FF4jJCacheManager.java

package org.ff4j.cache;

/*
 * #%L
 * ff4j-store-jcache
 * %%
 * Copyright (C) 2013 - 2015 FF4J
 * %%
 * 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.
 * #L%
 */


import java.util.HashSet;
import java.util.Set;

import javax.cache.Cache;
import javax.cache.CacheManager;
import javax.cache.Caching;
import javax.cache.configuration.MutableConfiguration;
import javax.cache.spi.CachingProvider;

import org.ff4j.core.Feature;
import org.ff4j.property.Property;

/**
 * Implementation of {@link FF4JCacheManager} with reference interface JCache {@link Cache}.
 * 
 * @author Cedrick Lunven (@clunven)</a>
 */
public class FF4jJCacheManager implements FF4JCacheManager {    
    
    /** cache name of the features. */
    protected static final String CACHENAME_FEATURES      = "ff4jFeatures";
    
    /** cache name of the properties. */
    protected static final String CACHENAME_PROPERTIES    = "ff4jProperties";
    
    /** JCache associated CachingProvider in order to create 'CacheManager'. */
    private CachingProvider cachingProvider;
    
    /** JCache associated cache manager. */
    private CacheManager cacheManager; 
    
    /** Implementing a JCache CacheProvider. */
    protected Cache<String, Feature> featuresCache;
    
    /** Implementing a JCache CacheProvider. */
    @SuppressWarnings("rawtypes")
    protected Cache<String, Property> propertiesCache; 
    
    /**
     * Initialisation of internal caches.
     */
    public FF4jJCacheManager() {
    }
    
    /**
     * Constructory avec provider.
     *
     * @param provider
     */
    public FF4jJCacheManager(CachingProvider provider) {
        this.cachingProvider = provider;
        initCaches();
    }
    
    /**
     * Initialisation of internal caches.
     */
    public FF4jJCacheManager(String providerClassName) {
        this.cachingProvider = initCachingProvider(providerClassName);
        initCaches();
    }
    
    private void initCaches() {
        // invoke the jCache 'getCacheManager()' to init cache Manager
        this.cacheManager    = getCachingProvider().getCacheManager();
        featuresCache        = createCacheForFeatures();
        propertiesCache      = createCacheForProperties();
    }
    
    /**
     * Default initialisation of cache.
     *
     * @return
     */
    protected Cache<String, Feature> createCacheForFeatures() {
        if (null == getCacheManager().getCache(CACHENAME_FEATURES, String.class, Feature.class)) {
            getCacheManager().createCache(CACHENAME_FEATURES, getFeatureCacheConfiguration());
        }
        return getCacheManager().getCache(CACHENAME_FEATURES, String.class, Feature.class);
    }
    
    /**
     * Default initialisation of cache.
     *
     * @return
     */
    @SuppressWarnings("rawtypes")
    protected Cache<String, Property> createCacheForProperties() {
        if (null == getCacheManager().getCache(CACHENAME_PROPERTIES, String.class, Property.class)) {
            getCacheManager().createCache(CACHENAME_PROPERTIES, getPropertyCacheConfiguration());
        }
        return getCacheManager().getCache(CACHENAME_PROPERTIES, String.class, Property.class);
    }


    /** {@inheritDoc} */
    public Set<String> listCachedFeatureNames() {
        Set<String> keys = new HashSet<>();
        // Implements iterate, more elegant as stream how ?
        getFeaturesCache().forEach(e->keys.add(e.getKey()));
        return keys;
    }
    
    /** {@inheritDoc} */
    public Object getNativeCache() {
        if (featuresCache == null) {
            throw new IllegalArgumentException("Cannot ");
        }
        return featuresCache;
    }

    /** {@inheritDoc} */
    public String getCacheProviderName() {
        return "jCache:" + featuresCache.getName() + 
                ":" + featuresCache.getCacheManager().getCachingProvider().toString();
    }   

    /** {@inheritDoc} */
    @Override
    public void clearFeatures() {
        getFeaturesCache().clear();
    }

    /** {@inheritDoc} */
    @Override
    public void clearProperties() {
        getPropertiesCache().clear();
    }

    /** {@inheritDoc} */
    @Override
    public void evictFeature(String featureId) {
        if (getFeaturesCache().containsKey(featureId)) {
            getFeaturesCache().remove(featureId);
        }
    }

    /** {@inheritDoc} */
    @Override
    public void evictProperty(String propertyName) {
        if (getPropertiesCache().containsKey(propertyName)) {
            getPropertiesCache().remove(propertyName);
        }
    }

    /** {@inheritDoc} */
    @Override
    public void putFeature(Feature feat) {
        getFeaturesCache().put(feat.getUid(), feat);
    }

    /** {@inheritDoc} */
    @Override
    public void putProperty(Property<?> feat) {
        getPropertiesCache().put(feat.getName(), feat);
    }

    /** {@inheritDoc} */
    @Override
    public Feature getFeature(String featureId) {
        return getFeaturesCache().get(featureId);
    }

    /** {@inheritDoc} */
    @Override
    public Property<?> getProperty(String name) {
        return getPropertiesCache().get(name);
    }

    /** {@inheritDoc} */
    @Override
    public Set<String> listCachedPropertyNames() {
        Set<String> keys = new HashSet<>();
        // Implements iterate, more elegant as stream how ?
        getPropertiesCache().forEach(e->keys.add(e.getKey()));
        return keys;
    }

    /** {@inheritDoc} */
    @Override
    public Object getFeatureNativeCache() {
        return getFeaturesCache();
    }

    /** {@inheritDoc} */
    @Override
    public Object getPropertyNativeCache() {
        return getPropertiesCache();
    }

    /**
     * Getter accessor for attribute 'featuresCache'.
     *
     * @return
     *       current value of 'featuresCache'
     */
    public Cache<String, Feature> getFeaturesCache() {
        if (featuresCache == null) {
            initCaches();
        }
        return featuresCache;
    }

    /**
     * Setter accessor for attribute 'featuresCache'.
     * @param featuresCache
     * 		new value for 'featuresCache '
     */
    public void setFeaturesCache(Cache<String, Feature> featuresCache) {
        this.featuresCache = featuresCache;
    }

    /**
     * Getter accessor for attribute 'propertiesCache'.
     *
     * @return
     *       current value of 'propertiesCache'
     */
    @SuppressWarnings("rawtypes")
    public Cache<String, Property> getPropertiesCache() {
        if (propertiesCache == null) {
            initCaches();
        }
        return propertiesCache;
    }
    
    /**
     * Initialize cache configuration, could be overriden.
     *
     * @return
     *      cache default configuration
     */
    protected MutableConfiguration< String, Feature> getFeatureCacheConfiguration() {
        MutableConfiguration<String, Feature> featuresCacheConfig = new MutableConfiguration<>();        
        featuresCacheConfig.setTypes(String.class, Feature.class);
        featuresCacheConfig.setStoreByValue(true);
        featuresCacheConfig.setStatisticsEnabled(false);
        return featuresCacheConfig;
    }
    
    /**
     * Initialize cache configuration, could be overriden.
     *
     * @return
     *      cache default configuration
     */
    @SuppressWarnings("rawtypes")
    protected MutableConfiguration< String, Property> getPropertyCacheConfiguration() {
        MutableConfiguration<String, Property> propertiesCacheConfig = new MutableConfiguration<>();        
        propertiesCacheConfig.setTypes(String.class, Property.class);
        propertiesCacheConfig.setStoreByValue(true);
        propertiesCacheConfig.setStatisticsEnabled(false);
        return propertiesCacheConfig;
    }
    
    /**
     * Default Initialisation of {@link CachingProvider}. It will work only is there is
     * a single {@link CachingProvider} implementation within classpath. Otherwise should must
     * overriden it to initialize with your own.
     *
     * @return
     *      specialization of {@link CachingProvider} (JCache)
     */
    protected CachingProvider initCachingProvider(String cachingProviderClassname) {
        try {
            if (cachingProviderClassname == null) {
                return Caching.getCachingProvider();
            }
            return Caching.getCachingProvider(cachingProviderClassname);
        } catch(RuntimeException re) {
            /* 
             * Some cache implementation do not provide CachingProvider but the cacheManager
             * work properly. As a consequence, caching provider can be null and should not throw
             * caching exception.
             */
            return null;
        }
    }
    
    /**
     * Getter accessor for attribute 'cachingProvider'.
     *
     * @return
     *       current value of 'cachingProvider'
     */
    public CachingProvider getCachingProvider() {
        if (cachingProvider == null) {
            throw new IllegalStateException("Cannot initialize caches, cacheProvider not provided");
        }
        return cachingProvider;
    }
    
    /**
     * Initialize cache provider.
     *
     * @param provider
     *      target cache provider
     */
    public void setCachingProvider(CachingProvider provider) {
        this.cachingProvider = provider;
        initCaches();
    }

    /**
     * Getter accessor for attribute 'cacheManager'.
     *
     * @return
     *       current value of 'cacheManager'
     */
    public CacheManager getCacheManager() {
        if (cacheManager == null) {
            throw new IllegalArgumentException("Cache manager must not be null");
        }
        return cacheManager;
    }

}