log

Documentation

Overview

Package log provides the implementation of a shim between the standard log package and event handlers.

The package exposes an API that mimics the standard library, in most cases it can be used as a drop in replacement by simply rewriting the import from "log" to "github.com/segmentio/events/log".

Importing this package has the side effect of configuring the default output of the log package to route events to the default logger of the events package.

Index

• Constants
• func Fatal(v ...interface{})
• func Fatalf(format string, v ...interface{})
• func Fatalln(v ...interface{})
• func Flags() int
• func New(out io.Writer, prefix string, flags int) *log.Logger
• func NewHandler(w io.Writer) events.Handler
• func NewLogger(prefix string, flags int, handler events.Handler) *log.Logger
• func Output(calldepth int, s string) error
• func Panic(v ...interface{})
• func Panicf(format string, v ...interface{})
• func Panicln(v ...interface{})
• func Prefix() string
• func Print(v ...interface{})
• func Printf(format string, v ...interface{})
• func Println(v ...interface{})
• func SetFlags(flags int)
• func SetOutput(w io.Writer)
• func SetPrefix(prefix string)
• type Writer
  • func NewWriter(prefix string, flags int, handler events.Handler) *Writer
  • func (w *Writer) Write(b []byte) (int, error)

Constants

const (
	// Bits or'ed together to control what's printed.
	// There is no control over the order they appear (the order listed
	// here) or the format they present (as described in the comments).
	// The prefix is followed by a colon only when Llongfile or Lshortfile
	// is specified.
	// For example, flags Ldate | Ltime (or LstdFlags) produce,
	//2009/01/23 01:23:23 message
	// while flags Ldate | Ltime | Lmicroseconds | Llongfile produce,
	//2009/01/23 01:23:23.123123 /a/b/c/d.go:23: message
	Ldate         = log.Ldate         // the date in the local time zone: 2009/01/23
	Ltime         = log.Ltime         // the time in the local time zone: 01:23:23
	Lmicroseconds = log.Lmicroseconds // microsecond resolution: 01:23:23.123123.  assumes Ltime.
	Llongfile     = log.Llongfile     // full file name and line number: /a/b/c/d.go:23
	Lshortfile    = log.Lshortfile    // final file name element and line number: d.go:23. overrides Llongfile
	LUTC          = log.LUTC          // if Ldate or Ltime is set, use UTC rather than the local time zone
	LstdFlags     = log.LstdFlags     // initial values for the standard logger
)

Functions

func Fatal

func Fatal(v ...interface{})

Fatal is equivalent to Print() followed by a call to os.Exit(1).

func Fatalf

func Fatalf(format string, v ...interface{})

Fatalf is equivalent to Printf() followed by a call to os.Exit(1).

func Fatalln

func Fatalln(v ...interface{})

Fatalln is equivalent to Println() followed by a call to os.Exit(1).

func Flags

func Flags() int

Flags returns the output flags for the standard logger.

func New

func New(out io.Writer, prefix string, flags int) *log.Logger

New creates a new Logger. The out variable sets the destination to which log data will be written. The prefix appears at the beginning of each generated log line. The flag argument defines the logging properties.

func NewHandler

func NewHandler(w io.Writer) events.Handler

NewHandler creates an event handler with best suits w.

If w is nil the function returns nil (which a logger interprets as using the default handler).

func NewLogger

func NewLogger(prefix string, flags int, handler events.Handler) *log.Logger

NewLogger creates a new logger. The prefix and flags arguments configure the behavior of the logger, while handler sets the destination to which log events are sent.

func Output

func Output(calldepth int, s string) error

Output writes the output for a logging event. The string s contains the text to print after the prefix specified by the flags of the Logger. A newline is appended if the last character of s is not already a newline. Calldepth is the count of the number of frames to skip when computing the file name and line number if Llongfile or Lshortfile is set; a value of 1 will print the details for the caller of Output.

func Panic

func Panic(v ...interface{})

Panic is equivalent to Print() followed by a call to panic().

func Panicf

func Panicf(format string, v ...interface{})

Panicf is equivalent to Printf() followed by a call to panic().

func Panicln

func Panicln(v ...interface{})

Panicln is equivalent to Println() followed by a call to panic().

func Prefix

func Prefix() string

Prefix returns the output prefix for the standard logger.

func Print

func Print(v ...interface{})

Print calls Output to print to the standard logger. Arguments are handled in the manner of fmt.Print.

func Printf

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

Printf calls Output to print to the standard logger. Arguments are handled in the manner of fmt.Printf.

func Println

func Println(v ...interface{})

Println calls Output to print to the standard logger. Arguments are handled in the manner of fmt.Println.

func SetFlags

func SetFlags(flags int)

SetFlags sets the output flags for the standard logger.

func SetOutput

func SetOutput(w io.Writer)

SetOutput sets the output destination for the standard logger.

func SetPrefix

func SetPrefix(prefix string)

SetPrefix sets the output prefix for the standard logger.

Types

type Writer

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

Writer is an implementation of an io.Writer which is designed to be set as output on a logger from the standard log package.

The Writer parses the lines it receives when its Write method is called and constructs events that are then passed to its handler.

It is safe to use an Writer from multiple goroutines. However a single writer should be associated with a single logger, the behavior is undefined.

func NewWriter

func NewWriter(prefix string, flags int, handler events.Handler) *Writer

NewWriter constructs a new Writer value which is intended to be set on a logger configured with prefix and flags, the output forwards events to the given handler.

func (*Writer) Write

func (w *Writer) Write(b []byte) (int, error)

Write satisfies the io.Writer interface.