gecko-dev/ef/Utilities/General/NewFastBitSet.h
1999-11-02 06:38:29 +00:00

235 lines
6.9 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* The contents of this file are subject to the Netscape Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/NPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
*/
#ifndef _FAST_BITSET_H_
#define _FAST_BITSET_H_
#include "Fundamentals.h"
#include "Pool.h"
// ----------------------------------------------------------------------------
// FastBitSet
//
// !!!! A FastBitSet cannot have a null number bits.
//
class FastBitSet
{
friend class FastBitMatrix; // The bit matrix will need to access bits & sizeInWord.
private:
Uint32* bits; // Array of words to store the bits.
Uint32 sizeInWords; // Number of words allocated.
#ifdef DEBUG_LOG
Uint32 sizeInBits; // Number of bits (only used in printPretty*()).
#endif /* DEBUG_LOG */
Uint32 getNumberOfWords(Uint32 numberOfBits) const {return (numberOfBits + 31) >> 5;}
Uint32 getWordOffset(Uint32 bitPos) const {return bitPos >> 5;}
Uint8 getBitOffset(Uint32 bitPos) const {return bitPos & 31;}
FastBitSet(const FastBitSet&); // No Copy constructor.
public:
// This is not a valid bitset. The method sizeTo must be called before any
// use of this instance.
FastBitSet() : sizeInWords(0) {}
// Instanciate and allocate the bits.
inline FastBitSet(Pool& pool, Uint32 sizeInBits);
// This FastBitSet gets its bits from memory.
inline FastBitSet(Uint32* bits, Uint32 sizeInBits);
// This FastBitSet copy its bits from memory..
inline FastBitSet(Pool& pool, Uint32* bits, Uint32 sizeInBits);
// Resize the bitset to sizeInBits.
void sizeTo(Pool& pool, Uint32 sizeInBits);
// Resize the bitset and clear all the bits.
inline void sizeToAndClear(Pool& pool, Uint32 sizeInBits);
// Set all the bits in this bitset.
inline void set();
// Set the bit at pos.
inline void set(Uint32 pos) {PR_ASSERT(sizeInWords); bits[getWordOffset(pos)] |= (1<<getBitOffset(pos));}
// Set the bits from position 'from' to position 'to'.
void set(Uint32 from, Uint32 to);
// Set the bits (in this bitset) that are defined in x and return true if this bitset changed.
bool set(const FastBitSet& x);
// Clear all the bits in this bitset.
inline void clear();
// Clear the bit at pos.
inline void clear(Uint32 pos) {PR_ASSERT(sizeInWords); bits[getWordOffset(pos)] &= ~(1<<getBitOffset(pos));}
// Clear the bits from position 'from' to position 'to'.
inline void clear(Uint32 from, Uint32 to);
// Clear the bits (in this bitset) that are defined in x and return true if this bitset changed.
bool clear(const FastBitSet& x);
// Test the bit at pos.
inline bool test(Uint32 pos) const {PR_ASSERT(sizeInWords); return (bits[getWordOffset(pos)]>>getBitOffset(pos))&1;}
// Count the number of bits at '1'.
inline Uint32 countOnes();
// Count the number of bits at '0'.
inline Uint32 countZeros();
// Return the '1' bit just after pos or -1 if not found.
Int32 nextOne(Int32 pos) const;
// Return the '1' bit just before pos or -1 if not found.
Int32 previousOne(Int32 pos) const;
// Return the first '1' bit in the bitset or -1 if not found.
inline Int32 firstOne() const {return nextOne(-1);}
// Return the last '1' bit in the bitset or -1 if not found.
inline Int32 lastOne() const {return previousOne(sizeInWords << 5);}
// Return the '0' bit just after pos or -1 if not found.
Int32 nextZero(Int32 pos) const;
// Return the '0' bit just before pos or -1 if not found.
Int32 previousZero(Int32 pos) const;
// Return the first '0' bit in the bitset or -1 if not found.
inline Int32 firstZero() const {return nextZero(-1);}
// Return the last '1' bit in the bitset or -1 if not found.
inline Int32 lastZero() const {return previousZero(sizeInWords << 5);}
// Return true if at the end of the BitSet.
inline bool done(Int32 pos) const {return pos == -1;}
// Return true if the bitset is empty.
inline bool empty() {return done(firstOne());}
// Arithmetic operators.
FastBitSet& operator |= (const FastBitSet& x);
FastBitSet& operator &= (const FastBitSet& x);
FastBitSet& operator ^= (const FastBitSet& x);
FastBitSet& operator -= (const FastBitSet& x);
// Comparison operators.
friend bool operator == (const FastBitSet& x, const FastBitSet& y);
friend bool operator != (const FastBitSet& x, const FastBitSet& y) {return !(x == y);}
// Copy operator.
FastBitSet& operator = (const FastBitSet& x);
#ifdef DEBUG_LOG
// Print the bitset.
void printPretty(FILE* f) const;
// Print the diffs with the given bitset.
void printDiff(FILE* f, const FastBitSet& x) const;
// Print all the '1' bits.
void printPrettyOnes(FILE* f) const;
// Print all the '0' bits.
void printPrettyZeros(FILE* f) const;
#endif
};
// ----------------------------------------------------------------------------
// Inlines.
//
// Set all the bits in this bitset.
//
inline void FastBitSet::set()
{
PR_ASSERT(sizeInWords);
Uint32* ptr = bits;
Int32 count = sizeInWords - 1;
register Uint32 ones = Uint32(~0);
do {
ptr[count] = ones;
} while(--count >= 0);
}
//
// Clear all the bits in this bitset.
//
inline void FastBitSet::clear()
{
PR_ASSERT(sizeInWords);
Uint32* ptr = bits;
Int32 count = sizeInWords - 1;
register Uint32 zeros = Uint32(0);
do {
ptr[count] = zeros;
} while(--count >= 0);
}
//
// Count the number of bits at '1'.
//
inline Uint32 FastBitSet::countOnes()
{
Uint32 counter = 0;
for (Int32 i = firstOne(); !done(i); i = nextOne(i))
counter++;
return counter;
}
//
// Count the number of bits at '0'.
//
inline Uint32 FastBitSet::countZeros()
{
Uint32 counter = 0;
for (Int32 i = firstZero(); !done(i); i = nextZero(i))
counter++;
return counter;
}
inline void FastBitSet::sizeToAndClear(Pool& pool, Uint32 sizeInBits)
{
sizeTo(pool, sizeInBits);
clear();
}
inline FastBitSet::FastBitSet(Pool& pool, Uint32 sizeInBits) :
sizeInWords(0)
{
sizeToAndClear(pool, sizeInBits);
}
inline FastBitSet::FastBitSet(Pool& pool, Uint32* bits, Uint32 sizeInBits) :
sizeInWords(0)
{
sizeTo(pool, sizeInBits);
PR_ASSERT(sizeInWords);
Int32 count = sizeInWords - 1;
Uint32* dst = bits;
do {
dst[count] = bits[count];
} while (--count >= 0);
}
inline FastBitSet::FastBitSet(Uint32* bits, Uint32 sizeInBits) :
bits(bits), sizeInWords(getNumberOfWords(sizeInBits))
{
#ifdef DEBUG_LOG
this->sizeInBits = sizeInBits;
#endif /* DEBUG_LOG */
}
#endif /* _FAST_BITSET_H_ */