PerformanceProfiler.java

package at.favre.lib.dali.builder;

import android.util.Log;

import java.util.ArrayList;
import java.util.List;

import at.favre.lib.dali.util.BenchmarkUtil;

/**
 * A simple Profiler that helps in measuring parts of code.
 *
 * This will use nano seconds (if possible with SDK)
 */
public class PerformanceProfiler {
	private final static String TAG = PerformanceProfiler.class.getSimpleName();

	private String description;
	private List<Duration> durations;
	private boolean isActivated;

	public PerformanceProfiler(String description) {
		this(description,true);
	}

	/**
	 * @param description describes the task
	 * @param isActivated if this is false, every call to a method will do exactly nothing to
	 *                       avoid to have unnecessary overhead
	 */
	public PerformanceProfiler(String description, boolean isActivated) {
		this.description = description;
		this.durations = new ArrayList<Duration>();
		this.isActivated = isActivated;
	}

	/**
	 * Start a task. The id is needed to end the task
	 * @param id
	 * @param taskName
	 */
	public void startTask(int id, String taskName) {
		if(isActivated) {
			durations.add(new Duration(id, taskName, BenchmarkUtil.elapsedRealTimeNanos()));
		}
	}

	public void endTask(int id) {
		endTask(id,null);
	}

	public void endTask(int id,String additionalInfo) {
		if(isActivated) {
			for (Duration duration : durations) {
				if (duration.getId() == id) {
					duration.setEndTimstamp(BenchmarkUtil.elapsedRealTimeNanos());
					if (additionalInfo != null) {
						duration.setAdditionalInfo(additionalInfo);
					}
					return;
				}
			}
			Log.w(TAG, "Could not find task with id " + id);
		}
	}

	/**
	 * Returns the duration of the measured tasks in ms
	 */
	public double getDurationMs() {
		double durationMs = 0;
		for (Duration duration : durations) {
			if(duration.taskFinished()) {
				durationMs += duration.getDurationMS();
			}
		}
		return durationMs;
	}

	public void printResultToLog(String tag) {
		if(isActivated) {
			StringBuilder sb = new StringBuilder("->\nLog profile for task " + description+" - "+ BenchmarkUtil.formatNum(getDurationMs(),"0.##")+"ms\n----------------------------------------\n");
			for (Duration duration : durations) {
				String logMsg = " * "+duration.getTaskDescription();
				if(duration.getAdditionalInfo() != null && !duration.getAdditionalInfo().isEmpty()) {
					logMsg += " / "+duration.getAdditionalInfo();
				}
				if(duration.taskFinished()) {
					logMsg += " - " + BenchmarkUtil.formatNum(duration.getDurationMS(),"0.##") + "ms";
				} else {
					logMsg += " - unfinished";
				}
				sb.append(logMsg+"\n");
			}

			Log.d(tag, sb.toString());
		}
	}

	public void printResultToLog() {
		printResultToLog(TAG);
	}

	public static class Duration {
		private int id;
		private String taskDescription;
		private String additionalInfo;
		private long startTimestamp;
		private long duration=-1;


		public Duration(int id, String taskDescription, long startTimestamp) {
			this.id = id;
			this.taskDescription = taskDescription;
			this.startTimestamp = startTimestamp;
		}

		public String getAdditionalInfo() {
			return additionalInfo;
		}

		public void setAdditionalInfo(String additionalInfo) {
			this.additionalInfo = additionalInfo;
		}

		public void setEndTimstamp(long endTimstamp) {
			duration = endTimstamp - startTimestamp;
		}

		public long getDuration() {
			return duration;
		}

		public double getDurationMS() {
			return duration / 1000000d;
		}

		public boolean taskFinished() {
			return duration != -1;
		}

		public String getTaskDescription() {
			return taskDescription;
		}

		public int getId() {
			return id;
		}
	}

}