/*
Derby - Class org.apache.derby.impl.store.access.btree.index.B2IForwardScan
Copyright 1999, 2004 The Apache Software Foundation or its licensors, as applicable.
Licensed 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.derby.impl.store.access.btree.index;
import org.apache.derby.iapi.services.sanity.SanityManager;
import org.apache.derby.iapi.error.StandardException;
import org.apache.derby.iapi.store.access.conglomerate.Conglomerate;
import org.apache.derby.iapi.store.access.conglomerate.TransactionManager;
import org.apache.derby.iapi.store.access.ConglomerateController;
import org.apache.derby.iapi.store.access.DynamicCompiledOpenConglomInfo;
import org.apache.derby.iapi.store.access.GenericScanController;
import org.apache.derby.iapi.store.access.Qualifier;
import org.apache.derby.iapi.store.access.ScanController;
import org.apache.derby.iapi.store.access.StaticCompiledOpenConglomInfo;
import org.apache.derby.iapi.store.access.TransactionController;
import org.apache.derby.iapi.store.raw.ContainerHandle;
import org.apache.derby.iapi.store.raw.LockingPolicy;
import org.apache.derby.iapi.store.raw.Transaction;
import org.apache.derby.iapi.types.DataValueDescriptor;
import org.apache.derby.iapi.types.RowLocation;
import org.apache.derby.iapi.services.io.FormatableBitSet;
import org.apache.derby.impl.store.access.btree.BTreeController;
import org.apache.derby.impl.store.access.btree.BTreeLockingPolicy;
import org.apache.derby.impl.store.access.btree.BTreeForwardScan;
import org.apache.derby.impl.store.access.conglomerate.ConglomerateUtil;
/**
The btree secondary index implementation of ScanManager which provides reading
and deleting of entries in the btree secondary index.
This supports setting up and
iterating through a set of rows while providing a start key, stop key,
and a set of AND and OR qualifiers to skip unwanted rows. Currently
derby only supports forward scans (but individual columns can have
descending order). This interface is also used to delete rows from
the conglomerate. Note that update is not supported, it must be
implemented as a delete, followed by an insert.
Note most work of this class is inherited from the generic btree implementation.
This class initializes the top level object and deals with locking information
specific to a secondary index implementation of a btree.
**/
public class B2IForwardScan extends BTreeForwardScan
{
/*
** Fields of B2IForwardScan.
*/
private ConglomerateController base_cc_for_locking;
private int init_isolation_level;
/*
** Methods of B2IForwardScan.
*/
B2IForwardScan()
{
// Perform the generic b-tree scan construction.
super();
}
/**
Close the scan.
@see GenericScanController#newRowLocationTemplate
**/
public void close()
throws StandardException
{
super.close();
if (base_cc_for_locking != null)
{
base_cc_for_locking.close();
base_cc_for_locking = null;
}
}
/**
Close the scan, a commit or abort is about to happen.
**/
public boolean closeForEndTransaction(boolean closeHeldScan)
throws StandardException
{
boolean ret_val = super.closeForEndTransaction(closeHeldScan);
if (base_cc_for_locking != null)
{
base_cc_for_locking.close();
base_cc_for_locking = null;
}
return(ret_val);
}
/**
* Open the container after it has been closed previously.
* <p>
* Open the container, obtaining necessary locks. Most work is actually
* done by RawStore.openContainer(). Will only reopen() if the container
* is not already open.
*
* @exception StandardException Standard exception policy.
**/
public ContainerHandle reopen()
throws StandardException
{
ContainerHandle container = super.reopen();
B2I b2i = (B2I) getConglomerate();
// open and lock the base table.
int base_open_mode =
getOpenMode() | TransactionController.OPENMODE_FOR_LOCK_ONLY;
// TODO - figure out what to do with static_info stuff
// open the base conglomerate - just to get lock
/*
if (static_info != null)
{
base_cc_for_locking =
xact_manager.openCompiledConglomerate(
false,
base_open_mode, lock_level, isolation_level,
static_info.base_table_static_info,
((Conglomerate) static_info.getConglom()).
getDynamicCompiledConglomInfo(
b2i.baseConglomerateId));
}
else
*/
{
base_cc_for_locking =
getXactMgr().openConglomerate(
b2i.baseConglomerateId,
false,
base_open_mode, init_lock_level,
init_isolation_level);
setLockingPolicy(
b2i.getBtreeLockingPolicy(
getXactMgr().getRawStoreXact(),
getLockLevel(),
getOpenMode(),
init_isolation_level,
base_cc_for_locking, this));
}
return(container);
}
/**
Initialize the scan for use.
<p>
Any changes to this method may have to be reflected in close as well.
<p>
The btree init opens the container (super.init), and stores away the
state of the qualifiers. The actual searching for the first position
is delayed until the first next() call.
@exception StandardException Standard exception policy.
**/
public void init(
TransactionManager xact_manager,
Transaction rawtran,
boolean hold,
int open_mode,
int lock_level,
LockingPolicy locking_policy,
int isolation_level,
boolean open_for_locking,
FormatableBitSet scanColumnList,
DataValueDescriptor[] startKeyValue,
int startSearchOperator,
Qualifier qualifier[][],
DataValueDescriptor[] stopKeyValue,
int stopSearchOperator,
B2I conglomerate,
B2IUndo undo,
B2IStaticCompiledInfo static_info,
DynamicCompiledOpenConglomInfo dynamic_info)
throws StandardException
{
// open and lock the base table.
int base_open_mode =
open_mode | TransactionController.OPENMODE_FOR_LOCK_ONLY;
// open the base conglomerate - just to get lock
if (static_info != null)
{
base_cc_for_locking =
xact_manager.openCompiledConglomerate(
false,
base_open_mode, lock_level, isolation_level,
static_info.base_table_static_info,
/* TODO - maintain a dynamic info for this */
((Conglomerate) static_info.getConglom()).
getDynamicCompiledConglomInfo(
conglomerate.baseConglomerateId));
}
else
{
base_cc_for_locking =
xact_manager.openConglomerate(
conglomerate.baseConglomerateId, false, base_open_mode, lock_level,
isolation_level);
}
BTreeLockingPolicy b2i_locking_policy =
conglomerate.getBtreeLockingPolicy(
rawtran, lock_level, open_mode, isolation_level,
base_cc_for_locking, this);
super.init(
xact_manager,
rawtran,
hold,
open_mode,
lock_level,
b2i_locking_policy,
scanColumnList,
startKeyValue,
startSearchOperator,
qualifier,
stopKeyValue,
stopSearchOperator,
conglomerate,
undo,
static_info,
dynamic_info);
// todo - should just save the isolation level in OpenBtree but
// save it here for now.
init_isolation_level = isolation_level;
}
}