/*
 * FindBugs - Find bugs in Java programs
 * Copyright (C) 2004, University of Maryland
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package edu.umd.cs.findbugs;

import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

import edu.umd.cs.findbugs.ba.Location;

A ResourceCollection defines all of the resources created and used in a
particular method. It serves two related purposes:

Define all of the resources which exist in the method, and
Record where resources created in the method are created


This distinction is important because some resources which exist in the
method aren't created in the method: for example, resources passed in as
parameters.
Author:
David Hovemeyer/**
 * A ResourceCollection defines all of the resources created and used in a
 * particular method. It serves two related purposes:
 * <ol>
 * <li>Define all of the resources which exist in the method, and
 * <li>Record where resources created in the method are created
 * </ol>
 * <p>
 * This distinction is important because some resources which exist in the
 * method aren't created in the method: for example, resources passed in as
 * parameters.
 *
 * @author David Hovemeyer
 */
public class ResourceCollection<Resource> {
    private final List<Resource> resourceList;

    private final Map<Location, Resource> locationToResourceMap;

    
Constructor. Creates empty collection.
/**
     * Constructor. Creates empty collection.
     */
    public ResourceCollection() {
        this.resourceList = new LinkedList<Resource>();
        this.locationToResourceMap = new HashMap<Location, Resource>();
    }

    
Add a preexisting resource. That is, one that is not created within the
analyzed method. Resources passed to the method as parameters fall into
this category.
Params:
resource – 
           the preexisting resource/**
     * Add a preexisting resource. That is, one that is not created within the
     * analyzed method. Resources passed to the method as parameters fall into
     * this category.
     *
     * @param resource
     *            the preexisting resource
     */
    public void addPreexistingResource(Resource resource) {
        resourceList.add(resource);
    }

    
Add a resource created within the analyzed method.
Params:
location – 
           the location
resource – 
           the resource created at that location/**
     * Add a resource created within the analyzed method.
     *
     * @param location
     *            the location
     * @param resource
     *            the resource created at that location
     */
    public void addCreatedResource(Location location, Resource resource) {
        resourceList.add(resource);
        locationToResourceMap.put(location, resource);
    }

    
Return whether or not there are any resources in the collection.
/**
     * Return whether or not there are any resources in the collection.
     */
    public boolean isEmpty() {
        return resourceList.isEmpty();
    }

    
Get an Iterator over all resources in the method. This includes both
preexisting and created resources.
/**
     * Get an Iterator over all resources in the method. This includes both
     * preexisting and created resources.
     */
    public Iterator<Resource> resourceIterator() {
        return resourceList.iterator();
    }

    
Get the resource that is created at given location.
Params:
location – 
           the Location
Returns:
the Resource created at that location, or null if no resource is
        created at the location/**
     * Get the resource that is created at given location.
     *
     * @param location
     *            the Location
     * @return the Resource created at that location, or null if no resource is
     *         created at the location
     */
    public Resource getCreatedResource(Location location) {
        return locationToResourceMap.get(location);
    }
}