/*
|
* CDDL HEADER START
|
*
|
* The contents of this file are subject to the terms of the
|
* Common Development and Distribution License, Version 1.0 only
|
* (the "License"). You may not use this file except in compliance
|
* with the License.
|
*
|
* You can obtain a copy of the license at
|
* trunk/opends/resource/legal-notices/OpenDS.LICENSE
|
* or https://OpenDS.dev.java.net/OpenDS.LICENSE.
|
* See the License for the specific language governing permissions
|
* and limitations under the License.
|
*
|
* When distributing Covered Code, include this CDDL HEADER in each
|
* file and include the License file at
|
* trunk/opends/resource/legal-notices/OpenDS.LICENSE. If applicable,
|
* add the following below this CDDL HEADER, with the fields enclosed
|
* by brackets "[]" replaced with your own identifying information:
|
* Portions Copyright [yyyy] [name of copyright owner]
|
*
|
* CDDL HEADER END
|
*
|
*
|
* Copyright 2006-2008 Sun Microsystems, Inc.
|
*/
|
package org.opends.server.replication.common;
|
|
import java.io.UnsupportedEncodingException;
|
import java.util.ArrayList;
|
import java.util.Date;
|
import java.util.HashMap;
|
import java.util.HashSet;
|
import java.util.Iterator;
|
import java.util.List;
|
import java.util.Set;
|
import java.util.zip.DataFormatException;
|
|
import org.opends.server.protocols.asn1.ASN1OctetString;
|
|
|
/**
|
* ServerState class.
|
* This object is used to store the last update seen on this server
|
* from each server.
|
* It is exchanged with the replication servers at connection establishment
|
* time.
|
*/
|
public class ServerState implements Iterable<Short>
|
{
|
private HashMap<Short, ChangeNumber> list;
|
private boolean saved = true;
|
|
/**
|
* Creates a new empty ServerState.
|
*/
|
public ServerState()
|
{
|
list = new HashMap<Short, ChangeNumber>();
|
}
|
|
/**
|
* Empty the ServerState.
|
* After this call the Server State will be in the same state
|
* as if it was just created.
|
*/
|
public void clear()
|
{
|
synchronized (this)
|
{
|
list.clear();
|
}
|
}
|
|
|
/**
|
* Creates a new ServerState object from its encoded form.
|
*
|
* @param in The byte array containing the encoded ServerState form.
|
* @param pos The position in the byte array where the encoded ServerState
|
* starts.
|
* @param endpos The position in the byte array where the encoded ServerState
|
* ends.
|
* @throws DataFormatException If the encoded form was not correct.
|
*/
|
public ServerState(byte[] in, int pos, int endpos)
|
throws DataFormatException
|
{
|
try
|
{
|
list = new HashMap<Short, ChangeNumber>();
|
|
while (endpos > pos)
|
{
|
/*
|
* read the ServerId
|
*/
|
int length = getNextLength(in, pos);
|
String serverIdString = new String(in, pos, length, "UTF-8");
|
short serverId = Short.valueOf(serverIdString);
|
pos += length +1;
|
|
/*
|
* read the ChangeNumber
|
*/
|
length = getNextLength(in, pos);
|
String cnString = new String(in, pos, length, "UTF-8");
|
ChangeNumber cn = new ChangeNumber(cnString);
|
pos += length +1;
|
|
/*
|
* Add the serverid
|
*/
|
list.put(serverId, cn);
|
}
|
|
} catch (UnsupportedEncodingException e)
|
{
|
throw new DataFormatException("UTF-8 is not supported by this jvm.");
|
}
|
}
|
|
/**
|
* Get the length of the next String encoded in the in byte array.
|
*
|
* @param in the byte array where to calculate the string.
|
* @param pos the position whre to start from in the byte array.
|
* @return the length of the next string.
|
* @throws DataFormatException If the byte array does not end with null.
|
*/
|
private int getNextLength(byte[] in, int pos) throws DataFormatException
|
{
|
int offset = pos;
|
int length = 0;
|
while (in[offset++] != 0)
|
{
|
if (offset >= in.length)
|
throw new DataFormatException("byte[] is not a valid modify msg");
|
length++;
|
}
|
return length;
|
}
|
|
/**
|
* Update the Server State with a ChangeNumber.
|
*
|
* @param changeNumber The committed ChangeNumber.
|
*
|
* @return a boolean indicating if the update was meaningful.
|
*/
|
public boolean update(ChangeNumber changeNumber)
|
{
|
if (changeNumber == null)
|
return false;
|
|
saved = false;
|
|
synchronized(this)
|
{
|
Short id = changeNumber.getServerId();
|
ChangeNumber oldCN = list.get(id);
|
if (oldCN == null || changeNumber.newer(oldCN))
|
{
|
list.put(id,changeNumber);
|
return true;
|
}
|
else
|
{
|
return false;
|
}
|
}
|
}
|
|
/**
|
* return a Set of String usable as a textual representation of
|
* a Server state.
|
* format : time seqnum id
|
*
|
* example :
|
* 1 00000109e4666da600220001
|
* 2 00000109e44567a600220002
|
*
|
* @return the representation of the Server state
|
*/
|
public Set<String> toStringSet()
|
{
|
HashSet<String> set = new HashSet<String>();
|
|
synchronized (this)
|
{
|
for (Short key : list.keySet())
|
{
|
ChangeNumber change = list.get(key);
|
Date date = new Date(change.getTime());
|
set.add(change.toString() + " " + date.toString());
|
}
|
}
|
|
return set;
|
}
|
|
/**
|
* Return an ArrayList of ANS1OctetString encoding the ChangeNumbers
|
* contained in the ServerState.
|
* @return an ArrayList of ANS1OctetString encoding the ChangeNumbers
|
* contained in the ServerState.
|
*/
|
public ArrayList<ASN1OctetString> toASN1ArrayList()
|
{
|
ArrayList<ASN1OctetString> values = new ArrayList<ASN1OctetString>(0);
|
|
synchronized (this)
|
{
|
for (Short id : list.keySet())
|
{
|
ASN1OctetString value = new ASN1OctetString(list.get(id).toString());
|
values.add(value);
|
}
|
}
|
return values;
|
}
|
/**
|
* Return the text representation of ServerState.
|
* @return the text representation of ServerState
|
*/
|
@Override
|
public String toString()
|
{
|
StringBuilder buffer = new StringBuilder();
|
|
synchronized (this)
|
{
|
for (Short key : list.keySet())
|
{
|
ChangeNumber change = list.get(key);
|
buffer.append(" ");
|
buffer.append(change);
|
}
|
}
|
|
return buffer.toString();
|
}
|
|
/**
|
* Get the largest ChangeNumber seen for a given LDAP server ID.
|
*
|
* @param serverId : the server ID
|
* @return the largest ChangeNumber seen
|
*/
|
public ChangeNumber getMaxChangeNumber(short serverId)
|
{
|
return list.get(serverId);
|
}
|
|
/**
|
* Add the tail into resultByteArray at position pos.
|
*/
|
private int addByteArray(byte[] tail, byte[] resultByteArray, int pos)
|
{
|
for (int i=0; i<tail.length; i++,pos++)
|
{
|
resultByteArray[pos] = tail[i];
|
}
|
resultByteArray[pos++] = 0;
|
return pos;
|
}
|
|
/**
|
* Encode this ServerState object and return its byte array representation.
|
*
|
* @return a byte array with an encoded representation of this object.
|
* @throws UnsupportedEncodingException if UTF8 is not supported by the JVM.
|
*/
|
public byte[] getBytes() throws UnsupportedEncodingException
|
{
|
synchronized (this)
|
{
|
int length = 0;
|
List<String> idList = new ArrayList<String>(list.size());
|
for (short id : list.keySet())
|
{
|
String temp = String.valueOf(id);
|
idList.add(temp);
|
length += temp.length() + 1;
|
}
|
List<String> cnList = new ArrayList<String>(list.size());
|
for (ChangeNumber cn : list.values())
|
{
|
String temp = cn.toString();
|
cnList.add(temp);
|
length += temp.length() + 1;
|
}
|
byte[] result = new byte[length];
|
|
int pos = 0;
|
for (int i=0; i< list.size(); i++)
|
{
|
String str = idList.get(i);
|
pos = addByteArray(str.getBytes("UTF-8"), result, pos);
|
str = cnList.get(i);
|
pos = addByteArray(str.getBytes("UTF-8"), result, pos);
|
}
|
return result;
|
}
|
}
|
|
/**
|
* {@inheritDoc}
|
*/
|
public Iterator<Short> iterator()
|
{
|
return list.keySet().iterator();
|
}
|
|
/**
|
* Check that all the ChangeNumbers in the covered serverState are also in
|
* this serverState.
|
*
|
* @param covered The ServerState that needs to be checked.
|
* @return A boolean indicating if this ServerState covers the ServerState
|
* given in parameter.
|
*/
|
public boolean cover(ServerState covered)
|
{
|
for (ChangeNumber coveredChange : covered.list.values())
|
{
|
ChangeNumber change = this.list.get(coveredChange.getServerId());
|
if ((change == null) || (change.older(coveredChange)))
|
{
|
return false;
|
}
|
}
|
return true;
|
}
|
|
/**
|
* Tests if the state is empty.
|
*
|
* @return True if the state is empty.
|
*/
|
public boolean isEmpty()
|
{
|
return list.isEmpty();
|
}
|
|
/**
|
* Make a duplicate of this state.
|
* @return The duplicate of this state.
|
*/
|
public ServerState duplicate()
|
{
|
ServerState newState = new ServerState();
|
synchronized (this)
|
{
|
for (Short key : list.keySet())
|
{
|
ChangeNumber change = list.get(key);
|
Short id = change.getServerId();
|
newState.list.put(id,change);
|
}
|
}
|
return newState;
|
}
|
|
/**
|
* Computes the number of changes a first server state has in advance
|
* compared to a second server state.
|
* @param ss1 The server state supposed to be newer than the second one
|
* @param ss2 The server state supposed to be older than the first one
|
* @return The difference of changes (sum of the differences for each server
|
* id changes). 0 If no gap between 2 states.
|
* @throws IllegalArgumentException If one of the passed state is null
|
*/
|
public static int diffChanges(ServerState ss1, ServerState ss2)
|
throws IllegalArgumentException
|
{
|
if ( (ss1 == null) || (ss2 == null) )
|
throw new IllegalArgumentException("Null server state(s)");
|
|
int diff = 0;
|
for (Short serverId : ss1.list.keySet())
|
{
|
ChangeNumber cn1 = ss1.list.get(serverId);
|
if (cn1 != null)
|
{
|
ChangeNumber cn2 = ss2.list.get(serverId);
|
if (cn2 != null)
|
{
|
diff += ChangeNumber.diffSeqNum(cn1, cn2);
|
} else {
|
// ss2 does not have a change for this server id but ss1, so the
|
// server holding ss1 has every changes represented in cn1 in advance
|
// compared to server hodling ss2, add this amount
|
diff += cn1.getSeqnum();
|
}
|
}
|
}
|
|
return diff;
|
}
|
|
/**
|
* Set the saved status of this ServerState.
|
*
|
* @param b A booelan indicating if the State has been safely stored.
|
*/
|
public void setSaved(boolean b)
|
{
|
saved = false;
|
}
|
|
/**
|
* Get the saved status of this ServerState.
|
*
|
* @return The saved status of this ServerState.
|
*/
|
public boolean isSaved()
|
{
|
return saved;
|
}
|
}
|
