/*
 * Copyright (c) 2013, 2018 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package org.glassfish.jersey.server.monitoring;

import java.util.Map;

import org.glassfish.jersey.server.model.ResourceMethod;

Monitoring statistics of the resource. The resource is a set of resource methods with specific characteristics that is not defined by this interface. The resource can be set of resource methods that are accessible on the same URI (in the case of MonitoringStatistics.getUriStatistics()) or the set of resource methods defined in one Class (in case of MonitoringStatistics.getResourceClassStatistics()). 
 Statistics retrieved from Jersey runtime might be mutable and thanks to it might provide inconsistent data as not all statistics are updated in the same time. To retrieve the immutable and consistent statistics data the method snapshot() should be used. 
 The principles of using statistics is similar to principles of using MonitoringStatistics. 
Author:
Miroslav Fuksa
See Also:
See monitoring statistics for general details about statistics./**
 * Monitoring statistics of the resource. The resource is a set of resource methods with specific characteristics
 * that is not defined by this interface. The resource can be set of resource methods that are accessible on
 * the same URI (in the case of {@link org.glassfish.jersey.server.monitoring.MonitoringStatistics#getUriStatistics()})
 * or the set of resource methods defined in one {@link Class} (in case
 * of {@link org.glassfish.jersey.server.monitoring.MonitoringStatistics#getResourceClassStatistics()}).
 * <p/>
 * Statistics retrieved from Jersey runtime might be mutable and thanks to it might provide inconsistent data
 * as not all statistics are updated in the same time. To retrieve the immutable and consistent
 * statistics data the method {@link #snapshot()} should be used.
 * <p/>
 *
 * The principles of using statistics
 * is similar to principles of using {@link MonitoringStatistics}.
 *
 * @author Miroslav Fuksa
 * @see MonitoringStatistics See monitoring statistics for general details about statistics.
 */
public interface ResourceStatistics {
    
Get execution statistics that contain measurements of times only for execution of resource methods. Durations average time, minimum time and maximum time measure only time of execution of resource methods code. It does not involve other request processing phases. 
Returns:
Execution statistics of all resource method in this resource./**
     * Get {@link ExecutionStatistics execution statistics} that contain measurements of times only for
     * execution of resource methods. Durations average time, minimum time and maximum time
     * measure only time of execution of resource methods code. It does not involve other request processing
     * phases.
     *
     * @return Execution statistics of all resource method in this resource.
     */
    public ExecutionStatistics getResourceMethodExecutionStatistics();

    
Get execution statistics that contain measurements of times for whole processing from time when request comes into the Jersey application until the response is written to the underlying IO container. The statistics involves only requests that were matched to resource methods defined in getResourceMethodStatistics(). 
Returns:
Execution statistics of entire request processing for all resource method from this resource./**
     * Get {@link ExecutionStatistics execution statistics} that contain measurements of times for
     * whole processing from time when request comes into the Jersey application until the response
     * is written to the underlying IO container. The statistics involves only requests that were matched
     * to resource methods defined in {@link #getResourceMethodStatistics()}.
     *
     * @return Execution statistics of entire request processing for all resource method from this resource.
     */
    public ExecutionStatistics getRequestExecutionStatistics();

    
Return the statistics for resource method. Keys of returned map are resource methods available in the resource and values are execution statistics of these resource methods. 
Returns:
Map with resource method keys and corresponding resource method statistics./**
     * Return the statistics for resource method. Keys of returned map are {@link ResourceMethod resource methods}
     * available in the resource and values are execution statistics of these resource methods.
     *
     * @return Map with {@link ResourceMethod resource method} keys
     *         and corresponding {@link ResourceMethodStatistics resource method statistics}.
     */
    public Map<ResourceMethod, ResourceMethodStatistics> getResourceMethodStatistics();

    
Get the immutable and consistent snapshot of the monitoring statistics. Working with snapshots might
have negative performance impact as snapshot must be created but ensures consistency of data over time.
However, the usage of snapshot is encouraged to avoid working with inconsistent data. Not all statistics
must be updated in the same time on mutable version of statistics.
Returns:
Snapshot of resource statistics.
Deprecated:
implementing class is immutable hence snapshot creation is not needed anymore/**
     * Get the immutable and consistent snapshot of the monitoring statistics. Working with snapshots might
     * have negative performance impact as snapshot must be created but ensures consistency of data over time.
     * However, the usage of snapshot is encouraged to avoid working with inconsistent data. Not all statistics
     * must be updated in the same time on mutable version of statistics.
     *
     * @return Snapshot of resource statistics.
     * @deprecated implementing class is immutable hence snapshot creation is not needed anymore
     */
    @Deprecated
    public ResourceStatistics snapshot();

}