    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}