cirbuf.h
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/*
This file is part of FlashMQ (https://www.flashmq.org)
Copyright (C) 2021 Wiebe Cazemier
FlashMQ is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as
published by the Free Software Foundation, version 3.
FlashMQ 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 Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public
License along with FlashMQ. If not, see <https://www.gnu.org/licenses/>.
*/
#ifndef CIRBUF_H
#define CIRBUF_H
#include <stddef.h>
#include <stdlib.h>
#include <stdint.h>
#include <limits.h>
// Optimized circular buffer, works only with sizes power of two.
class CirBuf
{
#ifdef TESTING
friend class MainTests;
#endif
char *buf = NULL;
uint32_t head = 0;
uint32_t tail = 0;
uint32_t size = 0;
bool primedForSizeReset = false;
public:
CirBuf(size_t size);
~CirBuf();
uint32_t usedBytes() const;
uint32_t freeSpace() const;
uint32_t maxWriteSize() const;
uint32_t maxReadSize() const;
char *headPtr();
char *tailPtr();
void advanceHead(uint32_t n);
void advanceTail(uint32_t n);
char peakAhead(uint32_t offset) const;
void ensureFreeSpace(size_t n, const size_t max = UINT_MAX);
void doubleSize(uint factor = 2);
uint32_t getSize() const;
void resetSizeIfEligable(size_t size);
void resetSize(size_t size);
void reset();
void write(const void *buf, size_t count);
void read(void *buf, const size_t count);
bool operator==(const CirBuf &other) const;
};
#endif // CIRBUF_H