github.com/dominant-strategies/go-quai@v0.28.2/common/big.go (about)

     1  // Copyright 2014 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package common
    18  
    19  import (
    20  	"math/big"
    21  	"modernc.org/mathutil"
    22  )
    23  
    24  // Common big integers often used
    25  var (
    26  	Big0     = big.NewInt(0)
    27  	Big1     = big.NewInt(1)
    28  	Big2     = big.NewInt(2)
    29  	Big3     = big.NewInt(3)
    30  	Big32    = big.NewInt(32)
    31  	Big256   = big.NewInt(256)
    32  	Big257   = big.NewInt(257)
    33  	Big2e256 = new(big.Int).Exp(big.NewInt(2), big.NewInt(256), big.NewInt(0))
    34  )
    35  
    36  func BigBitsToBits(original *big.Int) *big.Int {
    37  	e2e64 := big.NewInt(0).Exp(big.NewInt(2), big.NewInt(64), nil)
    38  	return big.NewInt(0).Div(original, e2e64)
    39  }
    40  
    41  func BitsToBigBits(original *big.Int) *big.Int {
    42  	c, m := mathutil.BinaryLog(original, 64)
    43  	bigBits := new(big.Int).Mul(big.NewInt(int64(c)), new(big.Int).Exp(big.NewInt(2), big.NewInt(64), nil))
    44  	bigBits = new(big.Int).Add(bigBits, m)
    45  	return bigBits
    46  }
    47  
    48  func BigBitsArrayToBitsArray(original []*big.Int) []*big.Int {
    49  	e2e64 := big.NewInt(0).Exp(big.NewInt(2), big.NewInt(64), nil)
    50  	bitsArray := make([]*big.Int, len(original))
    51  	for i, bits := range original {
    52  		bitsArray[i] = big.NewInt(0).Div(bits, e2e64)
    53  	}
    54  
    55  	return bitsArray
    56  }