diff options
Diffstat (limited to 'cli/vendor/github.com/ethereum/go-ethereum/common/math')
| -rw-r--r-- | cli/vendor/github.com/ethereum/go-ethereum/common/math/big.go | 259 | ||||
| -rw-r--r-- | cli/vendor/github.com/ethereum/go-ethereum/common/math/integer.go | 98 |
2 files changed, 357 insertions, 0 deletions
diff --git a/cli/vendor/github.com/ethereum/go-ethereum/common/math/big.go b/cli/vendor/github.com/ethereum/go-ethereum/common/math/big.go new file mode 100644 index 0000000..1af5b4d --- /dev/null +++ b/cli/vendor/github.com/ethereum/go-ethereum/common/math/big.go @@ -0,0 +1,259 @@ +// Copyright 2017 The go-ethereum Authors +// This file is part of the go-ethereum library. +// +// The go-ethereum library is free software: you can redistribute it and/or modify +// it under the terms of the GNU Lesser General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// The go-ethereum library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Lesser General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public License +// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>. + +// Package math provides integer math utilities. +package math + +import ( + "fmt" + "math/big" +) + +// Various big integer limit values. +var ( + tt255 = BigPow(2, 255) + tt256 = BigPow(2, 256) + tt256m1 = new(big.Int).Sub(tt256, big.NewInt(1)) + tt63 = BigPow(2, 63) + MaxBig256 = new(big.Int).Set(tt256m1) + MaxBig63 = new(big.Int).Sub(tt63, big.NewInt(1)) +) + +const ( + // number of bits in a big.Word + wordBits = 32 << (uint64(^big.Word(0)) >> 63) + // number of bytes in a big.Word + wordBytes = wordBits / 8 +) + +// HexOrDecimal256 marshals big.Int as hex or decimal. +type HexOrDecimal256 big.Int + +// NewHexOrDecimal256 creates a new HexOrDecimal256 +func NewHexOrDecimal256(x int64) *HexOrDecimal256 { + b := big.NewInt(x) + h := HexOrDecimal256(*b) + return &h +} + +// UnmarshalText implements encoding.TextUnmarshaler. +func (i *HexOrDecimal256) UnmarshalText(input []byte) error { + bigint, ok := ParseBig256(string(input)) + if !ok { + return fmt.Errorf("invalid hex or decimal integer %q", input) + } + *i = HexOrDecimal256(*bigint) + return nil +} + +// MarshalText implements encoding.TextMarshaler. +func (i *HexOrDecimal256) MarshalText() ([]byte, error) { + if i == nil { + return []byte("0x0"), nil + } + return []byte(fmt.Sprintf("%#x", (*big.Int)(i))), nil +} + +// Decimal256 unmarshals big.Int as a decimal string. When unmarshalling, +// it however accepts either "0x"-prefixed (hex encoded) or non-prefixed (decimal) +type Decimal256 big.Int + +// NewHexOrDecimal256 creates a new Decimal256 +func NewDecimal256(x int64) *Decimal256 { + b := big.NewInt(x) + d := Decimal256(*b) + return &d +} + +// UnmarshalText implements encoding.TextUnmarshaler. +func (i *Decimal256) UnmarshalText(input []byte) error { + bigint, ok := ParseBig256(string(input)) + if !ok { + return fmt.Errorf("invalid hex or decimal integer %q", input) + } + *i = Decimal256(*bigint) + return nil +} + +// MarshalText implements encoding.TextMarshaler. +func (i *Decimal256) MarshalText() ([]byte, error) { + return []byte(i.String()), nil +} + +// String implements Stringer. +func (i *Decimal256) String() string { + if i == nil { + return "0" + } + return fmt.Sprintf("%#d", (*big.Int)(i)) +} + +// ParseBig256 parses s as a 256 bit integer in decimal or hexadecimal syntax. +// Leading zeros are accepted. The empty string parses as zero. +func ParseBig256(s string) (*big.Int, bool) { + if s == "" { + return new(big.Int), true + } + var bigint *big.Int + var ok bool + if len(s) >= 2 && (s[:2] == "0x" || s[:2] == "0X") { + bigint, ok = new(big.Int).SetString(s[2:], 16) + } else { + bigint, ok = new(big.Int).SetString(s, 10) + } + if ok && bigint.BitLen() > 256 { + bigint, ok = nil, false + } + return bigint, ok +} + +// MustParseBig256 parses s as a 256 bit big integer and panics if the string is invalid. +func MustParseBig256(s string) *big.Int { + v, ok := ParseBig256(s) + if !ok { + panic("invalid 256 bit integer: " + s) + } + return v +} + +// BigPow returns a ** b as a big integer. +func BigPow(a, b int64) *big.Int { + r := big.NewInt(a) + return r.Exp(r, big.NewInt(b), nil) +} + +// BigMax returns the larger of x or y. +func BigMax(x, y *big.Int) *big.Int { + if x.Cmp(y) < 0 { + return y + } + return x +} + +// BigMin returns the smaller of x or y. +func BigMin(x, y *big.Int) *big.Int { + if x.Cmp(y) > 0 { + return y + } + return x +} + +// FirstBitSet returns the index of the first 1 bit in v, counting from LSB. +func FirstBitSet(v *big.Int) int { + for i := 0; i < v.BitLen(); i++ { + if v.Bit(i) > 0 { + return i + } + } + return v.BitLen() +} + +// PaddedBigBytes encodes a big integer as a big-endian byte slice. The length +// of the slice is at least n bytes. +func PaddedBigBytes(bigint *big.Int, n int) []byte { + if bigint.BitLen()/8 >= n { + return bigint.Bytes() + } + ret := make([]byte, n) + ReadBits(bigint, ret) + return ret +} + +// bigEndianByteAt returns the byte at position n, +// in Big-Endian encoding +// So n==0 returns the least significant byte +func bigEndianByteAt(bigint *big.Int, n int) byte { + words := bigint.Bits() + // Check word-bucket the byte will reside in + i := n / wordBytes + if i >= len(words) { + return byte(0) + } + word := words[i] + // Offset of the byte + shift := 8 * uint(n%wordBytes) + + return byte(word >> shift) +} + +// Byte returns the byte at position n, +// with the supplied padlength in Little-Endian encoding. +// n==0 returns the MSB +// Example: bigint '5', padlength 32, n=31 => 5 +func Byte(bigint *big.Int, padlength, n int) byte { + if n >= padlength { + return byte(0) + } + return bigEndianByteAt(bigint, padlength-1-n) +} + +// ReadBits encodes the absolute value of bigint as big-endian bytes. Callers must ensure +// that buf has enough space. If buf is too short the result will be incomplete. +func ReadBits(bigint *big.Int, buf []byte) { + i := len(buf) + for _, d := range bigint.Bits() { + for j := 0; j < wordBytes && i > 0; j++ { + i-- + buf[i] = byte(d) + d >>= 8 + } + } +} + +// U256 encodes as a 256 bit two's complement number. This operation is destructive. +func U256(x *big.Int) *big.Int { + return x.And(x, tt256m1) +} + +// U256Bytes converts a big Int into a 256bit EVM number. +// This operation is destructive. +func U256Bytes(n *big.Int) []byte { + return PaddedBigBytes(U256(n), 32) +} + +// S256 interprets x as a two's complement number. +// x must not exceed 256 bits (the result is undefined if it does) and is not modified. +// +// S256(0) = 0 +// S256(1) = 1 +// S256(2**255) = -2**255 +// S256(2**256-1) = -1 +func S256(x *big.Int) *big.Int { + if x.Cmp(tt255) < 0 { + return x + } + return new(big.Int).Sub(x, tt256) +} + +// Exp implements exponentiation by squaring. +// Exp returns a newly-allocated big integer and does not change +// base or exponent. The result is truncated to 256 bits. +// +// Courtesy @karalabe and @chfast +func Exp(base, exponent *big.Int) *big.Int { + result := big.NewInt(1) + + for _, word := range exponent.Bits() { + for i := 0; i < wordBits; i++ { + if word&1 == 1 { + U256(result.Mul(result, base)) + } + U256(base.Mul(base, base)) + word >>= 1 + } + } + return result +} diff --git a/cli/vendor/github.com/ethereum/go-ethereum/common/math/integer.go b/cli/vendor/github.com/ethereum/go-ethereum/common/math/integer.go new file mode 100644 index 0000000..50d3eba --- /dev/null +++ b/cli/vendor/github.com/ethereum/go-ethereum/common/math/integer.go @@ -0,0 +1,98 @@ +// Copyright 2017 The go-ethereum Authors +// This file is part of the go-ethereum library. +// +// The go-ethereum library is free software: you can redistribute it and/or modify +// it under the terms of the GNU Lesser General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// The go-ethereum library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Lesser General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public License +// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>. + +package math + +import ( + "fmt" + "math/bits" + "strconv" +) + +// Integer limit values. +const ( + MaxInt8 = 1<<7 - 1 + MinInt8 = -1 << 7 + MaxInt16 = 1<<15 - 1 + MinInt16 = -1 << 15 + MaxInt32 = 1<<31 - 1 + MinInt32 = -1 << 31 + MaxInt64 = 1<<63 - 1 + MinInt64 = -1 << 63 + MaxUint8 = 1<<8 - 1 + MaxUint16 = 1<<16 - 1 + MaxUint32 = 1<<32 - 1 + MaxUint64 = 1<<64 - 1 +) + +// HexOrDecimal64 marshals uint64 as hex or decimal. +type HexOrDecimal64 uint64 + +// UnmarshalText implements encoding.TextUnmarshaler. +func (i *HexOrDecimal64) UnmarshalText(input []byte) error { + int, ok := ParseUint64(string(input)) + if !ok { + return fmt.Errorf("invalid hex or decimal integer %q", input) + } + *i = HexOrDecimal64(int) + return nil +} + +// MarshalText implements encoding.TextMarshaler. +func (i HexOrDecimal64) MarshalText() ([]byte, error) { + return []byte(fmt.Sprintf("%#x", uint64(i))), nil +} + +// ParseUint64 parses s as an integer in decimal or hexadecimal syntax. +// Leading zeros are accepted. The empty string parses as zero. +func ParseUint64(s string) (uint64, bool) { + if s == "" { + return 0, true + } + if len(s) >= 2 && (s[:2] == "0x" || s[:2] == "0X") { + v, err := strconv.ParseUint(s[2:], 16, 64) + return v, err == nil + } + v, err := strconv.ParseUint(s, 10, 64) + return v, err == nil +} + +// MustParseUint64 parses s as an integer and panics if the string is invalid. +func MustParseUint64(s string) uint64 { + v, ok := ParseUint64(s) + if !ok { + panic("invalid unsigned 64 bit integer: " + s) + } + return v +} + +// SafeSub returns x-y and checks for overflow. +func SafeSub(x, y uint64) (uint64, bool) { + diff, borrowOut := bits.Sub64(x, y, 0) + return diff, borrowOut != 0 +} + +// SafeAdd returns x+y and checks for overflow. +func SafeAdd(x, y uint64) (uint64, bool) { + sum, carryOut := bits.Add64(x, y, 0) + return sum, carryOut != 0 +} + +// SafeMul returns x*y and checks for overflow. +func SafeMul(x, y uint64) (uint64, bool) { + hi, lo := bits.Mul64(x, y) + return lo, hi != 0 +} |
