risetchecker.java

derby database source code.good for you.

/*

   Derby - Class org.apache.derby.impl.sql.execute.RISetChecker

   Copyright 1998, 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.sql.execute;

import org.apache.derby.iapi.services.sanity.SanityManager;
import org.apache.derby.iapi.error.StandardException;

import org.apache.derby.iapi.sql.execute.ExecRow;
import org.apache.derby.iapi.sql.execute.ExecIndexRow;
import org.apache.derby.iapi.store.access.TransactionController;

/**
 * Checks a set or referential integrity constraints.  Used
 * to shield the caller from ReferencedKeyRIChecker and
 * ForeignKeyRICheckers.
 */
public class RISetChecker
{
	private GenericRIChecker[] 	checkers;

	/**
	 * @param tc		the xact controller
	 * @param fkInfo[]	the foreign key information 
	 *
	 * @exception StandardException		Thrown on failure
	 */
	public RISetChecker(TransactionController tc, FKInfo fkInfo[])
		throws StandardException
	{
		if (fkInfo == null)
		{
			return;
		}

		checkers = new GenericRIChecker[fkInfo.length];

		for (int i = 0; i < fkInfo.length; i++)
		{
			checkers[i] = (fkInfo[i].type == FKInfo.FOREIGN_KEY) ?
				(GenericRIChecker)new ForeignKeyRIChecker(tc, fkInfo[i]) :
				(GenericRIChecker)new ReferencedKeyRIChecker(tc, fkInfo[i]);
		}
	}

	/**
	 * Do any work needed to reopen our ri checkers
	 * for another round of checks.  Must do a close()
	 * first.
	 *
	 * @exception StandardException on error
	 */
	void reopen() throws StandardException
	{
		// currently a noop
	}

	/**
	 * Check that there are no referenced primary keys in
	 * the passed in row.  So for each foreign key that
	 * references a primary key constraint, make sure
	 * that there is no row that matches the values in
	 * the passed in row.
	 *
	 * @param row	the row to check
	 *
	 * @exception StandardException on unexpected error, or
	 *		on a primary/unique key violation
	 */
	public void doPKCheck(ExecRow row, boolean restrictCheckOnly) throws StandardException
	{
		if (checkers == null)
			return;

		for (int i = 0; i < checkers.length; i++)
		{
			if (checkers[i] instanceof ReferencedKeyRIChecker)
			{
				checkers[i].doCheck(row,restrictCheckOnly);
			}
		}
	}

	/**
	 * Check that everything in the row is ok, i.e.
	 * that there are no foreign keys in the passed
	 * in row that have invalid values.
	 *
	 * @param row	the row to check
	 *
	 * @exception StandardException on unexpected error, or
	 *		on a primary/unique key violation
	 */
	public void doFKCheck(ExecRow row) throws StandardException
	{
		if (checkers == null)
			return;

		for (int i = 0; i < checkers.length; i++)
		{
			if (checkers[i] instanceof ForeignKeyRIChecker)
			{
				checkers[i].doCheck(row);
			}
		}
	}

	/**
	 * Execute the specific RI check on the passed in row.
	 *
	 * @param fkIndex	index into fkInfo
	 * @param row		the row to check
	 *
	 * @exception StandardException on unexpected error, or
	 *		on a primary/unique key violation
	 */
	public void doRICheck(int index, ExecRow row, boolean restrictCheckOnly) throws StandardException
	{
		if (SanityManager.DEBUG)
		{
			if (checkers == null)
			{
				SanityManager.THROWASSERT("no checkers, how can i execute checker "+index);
			}

			if (index >= checkers.length)
			{
				SanityManager.THROWASSERT("there are only "+
					checkers.length+" checkers, "+index+" is invalid");
			}
		}

		checkers[index].doCheck(row, restrictCheckOnly);
	}

	/**
	 * clean up
	 *
	 * @exception StandardException on error
	 */
	public void close() throws StandardException
	{
		if (checkers == null)
			return;

		for (int i = 0; i < checkers.length; i++)
		{
			checkers[i].close();
		}
	}	
}