Progress

This tiny library can be used to show some kind of progress indicator while executing some long running task. Especially, while writing small kotlin scripts it is tedious to reinvent a minimal progress indicator. Therefore this library provide an easy yet flexible interface for progress control. Further, in the case of simply printing to a console, a couple of pre-formatted values are at hand to compose a progress statement quickly: Like a progress bar, the elapsed and remaining time etc. (see complete set of features below).

Acknowledgement

This library was inspired by the R package progress.

Example

import com.zypus.progress.Progress

fun main() {
    // Create a control with 100 ticks.
    val control = Progress.control(100L) {
        // On each update print (reprint) an informative statement about the progress.
        print("\r [$bar] $percent eta: $eta")
    }
    
    // Do the work.
    for (i in 1..100) {
        // Some expensive task.
        control.tick()
    }
}

The output of this small program will look something like this:

[======--------------]  30.0% eta: 10s

Features

Pre-formatted values

This is the complete set of pre-formatted features available in the progress update. (Of course the raw values are also available.)

Property	Type	Example	Note
current	String	556
total	String	1000
percent	String	45.3%
bar	String	====----	There is also a function bar() to customise the style of the bar.
spin	String	/	A string that changes each update and simulates a spinning element. Useful to indicate activity while no progress is made or the progress is unknown.
elapsed	String	10s
eta	String	1m25s	Estimate by linear interpolation.
bytes	String	5.4kB
totalBytes	String	100MB
rate	String	12.4kB/s
custom	T?	step 3	Can be any generic class.
currentTicks	Long	556	Raw value.
totalTicks	Long	1000	Raw value.
duration	Duration		Raw value.

Extension functions

For convenience this library adds extension functions for Collections, Iterables, Sequences and for reading files to minimise the boilerplate even further:

import com.zypus.progress.forEachBlockWithProgress

val file: java.io.File = // some File

// Read and process a potentially huge file.
file.forEachBlockWithProgress { buffer, bytesRead ->
	// process the file
}

And get output like this for free:

(/)   6.0s [===========---------]  55.0% (  2.27MB/4.12MB @ 378.2kB/s) eta:   5.0s

Installation

To get started simply add it as a dependency via jcenter:

Gradle

compile "com.zypus:progress:1.0.0"

Maven

<dependency>
   <groupId>com.zypus</groupId>
   <artifactId>progress</artifactId>
   <version>1.0.0</version>
</dependency>

Licence

Apache License 2.0