DraftCNDB.java revision e371bf13d3f899f1de594880fafe67b990d65899
/*
* 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
* 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 2009 Sun Microsystems, Inc.
* Portions Copyright 2011-2013 ForgeRock AS
*/
/**
* This class implements the interface between the underlying database
* and the dbHandler class.
* This is the only class that should have code using the BDB interfaces.
*/
public class DraftCNDB
{
private static final int DATABASE_EMPTY = 0;
/**
* The lock used to provide exclusive access to the thread that close the db
* (shutdown or clear).
*/
/**
* Creates a new database or open existing database that will be used
* to store and retrieve changes from an LDAP server.
* @param dbenv The Db environment to use to create the db.
* @throws ChangelogException If a database problem happened.
*/
{
// Get or create the associated ReplicationServerDomain and Db.
}
/**
* Add an entry to the database.
* @param draftCN the provided draftCN.
*
* @param value the provided value to be stored associated
* with this draftCN.
* @param domainBaseDN the provided domainBaseDn to be stored associated
* with this draftCN.
* @param csn the provided replication CSN to be
* stored associated with this draftCN.
*/
{
try
{
// Use a transaction so that we can override durability.
try
{
// If the DB has been closed then return immediately.
if (isDBClosed())
{
return;
}
}
finally
{
}
}
catch (DatabaseException e)
{
}
catch (ChangelogException e)
{
}
}
/**
* Aborts the current transaction. It has no effect if the transaction has
* committed.
*
* @param txn
* the transaction to abort
*/
{
{
try
{
}
catch (DatabaseException ignored)
{
// Ignore.
}
}
}
/**
* Shutdown the database.
*/
public void shutdown()
{
try
{
}
catch (DatabaseException e)
{
}
finally
{
}
}
/**
* Create a cursor that can be used to search or iterate on this DB.
*
* @param draftCN The draftCN from which the cursor must start.
* @throws ChangelogException If a database error prevented the cursor
* creation.
* @return The ReplServerDBCursor.
*/
{
return new DraftCNDBCursor(draftCN);
}
/**
* Create a cursor that can be used to delete some record from this
* ReplicationServer database.
*
* @throws ChangelogException If a database error prevented the cursor
* creation.
* @return The ReplServerDBCursor.
*/
{
return new DraftCNDBCursor();
}
{
try
{
}
finally
{
}
}
/**
* Read the first Change from the database, 0 when none.
* @return the first draftCN.
*/
public int readFirstDraftCN()
{
try
{
try
{
// If the DB has been closed then return immediately.
if (isDBClosed())
{
return 0;
}
{
return DATABASE_EMPTY;
}
}
finally
{
}
}
catch (DatabaseException e)
{
return 0;
}
}
/**
* Return the record count.
* @return the record count.
*/
public long count()
{
try
{
// If the DB has been closed then return immediately.
if (isDBClosed())
{
return 0L;
}
}
catch (Exception e)
{
}
finally
{
}
return 0L;
}
/**
* Read the last draftCN from the database.
* @return the last draftCN.
*/
public int readLastDraftCN()
{
try
{
try
{
// If the DB has been closed then return immediately.
if (isDBClosed())
{
return 0;
}
{
return DATABASE_EMPTY;
}
}
finally
{
}
}
catch (DatabaseException e)
{
return 0;
}
}
/**
* {@inheritDoc}
*/
{
return "DraftCNDB";
}
/**
* This Class implements a cursor that can be used to browse the database.
*/
public class DraftCNDBCursor implements Closeable
{
/**
* The transaction that will protect the actions done with the cursor.
* Will be let null for a read cursor.
* Will be set non null for a write cursor.
*/
private final Transaction txn;
private final DatabaseEntry key;
private final DatabaseEntry entry;
private boolean isClosed = false;
/**
* Creates a cursor that can be used for browsing the db.
*
* @param startingDraftCN
* the draftCN from which the cursor must start.
* @throws ChangelogException
* when the startingDraftCN does not exist.
*/
{
this.entry = new DatabaseEntry();
// Take the lock. From now on, whatever error that happen in the life
// of this cursor should end by unlocking that lock. We must also
// unlock it when throwing an exception.
try
{
// If the DB has been closed then create empty cursor.
if (isDBClosed())
{
isClosed = true;
return;
}
if (startingDraftCN >= 0)
{
{
// We could not move the cursor to the expected startingDraftCN
{
// We could not even move the cursor closed to it => failure
throw new ChangelogException(
+ " is not available"));
}
{
localCursor.close();
}
else
{
}
}
else
{
}
}
this.cursor = localCursor;
}
catch (DatabaseException e)
{
// Unlocking is required before throwing any exception
throw new ChangelogException(e);
}
catch (ChangelogException e)
{
// Unlocking is required before throwing any exception
throw e;
}
}
private DraftCNDBCursor() throws ChangelogException
{
this.key = new DatabaseEntry();
this.entry = new DatabaseEntry();
// We'll go on only if no close or no clear is running
try
{
// If the DB has been closed then create empty cursor.
if (isDBClosed())
{
isClosed = true;
return;
}
// Create the transaction that will protect whatever done with this
// write cursor.
this.cursor = localCursor;
}
catch (DatabaseException e)
{
throw new ChangelogException(e);
}
catch (ChangelogException e)
{
throw e;
}
}
/**
* Close the ReplicationServer Cursor.
*/
public void close()
{
synchronized (this)
{
if (isClosed)
{
return;
}
isClosed = true;
}
{
try
{
}
catch (DatabaseException e)
{
}
}
}
/**
* Abort the Cursor after a Deadlock Exception.
* This method catch and ignore the DeadlockException because
* this must be done when aborting a cursor after a DeadlockException
* (per the Cursor documentation).
* This should not be used in any other case.
*/
public void abort()
{
synchronized (this)
{
if (isClosed)
{
return;
}
isClosed = true;
}
{
try
{
}
catch (DatabaseException e)
{
}
}
}
/**
* Getter for the value field of the current cursor.
* @return The current value field.
*/
public String currentValue()
{
if (isClosed)
{
return null;
}
try
{
if (seqnumData != null)
{
return seqnumData.getValue();
}
}
catch(Exception e)
{
}
return null;
}
/**
* Getter for the baseDN field of the current cursor.
* @return The current baseDN.
*/
public String currentBaseDN()
{
if (isClosed)
{
return null;
}
try
{
if (seqnumData != null)
{
return seqnumData.getBaseDN();
}
}
catch(Exception e)
{
}
return null;
}
/**
* Getter for the integer value of the current cursor, representing
* the current DraftChangeNumber being processed.
*
* @return the current DraftCN as an integer.
*/
public int currentKey()
{
if (isClosed)
{
return -1;
}
try
{
}
catch (Exception e)
{
}
return -1;
}
/**
* Returns the replication CSN associated with the current key.
* @return the replication CSN
*/
public CSN currentCSN()
{
if (isClosed)
{
return null;
}
try
{
if (seqnumData != null)
{
return seqnumData.getCSN();
}
}
catch(Exception e)
{
}
return null;
}
/**
* Go to the next record on the cursor.
* @return the next record on this cursor.
* @throws ChangelogException a.
*/
public boolean next() throws ChangelogException
{
if (isClosed)
{
return false;
}
try {
{
seqnumData = null;
return false;
}
}
catch(Exception e)
{
}
return true;
}
/**
* Delete the record at the current cursor position.
*
* @throws ChangelogException In case of database problem.
*/
public void delete() throws ChangelogException
{
if (isClosed)
{
throw new IllegalStateException("DraftCNDB already closed");
}
try
{
}
catch (DatabaseException e)
{
throw new ChangelogException(e);
}
}
/**
* Returns the current key associated with this cursor.
*
* @return The current key associated with this cursor.
*/
public DatabaseEntry getKey()
{
if (isClosed)
{
return null;
}
return key;
}
}
/**
* Clears this change DB from the changes it contains.
*
* @throws ChangelogException Throws a DatabaseException when it occurs.
*/
public void clear() throws ChangelogException
{
// The coming users will be blocked until the clear is done
try
{
// If the DB has been closed then return immediately.
if (isDBClosed())
{
return;
}
// Closing is requested by the Berkeley DB before truncate
// Clears the changes
// RE-create the db
}
catch(Exception e)
{
e.getMessage() + " " +
}
finally
{
// Relax the waiting users
}
}
/**
* Returns {@code true} if the DB is closed. This method assumes that either
*
* @return {@code true} if the DB is closed.
*/
private boolean isDBClosed()
{
}
}