KasmVNC/common/rdr/FdInStream.cxx
Pierre Ossman fde088ce65 Improved bandwidth monitoring
Now measures over an entire update, which should hopefully give us more
stable values. They are still small values for fast networks though so
increase precision in the values we keep.
2021-03-29 10:52:51 +03:00

143 lines
3.7 KiB
C++

/* 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)
{
}
FdInStream::FdInStream(int fd_, FdInStreamBlockCallback* blockCallback_)
: fd(fd_), timeoutms(0), blockCallback(blockCallback_)
{
}
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)
{
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();
return n;
}