aria2/src/Sequence.h

102 lines
2.5 KiB
C++

/* <!-- copyright */
/*
* aria2 - The high speed download utility
*
* Copyright (C) 2006 Tatsuhiro Tsujikawa
*
* 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 2 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* In addition, as a special exception, the copyright holders give
* permission to link the code of portions of this program with the
* OpenSSL library under certain conditions as described in each
* individual source file, and distribute linked combinations
* including the two.
* You must obey the GNU General Public License in all respects
* for all of the code used other than OpenSSL. If you modify
* file(s) with this exception, you may extend this exception to your
* version of the file(s), but you are not obligated to do so. If you
* do not wish to do so, delete this exception statement from your
* version. If you delete this exception statement from all source
* files in the program, then also delete it here.
*/
/* copyright --> */
#ifndef _D_SEQUENCE_H_
#define _D_SEQUENCE_H_
#include <deque>
namespace aria2 {
template<typename T>
class Sequence
{
public:
// Generates value in [_first, _last). _last is not included.
class Value {
private:
T _first;
T _last;
public:
Value(const T& first, const T& last):_first(first), _last(last) {}
T next()
{
return _first++;
}
bool hasNext() const
{
return _first != _last;
}
};
typedef std::deque<Value> Values;
private:
Values _values;
public:
Sequence(const Values& values):
_values(values) {}
T next()
{
if(_values.empty()) {
return T();
}
T t = _values.front().next();
if(!_values.front().hasNext()) {
_values.pop_front();
}
return t;
}
bool hasNext()
{
return !_values.empty();
}
std::deque<T> flush()
{
std::deque<T> r;
while(hasNext()) {
r.push_back(next());
}
return r;
}
};
} // namespace aria2
#endif // _D_SEQUENCE_H_