eu.shiftforward.apso.ProgressBar.scala Maven / Gradle / Ivy
package eu.shiftforward.apso
import scala.compat.Platform._
/**
* A widget for printing a dynamic progress bar in a console.
* @param total the number representing the full progress bar
* @param width the line width of the progress bar
* @param throughputUnit the throughput unit that is being measured
* @param throughputTransformer a function to transform the measured throughput
* value, before displaying it
*/
case class ProgressBar(
total: Long = 100,
width: Int = 80,
throughputUnit: String = "ops",
throughputTransformer: Double => Double = identity) {
private[this] var done = 0L
private[this] val startTimestamp = currentTime
private[this] val workchars = List('|', '/', '-', '\\')
private[this] var lastChar = 0
private[this] def workChar = {
if (lastChar >= (workchars.length - 1)) lastChar = 0
else lastChar += 1
workchars(lastChar)
}
/**
* Increase the progress by one.
*/
def tick() {
tick(1)
}
/**
* Increase the progress by the given number of units.
* @param inc the number of progress units to increase
*/
def tick(inc: Long) {
if (!isFinished) {
done += inc
if (done > total) done = total
val currentTimestamp = currentTime
val throughput =
done.toDouble / (currentTimestamp - startTimestamp) * 1000
val percent = done.toDouble / total
val res = new StringBuilder(width)
val prefix = f"${(percent * 100).toInt}%3d%% ["
val suffix = f"] $workChar [ ${throughputTransformer(throughput)}%2.2f ] $throughputUnit/s "
val remainingWidth = width - prefix.length - suffix.length - (if (percent < 1.0) 1 else 0)
res.append("\r")
res.append(prefix)
res.append("=" * (remainingWidth * percent).toInt)
if (percent < 1.0) res.append(">")
res.append(" " * (remainingWidth - (remainingWidth * percent).toInt))
res.append(suffix)
print(res.mkString)
if (isFinished) {
System.out.flush()
println()
}
}
}
/**
* Returns `true` if this progress bar is full.
* @return `true` if this progress bar is full, `false` otherwise.
*/
def isFinished = done >= total
}