001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.activemq.transport.protocol;
018
019import org.apache.activemq.command.WireFormatInfo;
020import org.apache.activemq.openwire.OpenWireFormat;
021import org.apache.activemq.openwire.OpenWireFormatFactory;
022
023/**
024 *
025 *
026 */
027public class OpenWireProtocolVerifier  implements ProtocolVerifier {
028
029    protected final OpenWireFormatFactory wireFormatFactory;
030
031    public OpenWireProtocolVerifier(OpenWireFormatFactory wireFormatFactory) {
032        this.wireFormatFactory = wireFormatFactory;
033    }
034
035    /* (non-Javadoc)
036     * @see org.apache.activemq.broker.transport.protocol.ProtocolVerifier#isProtocol(byte[])
037     */
038    @Override
039    public boolean isProtocol(byte[] value) {
040        if (value.length < 8) {
041           throw new IllegalArgumentException("Protocol header length changed "
042                                                 + value.length);
043        }
044
045        int start = !((OpenWireFormat)wireFormatFactory.createWireFormat()).isSizePrefixDisabled() ? 4 : 0;
046        int j = 0;
047        // type
048        if (value[start] != WireFormatInfo.DATA_STRUCTURE_TYPE) {
049           return false;
050        }
051        start++;
052        WireFormatInfo info = new WireFormatInfo();
053        final byte[] magic = info.getMagic();
054        int remainingLen = value.length - start;
055        int useLen = remainingLen > magic.length ? magic.length : remainingLen;
056        useLen += start;
057        // magic
058        for (int i = start; i < useLen; i++) {
059           if (value[i] != magic[j]) {
060              return false;
061           }
062           j++;
063        }
064        return true;
065    }
066
067}