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/*************************************************************************
** StreamCounter.h **
** **
** This file is part of dvisvgm -- the DVI to SVG converter **
** Copyright (C) 2005-2009 Martin Gieseking <martin.gieseking@uos.de> **
** **
** This program 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 3 of **
** the License, or (at your option) any later version. **
** **
** This program 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 program; if not, see <http://www.gnu.org/licenses/>. **
*************************************************************************/
#ifndef STREAMCOUNTER_H
#define STREAMCOUNTER_H
#include <ostream>
#include "types.h"
/** This class template is used to count the number of characters
* written to a stream buffer. It simply counts the characters written
* and forwards them to the target buffer. */
template <typename C, typename T=std::char_traits<C> >
class CountingStreamBuf : public std::basic_streambuf<C,T>
{
public:
explicit CountingStreamBuf (std::basic_streambuf<C,T> *b)
: targetBuf(b), counter(0) {}
UInt64 count () const {return counter;}
void reset () {counter = 0;}
protected:
CountingStreamBuf (const CountingStreamBuf &csb);
CountingStreamBuf& operator = (const CountingStreamBuf &csb);
typename T::int_type overflow (typename T::int_type c=T::eof()) {
typename T::int_type n = targetBuf->sputc(c);
if (!T::eq_int_type(c, T::eof()) && !T::eq_int_type(n, T::eof()))
counter++;
return n;
}
std::streamsize xsputn (const C *buf, std::streamsize bufsize) {
std::streamsize n = targetBuf->sputn(buf, bufsize);
counter += n;
return n;
}
private:
std::basic_streambuf<C,T> *targetBuf;
UInt64 counter;
};
/** This class template assigns a counting buffer to a stream. It makes
* the use of CountingStreamBuf more comfortable. */
template <typename C, typename T=std::char_traits<C> >
class StreamCounter
{
public:
explicit StreamCounter (std::basic_ios<C,T> &stream)
: targetStream(stream),
targetBuf(stream.rdbuf()),
countingBuf(new CountingStreamBuf<C,T>(stream.rdbuf()))
{
stream.rdbuf(countingBuf);
valid = true;
}
~StreamCounter () {
if (valid)
targetStream.rdbuf(targetBuf);
delete countingBuf;
}
UInt64 count () const {return countingBuf->count();}
void reset () {countingBuf->reset();}
void invalidate () {valid = false;}
protected:
StreamCounter (const StreamCounter &csf);
StreamCounter operator = (const StreamCounter &csf);
private:
bool valid; ///< true if target stream is valid
std::basic_ios<C,T> &targetStream;
std::basic_streambuf<C,T> *targetBuf;
CountingStreamBuf<C,T> *countingBuf;
};
#endif
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