br.com.objectos.wiki.core.page.WikiPageCacheGuice.java Source code

Introduction

Here is the source code for br.com.objectos.wiki.core.page.WikiPageCacheGuice.java

Source

/*
 * Copyright 2013 Objectos, Fbrica de Software LTDA.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package br.com.objectos.wiki.core.page;

import br.com.objectos.comuns.base.cache.CacheBuilder;

import com.google.common.base.Optional;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.CacheLoader.InvalidCacheLoadException;
import com.google.common.cache.LoadingCache;
import com.google.inject.Inject;
import com.google.inject.Singleton;

/**
 * @author edenir.anschau@objectos.com.br (Edenir Norberto Anschau)
 */
@Singleton
class WikiPageCacheGuice implements WikiPageCache {

    private final LoadingCache<WikiPageKey, WikiPage> pageKeyCache;
    private final FindWikiPage findWikiPage;

    @Inject
    public WikiPageCacheGuice(CacheBuilder cacheBuilder, FindWikiPage findWikiPage) {
        this.pageKeyCache = cacheBuilder.medium().build(new WikiPageKeyLoader());
        this.findWikiPage = findWikiPage;
    }

    @Override
    public Optional<WikiPage> byWikiPageKey(WikiPageKey pageKey) {
        try {
            WikiPage page = pageKeyCache.getUnchecked(pageKey);
            return Optional.fromNullable(page);
        } catch (InvalidCacheLoadException e) {
            return Optional.absent();
        }
    }

    private class WikiPageKeyLoader extends CacheLoader<WikiPageKey, WikiPage> {
        @Override
        public WikiPage load(WikiPageKey key) throws Exception {
            return findWikiPage.byWikiPageKey(key);
        }
    }

}