ProfilerCollector.java

/*
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     its contributors may be used to endorse or promote products derived
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package cloud.orbit.profiler;

import java.util.Map;
import java.util.Set;
import java.util.WeakHashMap;

/**
 * This is a mini execution profiler that can seat in a server
 * collecting profile samples when triggered externally.
 * <p/>
 * It can be used to have online profile information about the worst performance bottlenecks.
 * <p/>
 * The profile collector is not thread safe.
 *
 * @author Daniel Sperry
 */
public class ProfilerCollector
{
    public static final String GLOBAL = "global";
    private Map<Object, ProfilerData> collectedData = new WeakHashMap<>();

    public ProfilerCollector()
    {
    }

    public void collect()
    {
        // only sure way to get all threads
        final Set<Thread> threads = Thread.getAllStackTraces().keySet();
        final Thread currentThread = Thread.currentThread();

        for (final Thread thread : threads)
        {
            if (currentThread != thread)
            {
                // lets the application decide what to collect and event o edit the stack trace
                // gets the stack trace again to minimize drift
                collect(thread);
            }
        }
    }

    /**
     * Override this method to collect based other criteria
     * <p/>
     * If the application knows that a certain type of task happens in a certain thread,
     * it is possible to group the information by that type of task.
     *
     * <p/> Example collect the information grouped by request path, api call, or actor.
     *
     * <p/>It's advisable to either override this method or to call collectByKey directly
     *
     * <p/>Collecting per thread usually produces too much information.
     * Some idle threads are also irrelevant for instance idle worker threads and skew the data.
     */
    public void collect(Thread thread)
    {
        final StackTraceElement[] stackTrace = thread.getStackTrace();
        // default implementation just bundles all information together
        collectByKey(GLOBAL, stackTrace);
    }

    public void collectByKey(final Object key, final StackTraceElement[] stackTrace)
    {
        ProfilerData profilerData = collectedData.get(key);
        if (profilerData == null)
        {
            profilerData = new ProfilerData();
            collectedData.put(key, profilerData);
        }
        profilerData.collect(stackTrace);
    }

    public Map<Object, ProfilerData> getProfilerData()
    {
        return collectedData;
    }

    public void clear()
    {
        collectedData.clear();
    }
}