dependent.java

derby database source code.good for you.

/*

   Derby - Class org.apache.derby.iapi.sql.depend.Dependent

   Copyright 1997, 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.iapi.sql.depend;

import	org.apache.derby.catalog.Dependable;

import org.apache.derby.iapi.error.StandardException;

import org.apache.derby.iapi.sql.conn.LanguageConnectionContext;

/**
	A dependent has the ability to know whether or not it
	is valid and to mark itself as valid or invalid.
	Marking itself as invalid usually means it cannot be used
	in the system until it is revalidated, but this is in no
	way enforced by this interface.
 */
public interface Dependent  extends Dependable
{

	/**
		Check that all of the dependent's dependencies are valid.

		@return true if the dependent is currently valid
	 */
	boolean isValid();

	/**
		Prepare to mark the dependent as invalid (due to at least one of
		its dependencies being invalid).

		@param action	The action causing the invalidation
		@param p		the provider
		@param lcc		The LanguageConnectionContext

		@exception StandardException thrown if unable to make it invalid
	 */
	void prepareToInvalidate(Provider p, int action, 
							 LanguageConnectionContext lcc) 
		throws StandardException;

	/**
		Mark the dependent as invalid (due to at least one of
		its dependencies being invalid).

		@param	action	The action causing the invalidation
		@param lcc		The LanguageConnectionContext

		@exception StandardException thrown if unable to make it invalid
	 */
	void makeInvalid(int action,
					 LanguageConnectionContext lcc) 
			throws StandardException;

	/**
		Attempt to revalidate the dependent. For prepared statements,
		this could go through its dependencies and check that they
		are up to date; if not, it would recompile the statement.
		Any failure during this attempt should throw
		DependencyStatementException.unableToRevalidate().

		@param lcc		The LanguageConnectionContext

		@exception StandardException thrown if unable to make it valid
	 */
	void makeValid(LanguageConnectionContext lcc) 
		throws StandardException;
}