/*
Derby - Class org.apache.derby.impl.sql.compile.LockTableNode
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to you 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.sql.compile;
import org.apache.derby.iapi.error.StandardException;
import org.apache.derby.iapi.reference.SQLState;
import org.apache.derby.iapi.services.sanity.SanityManager;
import org.apache.derby.iapi.sql.compile.CompilerContext;
import org.apache.derby.iapi.sql.conn.Authorizer;
import org.apache.derby.iapi.sql.dictionary.ConglomerateDescriptor;
import org.apache.derby.iapi.sql.dictionary.DataDictionary;
import org.apache.derby.iapi.sql.dictionary.SchemaDescriptor;
import org.apache.derby.iapi.sql.dictionary.TableDescriptor;
import org.apache.derby.iapi.sql.execute.ConstantAction;
/**
* A LockTableNode is the root of a QueryTree that represents a LOCK TABLE command:
* LOCK TABLE <TableName> IN SHARE/EXCLUSIVE MODE
*
*/
public class LockTableNode extends MiscellaneousStatementNode
{
private TableName tableName;
private boolean exclusiveMode;
private long conglomerateNumber;
private TableDescriptor lockTableDescriptor;
/**
* Initializer for LockTableNode
*
* @param tableName The table to lock
* @param exclusiveMode boolean, whether or not to get an exclusive lock.
*/
public void init(Object tableName, Object exclusiveMode)
{
this.tableName = (TableName) tableName;
this.exclusiveMode = ((Boolean) exclusiveMode).booleanValue();
}
/**
* Convert this object to a String. See comments in QueryTreeNode.java
* for how this should be done for tree printing.
*
* @return This object as a String
*/
public String toString()
{
if (SanityManager.DEBUG)
{
return "tableName: " + tableName + "\n" +
"exclusiveMode: " + exclusiveMode + "\n" +
"conglomerateNumber: " + conglomerateNumber + "\n" +
super.toString();
}
else
{
return "";
}
}
public String statementToString()
{
return "LOCK TABLE";
}
/**
* Bind this LockTableNode. This means looking up the table,
* verifying it exists and getting the heap conglomerate number.
*
*
* @exception StandardException Thrown on error
*/
public void bindStatement() throws StandardException
{
CompilerContext cc = getCompilerContext();
ConglomerateDescriptor cd;
DataDictionary dd = getDataDictionary();
SchemaDescriptor sd;
String schemaName = tableName.getSchemaName();
sd = getSchemaDescriptor(schemaName);
// Users are not allowed to lock system tables
if (sd.isSystemSchema())
{
throw StandardException.newException(SQLState.LANG_NO_USER_DDL_IN_SYSTEM_SCHEMA,
statementToString(), schemaName);
}
lockTableDescriptor = getTableDescriptor(tableName.getTableName(), sd);
if (lockTableDescriptor == null)
{
// Check if the reference is for a synonym.
TableName synonymTab = resolveTableToSynonym(tableName);
if (synonymTab == null)
throw StandardException.newException(SQLState.LANG_TABLE_NOT_FOUND, tableName);
tableName = synonymTab;
sd = getSchemaDescriptor(tableName.getSchemaName());
lockTableDescriptor = getTableDescriptor(synonymTab.getTableName(), sd);
if (lockTableDescriptor == null)
throw StandardException.newException(SQLState.LANG_TABLE_NOT_FOUND, tableName);
}
//throw an exception if user is attempting to lock a temporary table
if (lockTableDescriptor.getTableType() == TableDescriptor.GLOBAL_TEMPORARY_TABLE_TYPE)
{
throw StandardException.newException(SQLState.LANG_NOT_ALLOWED_FOR_DECLARED_GLOBAL_TEMP_TABLE);
}
conglomerateNumber = lockTableDescriptor.getHeapConglomerateId();
/* Get the base conglomerate descriptor */
cd = lockTableDescriptor.getConglomerateDescriptor(conglomerateNumber);
/* Statement is dependent on the TableDescriptor and ConglomerateDescriptor */
cc.createDependency(lockTableDescriptor);
cc.createDependency(cd);
if (isPrivilegeCollectionRequired())
{
// need SELECT privilege to perform lock table statement.
cc.pushCurrentPrivType(Authorizer.SELECT_PRIV);
cc.addRequiredTablePriv(lockTableDescriptor);
cc.popCurrentPrivType();
}
}
/**
* Return true if the node references SESSION schema tables (temporary or permanent)
*
* @return true if references SESSION schema tables, else false
*
* @exception StandardException Thrown on error
*/
public boolean referencesSessionSchema()
throws StandardException
{
//If lock table is on a SESSION schema table, then return true.
return isSessionSchema(lockTableDescriptor.getSchemaName());
}
/**
* Create the Constant information that will drive the guts of Execution.
*
* @exception StandardException Thrown on failure
*/
public ConstantAction makeConstantAction() throws StandardException
{
return getGenericConstantActionFactory().getLockTableConstantAction(
tableName.getFullTableName(),
conglomerateNumber,
exclusiveMode);
}
}