BitPool.h

Go to the documentation of this file.

// SPDX-License-Identifier: AGPL-3.0-only
// Copyright (c) 2026 Douglas Quigg (dstroy0) <dquigg123@gmail.com>
// https://github.com/dstroy0/XPoint
 
#ifndef BITPOOL_H
#define BITPOOL_H
 
#include <stdint.h>
#include <string.h>
 
#if defined(__GNUC__) || defined(__clang__)
#define XPOINT_PACKED __attribute__((packed))
#else
#define XPOINT_PACKED
#endif
 
class XPOINT_PACKED BitPool
{
  public:
    static uint16_t wordsFor(uint32_t nBits)
    {
        return (nBits == 0u) ? 0u : (uint16_t)((nBits + 31u) / 32u);
    }
 
    explicit BitPool(uint32_t nBits);
 
    BitPool(uint32_t *words, uint32_t nBits);
 
    ~BitPool();
 
    BitPool(const BitPool &) = delete;
    BitPool &operator=(const BitPool &) = delete;
 
    bool valid() const
    {
        return _words != nullptr;
    }
 
    bool get(uint32_t n) const
    {
        return (_words[n >> 5] >> (n & 0x1Fu)) & 1u;
    }
 
    void set(uint32_t n, bool v)
    {
        if (v)
            _words[n >> 5] |= (1u << (n & 0x1Fu));
        else
            _words[n >> 5] &= ~(1u << (n & 0x1Fu));
    }
 
    void clear();
 
  private:
    uint32_t *_words;
    uint16_t _nWords;
    bool _owns;
};
 
#endif // BITPOOL_H