001// Copyright 2023 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007// http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014package org.apache.tapestry5.services.pageload;
015
016import java.lang.ref.SoftReference;
017import java.util.Arrays;
018import java.util.Collections;
019import java.util.Set;
020import java.util.stream.Collectors;
021
022/**
023 * Defines the types of reference the page cache can use.
024 * @see PageCachingReferenceTypeService
025 * @since 5.8.3
026 */
027public enum ReferenceType
028{
029    /**
030     * Use a soft reference ({@linkplain SoftReference}) to cached page instances.
031     */
032    SOFT, 
033    
034    /**
035     * Use a strong (normal) reference to cached page instances.
036     */
037    STRONG;
038    
039    /**
040     * Utility method that returns {@linkplain PageCachingReferenceTypeService}
041     * matching page names in a case-insensitive way.
042     * @return a {@linkplain PageCachingReferenceTypeService} instance.
043     */
044    public PageCachingReferenceTypeService forPages(String... canonicalPageNames)
045    {
046        final Set<String> pageNames = Collections.unmodifiableSet(
047                Arrays.stream(canonicalPageNames).
048                    map(String::toLowerCase).
049                    collect(Collectors.toSet()));
050        return (p) -> pageNames.contains(p.toLowerCase()) ? this : null;
051    }
052    
053}