001/*
002 * This library is part of OpenCms -
003 * The Open Source Content Management System
004 *
005 * Copyright (c) Alkacon Software GmbH & Co. KG (https://www.alkacon.com)
006 *
007 * This library is free software; you can redistribute it and/or
008 * modify it under the terms of the GNU Lesser General Public
009 * License as published by the Free Software Foundation; either
010 * version 2.1 of the License, or (at your option) any later version.
011 *
012 * This library is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015 * Lesser General Public License for more details.
016 *
017 * For further information about Alkacon Software GmbH & Co. KG, please see the
018 * company website: https://www.alkacon.com
019 *
020 * For further information about OpenCms, please see the
021 * project website: https://www.opencms.org
022 *
023 * You should have received a copy of the GNU Lesser General Public
024 * License along with this library; if not, write to the Free Software
025 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
026 */
027
028package org.opencms.loader.imagecache;
029
030import java.util.Collections;
031import java.util.EnumSet;
032import java.util.Set;
033
034/**
035 * Describes the maintenance operations supported by an image cache backend.<p>
036 */
037public final class CmsImageCacheCapabilities {
038
039    /** Individual backend capabilities. */
040    public enum Capability {
041
042        /** All cache entries can be listed. */
043        LIST_ENTRIES,
044
045        /** Listed entries contain a last-modified timestamp. */
046        ENTRY_TIMESTAMPS,
047
048        /** Individual entries can be deleted. */
049        DELETE_ENTRIES,
050
051        /** The complete cache can be cleared. */
052        CLEAR,
053
054        /** Individual entries can be renewed without regenerating their content. */
055        RENEW_ENTRIES
056    }
057
058    /** The supported capabilities. */
059    private final Set<Capability> m_capabilities;
060
061    /**
062     * Creates a capability set.<p>
063     *
064     * @param capabilities the supported capabilities
065     */
066    private CmsImageCacheCapabilities(EnumSet<Capability> capabilities) {
067
068        m_capabilities = Collections.unmodifiableSet(EnumSet.copyOf(capabilities));
069    }
070
071    /**
072     * Creates a capability set.<p>
073     *
074     * @param capabilities the supported capabilities
075     * @return the capability set
076     */
077    public static CmsImageCacheCapabilities of(Capability... capabilities) {
078
079        EnumSet<Capability> values = EnumSet.noneOf(Capability.class);
080        Collections.addAll(values, capabilities);
081        return new CmsImageCacheCapabilities(values);
082    }
083
084    /**
085     * Returns the supported capabilities.<p>
086     *
087     * @return the supported capabilities
088     */
089    public Set<Capability> asSet() {
090
091        return m_capabilities;
092    }
093
094    /**
095     * Checks whether a capability is supported.<p>
096     *
097     * @param capability the capability
098     * @return whether the capability is supported
099     */
100    public boolean supports(Capability capability) {
101
102        return m_capabilities.contains(capability);
103    }
104}