common

package
v0.0.0-...-7505a0c Latest Latest
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This package is not in the latest version of its module.

 Go to latest Published: Jan 29, 2019 License: LGPL-3.0 Imports: 25 Imported by: 0

Documentation

Overview

Package math provides integer math utilities.

Index

Constants

View Source 
const (
	PendingBlockNumber  = BlockNumber(-2)
	LatestBlockNumber   = BlockNumber(-1)
	EarliestBlockNumber = BlockNumber(0)
)
View Source 
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
)

Integer limit values.

View Source 
const (
	ChainIdSize = 64
)

Variables

View Source 
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))

	Big1   = big.NewInt(1)
	Big2   = big.NewInt(2)
	Big3   = big.NewInt(3)
	Big0   = big.NewInt(0)
	Big32  = big.NewInt(32)
	Big256 = big.NewInt(256)
	Big257 = big.NewInt(257)
)

Various big integer limit values.

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 AbsolutePath 

func AbsolutePath(datadir string, filename string) string

func AppDataDir 

func AppDataDir(appName string, roaming bool) string

AppDataDir returns an operating system specific directory to be used for storing application data for an application.

The appName parameter is the name of the application the data directory is being requested for. This function will prepend a period to the appName for POSIX style operating systems since that is standard practice. An empty appName or one with a single dot is treated as requesting the current directory so only "." will be returned. Further, the first character of appName will be made lowercase for POSIX style operating systems and uppercase for Mac and Windows since that is standard practice.

The roaming parameter only applies to Windows where it specifies the roaming application data profile (%APPDATA%) should be used instead of the local one (%LOCALAPPDATA%) that is used by default.

Example results: 

dir := AppDataDir("myapp", false)
 POSIX (Linux/BSD): ~/.myapp
 Mac OS: $HOME/Library/Application Support/Myapp
 Windows: %LOCALAPPDATA%\Myapp
 Plan 9: $home/myapp

func BigEndianByteAt 

func BigEndianByteAt(bigint *big.Int, n int) byte

BigEndianByteAt returns the byte at position n, in Big-Endian encoding So n==0 returns the least significant byte

func BigMax 

func BigMax(x, y *big.Int) *big.Int

BigMax returns the larger of x or y.

func BigMin 

func BigMin(x, y *big.Int) *big.Int

BigMin returns the smaller of x or y.

func BigPow 

func BigPow(a, b int64) *big.Int

BigPow returns a ** b as a big integer.

func Byte 

func Byte(bigint *big.Int, padlength, n int) byte

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 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 EachChildFile 

func EachChildFile(directory string, process func(path string) (bool, error)) error

EachChildFile get child fi and process ,if get error after processing stop, if get a stop flag , stop

func EachDirectory 

func EachDirectory(directory string, process func(path string) (bool, error)) error

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 Exp 

func Exp(base, exponent *big.Int) *big.Int

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 ExpandPath 

func ExpandPath(p string) string

Expands a file path 1. replace tilde with users home dir 2. expands embedded environment variables 3. cleans the path, e.g. /a/b/../c -> /a/c Note, it has limitations, e.g. ~someuser/tmp will not be expanded

func FirstBitSet 

func FirstBitSet(v *big.Int) int

FirstBitSet returns the index of the first 1 bit in v, counting from LSB.

func GenUnique 

func GenUnique() ([]byte, error)

func GlobalBig 

func GlobalBig(ctx *cli.Context, name string) *big.Int

GlobalBig returns the value of a BigFlag from the global flag set.

func HmAC 

func HmAC(message, key []byte) []byte

func HomeDir 

func HomeDir() string

func IsDirExists 

func IsDirExists(path string) bool

func IsFileExists 

func IsFileExists(path string) bool

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 MustParseBig256 

func MustParseBig256(s string) *big.Int

MustParseBig256 parses s as a 256 bit big integer and panics if the string is invalid.

func MustParseUint64 

func MustParseUint64(s string) uint64

MustParseUint64 parses s as an integer and panics if the string is invalid.

func PaddedBigBytes 

func PaddedBigBytes(bigint *big.Int, n int) []byte

PaddedBigBytes encodes a big integer as a big-endian byte slice. The length of the slice is at least n bytes.

func ParseBig256 

func ParseBig256(s string) (*big.Int, bool)

ParseBig256 parses s as a 256 bit integer in decimal or hexadecimal syntax. Leading zeros are accepted. The empty string parses as zero.

func ParseUint64 

func ParseUint64(s string) (uint64, bool)

ParseUint64 parses s as an integer in decimal or hexadecimal syntax. Leading zeros are accepted. The empty string parses as zero.

func ReadBits 

func ReadBits(bigint *big.Int, buf []byte)

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 S256 

func S256(x *big.Int) *big.Int

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 SafeAdd 

func SafeAdd(x, y uint64) (uint64, bool)

SafeAdd returns the result and whether overflow occurred.

func SafeMul 

func SafeMul(x, y uint64) (uint64, bool)

SafeMul returns multiplication result and whether overflow occurred.

func SafeSub 

func SafeSub(x, y uint64) (uint64, bool)

SafeSub returns subtraction result and whether overflow occurred.

func U256 

func U256(x *big.Int) *big.Int

U256 encodes as a 256 bit two's complement number. This operation is destructive.

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.

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 BigFlag 

type BigFlag struct {
	Name  string
	Value *big.Int
	Usage string
}

BigFlag is a command line flag that accepts 256 bit big integers in decimal or hexadecimal syntax.

func (BigFlag) Apply 

func (f BigFlag) Apply(set *flag.FlagSet)

func (BigFlag) GetName 

func (f BigFlag) GetName() string

func (BigFlag) String 

func (f BigFlag) String() string

type BlockNumber 

type BlockNumber int64

func (BlockNumber) Int64 

func (bn BlockNumber) Int64() int64

func (*BlockNumber) UnmarshalJSON 

func (bn *BlockNumber) UnmarshalJSON(data []byte) error

UnmarshalJSON parses the given JSON fragment into a BlockNumber. It supports: - "latest", "earliest" or "pending" as string arguments - the block number Returned errors: - an invalid block number error when the given argument isn't a known strings - an out of range error when the given block number is either too little or too large

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 ChainIdType 

type ChainIdType [ChainIdSize]byte

func Bytes2ChainId 

func Bytes2ChainId(b []byte) ChainIdType

func Hex2ChainId 

func Hex2ChainId(s string) ChainIdType

func (ChainIdType) Hex 

func (c ChainIdType) Hex() string

func (ChainIdType) MarshalText 

func (c ChainIdType) MarshalText() ([]byte, error)

func (*ChainIdType) SetBytes 

func (c *ChainIdType) SetBytes(b []byte)

func (*ChainIdType) UnmarshalJSON 

func (c *ChainIdType) UnmarshalJSON(input []byte) error

UnmarshalJSON implements json.Unmarshaler.

func (*ChainIdType) UnmarshalText 

func (c *ChainIdType) UnmarshalText(input []byte) error

UnmarshalText implements encoding.TextUnmarshaler

type DirectoryFlag 

type DirectoryFlag struct {
	Name  string
	Value DirectoryString
	Usage string
}

Custom cli.Flag type which expand the received string to an absolute path. e.g. ~/.ethereum -> /home/username/.ethereum

func (DirectoryFlag) Apply 

func (self DirectoryFlag) Apply(set *flag.FlagSet)

called by cli library, grabs variable from environment (if in env) and adds variable to flag set for parsing.

func (DirectoryFlag) GetName 

func (self DirectoryFlag) GetName() string

func (*DirectoryFlag) Set 

func (self *DirectoryFlag) Set(value string)

func (DirectoryFlag) String 

func (self DirectoryFlag) String() string

type DirectoryString 

type DirectoryString struct {
	Value string
}

Custom type which is registered in the flags library which cli uses for argument parsing. This allows us to expand Value to an absolute path when the argument is parsed

func (*DirectoryString) Set 

func (self *DirectoryString) Set(value string) error

func (*DirectoryString) String 

func (self *DirectoryString) String() string

type HexOrDecimal256 

type HexOrDecimal256 big.Int

HexOrDecimal256 marshals big.Int as hex or decimal.

func (*HexOrDecimal256) MarshalText 

func (i *HexOrDecimal256) MarshalText() ([]byte, error)

MarshalText implements encoding.TextMarshaler.

func (*HexOrDecimal256) UnmarshalText 

func (i *HexOrDecimal256) UnmarshalText(input []byte) error

UnmarshalText implements encoding.TextUnmarshaler.

type HexOrDecimal64 

type HexOrDecimal64 uint64

HexOrDecimal64 marshals uint64 as hex or decimal.

func (HexOrDecimal64) MarshalText 

func (i HexOrDecimal64) MarshalText() ([]byte, error)

MarshalText implements encoding.TextMarshaler.

func (*HexOrDecimal64) UnmarshalText 

func (i *HexOrDecimal64) UnmarshalText(input []byte) error

UnmarshalText implements encoding.TextUnmarshaler.

type TextMarshaler 

type TextMarshaler interface {
	encoding.TextMarshaler
	encoding.TextUnmarshaler
}

func GlobalTextMarshaler 

func GlobalTextMarshaler(ctx *cli.Context, name string) TextMarshaler

GlobalTextMarshaler returns the value of a TextMarshalerFlag from the global flag set.

type TextMarshalerFlag 

type TextMarshalerFlag struct {
	Name  string
	Value TextMarshaler
	Usage string
}

TextMarshalerFlag wraps a TextMarshaler value.

func (TextMarshalerFlag) Apply 

func (f TextMarshalerFlag) Apply(set *flag.FlagSet)

func (TextMarshalerFlag) GetName 

func (f TextMarshalerFlag) GetName() string

func (TextMarshalerFlag) String 

func (f TextMarshalerFlag) String() string

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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