diff options
Diffstat (limited to 'java/management/client/src/main/java/org/apache/qpid/management/domain/services/MessageTokenizer.java')
| -rw-r--r-- | java/management/client/src/main/java/org/apache/qpid/management/domain/services/MessageTokenizer.java | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/java/management/client/src/main/java/org/apache/qpid/management/domain/services/MessageTokenizer.java b/java/management/client/src/main/java/org/apache/qpid/management/domain/services/MessageTokenizer.java new file mode 100644 index 0000000000..9275255517 --- /dev/null +++ b/java/management/client/src/main/java/org/apache/qpid/management/domain/services/MessageTokenizer.java @@ -0,0 +1,152 @@ +/*
+*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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.
+ *
+ */
+
+package org.apache.qpid.management.domain.services;
+
+import java.io.IOException;
+import java.util.Enumeration;
+import java.util.Iterator;
+import java.util.LinkedList;
+
+import org.apache.qpid.api.Message;
+import org.apache.qpid.management.Messages;
+import org.apache.qpid.management.Protocol;
+import org.apache.qpid.nclient.util.ByteBufferMessage;
+import org.apache.qpid.transport.codec.BBDecoder;
+import org.apache.qpid.transport.util.Logger;
+
+/**
+ * The message tokenizer class allows a multi message listener to break a
+ * message into tokens where each token is itself a valid AMQP message.
+ *
+ * @author Andrea Gazzarini
+ * @see QPID-1368
+ */
+class MessageTokenizer implements Enumeration<Message>
+{
+ private final static Logger LOGGER = Logger.get(MessageTokenizer.class);
+
+ static byte [] MAGIC_NUMBER_BYTES;
+
+ private LinkedList<Message> _messages = new LinkedList<Message>();
+ private Iterator<Message> _iterator;
+
+ static
+ {
+ try
+ {
+ MAGIC_NUMBER_BYTES = Protocol.MAGIC_NUMBER.getBytes("UTF-8");
+ } catch(Exception exception)
+ {
+ throw new ExceptionInInitializerError(exception);
+ }
+ }
+
+ /**
+ * Builds a new Message tokenizer with the given message.
+ * Note that if the given message is not a "compound" message this tokenizer will producer only one token;
+ * That is, the token is a message equals to the given message.
+ *
+ * @param compoundMessage the compound message
+ * @throws IOException when it's not possible to read the given message content.
+ */
+ MessageTokenizer(Message compoundMessage) throws IOException
+ {
+ build(compoundMessage);
+ }
+
+ public boolean hasMoreElements()
+ {
+ return _iterator.hasNext();
+ }
+
+ public Message nextElement()
+ {
+ return _iterator.next();
+ }
+
+ /**
+ * Retruns the number of the tokens produced by this tokenizer.
+ *
+ * @return the number of the tokens produced by this tokenizer.
+ */
+ public int countTokens()
+ {
+ return _messages.size();
+ }
+
+ // Internal methods used for splitting the multi message byte array.
+ int indexOf(byte[] source, int startIndex)
+ {
+ int currentSourceIndex;
+ int currentExampleIndex;
+
+ if (startIndex + 3 > source.length)
+ return -1;
+
+ for (currentSourceIndex = startIndex; currentSourceIndex <= source.length - 3; currentSourceIndex++)
+ {
+ for (currentExampleIndex = 0; currentExampleIndex < 3; currentExampleIndex++)
+ {
+ if (source[currentSourceIndex + currentExampleIndex] != MAGIC_NUMBER_BYTES[currentExampleIndex])
+ break;
+ }
+
+ if (currentExampleIndex == 3)
+ return currentSourceIndex;
+ }
+ return -1;
+ }
+
+ // Internal method used for building the tokens.
+ private void build(Message compoundMessage) throws IOException
+ {
+ int startIndex = 0;
+ int indexOfMagicNumber = 0;
+
+ BBDecoder decoder = new BBDecoder();
+ decoder.init(compoundMessage.readData());
+ byte [] source = decoder.readReaminingBytes();
+
+ int howManyTokens = 1;
+
+ while ((indexOfMagicNumber = indexOf(source, startIndex+1)) != -1)
+ {
+ addMessageToken(source, startIndex, (indexOfMagicNumber-startIndex));
+ startIndex = indexOfMagicNumber;
+ howManyTokens++;
+ }
+ addMessageToken(source, startIndex, (source.length-startIndex));
+ _iterator = _messages.iterator();
+
+ LOGGER.debug(Messages.QMAN_200031_COMPOUND_MESSAGE_CONTAINS,howManyTokens);
+ };
+
+ // Builds & adds a new "message" token
+ private void addMessageToken(byte [] source,int startIndex,int length) throws IOException
+ {
+ byte [] messageData = new byte[length];
+ System.arraycopy(source, startIndex, messageData, 0, messageData.length);
+ Message message = new ByteBufferMessage();
+ message.appendData(messageData);
+ _messages.add(message);
+ }
+}
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