utils

package
v0.0.2 Latest Latest
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 Go to latest Published: Mar 12, 2021 License: ISC Imports: 41 Imported by: 0

Documentation

Overview

Package utils is used for common functions and tools used across the codebase.

Index

Constants

View Source 
const (
	// FormatBytes encodes the output as bytes
	FormatBytes = "bytes"
	// FormatPreformatted encodes the output, assumed to be hex, as bytes.
	FormatPreformatted = "preformatted"
	// FormatUint256 encodes the output as bytes containing a uint256
	FormatUint256 = "uint256"
	// FormatInt256 encodes the output as bytes containing an int256
	FormatInt256 = "int256"
	// FormatBool encodes the output as bytes containing a bool
	FormatBool = "bool"
)
View Source 
const (
	FastN = 2
	FastP = 1
)
View Source 
const (
	// DefaultSecretSize is the entroy in bytes to generate a base64 string of 64 characters.
	DefaultSecretSize = 48
	// EVMWordByteLen the length of an EVM Word Byte
	EVMWordByteLen = 32
	// EVMWordHexLen the length of an EVM Word Hex
	EVMWordHexLen = EVMWordByteLen * 2
)

Variables

View Source 
var (

	// MaxUint256 represents the largest number represented by an EVM word
	MaxUint256 = &big.Int{}
	// MaxInt256 represents the largest number represented by an EVM word using
	// signed encoding.
	MaxInt256 = &big.Int{}
	// MinInt256 represents the smallest number represented by an EVM word using
	// signed encoding.
	MinInt256 = &big.Int{}
)

"Constants" used by EVM words

View Source 
var (
	Client             *http.Client
	UnrestrictedClient *http.Client
)
View Source 
var DefaultScryptParams = ScryptParams{N: keystore.StandardScryptN, P: keystore.StandardScryptP}

DefaultScryptParams is for use in production. It used geth's standard level of encryption and is relatively expensive to decode. Avoid using this in tests.

View Source 
var EmptyHash = common.Hash{}

EmptyHash is a hash of all zeroes, otherwise in Ethereum as 0x0000000000000000000000000000000000000000000000000000000000000000

View Source 
var FastScryptParams = ScryptParams{N: FastN, P: FastP}

FastScryptParams is for use in tests, where you don't want to wear out your CPU with expensive key derivations, do not use it in production, or your encrypted keys will be easy to brute-force!

View Source 
var ZeroAddress = common.Address{}

ZeroAddress is an address of all zeroes, otherwise in Ethereum as 0x0000000000000000000000000000000000000000

Functions

func AddHexPrefix 

func AddHexPrefix(str string) string

AddHexPrefix adds the previx (0x) to a given hex string.

func CheckPasswordHash 

func CheckPasswordHash(password, hash string) bool

CheckPasswordHash wraps around bcrypt.CompareHashAndPassword for a friendlier API.

func CheckUint256 

func CheckUint256(n *big.Int) error

CheckUint256(n) returns an error if n is out of bounds for a uint256

func CombinedContext 

func CombinedContext(signals ...interface{}) (context.Context, context.CancelFunc)

CombinedContext creates a context that finishes when any of the provided signals finish. A signal can be a `context.Context`, a `chan struct{}`, or a `time.Duration` (which is transformed into a `context.WithTimeout`).

func ConcatBytes 

func ConcatBytes(bufs ...[]byte) []byte

ConcatBytes appends a bunch of byte arrays into a single byte array

func ContextFromChan 

func ContextFromChan(chStop <-chan struct{}) (context.Context, context.CancelFunc)

ContextFromChan creates a context that finishes when the provided channel receives or is closed.

func CopyFileWithMaxPerms 

func CopyFileWithMaxPerms(srcPath, dstPath string, perms os.FileMode) error

Copies the file at `srcPath` to `dstPath` and ensures that it has permissions that are no more permissive than the given ones.

func DebugPanic 

func DebugPanic()

func DecodeEthereumTx 

func DecodeEthereumTx(hex string) (types.Transaction, error)

DecodeEthereumTx takes an RLP hex encoded Ethereum transaction and returns a Transaction struct with all the fields accessible.

func DurationFromNow 

func DurationFromNow(t time.Time) time.Duration

DurationFromNow returns the amount of time since the Time field was last updated.

func EIP55CapitalizedAddress 

func EIP55CapitalizedAddress(possibleAddressString string) bool

EIP55CapitalizedAddress returns true iff possibleAddressString has the correct capitalization for an Ethereum address, per EIP 55

func EVMBytesToUint64 

func EVMBytesToUint64(buf []byte) uint64

func EVMEncodeBytes 

func EVMEncodeBytes(input []byte) []byte

EVMEncodeBytes encodes arbitrary bytes as bytes expected by the EVM

func EVMTranscodeBool 

func EVMTranscodeBool(value gjson.Result) ([]byte, error)

EVMTranscodeBool converts a json input to an EVM bool

func EVMTranscodeBytes 

func EVMTranscodeBytes(value gjson.Result) ([]byte, error)

EVMTranscodeBytes converts a json input to an EVM bytes array

func EVMTranscodeInt256 

func EVMTranscodeInt256(value gjson.Result) ([]byte, error)

EVMTranscodeInt256 converts a json input to an EVM int256

func EVMTranscodeJSONWithFormat 

func EVMTranscodeJSONWithFormat(value gjson.Result, format string) ([]byte, error)

EVMTranscodeJSONWithFormat given a JSON input and a format specifier, encode the value for use by the EVM

func EVMTranscodeUint256 

func EVMTranscodeUint256(value gjson.Result) ([]byte, error)

EVMTranscodeUint256 converts a json input to an EVM uint256

func EVMWordBigInt 

func EVMWordBigInt(val *big.Int) ([]byte, error)

EVMWordBigInt returns a big.Int as an EVM word byte array, with support for a signed representation. Returns error on overflow.

func EVMWordSignedBigInt 

func EVMWordSignedBigInt(val *big.Int) ([]byte, error)

EVMWordSignedBigInt returns a big.Int as an EVM word byte array, with support for a signed representation. Returns error on overflow.

func EVMWordUint128 

func EVMWordUint128(val *big.Int) ([]byte, error)

EVMWordUint128 returns a uint128 as an EVM word byte array.

func EVMWordUint64 

func EVMWordUint64(val uint64) []byte

EVMWordUint64 returns a uint64 as an EVM word byte array.

func EnsureDirAndMaxPerms 

func EnsureDirAndMaxPerms(path string, perms os.FileMode) error

Ensures that the given path exists, that it's a directory, and that it has permissions that are no more permissive than the given ones.

- If the path does not exist, it is created - If the path exists, but is not a directory, an error is returned - If the path exists, and is a directory, but has the wrong perms, it is chmod'ed

func EnsureFileMaxPerms 

func EnsureFileMaxPerms(file *os.File, perms os.FileMode) error

Ensures that the given file has permissions that are no more permissive than the given ones.

func EnsureFilepathMaxPerms 

func EnsureFilepathMaxPerms(filepath string, perms os.FileMode) error

Ensures that the file at the given filepath has permissions that are no more permissive than the given ones.

func FileContents 

func FileContents(path string) (string, error)

FileContents returns the contents of a file as a string.

func FileExists 

func FileExists(name string) bool

FileExists returns true if a file at the passed string exists.

func FilesInDir 

func FilesInDir(dir string) ([]string, error)

FilesInDir returns an array of filenames in the directory.

func FormatJSON 

func FormatJSON(v interface{}) ([]byte, error)

FormatJSON applies indent to format a JSON response.

func HasHexPrefix 

func HasHexPrefix(str string) bool

HasHexPrefix returns true if the string starts with 0x.

func HashPassword 

func HashPassword(password string) (string, error)

HashPassword wraps around bcrypt.GenerateFromPassword for a friendlier API.

func HexToUint256 

func HexToUint256(s string) (*big.Int, error)

HexToUint256 returns the uint256 represented by s, or an error if it doesn't represent one.

func ISO8601UTC 

func ISO8601UTC(t time.Time) string

ISO8601UTC formats given time to ISO8601.

func IsEmptyAddress 

func IsEmptyAddress(addr common.Address) bool

IsEmptyAddress checks that the address is empty, synonymous with the zero account/address. No logs can come from this address, as there is no contract present there.

See https://stackoverflow.com/questions/48219716/what-is-address0-in-solidity for the more info on the zero address. 

func IsFileOwnedBySeerlink(fileInfo os.FileInfo) (bool, error)

func IsQuoted 

func IsQuoted(input []byte) bool

IsQuoted checks if the first and last characters are either " or '.

func JustError 

func JustError(_ interface{}, err error) error

JustError takes a tuple and returns the last entry, the error.

func Keccak256 

func Keccak256(in []byte) ([]byte, error)

Keccak256 is a simplified interface for the legacy SHA3 implementation that Ethereum uses.

func LogIfError 

func LogIfError(err *error, msg string)

func LogListeningAddress 

func LogListeningAddress(address common.Address) string

LogListeningAddress returns the LogListeningAddress

func MaxBigs 

func MaxBigs(first *big.Int, bigs ...*big.Int) *big.Int

MaxBigs finds the maximum value of a list of big.Ints.

func MaxInt 

func MaxInt(first int, ints ...int) int

MaxInt finds the maximum value of a list of ints.

func MaxUint32 

func MaxUint32(first uint32, uints ...uint32) uint32

MaxUint32 finds the maximum value of a list of uint32s.

func MinUint 

func MinUint(first uint, vals ...uint) uint

MinUint finds the minimum value of a list of uints.

func MustHash 

func MustHash(in string) common.Hash

MustHash returns the keccak256 hash, or panics on failure.

func MustUnmarshalToMap 

func MustUnmarshalToMap(input string) map[string]interface{}

MustUnmarshalToMap performs UnmarshalToMap, panics upon failure

func NewBytes32ID 

func NewBytes32ID() string

NewBytes32ID returns a randomly generated UUID that conforms to Ethereum bytes32.

func NewSecret 

func NewSecret(n int) string

NewSecret returns a new securely random sequence of n bytes of entropy. The result is a base64 encoded string.

Panics on failed attempts to read from system's PRNG.

func NormalizedJSON 

func NormalizedJSON(val []byte) (string, error)

NormalizedJSON returns a JSON representation of an object that has been normalized to produce a consistent output for hashing.

NOTE: If this string is unmarshalled again, there is no guarantee that the final representation will be consistent with the string produced by this function due to differences in JSON implementations and information loss. e.g: 

JSON does not have a requirement to respect object key ordering.

func NullISO8601UTC 

func NullISO8601UTC(t null.Time) string

NullISO8601UTC returns formatted time if valid, empty string otherwise.

func ParseEthereumAddress 

func ParseEthereumAddress(addressString string) (common.Address, error)

ParseEthereumAddress returns addressString as a go-ethereum Address, or an error if it's invalid, e.g. if EIP 55 capitalization check fails

func RemoveHexPrefix 

func RemoveHexPrefix(str string) string

RemoveHexPrefix removes the prefix (0x) of a given hex string.

func RemoveQuotes 

func RemoveQuotes(input []byte) []byte

RemoveQuotes removes the first and last character if they are both either " or ', otherwise it is a noop.

func RetryWithBackoff 

func RetryWithBackoff(ctx context.Context, fn func() (retry bool))

func ReverseString 

func ReverseString(s string) string

ReverseString returns its argument string reversed rune-wise left to right.

func Sha256 

func Sha256(in string) (string, error)

Sha256 returns a hexadecimal encoded string of a hashed input

func StringToHex 

func StringToHex(in string) string

StringToHex converts a standard string to a hex encoded string.

func StripBearer 

func StripBearer(authorizationStr string) string

StripBearer removes the 'Bearer: ' prefix from the HTTP Authorization header.

func ToDecimal 

func ToDecimal(input interface{}) (decimal.Decimal, error)

func TooPermissive 

func TooPermissive(fileMode, maxAllowedPerms os.FileMode) bool

func Uint256ToBytes 

func Uint256ToBytes(x *big.Int) (uint256 []byte, err error)

Uint256ToBytes(x) is x represented as the bytes of a uint256

func Uint256ToHex 

func Uint256ToHex(n *big.Int) (string, error)

Uint256ToHex returns the hex representation of n, or error if out of bounds

func Uint64ToHex 

func Uint64ToHex(i uint64) string

Uint64ToHex converts the given uint64 value to a hex-value string.

func UnmarshalToMap 

func UnmarshalToMap(input string) (map[string]interface{}, error)

UnmarshalToMap takes an input json string and returns a map[string]interface i.e. a raw object

func WaitGroupChan 

func WaitGroupChan(wg *sync.WaitGroup) <-chan struct{}

WaitGroupChan creates a channel that closes when the provided sync.WaitGroup is done.

func WithJitter 

func WithJitter(d time.Duration) time.Duration

WithJitter adds +/- 10% to a duration

func WithoutZeroAddresses 

func WithoutZeroAddresses(addresses []common.Address) []common.Address

WithoutZeroAddresses returns a list of addresses excluding the zero address.

func WrapIfError 

func WrapIfError(err *error, msg string)

WrapIfError decorates an error with the given message. It is intended to be used with `defer` statements, like so: 

func SomeFunction() (err error) {
    defer WrapIfError(&err, "error in SomeFunction:")

    ...
}

func WriteFileWithMaxPerms 

func WriteFileWithMaxPerms(path string, data []byte, perms os.FileMode) error

Writes `data` to `path` and ensures that the file has permissions that are no more permissive than the given ones.

Types

type AfterNower 

type AfterNower interface {
	After(d time.Duration) <-chan time.Time
	Now() time.Time
}

AfterNower is an interface that fulfills the `After()` and `Now()` methods.

type Afterer 

type Afterer interface {
	After(d time.Duration) <-chan time.Time
}

Afterer is an interface that fulfills the After method, following the behavior of time.After.

type BackoffSleeper 

type BackoffSleeper struct {
	backoff.Backoff
	// contains filtered or unexported fields
}

BackoffSleeper is a sleeper that backs off on subsequent attempts.

func NewBackoffSleeper 

func NewBackoffSleeper() *BackoffSleeper

NewBackoffSleeper returns a BackoffSleeper that is configured to sleep for 0 seconds initially, then backs off from 1 second minimum to 10 seconds maximum.

func (*BackoffSleeper) After 

func (bs *BackoffSleeper) After() time.Duration

After returns the duration for the next stop, and increments the backoff.

func (*BackoffSleeper) Duration 

func (bs *BackoffSleeper) Duration() time.Duration

Duration returns the current duration value.

func (*BackoffSleeper) Reset 

func (bs *BackoffSleeper) Reset()

Reset resets the backoff intervals.

func (*BackoffSleeper) Sleep 

func (bs *BackoffSleeper) Sleep()

Sleep waits for the given duration, incrementing the back off.

type Big 

type Big big.Int

Big stores large integers and can deserialize a variety of inputs.

func NewBig 

func NewBig(i *big.Int) *Big

NewBig constructs a Big from *big.Int.

func NewBigI 

func NewBigI(i int64) *Big

func (*Big) Hex 

func (b *Big) Hex() string

Hex returns the hex encoding of b.

func (*Big) MarshalJSON 

func (b *Big) MarshalJSON() ([]byte, error)

MarshalJSON marshals this instance to base 10 number as string.

func (*Big) MarshalText 

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

MarshalText marshals this instance to base 10 number as string.

func (*Big) Scan 

func (b *Big) Scan(value interface{}) error

Scan reads the database value and returns an instance.

func (*Big) String 

func (b *Big) String() string

String returns the base 10 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 encoding.JSONUnmarshaler.

func (*Big) UnmarshalText 

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

UnmarshalText implements encoding.TextUnmarshaler.

func (Big) Value 

func (b Big) Value() (driver.Value, error)

Value returns this instance serialized for database storage.

type BigFloat 

type BigFloat big.Float

BigFloat accepts both string and float JSON values.

func (BigFloat) MarshalJSON 

func (b BigFloat) MarshalJSON() ([]byte, error)

MarshalJSON implements the json.Marshaler interface.

func (*BigFloat) UnmarshalJSON 

func (b *BigFloat) UnmarshalJSON(buf []byte) error

UnmarshalJSON implements the json.Unmarshal interface.

func (*BigFloat) Value 

func (b *BigFloat) Value() *big.Float

Value returns the big.Float value.

type BigIntSlice 

type BigIntSlice []*big.Int

BigIntSlice attaches the methods of sort.Interface to []*big.Int, sorting in increasing order.

func (BigIntSlice) Len 

func (s BigIntSlice) Len() int

func (BigIntSlice) Less 

func (s BigIntSlice) Less(i, j int) bool

func (BigIntSlice) Max 

func (s BigIntSlice) Max() *big.Int

Max returns the largest element

func (BigIntSlice) Sort 

func (s BigIntSlice) Sort()

Sort destructively sorts the slice

func (BigIntSlice) Swap 

func (s BigIntSlice) Swap(i, j int)

type BoundedPriorityQueue 

type BoundedPriorityQueue struct {
	// contains filtered or unexported fields
}

func NewBoundedPriorityQueue 

func NewBoundedPriorityQueue(capacities map[uint]uint) *BoundedPriorityQueue

func (*BoundedPriorityQueue) Add 

func (q *BoundedPriorityQueue) Add(priority uint, x interface{})

func (*BoundedPriorityQueue) Empty 

func (q *BoundedPriorityQueue) Empty() bool

func (*BoundedPriorityQueue) Take 

func (q *BoundedPriorityQueue) Take() interface{}

type BoundedQueue 

type BoundedQueue struct {
	// contains filtered or unexported fields
}

FIFO queue that discards older items when it reaches its capacity.

func NewBoundedQueue 

func NewBoundedQueue(capacity uint) *BoundedQueue

func (*BoundedQueue) Add 

func (q *BoundedQueue) Add(x interface{})

func (*BoundedQueue) Empty 

func (q *BoundedQueue) Empty() bool

func (*BoundedQueue) Full 

func (q *BoundedQueue) Full() bool

func (*BoundedQueue) Take 

func (q *BoundedQueue) Take() interface{}

type Clock 

type Clock struct{}

Clock is a basic type for scheduling events in the application.

func (Clock) After 

func (Clock) After(d time.Duration) <-chan time.Time

After returns the current time if the given duration has elapsed.

func (Clock) Now 

func (Clock) Now() time.Time

Now returns the current time.

type DependentAwaiter 

type DependentAwaiter interface {
	AwaitDependents() <-chan struct{}
	AddDependents(n int)
	DependentReady()
}

func NewDependentAwaiter 

func NewDependentAwaiter() DependentAwaiter

type HTTPRequest 

type HTTPRequest struct {
	Request *http.Request
	Config  HTTPRequestConfig
}

func (*HTTPRequest) SendRequest 

func (h *HTTPRequest) SendRequest(ctx context.Context) (responseBody []byte, statusCode int, err error)

type HTTPRequestConfig 

type HTTPRequestConfig struct {
	Timeout                        time.Duration
	MaxAttempts                    uint
	SizeLimit                      int64
	AllowUnrestrictedNetworkAccess bool
}

HTTPRequestConfig holds the configurable settings for an http request

type HTTPResponseTooLargeError 

type HTTPResponseTooLargeError struct {
	// contains filtered or unexported fields
}

func (*HTTPResponseTooLargeError) Error 

func (e *HTTPResponseTooLargeError) Error() string

type Mailbox 

type Mailbox struct {
	// contains filtered or unexported fields
}

func NewMailbox 

func NewMailbox(capacity uint64) *Mailbox

func (*Mailbox) Deliver 

func (m *Mailbox) Deliver(x interface{})

func (*Mailbox) Notify 

func (m *Mailbox) Notify() chan struct{}

func (*Mailbox) Retrieve 

func (m *Mailbox) Retrieve() interface{}

type MaxBytesReader 

type MaxBytesReader struct {
	// contains filtered or unexported fields
}

MaxBytesReader is inspired by https://github.com/gin-contrib/size/blob/master/size.go

func NewMaxBytesReader 

func NewMaxBytesReader(rc io.ReadCloser, limit int64) *MaxBytesReader

func (*MaxBytesReader) Close 

func (mbr *MaxBytesReader) Close() error

func (*MaxBytesReader) Read 

func (mbr *MaxBytesReader) Read(p []byte) (n int, err error)

type Nower 

type Nower interface {
	Now() time.Time
}

Nower is an interface that fulfills the Now method, following the behavior of time.Now.

type PausableTicker 

type PausableTicker struct {
	// contains filtered or unexported fields
}

func NewPausableTicker 

func NewPausableTicker(duration time.Duration) PausableTicker

func (*PausableTicker) Destroy 

func (t *PausableTicker) Destroy()

func (*PausableTicker) Pause 

func (t *PausableTicker) Pause()

func (*PausableTicker) Resume 

func (t *PausableTicker) Resume()

func (PausableTicker) Ticks 

func (t PausableTicker) Ticks() <-chan time.Time

type RemoteServerError 

type RemoteServerError struct {
	// contains filtered or unexported fields
}

func (*RemoteServerError) Error 

func (e *RemoteServerError) Error() string

type ResettableTimer 

type ResettableTimer struct {
	// contains filtered or unexported fields
}

func NewResettableTimer 

func NewResettableTimer() ResettableTimer

func (*ResettableTimer) Reset 

func (t *ResettableTimer) Reset(duration time.Duration)

func (*ResettableTimer) Stop 

func (t *ResettableTimer) Stop()

func (ResettableTimer) Ticks 

func (t ResettableTimer) Ticks() <-chan time.Time

type ScryptConfigReader 

type ScryptConfigReader interface {
	InsecureFastScrypt() bool
}

type ScryptParams 

type ScryptParams struct{ N, P int }

func GetScryptParams 

func GetScryptParams(config ScryptConfigReader) ScryptParams

type Sleeper 

type Sleeper interface {
	Reset()
	Sleep()
	After() time.Duration
	Duration() time.Duration
}

Sleeper interface is used for tasks that need to be done on some interval, excluding Cron, like reconnecting.

type SleeperTask 

type SleeperTask interface {
	Stop() error
	WakeUp()
}

SleeperTask represents a task that waits in the background to process some work.

func NewSleeperTask 

func NewSleeperTask(worker Worker) SleeperTask

NewSleeperTask takes a worker and returns a SleeperTask.

SleeperTask is guaranteed to call Work on the worker at least once for every WakeUp call. If the Worker is busy when WakeUp is called, the Worker will be called again immediately after it is finished. For this reason you should take care to make sure that Worker is idempotent. WakeUp does not block.

type SleeperTaskFuncWorker 

type SleeperTaskFuncWorker func()

func (SleeperTaskFuncWorker) Work 

func (fn SleeperTaskFuncWorker) Work()

type StartStopOnce 

type StartStopOnce struct {
	sync.RWMutex
	// contains filtered or unexported fields
}

func (*StartStopOnce) OkayToStart 

func (once *StartStopOnce) OkayToStart() (ok bool)

func (*StartStopOnce) OkayToStop 

func (once *StartStopOnce) OkayToStop() (ok bool)

func (*StartStopOnce) StartOnce 

func (once *StartStopOnce) StartOnce(name string, fn func() error) error

func (*StartStopOnce) State 

func (once *StartStopOnce) State() StartStopOnceState

func (*StartStopOnce) StopOnce 

func (once *StartStopOnce) StopOnce(name string, fn func() error) error

type StartStopOnceState 

type StartStopOnceState int
const (
	StartStopOnce_Unstarted StartStopOnceState = iota
	StartStopOnce_Started
	StartStopOnce_Stopped
)

type Worker 

type Worker interface {
	Work()
}

Worker is a simple interface that represents some work to do repeatedly

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