99 lines
3.1 KiB
C++
99 lines
3.1 KiB
C++
/******************************************************************************
|
|
QtAV: Multimedia framework based on Qt and FFmpeg
|
|
Copyright (C) 2012-2016 Wang Bin <wbsecg1@gmail.com>
|
|
|
|
* This file is part of QtAV (from 2015)
|
|
|
|
This library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
This library 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
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with this library; if not, write to the Free Software
|
|
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
******************************************************************************/
|
|
|
|
#ifndef QTAV_RING_H
|
|
#define QTAV_RING_H
|
|
|
|
#include <cassert>
|
|
#include <vector>
|
|
|
|
namespace FAV {
|
|
template<typename T, typename C>
|
|
class ring_api {
|
|
public:
|
|
ring_api() : m_0(0), m_1(0), m_s(0) {}
|
|
void push_back(const T &t);
|
|
void pop_front();
|
|
T &front() { return m_data[m_0]; }
|
|
const T &front() const { return m_data[m_0]; }
|
|
T &back() { return m_data[m_1]; }
|
|
const T &back() const { return m_data[m_1]; }
|
|
virtual size_t capacity() const = 0;
|
|
size_t size() const { return m_s;}
|
|
bool empty() const { return size() == 0;}
|
|
// need at() []?
|
|
const T &at(size_t i) const { assert(i < m_s); return m_data[index(m_0+i)];}
|
|
const T &operator[](size_t i) const { return at(i);}
|
|
T &operator[](size_t i) {assert(i < m_s); return m_data[index(m_0+i)];}
|
|
protected:
|
|
size_t index(size_t i) const { return i < capacity() ? i : i - capacity();} // i always [0,capacity())
|
|
size_t m_0, m_1;
|
|
size_t m_s;
|
|
C m_data;
|
|
};
|
|
|
|
template<typename T>
|
|
class ring : public ring_api<T, std::vector<T> > {
|
|
using ring_api<T, std::vector<T> >::m_data; // why need this?
|
|
public:
|
|
ring(size_t capacity) : ring_api<T, std::vector<T> >() {
|
|
m_data.reserve(capacity);
|
|
m_data.resize(capacity);
|
|
}
|
|
size_t capacity() const {return m_data.size();}
|
|
};
|
|
template<typename T, int N>
|
|
class static_ring : public ring_api<T, T[N]> {
|
|
using ring_api<T, T[N]>::m_data; // why need this?
|
|
public:
|
|
static_ring() : ring_api<T, T[N]>() {}
|
|
size_t capacity() const {return N;}
|
|
};
|
|
|
|
template<typename T, typename C>
|
|
void ring_api<T,C>::push_back(const T &t) {
|
|
if (m_s == capacity()) {
|
|
m_data[m_0] = t;
|
|
m_0 = index(++m_0);
|
|
m_1 = index(++m_1);
|
|
} else if (empty()) {
|
|
m_s = 1;
|
|
m_0 = m_1 = 0;
|
|
m_data[m_0] = t;
|
|
} else {
|
|
m_data[index(m_0 + m_s)] = t;
|
|
++m_1;
|
|
++m_s;
|
|
}
|
|
}
|
|
|
|
template<typename T, typename C>
|
|
void ring_api<T,C>::pop_front() {
|
|
assert(!empty());
|
|
if (empty())
|
|
return;
|
|
m_data[m_0] = T(); //erase the old data
|
|
m_0 = index(++m_0);
|
|
--m_s;
|
|
}
|
|
} //namespace FAV
|
|
#endif // QTAV_RING_H
|