001    // Copyright 2009, 2011 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    
015    package org.apache.tapestry5.services;
016    
017    import org.apache.tapestry5.ioc.annotations.UsesConfiguration;
018    import org.apache.tapestry5.services.assets.CompressionAnalyzer;
019    
020    /**
021     * Used to determine if the client supports GZIP compression of the response.
022     * 
023     * @since 5.1.0.0
024     */
025    @UsesConfiguration(String.class)
026    public interface ResponseCompressionAnalyzer
027    {
028        /**
029         * Checks the Accept-Encoding request header for a "gzip" token.
030         * 
031         * @return true if gzip is supported by client
032         */
033        boolean isGZipSupported();
034    
035        /**
036         * Checks to see if the indicated content type is compressable. Many formats are already compressed; pushing them
037         * through a GZip filter consumes cycles and makes them larger.
038         * <p/>
039         * Contribute content type strings to the service's configuration to mark them as not compressable.
040         * 
041         * @param contentType
042         *            the mime type of the content, such as "text/html" or "image/jpeg".
043         * @return true if compression is worthwhile
044         * @deprecated Deprecated in Tapestry 5.3. This method is to be removed at a later date. The service's configuration
045         *             is no longer used. Instead, contribute to and use {@link CompressionAnalyzer}.
046         */
047        boolean isCompressable(String contentType);
048    }