Stopwatch

Stopwatch is a Go package intended for simple stepwise benchmarking of code. It was written as a personal project of mine to familiarize with the language, feel free to contribute.

Installation

$ go get github.com/mpragliola/stopwatch

Usage

The usage is very simple:

• import the package in your .go file

• instantiate a stopwatch with stopwatch.New() (multiple instances will allow for independent measurements)

• mark checkpoints with .Mark(label)

• get the measurement directly as text dump (.Dump) or as struct (.Data()). In either case you will be able to read a table with a checkpoint's label, timestamp and delta timestamp from the previous one.

package foo

import "github.com/mpragliola/stopwatch"

// ... code

w := stopwatch.NewStart()
// code
w.Mark("Aggregated")
// code
w.Mark("Transformed")
// code
w.Dump()

Will output something similar to:

(Start)          |       0ms |       0ms |
Aggregated       |      35ms |     +35ms |      
Transformed      |      85ms |     +40ms |
(End)            |     113ms |     +28ms | 

As structured data

w.Dump() is a convenience method to output results immediately; we can also use them programmatically with w.Data(). It will return a []stopwatch.DataRow slice, where each DataRow item mirrors the above data in the .Label, .At and .Delta fields.

data := w.GetData()

fmt.Println(data[1].At) // time.Millisecond * 35
fmt.Println(data[2].Label) // "Transformed"

The time fields will be an instance of time.Duration rounded to time.Millisecond.

Halted stopwatch

stopwatch.NewStart() creates an "active" stopwatch, where the start time is already marked as a first entry and the clock is "ticking"; use stopwatch.New() instead to create a "halted" stopwatch; it will begin to count not from creation time but from the time you .Mark() the first time stamp:

w := stopwatch.New()
// code
w.Mark("Aggregated")
// code
w.Mark("Transformed")
// code
w.Dump()

Will output something similar to (notice the absence of Start):

Aggregated       |       0ms |      +0ms |      
Transformed      |      40ms |     +40ms |
(End)            |      68ms |     +28ms | 

Json

You can also get a JSON representation of the stopwatch with w.Json().