github.com/alexisvisco/debug

Debug

A tiny golang debugging utility based on https://github.com/visionmedia/debug principles.

Installation

go get github.com/AlexisVisco/Debug

Usage

debug expose some simple functions like Register, Get, Delete to manage debug.

Example http_debug.go

package main

import (
	"fmt"
	"log"
	"net/http"
	debug "github.com/AlexisVisco/debug"
)

var httpdeb, _ = debug.Register("http")

func handler(w http.ResponseWriter, r *http.Request) {
	fmt.Fprintf(w, "Hi there, I love %s!", r.URL.Path[1:])
	httpdeb.Log(fmt.Sprintf("%s %s", r.Method, r.URL.String()))
}

func main() {
	http.HandleFunc("/", handler)
	log.Fatal(http.ListenAndServe(":8080", nil))
}

Example infinite_debug.go

package main

import (
	debug "github.com/AlexisVisco/debug"
	"time"
	"strconv"
	"sync"
)

var fivesec, _ = debug.Register("5 times")
var nivesec, _ = debug.Register("9 times")
var wait sync.WaitGroup

var five = 0
var nine = 0

func main() {
	wait.Add(1)
	go doEvery(5 * time.Second, func(i time.Time) {
		fivesec.Log("5 = " + strconv.Itoa(five))
		five++
	})
	go doEvery(9 * time.Second, func(i time.Time) {
		nivesec.Log("9 = " + strconv.Itoa(nine))
		nine++
	})
	wait.Wait()
}

func doEvery(d time.Duration, f func(time.Time)) {
	for x := range time.Tick(d) {
		f(x)
	}
}

The DEBUG environment variable is then used to enable these based on space or comma-delimited names.

Wildcards

The * character may be used as a wildcard. Suppose for example your library has debuggers named "connect:bodyParser", "connect:compress", "connect:session", instead of listing all three with DEBUG=connect:bodyParser,connect:compress,connect:session, you may simply do DEBUG=connect:*.

Exclusion

The - prefix character may be used to exclude a debugger.
Example DEBUG=*,-test => atest OK, hello OK, test NOT OK
You can combine with wildcard obviously !

Environment Variables

You can set a few environment variables that will change the behavior of the debug logging:

Name	Purpose
DEBUG	Enables/disables specific debugging namespaces.
DEBUG_HIDE_DATE	Hide date from debug output (non-TTY).
DEBUG_COLORS	Whether or not to use colors in the debug output.
DEBUG_HIDE_LATENCY	Hide latency at the end of a tty output.

Documentation

Functions:

• NewDebug(name string) *Debug
• Register(name string) (*Debug, Err)
• Get(name string) (*Debug, Err)
• Delete(name string) Err
• Enable()
• Disable()

Methods:

• (d *Debug) Log(message string)
• (d *Debug) Sprint(message string)
• (d *Debug) SetWriter(writer io.Writer, tty bool) *Debug
• (d *Debug) SetFdWriter(file *os.File) *Debug

Functions

NewDebug

Prototype: NewDebug(name string) *Debug

Description:
Create a debug structure without registering it. Cannot be accessible with Get. Generate a random color from 31 to 37 and 91 to 97 as ainsi code.

debug := debug.NewDebug("woaw") 

Register

Prototype: Register(name string) (*Debug, Err)

Description:
Create a debug and registering it. Can be accessible with Get. NewDebug is used to create the structure.

Error:
Return an error if name is already in the registry.

debug, err := debug.Create("woaw")
if err {
  fmt.Printf("name %s already used !", "woaw")
}

Get

Prototype: Get(name string) (*Debug, Err)

Description:
Get a debug structure from it name.

Error:
Return an error if name is not in the registry.

debug, err := debug.Get("woaw")
if err {
  fmt.Printf("name %s has not been created !", "woaw")
}

Delete

Prototype: Delete(name string) Err

Description:
Delete a debug structure from the registry.

Error:
Return an error if name is not in the registry.

err := debug.Delete("woaw")
if err {
  fmt.Printf("name %s has not been created !", "woaw")
}

Enable

Prototype: Enable()

Description:
Enable printing with debug.

debug.Enable()

Disable

Prototype: Disable()

Description:
Disable printing with debug.

debug.Disable()

Methods

Log

Prototype: (d *Debug) Log(message string

Description:
Print if debug is active the message with the name of the debug and the latency between the last call if it was activated.

woaw, _ := debug.Create("woaw")

woaw.Log("Hola !")
woaw.Log("Hola 2 !")

Sprint

Prototype: (d *Debug) Sprint(message string)

Description:
Return the full string that should be printed.

woaw, _ := debug.Create("woaw")

str := waw.Sprint("Hola !")

SetWriter

Prototype: (d *Debug) SetWriter(writer io.Writer, tty bool) *Debug

Description:
Set the writer, if it's a terminal set to true the next parameter.

woaw, _ := debug.Create("woaw")

woaw.SetWriter(os.Stdout, true)

SetFdWriter

Prototype: (d *Debug) SetFdWriter(file *os.File) *Debug

Description:
This function will set the writer and determine if the file.Fd() is a terminal.

woaw, _ := debug.Create("woaw")

woaw.SetFdWriter(os.Stdout)