furnace/src/engine/fixedQueue.h

141 lines
3.4 KiB
C++

/**
* Furnace Tracker - multi-system chiptune tracker
* Copyright (C) 2021-2023 tildearrow and contributors
*
* 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.
*/
#ifndef _FIXED_QUEUE_H
#define _FIXED_QUEUE_H
#include <stdint.h>
#include "../ta-log.h"
template<typename T, size_t items> struct FixedQueue {
size_t readPos, writePos;
T data[items];
T& front();
T& back();
bool pop();
bool push(const T& item);
bool pop_front();
bool pop_back();
bool push_front(const T& item);
bool push_back(const T& item);
void clear();
bool empty();
size_t size();
FixedQueue():
readPos(0),
writePos(0) {}
};
template <typename T, size_t items> T& FixedQueue<T,items>::front() {
return data[readPos];
}
template <typename T, size_t items> T& FixedQueue<T,items>::back() {
if (writePos==0) return data[items-1];
return data[writePos-1];
}
template <typename T, size_t items> bool FixedQueue<T,items>::pop() {
if (readPos==writePos) return false;
if (++readPos>=items) readPos=0;
return true;
}
template <typename T, size_t items> bool FixedQueue<T,items>::push(const T& item) {
if (writePos==(readPos-1)) {
logW("queue overflow!");
return false;
}
if (writePos==items-1 && readPos==0) {
logW("queue overflow!");
return false;
}
data[writePos]=item;
if (++writePos>=items) writePos=0;
return true;
}
template <typename T, size_t items> bool FixedQueue<T,items>::pop_front() {
if (readPos==writePos) return false;
if (++readPos>=items) readPos=0;
return true;
}
template <typename T, size_t items> bool FixedQueue<T,items>::push_back(const T& item) {
if (writePos==(readPos-1)) {
logW("queue overflow!");
return false;
}
if (writePos==items-1 && readPos==0) {
logW("queue overflow!");
return false;
}
data[writePos]=item;
if (++writePos>=items) writePos=0;
return true;
}
template <typename T, size_t items> bool FixedQueue<T,items>::pop_back() {
if (readPos==writePos) return false;
if (writePos>0) {
writePos--;
} else {
writePos=items-1;
}
return true;
}
template <typename T, size_t items> bool FixedQueue<T,items>::push_front(const T& item) {
if (readPos==(writePos+1)) {
logW("stack overflow!");
return false;
}
if (readPos==0 && writePos==items-1) {
logW("stack overflow!");
return false;
}
if (readPos>0) {
readPos--;
} else {
readPos=items-1;
}
data[readPos]=item;
return true;
}
template <typename T, size_t items> void FixedQueue<T,items>::clear() {
readPos=0;
writePos=0;
}
template <typename T, size_t items> bool FixedQueue<T,items>::empty() {
return (readPos==writePos);
}
template <typename T, size_t items> size_t FixedQueue<T,items>::size() {
if (readPos>writePos) {
return items+writePos-readPos;
}
return writePos-readPos;
}
#endif