Profiler.java

package com.etsy.statsd.profiler;

import com.etsy.statsd.profiler.reporter.Reporter;
import com.google.common.base.Preconditions;

import java.util.Map;
import java.util.concurrent.TimeUnit;

/**
 * Interface for profilers
 *
 * @author Andrew Johnson
 */
public abstract class Profiler {
    public static final Class<?>[] CONSTRUCTOR_PARAM_TYPES = new Class<?>[]{Reporter.class, Arguments.class};

    private final Reporter<?> reporter;

    private long recordedStats = 0;
    public Profiler(Reporter reporter, Arguments arguments) {
        Preconditions.checkNotNull(reporter);
        this.reporter = reporter;
        handleArguments(arguments);
    }

    /**
     * Perform profiling
     */
    public abstract void profile();

    /**
     * Hook to flush any remaining data cached by the profiler at JVM shutdown
     */
    public abstract void flushData();

    /**
     * Get the period to use for this profiler in the ScheduledExecutorService
     *
     * @return The ScheduledExecutorThread period for this profiler
     */
    public abstract long getPeriod();

    /**
     * Get the unit of time that corresponds to the period for this profiler
     *
     * @return A TimeUnit corresponding the the period for this profiler
     */
    public abstract TimeUnit getTimeUnit();

    /**
     * CPUTracingProfiler can emit some metrics that indicate the upper and lower bound on the length of stack traces
     * This is helpful for querying this data for some backends (such as Graphite) that do not have rich query languages
     * Reporters can override this to disable these metrics
     *
     * @return true if the bounds metrics should be emitted, false otherwise
     */
    protected boolean emitBounds() {
        return reporter.emitBounds();
    }

    /**
     * Handle any additional arguments necessary for this profiler
     *
     * @param arguments The arguments given to the profiler
     */
    protected abstract void handleArguments(Arguments arguments);

    /**
     * Record a gauge value
     *
     * @param key The key for the gauge
     * @param value The value of the gauge
     */
    protected void recordGaugeValue(String key, long value) {
        recordedStats++;
        reporter.recordGaugeValue(key, value);
    }

    /**
     * @see #recordGaugeValue(String, long)
     */
    protected void recordGaugeValue(String key, double value) {
        recordedStats++;
        reporter.recordGaugeValue(key, value);
    }

    /**
     * Record multiple gauge values
     * This is useful for reporters that can send points in batch
     *
     * @param gauges A map of gauge names to values
     */
    protected void recordGaugeValues(Map<String, ? extends Number> gauges) {
        recordedStats++;
        reporter.recordGaugeValues(gauges);
    }

    public long getRecordedStats() { return recordedStats; }
}