/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.tinkerpop.gremlin.process.traversal.util;

import java.util.Collection;
import java.util.concurrent.TimeUnit;

/**
 * Contains the Metrics gathered for a Traversal as the result of the .profile()-step.
 *
 * @author Bob Briody (http://bobbriody.com)
 */
public interface TraversalMetrics {

    /**
     * The MetricsId used to obtain the element count via Metrics.getCount(String countKey)
     */
    public static final String ELEMENT_COUNT_ID = "elementCount";

    /**
     * The MetricsId used to obtain the traverser count via Metrics.getCount(String countKey)
     */
    public static final String TRAVERSER_COUNT_ID = "traverserCount";

    /**
     * The annotation key used to obtain the percent duration via Metrics.getAnnotation(String key)
     */
    public static final String PERCENT_DURATION_KEY = "percentDur";

    /**
     * Get the total duration taken by the Traversal.
     *
     * @param unit
     * @return total duration taken by the Traversal.
     */
    public long getDuration(TimeUnit unit);

    /**
     * Get an individual Metrics object by the index of the profiled Step.
     *
     * @param stepIndex
     * @return an individual Metrics object.
     */
    public Metrics getMetrics(final int stepIndex);

    /**
     * Get an individual Metrics object by the id of the profiled Step.
     *
     * @param id
     * @return an individual Metrics object.
     */
    public Metrics getMetrics(final String id);

    public Collection<? extends Metrics> getMetrics();
}