88275138ba
* Resize(): adds more space to the end of the bitmap.
* Shift(): moves all bits in the map up or down.
* Use size_t instead of int for indexes.
Also add unit tests for the new functions (they seem to be passing.)
Reference material for shift implementation:
2c56d43c1e/bitops.h (L977)
Change-Id: Ia85768aaeed7bd3ffef3a9f575f05331e048fe50
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5146
Reviewed-by: waddlesplash <waddlesplash@gmail.com>
88 lines
1.6 KiB
C++
88 lines
1.6 KiB
C++
/*
|
|
* Copyright 2013-2022, Haiku, Inc. All rights reserved.
|
|
* Distributed under the terms of the MIT License.
|
|
*
|
|
* Authors:
|
|
* Paweł Dziepak, pdziepak@quarnos.org
|
|
* Augustin Cavalier <waddlesplash>
|
|
*/
|
|
#ifndef KERNEL_UTIL_BITMAP_H
|
|
#define KERNEL_UTIL_BITMAP_H
|
|
|
|
|
|
#ifdef _KERNEL_MODE
|
|
# include <debug.h>
|
|
#else
|
|
# include <Debug.h>
|
|
#endif
|
|
|
|
#include <SupportDefs.h>
|
|
|
|
namespace BKernel {
|
|
|
|
class Bitmap {
|
|
public:
|
|
Bitmap(size_t bitCount);
|
|
~Bitmap();
|
|
|
|
status_t InitCheck();
|
|
|
|
status_t Resize(size_t bitCount);
|
|
void Shift(ssize_t bitCount);
|
|
|
|
inline bool Get(size_t index) const;
|
|
inline void Set(size_t index);
|
|
inline void Clear(size_t index);
|
|
|
|
ssize_t GetHighestSet() const;
|
|
|
|
private:
|
|
size_t fElementsCount;
|
|
size_t fSize;
|
|
addr_t* fBits;
|
|
|
|
static const int kBitsPerElement = (sizeof(addr_t) * 8);
|
|
};
|
|
|
|
|
|
bool
|
|
Bitmap::Get(size_t index) const
|
|
{
|
|
ASSERT(index < fSize);
|
|
|
|
const size_t kArrayElement = index / kBitsPerElement;
|
|
const addr_t kBitMask = addr_t(1) << (index % kBitsPerElement);
|
|
return fBits[kArrayElement] & kBitMask;
|
|
}
|
|
|
|
|
|
void
|
|
Bitmap::Set(size_t index)
|
|
{
|
|
ASSERT(index < fSize);
|
|
|
|
const size_t kArrayElement = index / kBitsPerElement;
|
|
const addr_t kBitMask = addr_t(1) << (index % kBitsPerElement);
|
|
fBits[kArrayElement] |= kBitMask;
|
|
}
|
|
|
|
|
|
void
|
|
Bitmap::Clear(size_t index)
|
|
{
|
|
ASSERT(index < fSize);
|
|
|
|
const size_t kArrayElement = index / kBitsPerElement;
|
|
const addr_t kBitMask = addr_t(1) << (index % kBitsPerElement);
|
|
fBits[kArrayElement] &= ~addr_t(kBitMask);
|
|
}
|
|
|
|
} // namespace BKernel
|
|
|
|
|
|
using BKernel::Bitmap;
|
|
|
|
|
|
#endif // KERNEL_UTIL_BITMAP_H
|
|
|