VTIL-Core/VTIL-Common/util/bitmap.hpp
2020-07-24 05:49:18 +02:00

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3.2 KiB
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// Copyright (c) 2020 Can Boluk and contributors of the VTIL Project
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// 3. Neither the name of VTIL Project nor the names of its contributors
// may be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
#pragma once
#include <iterator>
#include "../math/bitwise.hpp"
#ifdef _MSC_VER
#include <intrin.h>
#endif
namespace vtil
{
// Declares a bitmap of size N with fast search helpers.
//
template<size_t N>
struct bitmap
{
// Declare invalid iterator and block count.
//
static constexpr size_t npos = math::bit_npos;
static constexpr size_t block_count = ( N + 63 ) / 64;
// Store the bits, initialized to zero.
//
uint64_t blocks[ block_count ] = { 0 };
// Default construction / copy / move.
//
constexpr bitmap() = default;
constexpr bitmap( bitmap&& ) = default;
constexpr bitmap( const bitmap& ) = default;
constexpr bitmap& operator=( bitmap&& ) = default;
constexpr bitmap& operator=( const bitmap& ) = default;
// Find any bit with the given value in the array.
//
constexpr size_t find( bool value ) const
{
// Invoke find bit.
//
size_t idx = math::bit_find( std::begin( blocks ), std::end( blocks ), value );
// If block has leftovers, adjust for overflow.
//
if constexpr ( ( block_count * 64 ) != N )
{
if ( idx > N )
idx = math::bit_npos;
}
// Return the index.
//
return idx;
}
// Gets the value of the Nth bit.
//
constexpr bool get( size_t n ) const
{
dassert( n < N );
return math::bit_test( blocks[ n / 64 ], n & 63 );
}
// Sets the value of the Nth bit.
//
constexpr bool set( size_t n, bool v )
{
dassert( n < N );
if ( v ) return math::bit_set( blocks[ n / 64 ], n & 63 );
else return math::bit_reset( blocks[ n / 64 ], n & 63 );
}
};
};