base

package module
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 Go to latest Published: May 24, 2020 License: BSD-3-Clause Imports: 19 Imported by: 0

README

go-base

Documentation Go Report Card

Common Go utilities that are used across omegaUp's projects.

Documentation

Index

Constants

View Source 
const (
	// Kibibyte is 1024 Bytes.
	Kibibyte = Byte(1024)

	// Mebibyte is 1024 Kibibytes.
	Mebibyte = Byte(1024) * Kibibyte

	// Gibibyte is 1024 Mebibytes.
	Gibibyte = Byte(1024) * Mebibyte

	// Tebibyte is 1024 Gibibytes.
	Tebibyte = Byte(1024) * Gibibyte
)

Variables

This section is empty.

Functions

func ErrorCallerStackHandler 

func ErrorCallerStackHandler(maxLvl log15.Lvl, handler log15.Handler) log15.Handler

ErrorCallerStackHandler creates a handler that drops all logs that are less important than maxLvl, and also adds a stack trace to all events that are errors / critical, as well as the error values that have a stack trace.

func ErrorWithCategory 

func ErrorWithCategory(category error, cause error) error

ErrorWithCategory is similar to errors.Wrap, but instead of creating a new error as the wrapping message, a sentinel error is provided as a category. This category can then be inspected with HasErrorCategory.

func FloatToRational 

func FloatToRational(floatVal float64) *big.Rat

FloatToRational returns a rational that's within 1e-6 of the floating-point value.

func HasErrorCategory 

func HasErrorCategory(err error, category error) bool

HasErrorCategory returns whether the provided error belongs to the provided category.

func NopOpenedCallback 

func NopOpenedCallback(*os.File, bool) error

NopOpenedCallback is an OpenedCallback that does nothing.

func ParseRational 

func ParseRational(str string) (*big.Rat, error)

ParseRational returns a rational that's within 1e-6 of the floating-point value that has been serialized as a string.

func RationalDiv 

func RationalDiv(num, denom *big.Rat) *big.Rat

RationalDiv implements division between two rationals.

func RationalToFloat 

func RationalToFloat(val *big.Rat) float64

RationalToFloat returns the closest float value to the given big.Rat.

func RotatingLog 

func RotatingLog(file string, level string) (log15.Logger, error)

RotatingLog opens a log15.Logger, and if it will be pointed to a real file, it installs a SIGHUP handler that will atomically reopen the file and redirect all future logging operations.

func StderrLog 

func StderrLog() log15.Logger

StderrLog creates a log15.Logger that outputs to stderr and prints the stack for the log call and the error stack trace if available.

func UnwrapCauseFromErrorCategory 

func UnwrapCauseFromErrorCategory(err error, category error) error

UnwrapCauseFromErrorCategory finds an error with the specified category in the chain and returns its Cause(). Returns nil if no such error was found.

Types

type Byte 

type Byte int64

A Byte is a unit of digital information.

func MaxBytes 

func MaxBytes(x, y Byte) Byte

MaxBytes returns the larger of x or y.

func MinBytes 

func MinBytes(x, y Byte) Byte

MinBytes returns the smaller of x or y.

func (Byte) Bytes 

func (b Byte) Bytes() int64

Bytes returns the Byte as an integer number of bytes.

func (Byte) Gibibytes 

func (b Byte) Gibibytes() float64

Gibibytes returns the Byte as an floating point number of Gibibytes.

func (Byte) Kibibytes 

func (b Byte) Kibibytes() float64

Kibibytes returns the Byte as an floating point number of Kibibytes.

func (Byte) MarshalJSON 

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

MarshalJSON implements the json.Marshaler interface. The result is an integer number of bytes.

func (Byte) Mebibytes 

func (b Byte) Mebibytes() float64

Mebibytes returns the Byte as an floating point number of Mebibytes.

func (Byte) Tebibytes 

func (b Byte) Tebibytes() float64

Tebibytes returns the Byte as an floating point number of Tebibytes.

func (*Byte) UnmarshalJSON 

func (b *Byte) UnmarshalJSON(data []byte) error

UnmarshalJSON implements the json.Unmarshaler interface. The result can be an integer number of bytes, or a quoted string that MarshalJSON() can understand.

type Duration 

type Duration time.Duration

Duration is identical to time.Duration, except it can implements the json.Marshaler interface with time.Duration.String() and time.Duration.ParseDuration().

func MaxDuration 

func MaxDuration(x, y Duration) Duration

MaxDuration returns the larger of x or y.

func MinDuration 

func MinDuration(x, y Duration) Duration

MinDuration returns the smaller of x or y.

func (Duration) MarshalJSON 

func (d Duration) MarshalJSON() ([]byte, error)

MarshalJSON implements the json.Marshaler interface. The duration is a quoted string in RFC 3339 format, with sub-second precision added if present.

func (Duration) Milliseconds 

func (d Duration) Milliseconds() float64

Milliseconds returns the duration as a floating point number of milliseconds.

func (Duration) Seconds 

func (d Duration) Seconds() float64

Seconds returns the duration as a floating point number of seconds.

func (Duration) String 

func (d Duration) String() string

String returns a string representing the duration in the form "72h3m0.5s". Leading zero units are omitted. As a special case, durations less than one second format use a smaller unit (milli-, micro-, or nanoseconds) to ensure that the leading digit is non-zero. The zero duration formats as 0s.

func (*Duration) UnmarshalJSON 

func (d *Duration) UnmarshalJSON(data []byte) error

UnmarshalJSON implements the json.Unmarshaler interface. The duration is expected to be a quoted string that time.ParseDuration() can understand.

type LRUCache 

type LRUCache struct {
	sync.Mutex
	// contains filtered or unexported fields
}

LRUCache handles a pool of sized resources. It has a fixed maximum size with a least-recently used eviction policy.

func NewLRUCache 

func NewLRUCache(sizeLimit Byte) *LRUCache

NewLRUCache returns an empty LRUCache with the provided size limit.

func (*LRUCache) EntryCount 

func (c *LRUCache) EntryCount() int

EntryCount is the number of elements in the LRUCache.

func (*LRUCache) EvictableSize 

func (c *LRUCache) EvictableSize() Byte

EvictableSize is the size in bytes of all elements that are being considered for eviction. This is, not currently being used.

func (*LRUCache) Get 

func (c *LRUCache) Get(
	key string,
	factory SizedEntryFactory,
) (*SizedEntryRef, error)

Get atomically gets a previously-created entry if it was found in the cache, or a newly-created one otherwise. It is the caller's responsibility to call Put() with the returned SizedEntryRef method once it's no longer needed so that the underlying resource can be evicted from the cache, if needed.

func (*LRUCache) OvercommittedSize 

func (c *LRUCache) OvercommittedSize() Byte

OvercommittedSize is the size in bytes that have been allocated above the LRUCache's size limit. This number can be non-zero when all the elements in the cache are currently being used and cannot yet be evicted.

func (*LRUCache) Put 

func (c *LRUCache) Put(r *SizedEntryRef)

Put marks a SizedEntryRef as no longer being referred to, so that it can be considered for eviction.

func (*LRUCache) Size 

func (c *LRUCache) Size() Byte

Size is the total size in bytes of all the elements in the LRUCache.

type Metrics 

type Metrics interface {
	// GaugeAdd increments a gauge. A gauge is a metric that represents a single
	// numerical value that can arbitrarily go up and down.
	GaugeAdd(name string, value float64)

	// CounterAdd increments a counter. A counter is a metric that represents a
	// single numerical value that only ever goes up.
	CounterAdd(name string, value float64)

	// SummaryObserve adds an observation to a summary. A summary is an aggregate
	// metric that supports querying percentiles.
	SummaryObserve(name string, value float64)
}

Metrics is an interface that supports updating different kinds of metrics. All its functions are thread-safe.

type NoOpMetrics 

type NoOpMetrics struct {
}

NoOpMetrics is an implementation of Metrics that does nothing.

func (*NoOpMetrics) CounterAdd 

func (n *NoOpMetrics) CounterAdd(name string, value float64)

CounterAdd adds the specified value to a counter of the specified name. Value should be non-negative.

func (*NoOpMetrics) GaugeAdd 

func (n *NoOpMetrics) GaugeAdd(name string, value float64)

GaugeAdd adds the specified value to a gauge of the specified name.

func (*NoOpMetrics) SummaryObserve 

func (n *NoOpMetrics) SummaryObserve(name string, value float64)

SummaryObserve adds the specified value to a summary of the specified name.

type OpenedCallback 

type OpenedCallback func(f *os.File, isEmpty bool) error

OpenedCallback allows the caller to specify an action to be performed when the file is opened and before it is available for writing.

type RotatingFile 

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

A RotatingFile is an io.WriteCloser that supports reopening through SIGHUP. It opens the underlying file in append-only mode. All operations are thread-safe.

func NewRotatingFile 

func NewRotatingFile(path string, mode os.FileMode, callback OpenedCallback) (*RotatingFile, error)

NewRotatingFile opens path for writing in append-only mode and listens for SIGHUP so that it can reopen the file automatically.

func (*RotatingFile) Close 

func (r *RotatingFile) Close() error

Close closes the underlying file and stops listening for SIGHUP.

func (*RotatingFile) Rotate 

func (r *RotatingFile) Rotate() error

Rotate reopens the file and closes the previous one.

func (*RotatingFile) Write 

func (r *RotatingFile) Write(b []byte) (int, error)

Write writes the bytes into the underlying file.

func (*RotatingFile) WriteString 

func (r *RotatingFile) WriteString(s string) (int, error)

WriteString is like Write, but writes the contents of string s rather than a slice of bytes.

type SizedEntry 

type SizedEntry interface {
	// Release will be called upon the entry being evicted from the cache.
	Release()

	// Size returns the number of bytes consumed by the entry.
	Size() Byte
}

A SizedEntry is an entry within the LRUCache that knows its own size.

type SizedEntryFactory 

type SizedEntryFactory func(key string) (SizedEntry, error)

A SizedEntryFactory is a factory that can create a SizedEntry given its key name.

type SizedEntryRef 

type SizedEntryRef struct {
	Value SizedEntry
	// contains filtered or unexported fields
}

A SizedEntryRef is a wrapper around a SizedEntry.

Source Files

View all Source files

Directories

Path Synopsis
logging
log15 Module
tracing
newrelic Module

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