInStream(int fd_, int timeoutms_,
bool closeWhenDone_)
: fd(fd_), closeWhenDone(closeWhenDone_),
timeoutms(timeoutms_), blockCallback(0),
timing(false), timeWaitedIn100us(5), timedKbits(0)
{
}
FdInStream::FdInStream(int fd_, FdInStreamBlockCallback* blockCallback_)
: fd(fd_), timeoutms(0), blockCallback(blockCallback_),
timing(false), timeWaitedIn100us(5), timedKbits(0)
{
}
FdInStream::~FdInStream()
{
if (closeWhenDone) close(fd);
}
void FdInStream::setTimeout(int timeoutms_) {
timeoutms = timeoutms_;
}
void FdInStream::setBlockCallback(FdInStreamBlockCallback* blockCallback_)
{
blockCallback = blockCallback_;
timeoutms = 0;
}
bool FdInStream::fillBuffer(size_t maxSize, bool wait)
{
size_t n = readWithTimeoutOrCallback((U8*)end, maxSize, wait);
if (n == 0)
return false;
end += n;
return true;
}
//
// readWithTimeoutOrCallback() reads up to the given length in bytes from the
// file descriptor into a buffer. If the wait argument is false, then zero is
// returned if no bytes can be read without blocking. Otherwise if a
// blockCallback is set, it will be called (repeatedly) instead of blocking.
// If alternatively there is a timeout set and that timeout expires, it throws
// a TimedOut exception. Otherwise it returns the number of bytes read. It
// never attempts to recv() unless select() indicates that the fd is readable -
// 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 recv()
// returning EINTR.
//
size_t FdInStream::readWithTimeoutOrCallback(void* buf, size_t len, bool wait)
{
struct timeval before, after;
if (timing)
gettimeofday(&before, 0);
int n;
while (true) {
do {
fd_set fds;
struct timeval tv;
struct timeval* tvp = &tv;
if (!wait) {
tv.tv_sec = tv.tv_usec = 0;
} else if (timeoutms != -1) {
tv.tv_sec = timeoutms / 1000;
tv.tv_usec = (timeoutms % 1000) * 1000;
} else {
tvp = 0;
}
FD_ZERO(&fds);
FD_SET(fd, &fds);
n = select(fd+1, &fds, 0, 0, tvp);
} while (n < 0 && errno == EINTR);
if (n > 0) break;
if (n < 0) throw SystemException("select",errno);
if (!wait) return 0;
if (!blockCallback) throw TimedOut();
blockCallback->blockCallback();
}
do {
n = ::recv(fd, (char*)buf, len, 0);
} while (n < 0 && errno == EINTR);
if (n < 0) throw SystemException("read",errno);
if (n == 0) throw EndOfStream();
if (timing) {
gettimeofday(&after, 0);
int newTimeWaited = ((after.tv_sec - before.tv_sec) * 10000 +
(after.tv_usec - before.tv_usec) / 100);
int newKbits = n * 8 / 1000;
// limit rate to between 10kbit/s and 40Mbit/s
if (newTimeWaited > newKbits*1000) newTimeWaited = newKbits*1000;
if (newTimeWaited < newKbits/4) newTimeWaited = newKbits/4;
timeWaitedIn100us += newTimeWaited;
timedKbits += newKbits;
}
return n;
}
void FdInStream::startTiming()
{
timing = true;
// Carry over up to 1s worth of previous rate for smoothing.
if (timeWaitedIn100us > 10000) {
timedKbits = timedKbits * 10000 / timeWaitedIn100us;
timeWaitedIn100us = 10000;
}
}
void FdInStream::stopTiming()
{
timing = false;
if (timeWaitedIn100us < timedKbits/2)
timeWaitedIn100us = timedKbits/2; // upper limit 20Mbit/s
}
unsigned int FdInStream::kbitsPerSecond()
{
// The following calculation will overflow 32-bit arithmetic if we have
// received more than about 50Mbytes (400Mbits) since we started timing, so
// it should be OK for a single RFB update.
return timedKbits * 10000 / timeWaitedIn100us;
}
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