849 lines
26 KiB
Go
849 lines
26 KiB
Go
// uint256: Fixed size 256-bit math library
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// Copyright 2020 uint256 Authors
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// SPDX-License-Identifier: BSD-3-Clause
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package uint256
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import (
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"database/sql"
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"database/sql/driver"
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"encoding"
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"encoding/binary"
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"encoding/json"
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"errors"
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"fmt"
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"io"
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"math"
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"math/big"
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"math/bits"
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"strings"
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)
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const (
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maxWords = 256 / bits.UintSize // number of big.Words in 256-bit
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// The constants below work as compile-time checks: in case evaluated to
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// negative value it cannot be assigned to uint type and compilation fails.
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// These particular expressions check if maxWords either 4 or 8 matching
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// 32-bit and 64-bit architectures.
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_ uint = -(maxWords & (maxWords - 1)) // maxWords is power of two.
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_ uint = -(maxWords & ^(4 | 8)) // maxWords is 4 or 8.
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)
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// Compile time interface checks
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var (
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_ driver.Valuer = (*Int)(nil)
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_ sql.Scanner = (*Int)(nil)
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_ encoding.TextMarshaler = (*Int)(nil)
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_ encoding.TextUnmarshaler = (*Int)(nil)
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_ json.Marshaler = (*Int)(nil)
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_ json.Unmarshaler = (*Int)(nil)
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)
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// ToBig returns a big.Int version of z.
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// Return `nil` if z is nil
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func (z *Int) ToBig() *big.Int {
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if z == nil {
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return nil
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}
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var b *big.Int
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z.IntoBig(&b)
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return b
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}
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// IntoBig sets a provided big.Int to the value of z.
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// Sets `nil` if z is nil (thus the double pointer).
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func (z *Int) IntoBig(b **big.Int) {
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if z == nil {
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*b = nil
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return
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}
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if *b == nil {
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*b = new(big.Int)
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}
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switch maxWords { // Compile-time check.
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case 4: // 64-bit architectures.
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if words := (*b).Bits(); cap(words) >= 4 {
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// Enough underlying space to set all the uint256 data
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words = words[:4]
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words[0] = big.Word(z[0])
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words[1] = big.Word(z[1])
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words[2] = big.Word(z[2])
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words[3] = big.Word(z[3])
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// Feed it back to normalize (up or down within the big.Int)
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(*b).SetBits(words)
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} else {
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// Not enough space to set all the words, have to allocate
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words := [4]big.Word{big.Word(z[0]), big.Word(z[1]), big.Word(z[2]), big.Word(z[3])}
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(*b).SetBits(words[:])
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}
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case 8: // 32-bit architectures.
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if words := (*b).Bits(); cap(words) >= 8 {
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// Enough underlying space to set all the uint256 data
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words = words[:8]
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words[0], words[1] = big.Word(z[0]), big.Word(z[0]>>32)
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words[2], words[3] = big.Word(z[1]), big.Word(z[1]>>32)
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words[4], words[5] = big.Word(z[2]), big.Word(z[2]>>32)
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words[6], words[7] = big.Word(z[3]), big.Word(z[3]>>32)
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// Feed it back to normalize (up or down within the big.Int)
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(*b).SetBits(words)
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} else {
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// Not enough space to set all the words, have to allocate
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words := [8]big.Word{
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big.Word(z[0]), big.Word(z[0] >> 32),
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big.Word(z[1]), big.Word(z[1] >> 32),
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big.Word(z[2]), big.Word(z[2] >> 32),
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big.Word(z[3]), big.Word(z[3] >> 32),
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}
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(*b).SetBits(words[:])
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}
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}
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}
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// FromBig is a convenience-constructor from big.Int.
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// Returns a new Int and whether overflow occurred.
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// OBS: If b is `nil`, this method returns `nil, false`
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func FromBig(b *big.Int) (*Int, bool) {
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if b == nil {
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return nil, false
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}
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z := &Int{}
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overflow := z.SetFromBig(b)
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return z, overflow
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}
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// MustFromBig is a convenience-constructor from big.Int.
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// Returns a new Int and panics if overflow occurred.
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// OBS: If b is `nil`, this method does _not_ panic, but
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// instead returns `nil`
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func MustFromBig(b *big.Int) *Int {
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if b == nil {
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return nil
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}
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z := &Int{}
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if z.SetFromBig(b) {
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panic("overflow")
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}
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return z
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}
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// Float64 returns the float64 value nearest to x.
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//
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// Note: The `big.Float` version of `Float64` also returns an 'Accuracy', indicating
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// whether the value was too small or too large to be represented by a
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// `float64`. However, the `uint256` type is unable to represent values
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// out of scope (|x| < math.SmallestNonzeroFloat64 or |x| > math.MaxFloat64),
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// therefore this method does not return any accuracy.
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func (z *Int) Float64() float64 {
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if z.IsUint64() {
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return float64(z.Uint64())
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}
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// See [1] for a detailed walkthrough of IEEE 754 conversion
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//
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// 1: https://www.wikihow.com/Convert-a-Number-from-Decimal-to-IEEE-754-Floating-Point-Representation
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bitlen := uint64(z.BitLen())
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// Normalize the number, by shifting it so that the MSB is shifted out.
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y := new(Int).Lsh(z, uint(1+256-bitlen))
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// The number with the leading 1 shifted out is the fraction.
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fraction := y[3]
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// The exp is calculated from the number of shifts, adjusted with the bias.
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// double-precision uses 1023 as bias
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biased_exp := 1023 + bitlen - 1
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// The IEEE 754 double-precision layout is as follows:
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// 1 sign bit (we don't bother with this, since it's always zero for uints)
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// 11 exponent bits
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// 52 fraction bits
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// --------
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// 64 bits
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return math.Float64frombits(biased_exp<<52 | fraction>>12)
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}
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// SetFromHex sets z from the given string, interpreted as a hexadecimal number.
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// OBS! This method is _not_ strictly identical to the (*big.Int).SetString(..., 16) method.
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// Notable differences:
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// - This method _require_ "0x" or "0X" prefix.
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// - This method does not accept zero-prefixed hex, e.g. "0x0001"
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// - This method does not accept underscore input, e.g. "100_000",
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// - This method does not accept negative zero as valid, e.g "-0x0",
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// - (this method does not accept any negative input as valid)
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func (z *Int) SetFromHex(hex string) error {
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return z.fromHex(hex)
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}
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// fromHex is the internal implementation of parsing a hex-string.
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func (z *Int) fromHex(hex string) error {
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if err := checkNumberS(hex); err != nil {
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return err
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}
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if len(hex) > 66 {
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return ErrBig256Range
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}
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z.Clear()
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end := len(hex)
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for i := 0; i < 4; i++ {
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start := end - 16
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if start < 2 {
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start = 2
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}
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for ri := start; ri < end; ri++ {
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nib := bintable[hex[ri]]
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if nib == badNibble {
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return ErrSyntax
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}
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z[i] = z[i] << 4
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z[i] += uint64(nib)
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}
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end = start
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}
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return nil
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}
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// FromHex is a convenience-constructor to create an Int from
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// a hexadecimal string. The string is required to be '0x'-prefixed
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// Numbers larger than 256 bits are not accepted.
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func FromHex(hex string) (*Int, error) {
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var z Int
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if err := z.fromHex(hex); err != nil {
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return nil, err
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}
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return &z, nil
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}
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// MustFromHex is a convenience-constructor to create an Int from
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// a hexadecimal string.
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// Returns a new Int and panics if any error occurred.
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func MustFromHex(hex string) *Int {
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var z Int
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if err := z.fromHex(hex); err != nil {
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panic(err)
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}
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return &z
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}
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// UnmarshalText implements encoding.TextUnmarshaler. This method
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// can unmarshal either hexadecimal or decimal.
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// - For hexadecimal, the input _must_ be prefixed with 0x or 0X
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func (z *Int) UnmarshalText(input []byte) error {
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if len(input) >= 2 && input[0] == '0' && (input[1] == 'x' || input[1] == 'X') {
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return z.fromHex(string(input))
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}
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return z.SetFromDecimal(string(input))
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}
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// SetFromBig converts a big.Int to Int and sets the value to z.
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// TODO: Ensure we have sufficient testing, esp for negative bigints.
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func (z *Int) SetFromBig(b *big.Int) bool {
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z.Clear()
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words := b.Bits()
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overflow := len(words) > maxWords
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switch maxWords { // Compile-time check.
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case 4: // 64-bit architectures.
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if len(words) > 0 {
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z[0] = uint64(words[0])
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if len(words) > 1 {
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z[1] = uint64(words[1])
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if len(words) > 2 {
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z[2] = uint64(words[2])
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if len(words) > 3 {
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z[3] = uint64(words[3])
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}
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}
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}
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}
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case 8: // 32-bit architectures.
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numWords := len(words)
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if overflow {
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numWords = maxWords
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}
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for i := 0; i < numWords; i++ {
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if i%2 == 0 {
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z[i/2] = uint64(words[i])
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} else {
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z[i/2] |= uint64(words[i]) << 32
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}
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}
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}
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if b.Sign() == -1 {
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z.Neg(z)
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}
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return overflow
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}
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// Format implements fmt.Formatter. It accepts the formats
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// 'b' (binary), 'o' (octal with 0 prefix), 'O' (octal with 0o prefix),
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// 'd' (decimal), 'x' (lowercase hexadecimal), and
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// 'X' (uppercase hexadecimal).
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// Also supported are the full suite of package fmt's format
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// flags for integral types, including '+' and ' ' for sign
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// control, '#' for leading zero in octal and for hexadecimal,
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// a leading "0x" or "0X" for "%#x" and "%#X" respectively,
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// specification of minimum digits precision, output field
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// width, space or zero padding, and '-' for left or right
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// justification.
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func (z *Int) Format(s fmt.State, ch rune) {
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z.ToBig().Format(s, ch)
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}
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// SetBytes8 is identical to SetBytes(in[:8]), but panics is input is too short
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func (z *Int) SetBytes8(in []byte) *Int {
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_ = in[7] // bounds check hint to compiler; see golang.org/issue/14808
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z[3], z[2], z[1] = 0, 0, 0
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z[0] = binary.BigEndian.Uint64(in[0:8])
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return z
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}
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// SetBytes16 is identical to SetBytes(in[:16]), but panics is input is too short
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func (z *Int) SetBytes16(in []byte) *Int {
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_ = in[15] // bounds check hint to compiler; see golang.org/issue/14808
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z[3], z[2] = 0, 0
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z[1] = binary.BigEndian.Uint64(in[0:8])
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z[0] = binary.BigEndian.Uint64(in[8:16])
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return z
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}
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// SetBytes16 is identical to SetBytes(in[:24]), but panics is input is too short
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func (z *Int) SetBytes24(in []byte) *Int {
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_ = in[23] // bounds check hint to compiler; see golang.org/issue/14808
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z[3] = 0
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z[2] = binary.BigEndian.Uint64(in[0:8])
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z[1] = binary.BigEndian.Uint64(in[8:16])
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z[0] = binary.BigEndian.Uint64(in[16:24])
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return z
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}
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func (z *Int) SetBytes32(in []byte) *Int {
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_ = in[31] // bounds check hint to compiler; see golang.org/issue/14808
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z[3] = binary.BigEndian.Uint64(in[0:8])
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z[2] = binary.BigEndian.Uint64(in[8:16])
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z[1] = binary.BigEndian.Uint64(in[16:24])
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z[0] = binary.BigEndian.Uint64(in[24:32])
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return z
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}
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func (z *Int) SetBytes1(in []byte) *Int {
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z[3], z[2], z[1] = 0, 0, 0
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z[0] = uint64(in[0])
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return z
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}
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func (z *Int) SetBytes9(in []byte) *Int {
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_ = in[8] // bounds check hint to compiler; see golang.org/issue/14808
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z[3], z[2] = 0, 0
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z[1] = uint64(in[0])
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z[0] = binary.BigEndian.Uint64(in[1:9])
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return z
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}
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func (z *Int) SetBytes17(in []byte) *Int {
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_ = in[16] // bounds check hint to compiler; see golang.org/issue/14808
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z[3] = 0
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z[2] = uint64(in[0])
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z[1] = binary.BigEndian.Uint64(in[1:9])
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z[0] = binary.BigEndian.Uint64(in[9:17])
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return z
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}
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func (z *Int) SetBytes25(in []byte) *Int {
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_ = in[24] // bounds check hint to compiler; see golang.org/issue/14808
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z[3] = uint64(in[0])
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z[2] = binary.BigEndian.Uint64(in[1:9])
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z[1] = binary.BigEndian.Uint64(in[9:17])
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z[0] = binary.BigEndian.Uint64(in[17:25])
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return z
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}
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func (z *Int) SetBytes2(in []byte) *Int {
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_ = in[1] // bounds check hint to compiler; see golang.org/issue/14808
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z[3], z[2], z[1] = 0, 0, 0
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z[0] = uint64(binary.BigEndian.Uint16(in[0:2]))
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return z
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}
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func (z *Int) SetBytes10(in []byte) *Int {
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_ = in[9] // bounds check hint to compiler; see golang.org/issue/14808
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z[3], z[2] = 0, 0
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z[1] = uint64(binary.BigEndian.Uint16(in[0:2]))
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z[0] = binary.BigEndian.Uint64(in[2:10])
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return z
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}
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func (z *Int) SetBytes18(in []byte) *Int {
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_ = in[17] // bounds check hint to compiler; see golang.org/issue/14808
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z[3] = 0
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z[2] = uint64(binary.BigEndian.Uint16(in[0:2]))
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z[1] = binary.BigEndian.Uint64(in[2:10])
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z[0] = binary.BigEndian.Uint64(in[10:18])
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return z
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}
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func (z *Int) SetBytes26(in []byte) *Int {
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_ = in[25] // bounds check hint to compiler; see golang.org/issue/14808
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z[3] = uint64(binary.BigEndian.Uint16(in[0:2]))
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z[2] = binary.BigEndian.Uint64(in[2:10])
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z[1] = binary.BigEndian.Uint64(in[10:18])
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z[0] = binary.BigEndian.Uint64(in[18:26])
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return z
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}
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func (z *Int) SetBytes3(in []byte) *Int {
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_ = in[2] // bounds check hint to compiler; see golang.org/issue/14808
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z[3], z[2], z[1] = 0, 0, 0
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z[0] = uint64(binary.BigEndian.Uint16(in[1:3])) | uint64(in[0])<<16
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return z
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}
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func (z *Int) SetBytes11(in []byte) *Int {
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_ = in[10] // bounds check hint to compiler; see golang.org/issue/14808
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z[3], z[2] = 0, 0
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z[1] = uint64(binary.BigEndian.Uint16(in[1:3])) | uint64(in[0])<<16
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z[0] = binary.BigEndian.Uint64(in[3:11])
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return z
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}
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func (z *Int) SetBytes19(in []byte) *Int {
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_ = in[18] // bounds check hint to compiler; see golang.org/issue/14808
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z[3] = 0
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z[2] = uint64(binary.BigEndian.Uint16(in[1:3])) | uint64(in[0])<<16
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z[1] = binary.BigEndian.Uint64(in[3:11])
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z[0] = binary.BigEndian.Uint64(in[11:19])
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return z
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}
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func (z *Int) SetBytes27(in []byte) *Int {
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_ = in[26] // bounds check hint to compiler; see golang.org/issue/14808
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z[3] = uint64(binary.BigEndian.Uint16(in[1:3])) | uint64(in[0])<<16
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z[2] = binary.BigEndian.Uint64(in[3:11])
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z[1] = binary.BigEndian.Uint64(in[11:19])
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z[0] = binary.BigEndian.Uint64(in[19:27])
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return z
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}
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func (z *Int) SetBytes4(in []byte) *Int {
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_ = in[3] // bounds check hint to compiler; see golang.org/issue/14808
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z[3], z[2], z[1] = 0, 0, 0
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z[0] = uint64(binary.BigEndian.Uint32(in[0:4]))
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return z
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}
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func (z *Int) SetBytes12(in []byte) *Int {
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_ = in[11] // bounds check hint to compiler; see golang.org/issue/14808
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z[3], z[2] = 0, 0
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z[1] = uint64(binary.BigEndian.Uint32(in[0:4]))
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z[0] = binary.BigEndian.Uint64(in[4:12])
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return z
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}
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func (z *Int) SetBytes20(in []byte) *Int {
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_ = in[19] // bounds check hint to compiler; see golang.org/issue/14808
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z[3] = 0
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z[2] = uint64(binary.BigEndian.Uint32(in[0:4]))
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z[1] = binary.BigEndian.Uint64(in[4:12])
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z[0] = binary.BigEndian.Uint64(in[12:20])
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return z
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}
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func (z *Int) SetBytes28(in []byte) *Int {
|
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_ = in[27] // bounds check hint to compiler; see golang.org/issue/14808
|
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z[3] = uint64(binary.BigEndian.Uint32(in[0:4]))
|
|
z[2] = binary.BigEndian.Uint64(in[4:12])
|
|
z[1] = binary.BigEndian.Uint64(in[12:20])
|
|
z[0] = binary.BigEndian.Uint64(in[20:28])
|
|
return z
|
|
}
|
|
|
|
func (z *Int) SetBytes5(in []byte) *Int {
|
|
_ = in[4] // bounds check hint to compiler; see golang.org/issue/14808
|
|
z[3], z[2], z[1] = 0, 0, 0
|
|
z[0] = bigEndianUint40(in[0:5])
|
|
return z
|
|
}
|
|
|
|
func (z *Int) SetBytes13(in []byte) *Int {
|
|
_ = in[12] // bounds check hint to compiler; see golang.org/issue/14808
|
|
z[3], z[2] = 0, 0
|
|
z[1] = bigEndianUint40(in[0:5])
|
|
z[0] = binary.BigEndian.Uint64(in[5:13])
|
|
return z
|
|
}
|
|
|
|
func (z *Int) SetBytes21(in []byte) *Int {
|
|
_ = in[20] // bounds check hint to compiler; see golang.org/issue/14808
|
|
z[3] = 0
|
|
z[2] = bigEndianUint40(in[0:5])
|
|
z[1] = binary.BigEndian.Uint64(in[5:13])
|
|
z[0] = binary.BigEndian.Uint64(in[13:21])
|
|
return z
|
|
}
|
|
|
|
func (z *Int) SetBytes29(in []byte) *Int {
|
|
_ = in[28] // bounds check hint to compiler; see golang.org/issue/14808
|
|
z[3] = bigEndianUint40(in[0:5])
|
|
z[2] = binary.BigEndian.Uint64(in[5:13])
|
|
z[1] = binary.BigEndian.Uint64(in[13:21])
|
|
z[0] = binary.BigEndian.Uint64(in[21:29])
|
|
return z
|
|
}
|
|
|
|
func (z *Int) SetBytes6(in []byte) *Int {
|
|
_ = in[5] // bounds check hint to compiler; see golang.org/issue/14808
|
|
z[3], z[2], z[1] = 0, 0, 0
|
|
z[0] = bigEndianUint48(in[0:6])
|
|
return z
|
|
}
|
|
|
|
func (z *Int) SetBytes14(in []byte) *Int {
|
|
_ = in[13] // bounds check hint to compiler; see golang.org/issue/14808
|
|
z[3], z[2] = 0, 0
|
|
z[1] = bigEndianUint48(in[0:6])
|
|
z[0] = binary.BigEndian.Uint64(in[6:14])
|
|
return z
|
|
}
|
|
|
|
func (z *Int) SetBytes22(in []byte) *Int {
|
|
_ = in[21] // bounds check hint to compiler; see golang.org/issue/14808
|
|
z[3] = 0
|
|
z[2] = bigEndianUint48(in[0:6])
|
|
z[1] = binary.BigEndian.Uint64(in[6:14])
|
|
z[0] = binary.BigEndian.Uint64(in[14:22])
|
|
return z
|
|
}
|
|
|
|
func (z *Int) SetBytes30(in []byte) *Int {
|
|
_ = in[29] // bounds check hint to compiler; see golang.org/issue/14808
|
|
z[3] = bigEndianUint48(in[0:6])
|
|
z[2] = binary.BigEndian.Uint64(in[6:14])
|
|
z[1] = binary.BigEndian.Uint64(in[14:22])
|
|
z[0] = binary.BigEndian.Uint64(in[22:30])
|
|
return z
|
|
}
|
|
|
|
func (z *Int) SetBytes7(in []byte) *Int {
|
|
_ = in[6] // bounds check hint to compiler; see golang.org/issue/14808
|
|
z[3], z[2], z[1] = 0, 0, 0
|
|
z[0] = bigEndianUint56(in[0:7])
|
|
return z
|
|
}
|
|
|
|
func (z *Int) SetBytes15(in []byte) *Int {
|
|
_ = in[14] // bounds check hint to compiler; see golang.org/issue/14808
|
|
z[3], z[2] = 0, 0
|
|
z[1] = bigEndianUint56(in[0:7])
|
|
z[0] = binary.BigEndian.Uint64(in[7:15])
|
|
return z
|
|
}
|
|
|
|
func (z *Int) SetBytes23(in []byte) *Int {
|
|
_ = in[22] // bounds check hint to compiler; see golang.org/issue/14808
|
|
z[3] = 0
|
|
z[2] = bigEndianUint56(in[0:7])
|
|
z[1] = binary.BigEndian.Uint64(in[7:15])
|
|
z[0] = binary.BigEndian.Uint64(in[15:23])
|
|
return z
|
|
}
|
|
|
|
func (z *Int) SetBytes31(in []byte) *Int {
|
|
_ = in[30] // bounds check hint to compiler; see golang.org/issue/14808
|
|
z[3] = bigEndianUint56(in[0:7])
|
|
z[2] = binary.BigEndian.Uint64(in[7:15])
|
|
z[1] = binary.BigEndian.Uint64(in[15:23])
|
|
z[0] = binary.BigEndian.Uint64(in[23:31])
|
|
return z
|
|
}
|
|
|
|
// Utility methods that are "missing" among the bigEndian.UintXX methods.
|
|
|
|
func bigEndianUint40(b []byte) uint64 {
|
|
_ = b[4] // bounds check hint to compiler; see golang.org/issue/14808
|
|
return uint64(b[4]) | uint64(b[3])<<8 | uint64(b[2])<<16 | uint64(b[1])<<24 |
|
|
uint64(b[0])<<32
|
|
}
|
|
|
|
func bigEndianUint48(b []byte) uint64 {
|
|
_ = b[5] // bounds check hint to compiler; see golang.org/issue/14808
|
|
return uint64(b[5]) | uint64(b[4])<<8 | uint64(b[3])<<16 | uint64(b[2])<<24 |
|
|
uint64(b[1])<<32 | uint64(b[0])<<40
|
|
}
|
|
|
|
func bigEndianUint56(b []byte) uint64 {
|
|
_ = b[6] // bounds check hint to compiler; see golang.org/issue/14808
|
|
return uint64(b[6]) | uint64(b[5])<<8 | uint64(b[4])<<16 | uint64(b[3])<<24 |
|
|
uint64(b[2])<<32 | uint64(b[1])<<40 | uint64(b[0])<<48
|
|
}
|
|
|
|
// MarshalSSZAppend _almost_ implements the fastssz.Marshaler (see below) interface.
|
|
// Originally, this method was named `MarshalSSZTo`, and ostensibly implemented the interface.
|
|
// However, it was noted (https://github.com/holiman/uint256/issues/170) that the
|
|
// actual implementation did not match the intended semantics of the interface: it
|
|
// inserted the data instead of appending.
|
|
//
|
|
// Therefore, the `MarshalSSZTo` has been removed: to force users into making a choice:
|
|
// - Use `MarshalSSZAppend`: this is the method that appends to the destination buffer,
|
|
// and returns a potentially newly allocated buffer. This method will become `MarshalSSZTo`
|
|
// in some future release.
|
|
// - Or use `MarshalSSZInto`: this is the original method which places the data into
|
|
// the destination buffer, without ever reallocating.
|
|
//
|
|
// fastssz.Marshaler interface:
|
|
//
|
|
// https://github.com/ferranbt/fastssz/blob/main/interface.go#L4
|
|
// type Marshaler interface {
|
|
// MarshalSSZTo(dst []byte) ([]byte, error)
|
|
// MarshalSSZ() ([]byte, error)
|
|
// SizeSSZ() int
|
|
// }
|
|
func (z *Int) MarshalSSZAppend(dst []byte) ([]byte, error) {
|
|
dst = binary.LittleEndian.AppendUint64(dst, z[0])
|
|
dst = binary.LittleEndian.AppendUint64(dst, z[1])
|
|
dst = binary.LittleEndian.AppendUint64(dst, z[2])
|
|
dst = binary.LittleEndian.AppendUint64(dst, z[3])
|
|
return dst, nil
|
|
}
|
|
|
|
// MarshalSSZInto is the first attempt to implement the fastssz.Marshaler interface,
|
|
// but which does not obey the intended semantics. See MarshalSSZAppend and
|
|
// - https://github.com/holiman/uint256/pull/171
|
|
// - https://github.com/holiman/uint256/issues/170
|
|
// @deprecated
|
|
func (z *Int) MarshalSSZInto(dst []byte) ([]byte, error) {
|
|
if len(dst) < 32 {
|
|
return nil, fmt.Errorf("%w: have %d, want %d bytes", ErrBadBufferLength, len(dst), 32)
|
|
}
|
|
binary.LittleEndian.PutUint64(dst[0:8], z[0])
|
|
binary.LittleEndian.PutUint64(dst[8:16], z[1])
|
|
binary.LittleEndian.PutUint64(dst[16:24], z[2])
|
|
binary.LittleEndian.PutUint64(dst[24:32], z[3])
|
|
|
|
return dst[32:], nil
|
|
}
|
|
|
|
// MarshalSSZ implements the fastssz.Marshaler interface and returns the integer
|
|
// marshalled into a newly allocated byte slice.
|
|
func (z *Int) MarshalSSZ() ([]byte, error) {
|
|
blob, _ := z.MarshalSSZAppend(make([]byte, 0, 32)) // ignore error, cannot fail, surely have 32 byte space in blob
|
|
return blob, nil
|
|
}
|
|
|
|
// SizeSSZ implements the fastssz.Marshaler interface and returns the byte size
|
|
// of the 256 bit int.
|
|
func (*Int) SizeSSZ() int {
|
|
return 32
|
|
}
|
|
|
|
// UnmarshalSSZ implements the fastssz.Unmarshaler interface and parses an encoded
|
|
// integer into the local struct.
|
|
func (z *Int) UnmarshalSSZ(buf []byte) error {
|
|
if len(buf) != 32 {
|
|
return fmt.Errorf("%w: have %d, want %d bytes", ErrBadEncodedLength, len(buf), 32)
|
|
}
|
|
z[0] = binary.LittleEndian.Uint64(buf[0:8])
|
|
z[1] = binary.LittleEndian.Uint64(buf[8:16])
|
|
z[2] = binary.LittleEndian.Uint64(buf[16:24])
|
|
z[3] = binary.LittleEndian.Uint64(buf[24:32])
|
|
|
|
return nil
|
|
}
|
|
|
|
// HashTreeRoot implements the fastssz.HashRoot interface's non-dependent part.
|
|
func (z *Int) HashTreeRoot() ([32]byte, error) {
|
|
b, _ := z.MarshalSSZAppend(make([]byte, 0, 32)) // ignore error, cannot fail
|
|
var hash [32]byte
|
|
copy(hash[:], b)
|
|
return hash, nil
|
|
}
|
|
|
|
// EncodeRLP implements the rlp.Encoder interface from go-ethereum
|
|
// and writes the RLP encoding of z to w.
|
|
func (z *Int) EncodeRLP(w io.Writer) error {
|
|
if z == nil {
|
|
_, err := w.Write([]byte{0x80})
|
|
return err
|
|
}
|
|
nBits := z.BitLen()
|
|
if nBits == 0 {
|
|
_, err := w.Write([]byte{0x80})
|
|
return err
|
|
}
|
|
if nBits <= 7 {
|
|
_, err := w.Write([]byte{byte(z[0])})
|
|
return err
|
|
}
|
|
nBytes := byte((nBits + 7) / 8)
|
|
var b [33]byte
|
|
binary.BigEndian.PutUint64(b[1:9], z[3])
|
|
binary.BigEndian.PutUint64(b[9:17], z[2])
|
|
binary.BigEndian.PutUint64(b[17:25], z[1])
|
|
binary.BigEndian.PutUint64(b[25:33], z[0])
|
|
b[32-nBytes] = 0x80 + nBytes
|
|
_, err := w.Write(b[32-nBytes:])
|
|
return err
|
|
}
|
|
|
|
// MarshalText implements encoding.TextMarshaler
|
|
// MarshalText marshals using the decimal representation (compatible with big.Int)
|
|
func (z *Int) MarshalText() ([]byte, error) {
|
|
return []byte(z.Dec()), nil
|
|
}
|
|
|
|
// MarshalJSON implements json.Marshaler.
|
|
// MarshalJSON marshals using the 'decimal string' representation. This is _not_ compatible
|
|
// with big.Int: big.Int marshals into JSON 'native' numeric format.
|
|
//
|
|
// The JSON native format is, on some platforms, (e.g. javascript), limited to 53-bit large
|
|
// integer space. Thus, U256 uses string-format, which is not compatible with
|
|
// big.int (big.Int refuses to unmarshal a string representation).
|
|
func (z *Int) MarshalJSON() ([]byte, error) {
|
|
return []byte(`"` + z.Dec() + `"`), nil
|
|
}
|
|
|
|
// UnmarshalJSON implements json.Unmarshaler. UnmarshalJSON accepts either
|
|
// - Quoted string: either hexadecimal OR decimal
|
|
// - Not quoted string: only decimal
|
|
func (z *Int) UnmarshalJSON(input []byte) error {
|
|
if len(input) < 2 || input[0] != '"' || input[len(input)-1] != '"' {
|
|
// if not quoted, it must be decimal
|
|
return z.SetFromDecimal(string(input))
|
|
}
|
|
return z.UnmarshalText(input[1 : len(input)-1])
|
|
}
|
|
|
|
// String returns the decimal encoding of b.
|
|
func (z *Int) String() string {
|
|
return z.Dec()
|
|
}
|
|
|
|
const (
|
|
hextable = "0123456789abcdef"
|
|
bintable = "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\x00\x01\x02\x03\x04\x05\x06\a\b\t\xff\xff\xff\xff\xff\xff\xff\n\v\f\r\x0e\x0f\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\n\v\f\r\x0e\x0f\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"
|
|
badNibble = 0xff
|
|
)
|
|
|
|
// Hex encodes z in 0x-prefixed hexadecimal form.
|
|
func (z *Int) Hex() string {
|
|
// This implementation is not optimal, it allocates a full
|
|
// 66-byte output buffer which it fills. It could instead allocate a smaller
|
|
// buffer, and omit the final crop-stage.
|
|
output := make([]byte, 66)
|
|
nibbles := (z.BitLen() + 3) / 4 // nibbles [0,64]
|
|
if nibbles == 0 {
|
|
nibbles = 1
|
|
}
|
|
// Start with the most significant
|
|
zWord := (nibbles - 1) / 16
|
|
for i := zWord; i >= 0; i-- {
|
|
off := (3 - i) * 16
|
|
output[off+2] = hextable[byte(z[i]>>60)&0xf]
|
|
output[off+3] = hextable[byte(z[i]>>56)&0xf]
|
|
output[off+4] = hextable[byte(z[i]>>52)&0xf]
|
|
output[off+5] = hextable[byte(z[i]>>48)&0xf]
|
|
output[off+6] = hextable[byte(z[i]>>44)&0xf]
|
|
output[off+7] = hextable[byte(z[i]>>40)&0xf]
|
|
output[off+8] = hextable[byte(z[i]>>36)&0xf]
|
|
output[off+9] = hextable[byte(z[i]>>32)&0xf]
|
|
output[off+10] = hextable[byte(z[i]>>28)&0xf]
|
|
output[off+11] = hextable[byte(z[i]>>24)&0xf]
|
|
output[off+12] = hextable[byte(z[i]>>20)&0xf]
|
|
output[off+13] = hextable[byte(z[i]>>16)&0xf]
|
|
output[off+14] = hextable[byte(z[i]>>12)&0xf]
|
|
output[off+15] = hextable[byte(z[i]>>8)&0xf]
|
|
output[off+16] = hextable[byte(z[i]>>4)&0xf]
|
|
output[off+17] = hextable[byte(z[i]&0xF)&0xf]
|
|
}
|
|
output[64-nibbles] = '0'
|
|
output[65-nibbles] = 'x'
|
|
return string(output[64-nibbles:])
|
|
}
|
|
|
|
// Scan implements the database/sql Scanner interface.
|
|
// It decodes a string, because that is what postgres uses for its numeric type
|
|
func (dst *Int) Scan(src interface{}) error {
|
|
if src == nil {
|
|
dst.Clear()
|
|
return nil
|
|
}
|
|
switch src := src.(type) {
|
|
case string:
|
|
return dst.scanScientificFromString(src)
|
|
case []byte:
|
|
return dst.scanScientificFromString(string(src))
|
|
}
|
|
return errors.New("unsupported type")
|
|
}
|
|
|
|
func (dst *Int) scanScientificFromString(src string) error {
|
|
if len(src) == 0 {
|
|
dst.Clear()
|
|
return nil
|
|
}
|
|
idx := strings.IndexByte(src, 'e')
|
|
if idx == -1 {
|
|
return dst.SetFromDecimal(src)
|
|
}
|
|
if err := dst.SetFromDecimal(src[:idx]); err != nil {
|
|
return err
|
|
}
|
|
if src[(idx+1):] == "0" {
|
|
return nil
|
|
}
|
|
exp := new(Int)
|
|
if err := exp.SetFromDecimal(src[(idx + 1):]); err != nil {
|
|
return err
|
|
}
|
|
if exp.GtUint64(77) { // 10**78 is larger than 2**256
|
|
return ErrBig256Range
|
|
}
|
|
exp.Exp(NewInt(10), exp)
|
|
if _, overflow := dst.MulOverflow(dst, exp); overflow {
|
|
return ErrBig256Range
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Value implements the database/sql/driver Valuer interface.
|
|
// It encodes a base 10 string.
|
|
// In Postgres, this will work with both integer and the Numeric/Decimal types
|
|
// In MariaDB/MySQL, this will work with the Numeric/Decimal types up to 65 digits, however any more and you should use either VarChar or Char(79)
|
|
// In SqLite, use TEXT
|
|
func (src *Int) Value() (driver.Value, error) {
|
|
return src.Dec(), nil
|
|
}
|
|
|
|
var (
|
|
ErrEmptyString = errors.New("empty hex string")
|
|
ErrSyntax = errors.New("invalid hex string")
|
|
ErrMissingPrefix = errors.New("hex string without 0x prefix")
|
|
ErrEmptyNumber = errors.New("hex string \"0x\"")
|
|
ErrLeadingZero = errors.New("hex number with leading zero digits")
|
|
ErrBig256Range = errors.New("hex number > 256 bits")
|
|
ErrBadBufferLength = errors.New("bad ssz buffer length")
|
|
ErrBadEncodedLength = errors.New("bad ssz encoded length")
|
|
)
|
|
|
|
func checkNumberS(input string) error {
|
|
l := len(input)
|
|
if l == 0 {
|
|
return ErrEmptyString
|
|
}
|
|
if l < 2 || input[0] != '0' ||
|
|
(input[1] != 'x' && input[1] != 'X') {
|
|
return ErrMissingPrefix
|
|
}
|
|
if l == 2 {
|
|
return ErrEmptyNumber
|
|
}
|
|
if len(input) > 3 && input[2] == '0' {
|
|
return ErrLeadingZero
|
|
}
|
|
return nil
|
|
}
|