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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
-
- #ifndef vncmin
- #define vncmin(a,b) (((a) < (b)) ? (a) : (b))
- #endif
- #ifndef vncmax
- #define vncmax(a,b) (((a) > (b)) ? (a) : (b))
- #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,
- MIN_BULK_SIZE = 1024 };
-
- FdInStream::FdInStream(int fd_, int timeoutms_, int bufSize_,
- bool closeWhenDone_)
- : fd(fd_), closeWhenDone(closeWhenDone_),
- timeoutms(timeoutms_), blockCallback(0),
- timing(false), timeWaitedIn100us(5), timedKbits(0),
- bufSize(bufSize_ ? bufSize_ : DEFAULT_BUF_SIZE), offset(0)
- {
- ptr = end = start = new U8[bufSize];
- }
-
- FdInStream::FdInStream(int fd_, FdInStreamBlockCallback* blockCallback_,
- int bufSize_)
- : fd(fd_), timeoutms(0), blockCallback(blockCallback_),
- timing(false), timeWaitedIn100us(5), timedKbits(0),
- bufSize(bufSize_ ? bufSize_ : DEFAULT_BUF_SIZE), offset(0)
- {
- ptr = end = start = new U8[bufSize];
- }
-
- FdInStream::~FdInStream()
- {
- delete [] start;
- if (closeWhenDone) close(fd);
- }
-
-
- void FdInStream::setTimeout(int timeoutms_) {
- timeoutms = timeoutms_;
- }
-
- void FdInStream::setBlockCallback(FdInStreamBlockCallback* blockCallback_)
- {
- blockCallback = blockCallback_;
- timeoutms = 0;
- }
-
- int FdInStream::pos()
- {
- return offset + ptr - start;
- }
-
- void FdInStream::readBytes(void* data, int length)
- {
- if (length < MIN_BULK_SIZE) {
- InStream::readBytes(data, length);
- return;
- }
-
- U8* dataPtr = (U8*)data;
-
- int n = end - ptr;
- if (n > length) n = length;
-
- memcpy(dataPtr, ptr, n);
- dataPtr += n;
- length -= n;
- ptr += n;
-
- while (length > 0) {
- n = readWithTimeoutOrCallback(dataPtr, length);
- dataPtr += n;
- length -= n;
- offset += n;
- }
- }
-
-
- int FdInStream::overrun(int itemSize, int nItems, bool wait)
- {
- if (itemSize > bufSize)
- throw Exception("FdInStream overrun: max itemSize exceeded");
-
- if (end - ptr != 0)
- memmove(start, ptr, end - ptr);
-
- offset += ptr - start;
- end -= ptr - start;
- ptr = start;
-
- int bytes_to_read;
- while (end < start + itemSize) {
- bytes_to_read = start + bufSize - end;
- if (!timing) {
- // When not timing, we must be careful not to read too much
- // extra data into the buffer. Otherwise, the line speed
- // estimation might stay at zero for a long time: All reads
- // during timing=1 can be satisfied without calling
- // readWithTimeoutOrCallback. However, reading only 1 or 2 bytes
- // bytes is ineffecient.
- bytes_to_read = vncmin(bytes_to_read, vncmax(itemSize*nItems, 8));
- }
- int n = readWithTimeoutOrCallback((U8*)end, bytes_to_read, wait);
- if (n == 0) return 0;
- end += n;
- }
-
- if (itemSize * nItems > end - ptr)
- nItems = (end - ptr) / itemSize;
-
- return nItems;
- }
-
- //
- // 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.
- //
-
- int FdInStream::readWithTimeoutOrCallback(void* buf, int 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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