    001    // Copyright 2009, 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
    015    package org.apache.tapestry5.services;
    016
    017    import org.apache.tapestry5.services.assets.CompressionAnalyzer;
    018
    019    /**
    020     * Used to determine if the client supports GZIP compression of the response.
    021     *
    022     * @see ResponseCompressionAnalyzer
    023     * @since 5.1.0.0
    024     */
    025    public interface ResponseCompressionAnalyzer
    026    {
    027        /**
    028         * Checks the Accept-Encoding request header for a "gzip" token. Ensures that the protocol is not "HTTP/1.0", which
    029         * does not correctly support GZip encoding (in older Internet Explorer browsers).
    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    }