util

package
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Published: Apr 17, 2020 License: MIT Imports: 7 Imported by: 4

Documentation

Overview

Package util provides common utility functions.

Index

Examples

Constants

This section is empty.

Variables

View Source
var (
	ErrEmptyString   = &decError{"empty hex string"}
	ErrSyntax        = &decError{"invalid hex string"}
	ErrMissingPrefix = &decError{"hex string without 0x prefix"}
	ErrOddLength     = &decError{"hex string of odd length"}
	ErrEmptyNumber   = &decError{"hex string 0x"}
	ErrLeadingZero   = &decError{"hex number with leading zero digits"}
	ErrUint64Range   = &decError{"hex number > 64 bits"}
	ErrUintRange     = &decError{fmt.Sprintf("hex number > %d bits", uintBits)}
	ErrBig256Range   = &decError{"hex number > 256 bits"}
)

Errors

Functions

func Bytes2Hex

func Bytes2Hex(d []byte) string

Bytes2Hex returns the hexadecimal encoding of d.

func BytesToUint32

func BytesToUint32(i []byte) uint32

BytesToUint32 interprets a byte slice as uint32, using little endian encoding.

func BytesToUint64

func BytesToUint64(i []byte) uint64

BytesToUint64 interprets a byte slice as uint64, using little endian encoding.

func CopyBytes

func CopyBytes(b []byte) (copiedBytes []byte)

CopyBytes returns an exact copy of the provided bytes.

func Decode

func Decode(input string) ([]byte, error)

Decode decodes a hex string with 0x prefix.

func DecodeBig

func DecodeBig(input string) (*big.Int, error)

DecodeBig decodes a hex string with 0x prefix as a quantity. Numbers larger than 256 bits are not accepted.

func DecodeUint64

func DecodeUint64(input string) (uint64, error)

DecodeUint64 decodes a hex string with 0x prefix as a quantity.

func Encode

func Encode(b []byte) string

Encode encodes b as a hex string with 0x prefix.

func EncodeBig

func EncodeBig(bigint *big.Int) string

EncodeBig encodes bigint as a hex string with 0x prefix. The sign of the integer is ignored.

func EncodeUint64

func EncodeUint64(i uint64) string

EncodeUint64 encodes i as a hex string with 0x prefix.

func FromHex

func FromHex(s string) []byte

FromHex returns the bytes represented by the hexadecimal string s. s may be prefixed with "0x".

func Hex2Bytes

func Hex2Bytes(str string) []byte

Hex2Bytes returns the bytes represented by the hexadecimal string str.

func LeftPadBytes

func LeftPadBytes(slice []byte, l int) []byte

LeftPadBytes zero-pads slice to the left up to length l.

func Min

func Min(a, b int) int

Min returns the smaller of the two inputs, both of type int.

func Min32

func Min32(a, b uint32) uint32

Min32 returns the smaller of the two inputs, both of type uint32.

func Min64

func Min64(a, b uint64) uint64

Min64 returns the smaller of the two inputs, both of type uint64.

func MustDecode

func MustDecode(input string) []byte

MustDecode decodes a hex string with 0x prefix. It panics for invalid input.

func MustDecodeBig

func MustDecodeBig(input string) *big.Int

MustDecodeBig decodes a hex string with 0x prefix as a quantity. It panics for invalid input.

func MustDecodeUint64

func MustDecodeUint64(input string) uint64

MustDecodeUint64 decodes a hex string with 0x prefix as a quantity. It panics for invalid input.

func Uint32ToBytes

func Uint32ToBytes(i uint32) []byte

Uint32ToBytes returns the byte representation of a uint32, using little endian encoding.

func Uint64ToBytes

func Uint64ToBytes(i uint64) []byte

Uint64ToBytes returns the byte representation of a uint64, using little endian encoding.

func Uint64ToBytesBigEndian

func Uint64ToBytesBigEndian(i uint64) []byte

Uint64ToBytesBigEndian returns the byte representation of a uint64, using big endian encoding (which is not the default for spacemesh).

func UnmarshalFixedJSON

func UnmarshalFixedJSON(typ reflect.Type, input, out []byte) error

UnmarshalFixedJSON decodes the input as a string with 0x prefix. The length of out determines the required input length. This function is commonly used to implement the UnmarshalJSON method for fixed-size types.

func UnmarshalFixedText

func UnmarshalFixedText(typname string, input, out []byte) error

UnmarshalFixedText decodes the input as a string with 0x prefix. The length of out determines the required input length. This function is commonly used to implement the UnmarshalText method for fixed-size types.

Example
package main

import (
	"encoding/json"
	"fmt"
)

type MyType [5]byte

func (v *MyType) UnmarshalText(input []byte) error {
	return UnmarshalFixedText("MyType", input, v[:])
}

func (v MyType) String() string {
	return Bytes(v[:]).String()
}

func main() {
	var v1, v2 MyType
	fmt.Println("v1 error:", json.Unmarshal([]byte(`"0x01"`), &v1))
	fmt.Println("v2 error:", json.Unmarshal([]byte(`"0x0101010101"`), &v2))
	fmt.Println("v2:", v2)
}
Output:

v1 error: hex string has length 2, want 10 for MyType
v2 error: <nil>
v2: 0x0101010101

func UnmarshalFixedUnprefixedText

func UnmarshalFixedUnprefixedText(typname string, input, out []byte) error

UnmarshalFixedUnprefixedText decodes the input as a string with optional 0x prefix. The length of out determines the required input length. This function is commonly used to implement the UnmarshalText method for fixed-size types.

Types

type Big

type Big big.Int

Big marshals/unmarshals as a JSON string with 0x prefix. The zero value marshals as "0x0".

Negative integers are not supported at this time. Attempting to marshal them will return an error. Values larger than 256bits are rejected by Unmarshal but will be marshaled without error.

func (Big) MarshalText

func (b Big) MarshalText() ([]byte, error)

MarshalText implements encoding.TextMarshaler

func (*Big) String

func (b *Big) String() string

String returns the hex encoding of b.

func (*Big) ToInt

func (b *Big) ToInt() *big.Int

ToInt converts b to a big.Int.

func (*Big) UnmarshalJSON

func (b *Big) UnmarshalJSON(input []byte) error

UnmarshalJSON implements json.Unmarshaler.

func (*Big) UnmarshalText

func (b *Big) UnmarshalText(input []byte) error

UnmarshalText implements encoding.TextUnmarshaler

type Bytes

type Bytes []byte

Bytes marshals/unmarshals as a JSON string with 0x prefix. The empty slice marshals as "0x".

func (Bytes) MarshalText

func (b Bytes) MarshalText() ([]byte, error)

MarshalText implements encoding.TextMarshaler

func (Bytes) String

func (b Bytes) String() string

String returns the hex encoding of b.

func (*Bytes) UnmarshalJSON

func (b *Bytes) UnmarshalJSON(input []byte) error

UnmarshalJSON implements json.Unmarshaler.

func (*Bytes) UnmarshalText

func (b *Bytes) UnmarshalText(input []byte) error

UnmarshalText implements encoding.TextUnmarshaler.

type Uint

type Uint uint

Uint marshals/unmarshals as a JSON string with 0x prefix. The zero value marshals as "0x0".

func (Uint) MarshalText

func (b Uint) MarshalText() ([]byte, error)

MarshalText implements encoding.TextMarshaler.

func (Uint) String

func (b Uint) String() string

String returns the hex encoding of b.

func (*Uint) UnmarshalJSON

func (b *Uint) UnmarshalJSON(input []byte) error

UnmarshalJSON implements json.Unmarshaler.

func (*Uint) UnmarshalText

func (b *Uint) UnmarshalText(input []byte) error

UnmarshalText implements encoding.TextUnmarshaler.

type Uint64

type Uint64 uint64

Uint64 marshals/unmarshals as a JSON string with 0x prefix. The zero value marshals as "0x0".

func (Uint64) MarshalText

func (b Uint64) MarshalText() ([]byte, error)

MarshalText implements encoding.TextMarshaler.

func (Uint64) String

func (b Uint64) String() string

String returns the hex encoding of b.

func (*Uint64) UnmarshalJSON

func (b *Uint64) UnmarshalJSON(input []byte) error

UnmarshalJSON implements json.Unmarshaler.

func (*Uint64) UnmarshalText

func (b *Uint64) UnmarshalText(input []byte) error

UnmarshalText implements encoding.TextUnmarshaler

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