You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
136 lines
2.8 KiB
136 lines
2.8 KiB
///////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// Copyright (c) 1998-1999, Microsoft Corp. All rights reserved.
|
|
//
|
|
// FILE
|
|
//
|
|
// BitVec.h
|
|
//
|
|
// SYNOPSIS
|
|
//
|
|
// This file implements the class BitVector
|
|
//
|
|
// MODIFICATION HISTORY
|
|
//
|
|
// 02/09/1998 Original version.
|
|
//
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
|
|
#ifndef _BITVEC_H_
|
|
#define _BITVEC_H_
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// CLASS
|
|
//
|
|
// BitVector
|
|
//
|
|
// DESCRIPTION
|
|
//
|
|
// Very simple bit vector optimized for use by the CSimpleTable class.
|
|
//
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
class BitVector
|
|
{
|
|
public:
|
|
// Type used to store bits.
|
|
typedef unsigned long Bucket;
|
|
|
|
BitVector()
|
|
: numBuckets(0), numSet(0), bits(NULL) { }
|
|
|
|
~BitVector()
|
|
{
|
|
delete[] bits;
|
|
}
|
|
|
|
// Returns true if any bits are set.
|
|
bool any() const
|
|
{
|
|
return numSet != 0;
|
|
}
|
|
|
|
// Returns the number of bits set.
|
|
size_t count() const
|
|
{
|
|
return numSet;
|
|
}
|
|
|
|
// Returns true if no bits are set.
|
|
bool none() const
|
|
{
|
|
return numSet == 0;
|
|
}
|
|
|
|
// Clears all bits.
|
|
void reset()
|
|
{
|
|
if (any())
|
|
{
|
|
memset(bits, 0, numBuckets * sizeof(Bucket));
|
|
|
|
numSet = 0;
|
|
}
|
|
}
|
|
|
|
// Resizes the bitvector to have room for at least 'n' bits. Also clears
|
|
// any existing bits.
|
|
bool resize(size_t n)
|
|
{
|
|
size_t newBuckets = (n + sizeof(Bucket) - 1)/sizeof(Bucket);
|
|
|
|
if (newBuckets >= numBuckets)
|
|
{
|
|
numBuckets = newBuckets;
|
|
|
|
delete[] bits;
|
|
|
|
bits = new (std::nothrow) Bucket[numBuckets];
|
|
if ( !bits )
|
|
{
|
|
return false;
|
|
}
|
|
}
|
|
|
|
memset(bits, 0, numBuckets * sizeof(Bucket));
|
|
|
|
numSet = 0;
|
|
return true;
|
|
}
|
|
|
|
// Sets the given bit.
|
|
void set(size_t i)
|
|
{
|
|
if (!test(i))
|
|
{
|
|
++numSet;
|
|
|
|
getBucket(i) |= getBit(i);
|
|
}
|
|
}
|
|
|
|
// Returns true if the given bit is set.
|
|
bool test(size_t i) const
|
|
{
|
|
return (getBucket(i) & getBit(i)) != 0;
|
|
}
|
|
|
|
protected:
|
|
// Return the bit for a given index.
|
|
static Bucket getBit(size_t i)
|
|
{ return (Bucket)1 << (i % sizeof(Bucket)); }
|
|
|
|
// Return the bucket for a given index.
|
|
Bucket& getBucket(size_t i) const
|
|
{ return bits[i / sizeof(Bucket)]; }
|
|
|
|
size_t numBuckets; // Number of bit buckets.
|
|
size_t numSet; // Number of bits currently set.
|
|
Bucket* bits; // Array of bit buckets.
|
|
|
|
// Not implemented.
|
|
BitVector(const BitVector&);
|
|
BitVector& operator=(const BitVector&);
|
|
};
|
|
|
|
#endif // _BITVEC_H_
|