github.com/core-coin/go-core/v2@v2.1.9/mobile/big.go (about)

     1  // Copyright 2016 by the Authors
     2  // This file is part of the go-core library.
     3  //
     4  // The go-core 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-core 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-core library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  // Contains all the wrappers from the math/big package.
    18  
    19  package gocore
    20  
    21  import (
    22  	"errors"
    23  	"math/big"
    24  
    25  	"github.com/core-coin/go-core/v2/common"
    26  )
    27  
    28  // A BigInt represents a signed multi-precision integer.
    29  type BigInt struct {
    30  	bigint *big.Int
    31  }
    32  
    33  // NewBigInt allocates and returns a new BigInt set to x.
    34  func NewBigInt(x int64) *BigInt {
    35  	return &BigInt{big.NewInt(x)}
    36  }
    37  
    38  // NewBigIntFromString allocates and returns a new BigInt set to x
    39  // interpreted in the provided base.
    40  func NewBigIntFromString(x string, base int) *BigInt {
    41  	b, success := new(big.Int).SetString(x, base)
    42  	if !success {
    43  		return nil
    44  	}
    45  	return &BigInt{b}
    46  }
    47  
    48  // GetBytes returns the absolute value of x as a big-endian byte slice.
    49  func (bi *BigInt) GetBytes() []byte {
    50  	return bi.bigint.Bytes()
    51  }
    52  
    53  // String returns the value of x as a formatted decimal string.
    54  func (bi *BigInt) String() string {
    55  	return bi.bigint.String()
    56  }
    57  
    58  // GetInt64 returns the int64 representation of x. If x cannot be represented in
    59  // an int64, the result is undefined.
    60  func (bi *BigInt) GetInt64() int64 {
    61  	return bi.bigint.Int64()
    62  }
    63  
    64  // SetBytes interprets buf as the bytes of a big-endian unsigned integer and sets
    65  // the big int to that value.
    66  func (bi *BigInt) SetBytes(buf []byte) {
    67  	bi.bigint.SetBytes(common.CopyBytes(buf))
    68  }
    69  
    70  // SetInt64 sets the big int to x.
    71  func (bi *BigInt) SetInt64(x int64) {
    72  	bi.bigint.SetInt64(x)
    73  }
    74  
    75  // Sign returns:
    76  //
    77  //	-1 if x <  0
    78  //	 0 if x == 0
    79  //	+1 if x >  0
    80  func (bi *BigInt) Sign() int {
    81  	return bi.bigint.Sign()
    82  }
    83  
    84  // SetString sets the big int to x.
    85  //
    86  // The string prefix determines the actual conversion base. A prefix of "0x" or
    87  // "0X" selects base 16; the "0" prefix selects base 8, and a "0b" or "0B" prefix
    88  // selects base 2. Otherwise the selected base is 10.
    89  func (bi *BigInt) SetString(x string, base int) {
    90  	bi.bigint.SetString(x, base)
    91  }
    92  
    93  // BigInts represents a slice of big ints.
    94  type BigInts struct{ bigints []*big.Int }
    95  
    96  // NewBigInts creates a slice of uninitialized big numbers.
    97  func NewBigInts(size int) *BigInts {
    98  	return &BigInts{
    99  		bigints: make([]*big.Int, size),
   100  	}
   101  }
   102  
   103  // Size returns the number of big ints in the slice.
   104  func (bi *BigInts) Size() int {
   105  	return len(bi.bigints)
   106  }
   107  
   108  // Get returns the bigint at the given index from the slice.
   109  func (bi *BigInts) Get(index int) (bigint *BigInt, _ error) {
   110  	if index < 0 || index >= len(bi.bigints) {
   111  		return nil, errors.New("index out of bounds")
   112  	}
   113  	return &BigInt{bi.bigints[index]}, nil
   114  }
   115  
   116  // Set sets the big int at the given index in the slice.
   117  func (bi *BigInts) Set(index int, bigint *BigInt) error {
   118  	if index < 0 || index >= len(bi.bigints) {
   119  		return errors.New("index out of bounds")
   120  	}
   121  	bi.bigints[index] = bigint.bigint
   122  	return nil
   123  }
   124  
   125  // GetString returns the value of x as a formatted string in some number base.
   126  func (bi *BigInt) GetString(base int) string {
   127  	return bi.bigint.Text(base)
   128  }