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/*************************************************************************
** InputBuffer.hpp **
** **
** This file is part of dvisvgm -- a fast DVI to SVG converter **
** Copyright (C) 2005-2022 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 INPUTBUFFER_HPP
#define INPUTBUFFER_HPP
#include <algorithm>
#include <cstring>
#include <istream>
#include <string>
#include <ostream>
struct InputBuffer {
virtual ~InputBuffer () =default;
virtual int get () =0;
virtual int peek () const =0;
virtual int peek (size_t n) const =0;
virtual bool eof () const =0;
virtual void invalidate () =0;
};
class StreamInputBuffer : public InputBuffer {
public:
explicit StreamInputBuffer (std::istream &is, size_t bufsize=1024);
StreamInputBuffer (const StreamInputBuffer &ib) =delete;
~StreamInputBuffer () override;
int get () override;
int peek () const override;
int peek (size_t n) const override;
bool eof () const override {return pos() == _size1 && _size2 == 0;}
void invalidate () override {_bufptr = _buf1+_size1; _size2 = 0;}
void operator = (const StreamInputBuffer &ib) =delete;
protected:
int fillBuffer (uint8_t *buf);
size_t pos () const {return _bufptr-_buf1;}
private:
std::istream &_is;
const size_t _bufsize; ///< maximal number of bytes each buffer can hold
uint8_t *_buf1; ///< pointer to first buffer
uint8_t *_buf2; ///< pointer to second buffer
size_t _size1; ///< number of bytes in buffer 1
size_t _size2; ///< number of bytes in buffer 2
uint8_t *_bufptr; ///< pointer to next byte to read
};
class StringInputBuffer : public InputBuffer {
public:
explicit StringInputBuffer (const std::string &str) : _str(&str) {}
StringInputBuffer (const StreamInputBuffer &ib) =delete;
void assign (const std::string &str) {_str = &str; _pos=0;}
int get () override {return _pos < _str->length() ? _str->at(_pos++) : -1;}
int peek () const override {return _pos < _str->length() ? _str->at(_pos) : -1;}
int peek (size_t n) const override {return _pos+n < _str->length() ? _str->at(_pos+n) : -1;}
bool eof () const override {return _pos >= _str->length();}
void invalidate () override {_pos = _str->length();}
private:
const std::string *_str;
size_t _pos=0;
};
class CharInputBuffer : public InputBuffer {
public:
CharInputBuffer (const char *buf, size_t size) : _pos(buf), _size(buf ? size : 0) {}
CharInputBuffer (const CharInputBuffer &ib) =delete;
int get () override {
if (_size == 0)
return -1;
else {
_size--;
return *_pos++;
}
}
void assign (const char *buf, size_t size) {
_pos = buf;
_size = size;
}
void assign (const char *buf) {assign(buf, std::strlen(buf));}
int peek () const override {return _size > 0 ? *_pos : -1;}
int peek (size_t n) const override {return _size >= n ? _pos[n] : -1;}
bool eof () const override {return _size == 0;}
void invalidate () override {_size = 0;}
private:
const char *_pos;
size_t _size;
};
class SplittedCharInputBuffer : public InputBuffer {
public:
SplittedCharInputBuffer (const char *buf1, size_t s1, const char *buf2, size_t s2);
SplittedCharInputBuffer (const SplittedCharInputBuffer &ib) =delete;
int get () override;
int peek () const override;
int peek (size_t n) const override;
bool eof () const override {return _size[_index] == 0;}
void invalidate () override {_size[_index] = 0;}
private:
const char *_buf[2];
size_t _size[2];
int _index;
};
class TextStreamInputBuffer : public StreamInputBuffer {
public:
explicit TextStreamInputBuffer (std::istream &is) : StreamInputBuffer(is) {}
int get () override;
int line () const {return _line;}
int col () const {return _col;}
private:
int _line=1, _col=1;
};
#endif
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