axmol/scripting/javascript/spidermonkey-win32/include/ds/BitArray.h

59 lines
1.5 KiB
C++

/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=4 sw=4 et tw=99 ft=cpp:
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef BitArray_h__
#define BitArray_h__
#include "jstypes.h"
#include "js/TemplateLib.h"
namespace js {
template <size_t nbits>
class BitArray {
private:
uintptr_t map[nbits / JS_BITS_PER_WORD + (nbits % JS_BITS_PER_WORD == 0 ? 0 : 1)];
public:
void clear(bool value) {
if (value)
memset(map, 0xFF, sizeof(map));
else
memset(map, 0, sizeof(map));
}
inline bool get(size_t offset) const {
uintptr_t index, mask;
getMarkWordAndMask(offset, &index, &mask);
return map[index] & mask;
}
inline void set(size_t offset) {
uintptr_t index, mask;
getMarkWordAndMask(offset, &index, &mask);
map[index] |= mask;
}
inline void unset(size_t offset) {
uintptr_t index, mask;
getMarkWordAndMask(offset, &index, &mask);
map[index] &= ~mask;
}
private:
inline void getMarkWordAndMask(size_t offset,
uintptr_t *indexp, uintptr_t *maskp) const {
*indexp = offset >> tl::FloorLog2<JS_BITS_PER_WORD>::result;
*maskp = uintptr_t(1) << (offset & (JS_BITS_PER_WORD - 1));
}
};
} /* namespace js */
#endif