mirror of
https://github.com/vtil-project/VTIL-Core
synced 2026-08-17 08:23:03 -04:00
73 lines
No EOL
2.9 KiB
C++
73 lines
No EOL
2.9 KiB
C++
// 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 mosquitto 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 <stdint.h>
|
|
#include <array>
|
|
|
|
namespace vtil
|
|
{
|
|
// Initialize default random seed from __TIME__ macro.
|
|
//
|
|
static constexpr uint64_t crandom_default_seed = ([]()
|
|
{
|
|
uint64_t value = 0xa0d82d3adc00b109;
|
|
for ( char c : __TIME__ )
|
|
value = ( value ^ c ) * 0x100000001B3;
|
|
return value;
|
|
} )();
|
|
|
|
// Linear congruential generator using the constants from Numerical Recipes.
|
|
//
|
|
static constexpr uint64_t lce_64( uint64_t& value )
|
|
{
|
|
return ( value = 1664525 * value + 1013904223 );
|
|
}
|
|
|
|
// Generates a single u64 random number, optionally skipping the first N numbers based on the offset given.
|
|
//
|
|
static constexpr uint64_t make_crandom( size_t offset = 0 )
|
|
{
|
|
uint64_t value = crandom_default_seed;
|
|
while ( offset-- != 0 ) lce_64( value );
|
|
return lce_64( value );
|
|
}
|
|
|
|
// Generates N u64 random numbers, optionally skipping the first N numbers based on the offset given.
|
|
//
|
|
template<size_t... I>
|
|
static constexpr std::array<size_t, sizeof...( I )> make_crandom_n( size_t offset, std::index_sequence<I...> )
|
|
{
|
|
uint64_t value = offset ? make_crandom( offset - 1 ) : crandom_default_seed;
|
|
return { lce_64( ( I, value ) )... };
|
|
}
|
|
template<size_t N>
|
|
static constexpr auto make_crandom_n( size_t offset = 0 )
|
|
{
|
|
return make_crandom_n( offset, std::make_index_sequence<N>{} );
|
|
}
|
|
}; |