TaskProfiler.java

package codechicken.core;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map.Entry;

public class TaskProfiler {
    public static class ProfilerResult {
        public final String name;
        public final long time;
        public final double fraction;

        public ProfilerResult(String name, long time, long totalTime) {
            this.name = name;
            this.time = time;
            fraction = time / (double) totalTime;
        }
    }

    public HashMap<String, Long> times = new HashMap<String, Long>();

    public String currentSection;
    private long startTime;
    private long totalTime;

    public void start(String section) {
        if (currentSection != null) {
            end();
        }

        currentSection = section;
        startTime = System.nanoTime();
    }

    public void end() {
        long time = System.nanoTime() - startTime;
        totalTime += time;

        Long prev = times.get(currentSection);
        if (prev == null) {
            prev = 0L;
        }
        times.put(currentSection, prev + time);
        currentSection = null;
    }

    public List<ProfilerResult> getResults() {
        ArrayList<ProfilerResult> results = new ArrayList<ProfilerResult>(times.size());
        for (Entry<String, Long> e : times.entrySet()) {
            results.add(new ProfilerResult(e.getKey(), e.getValue(), totalTime));
        }
        return results;
    }

    public void clear() {
        if (currentSection != null) {
            end();
        }
        times.clear();
        totalTime = 0;
    }
}