+++ /dev/null
-/*
- * Copyright (C) 2010 Apple Inc. All rights reserved.
- *
- * 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 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 Bitmap_h
-#define Bitmap_h
-
-#include "FixedArray.h"
-#include "StdLibExtras.h"
-#include <stdint.h>
-#include <string.h>
-
-namespace WTF {
-
-template<size_t size>
-class Bitmap {
-private:
- typedef uint32_t WordType;
-
-public:
- Bitmap();
-
- bool get(size_t) const;
- void set(size_t);
- bool testAndSet(size_t);
- size_t nextPossiblyUnset(size_t) const;
- void clear(size_t);
- void clearAll();
- int64_t findRunOfZeros(size_t) const;
- size_t count(size_t = 0) const;
- size_t isEmpty() const;
- size_t isFull() const;
-
-private:
- static const WordType wordSize = sizeof(WordType) * 8;
- static const WordType words = (size + wordSize - 1) / wordSize;
-
- // the literal '1' is of type signed int. We want to use an unsigned
- // version of the correct size when doing the calculations because if
- // WordType is larger than int, '1 << 31' will first be sign extended
- // and then casted to unsigned, meaning that set(31) when WordType is
- // a 64 bit unsigned int would give 0xffff8000
- static const WordType one = 1;
-
- FixedArray<WordType, words> bits;
-};
-
-template<size_t size>
-inline Bitmap<size>::Bitmap()
-{
- clearAll();
-}
-
-template<size_t size>
-inline bool Bitmap<size>::get(size_t n) const
-{
- return !!(bits[n / wordSize] & (one << (n % wordSize)));
-}
-
-template<size_t size>
-inline void Bitmap<size>::set(size_t n)
-{
- bits[n / wordSize] |= (one << (n % wordSize));
-}
-
-template<size_t size>
-inline bool Bitmap<size>::testAndSet(size_t n)
-{
- WordType mask = one << (n % wordSize);
- size_t index = n / wordSize;
- bool result = bits[index] & mask;
- bits[index] |= mask;
- return result;
-}
-
-template<size_t size>
-inline void Bitmap<size>::clear(size_t n)
-{
- bits[n / wordSize] &= ~(one << (n % wordSize));
-}
-
-template<size_t size>
-inline void Bitmap<size>::clearAll()
-{
- memset(bits.data(), 0, sizeof(bits));
-}
-
-template<size_t size>
-inline size_t Bitmap<size>::nextPossiblyUnset(size_t start) const
-{
- if (!~bits[start / wordSize])
- return ((start / wordSize) + 1) * wordSize;
- return start + 1;
-}
-
-template<size_t size>
-inline int64_t Bitmap<size>::findRunOfZeros(size_t runLength) const
-{
- if (!runLength)
- runLength = 1;
-
- for (size_t i = 0; i <= (size - runLength) ; i++) {
- bool found = true;
- for (size_t j = i; j <= (i + runLength - 1) ; j++) {
- if (get(j)) {
- found = false;
- break;
- }
- }
- if (found)
- return i;
- }
- return -1;
-}
-
-template<size_t size>
-inline size_t Bitmap<size>::count(size_t start) const
-{
- size_t result = 0;
- for ( ; (start % wordSize); ++start) {
- if (get(start))
- ++result;
- }
- for (size_t i = start / wordSize; i < words; ++i)
- result += WTF::bitCount(bits[i]);
- return result;
-}
-
-template<size_t size>
-inline size_t Bitmap<size>::isEmpty() const
-{
- for (size_t i = 0; i < words; ++i)
- if (bits[i])
- return false;
- return true;
-}
-
-template<size_t size>
-inline size_t Bitmap<size>::isFull() const
-{
- for (size_t i = 0; i < words; ++i)
- if (~bits[i])
- return false;
- return true;
-}
-
-}
-#endif