Extending Steep through plugins

Progress estimators

A progress estimator plugin is a function that analyses the log output of a running processing service to estimate its current progress. For example, the plugin can look for percentages or number of bytes processed. The returned value contributes to the execution progress of a process chain (see the estimatedProgress property of the process chain data model).

The function takes the executable that is currently being run and a list of recently collected output lines. It returns an estimated progress between 0.0 (0%) and 1.0 (100%) or null if the progress could not be determined. The function will be called for each output line collected and the newest line is always at the end of the given list. If required, the function can be a suspend function.

Additional propertiesType
arrayAn array of IDs of the services this estimator plugin supports
Function interface
suspend fun myProgressEstimator(executable: model.processchain.Executable,
  recentLines: List<String>, vertx: io.vertx.core.Vertx): Double?
Example descriptor
- name: extractArchiveProgressEstimator
  type: progressEstimator
  scriptFile: conf/plugins/extractArchiveProgressEstimator.kt
    - extract-archive
Example plugin script
import model.processchain.Executable
import io.vertx.core.Vertx
suspend fun extractArchiveProgressEstimator(executable: Executable,
    recentLines: List<String>, vertx: Vertx): Double? {
  val lastLine = recentLines.last()
  val percentSign = lastLine.indexOf('%')
  if (percentSign > 0) {
    val percentStr = lastLine.substring(0, percentSign)
    val percent = percentStr.trim().toIntOrNull()
    if (percent != null) {
      return percent / 100.0
  return null