PipelineMetrics.java

//Dstl (c) Crown Copyright 2017
package uk.gov.dstl.baleen.core.metrics;

import com.codahale.metrics.Timer;

/**
 * Class to do pipeline level metrics, for example how long documents take to process
 * 
 * 
 */
public class PipelineMetrics {
	private String pipelineName;
	private Timer.Context documentTimerContext;
	
	private static final String DOCUMENT_TIMER = "documentProcessingTime";
	
	/**
	 * Construct a new PipelineMetrics instance
	 * 
	 * @param pipelineName Name of the pipeline
	 */
	public PipelineMetrics(String pipelineName){
		this.pipelineName = pipelineName;
	}
	
	/**
	 * Return the name of the pipeline associated with this PipelineMetrics instance
	 * 
	 * @return
	 */
	public String getPipelineName(){
		return pipelineName;
	}
	
	/**
	 * Start timing the processing of a document
	 */
	public void startDocumentProcess(){
		finishDocumentProcess();	//Check we've finished the timing of the previous document
		documentTimerContext = MetricsFactory.getInstance().getTimer(pipelineName, DOCUMENT_TIMER).time();
	}
	
	/**
	 * Finish timing the processing of a document
	 */
	public void finishDocumentProcess(){
		if(documentTimerContext != null){
			documentTimerContext.stop();
			documentTimerContext = null;
		}
	}
}