    001// Copyright 2011, 2012 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.
    014
    015package org.apache.tapestry5.internal.services.assets;
    016
    017import org.apache.tapestry5.services.assets.CompressionStatus;
    018import org.apache.tapestry5.services.assets.StreamableResource;
    019import org.apache.tapestry5.services.assets.StreamableResourceProcessing;
    020import org.apache.tapestry5.services.assets.StreamableResourceSource;
    021
    022/**
    023 * Specialization of {@link SRSCachingInterceptor} that only attempts to cache
    024 * compressed resources.
    025 */
    026public class SRSCompressedCachingInterceptor extends SRSCachingInterceptor
    027{
    028    public SRSCompressedCachingInterceptor(StreamableResourceSource delegate, ResourceChangeTracker tracker)
    029    {
    030        super(delegate, tracker);
    031    }
    032
    033    /**
    034     * Return true only if the resource is compressed.
    035     */
    036    @Override
    037    protected boolean isCacheable(StreamableResource resource)
    038    {
    039        return resource.getCompression() == CompressionStatus.COMPRESSED;
    040    }
    041
    042    /**
    043     * Returns true just when the processing enables compression.
    044     */
    045    @Override
    046    protected boolean enableCache(StreamableResourceProcessing processing)
    047    {
    048        return processing == StreamableResourceProcessing.COMPRESSION_ENABLED;
    049    }
    050}