001/*
002 * SPDX-License-Identifier: Apache-2.0
003 *
004 * Copyright 2025-2026 The Enola <https://enola.dev> Authors
005 *
006 * Licensed under the Apache License, Version 2.0 (the "License");
007 * you may not use this file except in compliance with the License.
008 * You may obtain a copy of the License at
009 *
010 *     https://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package dev.enola.ai.iri;
019
020import com.google.common.cache.CacheBuilder;
021import com.google.common.cache.CacheLoader;
022import com.google.common.cache.LoadingCache;
023
024import java.net.URI;
025import java.util.Optional;
026
027public class CachingProvider<T> implements Provider<T> {
028
029    private final Provider<T> delegate;
030    private final Iterable<String> uriTemplates;
031    private final Iterable<URI> uriExamples;
032
033    private final LoadingCache<URI, Optional<T>> cache =
034            CacheBuilder.newBuilder()
035                    .maximumSize(37)
036                    .build(
037                            new CacheLoader<>() {
038                                @Override
039                                public Optional<T> load(URI iri) {
040                                    return delegate.optional(iri);
041                                }
042                            });
043
044    public CachingProvider(Provider<T> delegate) {
045        this.delegate = delegate;
046        this.uriTemplates = delegate.uriTemplates();
047        this.uriExamples = delegate.uriExamples();
048    }
049
050    @Override
051    public String name() {
052        return delegate.name();
053    }
054
055    @Override
056    public String docURL() {
057        return delegate.docURL();
058    }
059
060    @Override
061    public Iterable<String> uriTemplates() {
062        return this.uriTemplates;
063    }
064
065    @Override
066    public Iterable<URI> uriExamples() {
067        return this.uriExamples;
068    }
069
070    @Override
071    public Optional<T> optional(URI uri) {
072        return cache.getUnchecked(uri);
073    }
074}