com.day.cq.reporting.AggregateManager Maven / Gradle / Ivy

/*
 * Copyright 1997-2010 Day Management AG
 * Barfuesserplatz 6, 4001 Basel, Switzerland
 * All Rights Reserved.
 *
 * This software is the confidential and proprietary information of
 * Day Management AG, ("Confidential Information"). You shall not
 * disclose such Confidential Information and shall use it only in
 * accordance with the terms of the license agreement you entered into
 * with Day.
 */

package com.day.cq.reporting;

import java.util.HashMap;
import java.util.Map;

/**
 * This class is used for managing aggregates; mainly for mapping aggregate types
 * to corresponding {@link Aggregate}s.
 */
// TODO: replace MedianAggregate and Percentile95Aggregate by Generics
public class AggregateManager {

    /**
     * The service to retrieve the aggregates from.
     */
    private final ComponentProvider componentService;

    /**
     * Map that defines the aggregate on a column base
     */
    protected Map aggregatePerColumn;

    /**
     * Creates a new AggregateManager.
     *
     * @param context The context for creating the report
     */
    public AggregateManager(Context context) {
        this.componentService = (context != null ? context.getComponentService() : null);
        this.aggregatePerColumn = new HashMap(16);
    }

    /**
     * Creates an {@link Aggregate} object for the specified aggregate type.
     *
     * @param type The type of the aggregate
     * @return The aggregate
     */
    private Aggregate createAggregateFromType(String type) {
        Aggregate aggregate = this.componentService.acquireAggregate(type);
        if (aggregate == null) {
            throw new IllegalArgumentException("Aggregate type '" + type + "' is not "
                + "supported by this implementation.");
        }
        return aggregate;
    }

    /**
     * Creates the aggregate for the specified column.
     *
     * @param col The aggregate for the specified column
     */
    public void createForColumn(Column col) {
        String type = col.getAggregateType();
        if (type != null) {
            Aggregate existingAggregate = this.aggregatePerColumn.get(col);
            if (existingAggregate != null) {
                this.componentService.releaseAggregate(existingAggregate);
            }
            this.aggregatePerColumn.put(col, this.createAggregateFromType(type));
        }
    }

    /**
     * Gets the aggregate for the specified column.
     *
     * @param col The column
     * @return The aggregate; null if no aggregate is available for the
     *         specified column
     */
    public Aggregate getForColumn(Column col) {
        return this.aggregatePerColumn.get(col);
    }

    /**
     * Cleans up the aggregates that were used.
     */
    public void cleanup() {
        for (Column col : this.aggregatePerColumn.keySet()) {
            Aggregate aggregateToRelease = this.aggregatePerColumn.get(col);
            this.componentService.releaseAggregate(aggregateToRelease);
        }
        this.aggregatePerColumn.clear();
    }

}