/*
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* CDDL HEADER START
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*
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* The contents of this file are subject to the terms of the
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* Common Development and Distribution License, Version 1.0 only
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* (the "License"). You may not use this file except in compliance
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* with the License.
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*
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* You can obtain a copy of the license at
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* trunk/opends/resource/legal-notices/OpenDS.LICENSE
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* or https://OpenDS.dev.java.net/OpenDS.LICENSE.
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* See the License for the specific language governing permissions
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* and limitations under the License.
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*
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* When distributing Covered Code, include this CDDL HEADER in each
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* file and include the License file at
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* trunk/opends/resource/legal-notices/OpenDS.LICENSE. If applicable,
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* add the following below this CDDL HEADER, with the fields enclosed
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* by brackets "[]" replaced with your own identifying information:
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* Portions Copyright [yyyy] [name of copyright owner]
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*
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* CDDL HEADER END
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*
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*
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* Portions Copyright 2006-2007 Sun Microsystems, Inc.
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*/
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package org.opends.server.replication.protocol;
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import java.io.UnsupportedEncodingException;
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import java.util.zip.DataFormatException;
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/**
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* This abstract message class is the superclass for start messages used
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* by LDAP servers and Replication servers to initiate their communications.
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* This class specifies a message header that contains the Replication
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* Protocol version.
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*/
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public abstract class StartMessage extends ReplicationMessage
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{
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private short protocolVersion;
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private long generationId;
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/**
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* The length of the header of this message.
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*/
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protected int headerLength;
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/**
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* Create a new StartMessage.
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*
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* @param protocolVersion The Replication Protocol version of the server
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* for which the StartMessage is created.
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* @param generationId The generationId for this server.
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*
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*/
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public StartMessage(short protocolVersion, long generationId)
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{
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this.protocolVersion = protocolVersion;
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this.generationId = generationId;
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}
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/**
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* Creates a new ServerStartMessage from its encoded form.
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*
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* @param type The type of the message to create.
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* @param encodedMsg The byte array containing the encoded form of the
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* StartMessage.
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* @throws DataFormatException If the byte array does not contain a valid
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* encoded form of the ServerStartMessage.
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*/
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public StartMessage(byte type, byte [] encodedMsg) throws DataFormatException
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{
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headerLength = decodeHeader(type, encodedMsg);
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}
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/**
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* Encode the header for the start message.
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*
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* @param type The type of the message to create.
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* @param additionalLength additional length needed to encode the remaining
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* part of the UpdateMessage.
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* @return a byte array containing the common header and enough space to
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* encode the reamining bytes of the UpdateMessage as was specified
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* by the additionalLength.
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* (byte array length = common header length + additionalLength)
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* @throws UnsupportedEncodingException if UTF-8 is not supported.
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*/
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public byte[] encodeHeader(byte type, int additionalLength)
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throws UnsupportedEncodingException
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{
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byte[] versionByte = Short.toString(protocolVersion).getBytes("UTF-8");
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byte[] byteGenerationID =
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String.valueOf(generationId).getBytes("UTF-8");
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/* The message header is stored in the form :
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* <message type><protocol version>
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*/
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int length = 1 + versionByte.length + 1 +
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byteGenerationID.length + 1 +
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additionalLength;
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byte[] encodedMsg = new byte[length];
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/* put the type of the operation */
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encodedMsg[0] = type;
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int pos = 1;
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/* put the protocol version */
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pos = addByteArray(versionByte, encodedMsg, pos);
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/* put the generationId */
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headerLength = addByteArray(byteGenerationID, encodedMsg, pos);
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return encodedMsg;
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}
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/**
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* Decode the Header part of this message, and check its type.
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*
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* @param type The type of this message.
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* @param encodedMsg the encoded form of the message.
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* @return the position at which the remaining part of the message starts.
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* @throws DataFormatException if the encodedMsg does not contain a valid
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* common header.
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*/
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public int decodeHeader(byte type, byte [] encodedMsg)
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throws DataFormatException
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{
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/* first byte is the type */
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if (encodedMsg[0] != type)
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throw new DataFormatException("byte[] is not a valid msg");
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try
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{
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/* then read the version */
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int pos = 1;
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int length = getNextLength(encodedMsg, pos);
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protocolVersion = Short.valueOf(
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new String(encodedMsg, pos, length, "UTF-8"));
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pos += length + 1;
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/* read the generationId */
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length = getNextLength(encodedMsg, pos);
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generationId = Long.valueOf(new String(encodedMsg, pos, length,
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"UTF-8"));
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pos += length +1;
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return pos;
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} catch (UnsupportedEncodingException e)
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{
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throw new DataFormatException("UTF-8 is not supported by this jvm.");
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}
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}
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/**
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* Get the version included in the Start Message mean the replication
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* protocol version used by the server that created the message.
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*
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* @return The version used by the server that created the message.
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*/
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public short getVersion()
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{
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return protocolVersion;
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}
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/**
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* Get the generationId from this message.
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* @return The generationId.
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*/
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public long getGenerationId()
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{
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return generationId;
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}
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}
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