log

Documentation

Overview

Package log implements a std log compatible logging system that draws some inspiration from the Python standard library [logging module](https://docs.python.org/3/library/logging.html). It supports multiple handlers, log levels, zero-allocation, scopes, custom formatting, and environment and runtime configuration.

When not used to replace std log, the import should use the package name "analog" as in:

import analog "github.com/anacrolix/log".

Index

• Variables
• func ContextWithLogger(ctx context.Context, logger Logger) context.Context
• func Levelf(level Level, format string, a ...interface{})
• func LineFormatter(msg Record) []byte
• func Print(a ...interface{})
• func Printf(format string, a ...interface{})
• func Println(a ...interface{})
• type ByteFormatter
• type Handler
• type Level
  • func (l Level) LessThan(r Level) bool
  • func (l Level) LogString() string
  • func (l *Level) UnmarshalText(text []byte) error
• type Logger
  • func ContextLogger(ctx context.Context) Logger
  • func (l Logger) FilterLevel(minLevel Level) Logger
  • func (l Logger) IsEnabledFor(level Level) bool
  • func (l Logger) IsZero() bool
  • func (l Logger) LazyLog(level Level, f func() Msg)
  • func (l Logger) LazyLogDefaultLevel(f func() Msg)
  • func (l Logger) Levelf(level Level, format string, a ...interface{})
  • func (l Logger) Log(m Msg)
  • func (l Logger) LogLevel(level Level, m Msg)
  • func (l Logger) Print(v ...interface{})
  • func (l Logger) Printf(format string, a ...interface{})
  • func (l Logger) Println(a ...interface{})
  • func (l Logger) SkipCallers(skip int) Logger
  • func (l Logger) WithContextText(s string) Logger
  • func (l Logger) WithContextValue(v interface{}) Logger
  • func (l Logger) WithDefaultLevel(level Level) Logger
  • func (l Logger) WithMap(f func(m Msg) Msg) Logger
  • func (l Logger) WithNames(names ...string) Logger
  • func (l Logger) WithText(f func(Msg) string) Logger
  • func (l Logger) WithValues(v ...interface{}) Logger
• type Msg
  • func Call() Msg
  • func Fmsg(format string, a ...interface{}) Msg
  • func Str(s string) (m Msg)
  • func (m Msg) Add(key, value interface{}) Msg
  • func (m Msg) AddValue(v interface{}) Msg
  • func (m Msg) AddValues(v ...interface{}) Msg
  • func (m Msg) HasValue(v interface{}) (has bool)
  • func (m Msg) Log(l Logger) Msg
  • func (m Msg) LogLevel(level Level, l Logger) Msg
  • func (m Msg) Skip(skip int) Msg
  • func (me Msg) String() string
  • func (m Msg) With(key, value interface{}) Msg
  • func (m Msg) WithText(f func(Msg) string) Msg
  • func (m Msg) WithValues(v ...interface{}) Msg
• type MsgImpl
• type Record
• type Rule
• type StreamHandler
  • func (me StreamHandler) Handle(r Record)

Variables

var (
	DefaultHandler = StreamHandler{
		W:   os.Stderr,
		Fmt: LineFormatter,
	}
	Default        Logger // Inited after GO_LOG is parsed.
	DiscardHandler = StreamHandler{
		W:   ioutil.Discard,
		Fmt: func(Record) []byte { return nil },
	}
)

var (
	Never    = Level{-1} // A message at this level should never be logged.
	NotSet   = Level{0}
	Debug    = Level{1}
	Info     = Level{2}
	Warning  = Level{3}
	Error    = Level{4}
	Critical = Level{5}
)

var (
	Panicf = log.Panicf
	Fatalf = log.Fatalf
	Fatal  = log.Fatal
)

Deprecated: Logging shouldn't include control flow.

var Fstr = Fmsg

Functions

func ContextWithLogger

func ContextWithLogger(ctx context.Context, logger Logger) context.Context

func Levelf

func Levelf(level Level, format string, a ...interface{})

func LineFormatter

func LineFormatter(msg Record) []byte

func Print

func Print(a ...interface{})

Prints the arguments to the Default Logger.

func Printf

func Printf(format string, a ...interface{})

func Println

func Println(a ...interface{})

Types

type ByteFormatter

type ByteFormatter func(Record) []byte

type Handler

type Handler interface {
	Handle(Record)
}

type Level

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

func (Level) LessThan

func (l Level) LessThan(r Level) bool

func (Level) LogString

func (l Level) LogString() string

func (*Level) UnmarshalText

func (l *Level) UnmarshalText(text []byte) error

type Logger

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

Logger handles logging in a specific context. It includes a bunch of helpers and compatibility over the loggerCore.

func ContextLogger

func ContextLogger(ctx context.Context) Logger

func (Logger) FilterLevel

func (l Logger) FilterLevel(minLevel Level) Logger

func (Logger) IsEnabledFor

func (l Logger) IsEnabledFor(level Level) bool

func (Logger) IsZero

func (l Logger) IsZero() bool

func (Logger) LazyLog

func (l Logger) LazyLog(level Level, f func() Msg)

func (Logger) LazyLogDefaultLevel

func (l Logger) LazyLogDefaultLevel(f func() Msg)

func (Logger) Levelf

func (l Logger) Levelf(level Level, format string, a ...interface{})

func (Logger) Log

func (l Logger) Log(m Msg)

func (Logger) LogLevel

func (l Logger) LogLevel(level Level, m Msg)

func (Logger) Print

func (l Logger) Print(v ...interface{})

Helper for compatibility with "log".Logger.

func (Logger) Printf

func (l Logger) Printf(format string, a ...interface{})

Helper for compatibility with "log".Logger.

func (Logger) Println

func (l Logger) Println(a ...interface{})

func (Logger) SkipCallers

func (l Logger) SkipCallers(skip int) Logger

func (Logger) WithContextText

func (l Logger) WithContextText(s string) Logger

func (Logger) WithContextValue

func (l Logger) WithContextValue(v interface{}) Logger

func (Logger) WithDefaultLevel

func (l Logger) WithDefaultLevel(level Level) Logger

func (Logger) WithMap

func (l Logger) WithMap(f func(m Msg) Msg) Logger

Returns a logger that for a given message propagates the result of `f` instead.

func (Logger) WithNames

func (l Logger) WithNames(names ...string) Logger

func (Logger) WithText

func (l Logger) WithText(f func(Msg) string) Logger

func (Logger) WithValues

func (l Logger) WithValues(v ...interface{}) Logger

Returns a logger that adds the given values to logged messages.

type Msg

type Msg struct {
	MsgImpl
}

func Call

func Call() Msg

func Fmsg

func Fmsg(format string, a ...interface{}) Msg

func Str

func Str(s string) (m Msg)

func (Msg) Add

func (m Msg) Add(key, value interface{}) Msg

func (Msg) AddValue

func (m Msg) AddValue(v interface{}) Msg

func (Msg) AddValues

func (m Msg) AddValues(v ...interface{}) Msg

func (Msg) HasValue

func (m Msg) HasValue(v interface{}) (has bool)

func (Msg) Log

func (m Msg) Log(l Logger) Msg

rename sink

func (Msg) LogLevel

func (m Msg) LogLevel(level Level, l Logger) Msg

func (Msg) Skip

func (m Msg) Skip(skip int) Msg

func (Msg) String

func (me Msg) String() string

func (Msg) With

func (m Msg) With(key, value interface{}) Msg

func (Msg) WithText

func (m Msg) WithText(f func(Msg) string) Msg

func (Msg) WithValues

func (m Msg) WithValues(v ...interface{}) Msg

TODO: What ordering should be applied to the values here, per MsgImpl.Values. For now they're traversed in order of the slice.

type MsgImpl

type MsgImpl interface {
	// Returns the message text. Allows for lazy evaluation/prefixing etc.
	Text() string
	// Sets the program counters in pc. Having it in the interface may allow us to cache/freeze them
	// for serialization etc.
	Callers(skip int, pc []uintptr) int
	// Iterates over the values as added LIFO.
	Values(callback valueIterCallback)
}

The minimal interface required for the Msg helper/wrapper to operate on.

type Record

type Record struct {
	Msg
	Level Level
	Names []string
}

type Rule

type Rule func(names []string) (level Level, matched bool)

type StreamHandler

type StreamHandler struct {
	W   io.Writer
	Fmt ByteFormatter
}

func (StreamHandler) Handle

func (me StreamHandler) Handle(r Record)