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// **********************************************************************
//
// Copyright (c) 2003-2009 ZeroC, Inc. All rights reserved.
//
// This copy of Ice is licensed to you under the terms described in the
// ICE_LICENSE file included in this distribution.
//
// **********************************************************************
package Freeze;
class EvictorIteratorI implements EvictorIterator
{
public boolean
hasNext()
{
if(_batchIterator != null && _batchIterator.hasNext())
{
return true;
}
else
{
_batchIterator = nextBatch();
return (_batchIterator != null);
}
}
public Ice.Identity
next()
{
if(hasNext())
{
return _batchIterator.next();
}
else
{
throw new NoSuchElementException();
}
}
EvictorIteratorI(ObjectStore store, TransactionI tx, int batchSize)
{
_store = store;
_more = (store != null);
_batchSize = batchSize;
_tx = tx;
assert batchSize > 0;
_key.setReuseBuffer(true);
//
// dlen is 0, so we should not retrieve any value
//
_value.setPartial(true);
}
private java.util.Iterator<Ice.Identity>
nextBatch()
{
EvictorI.DeactivateController deactivateController = _store.evictor().deactivateController();
deactivateController.lock();
com.sleepycat.db.Transaction txn = _tx == null ? null : _tx.dbTxn();
try
{
if(!_more)
{
return null;
}
Ice.Communicator communicator = _store.communicator();
byte[] firstKey = null;
if(_key.getSize() > 0)
{
firstKey = new byte[_key.getSize()];
System.arraycopy(_key.getData(), 0, firstKey, 0, firstKey.length);
}
for(;;)
{
com.sleepycat.db.Cursor dbc = null;
_batch = new java.util.ArrayList<Ice.Identity>();
try
{
//
// Move to the first record
//
boolean range = false;
if(firstKey != null)
{
//
// _key represents the next element not yet returned
// if it has been deleted, we want the one after
//
range = true;
}
dbc = _store.db().openCursor(txn, null);
boolean done = false;
do
{
com.sleepycat.db.OperationStatus status;
if(range)
{
status = dbc.getSearchKeyRange(_key, _value, null);
}
else
{
status = dbc.getNext(_key, _value, null);
}
_more = (status == com.sleepycat.db.OperationStatus.SUCCESS);
if(_more)
{
range = false;
if(_batch.size() < _batchSize)
{
Ice.Identity ident = ObjectStore.unmarshalKey(_key.getData(), communicator);
_batch.add(ident);
}
else
{
//
// Keep the last element in _key
//
done = true;
}
}
}
while(!done && _more);
break; // for (;;)
}
catch(com.sleepycat.db.DeadlockException dx)
{
if(_store.evictor().deadlockWarning())
{
communicator.getLogger().warning("Deadlock in Freeze.EvictorIteratorI.load while " +
"iterating over Db \"" + _store.evictor().filename() + "/" +
_store.dbName() + "\"");
}
if(_tx == null)
{
if(firstKey != null)
{
assert(_key.getData().length >= firstKey.length);
System.arraycopy(firstKey, 0, _key.getData(), 0, firstKey.length);
_key.setSize(firstKey.length);
}
else
{
_key.setSize(0);
}
//
// Retry
//
}
else
{
DeadlockException ex = new DeadlockException(
_store.evictor().errorPrefix() + "Db.cursor: " + dx.getMessage(), _tx);
ex.initCause(dx);
throw ex;
}
}
catch(com.sleepycat.db.DatabaseException dx)
{
DatabaseException ex = new DatabaseException();
ex.initCause(dx);
ex.message = _store.evictor().errorPrefix() + "Db.cursor: " + dx.getMessage();
throw ex;
}
finally
{
if(dbc != null)
{
try
{
dbc.close();
}
catch(com.sleepycat.db.DeadlockException dx)
{
if(_tx != null)
{
DeadlockException ex = new DeadlockException(
_store.evictor().errorPrefix() + "Db.cursor: " + dx.getMessage(), _tx);
ex.initCause(dx);
throw ex;
}
}
catch(com.sleepycat.db.DatabaseException dx)
{
//
// Ignored
//
}
}
}
}
if(_batch.size() == 0)
{
return null;
}
else
{
return _batch.listIterator();
}
}
finally
{
deactivateController.unlock();
}
}
private final ObjectStore _store;
private final TransactionI _tx;
private final int _batchSize;
private java.util.Iterator<Ice.Identity> _batchIterator;
private final com.sleepycat.db.DatabaseEntry _key = new com.sleepycat.db.DatabaseEntry();
private final com.sleepycat.db.DatabaseEntry _value = new com.sleepycat.db.DatabaseEntry();
private java.util.List<Ice.Identity> _batch = null;
private boolean _more = true;
}
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