executioncontext.java

derby database source code.good for you.

/*

   Derby - Class org.apache.derby.iapi.sql.execute.ExecutionContext

   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.execute;

import org.apache.derby.iapi.services.context.Context;

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

import org.apache.derby.iapi.sql.ResultSet;

/**
 * ExecutionContext stores the factories that are to be used by
 * the current connection. It also provides execution services
 * for statement atomicity.
 *
 * @author ames
 */
public interface ExecutionContext extends Context {

	/**
	 * this is the ID we expect execution contexts
	 * to be stored into a context manager under.
	 */
	String CONTEXT_ID = "ExecutionContext";
	
	
	/* Constants for scan isolation levels. */
	public static final int UNSPECIFIED_ISOLATION_LEVEL = 0;
	public static final int READ_UNCOMMITTED_ISOLATION_LEVEL = 1;
	public static final int READ_COMMITTED_ISOLATION_LEVEL = 2;
	public static final int REPEATABLE_READ_ISOLATION_LEVEL = 3;
	public static final int SERIALIZABLE_ISOLATION_LEVEL = 4;

	public static final int[] CS_TO_JDBC_ISOLATION_LEVEL_MAP = {
		java.sql.Connection.TRANSACTION_NONE,				// UNSPECIFIED_ISOLATION_LEVEL
		java.sql.Connection.TRANSACTION_READ_UNCOMMITTED,	// READ_UNCOMMITTED_ISOLATION_LEVEL
		java.sql.Connection.TRANSACTION_READ_COMMITTED,		// READ_COMMITTED_ISOLATION_LEVEL
		java.sql.Connection.TRANSACTION_REPEATABLE_READ,	// REPEATABLE_READ_ISOLATION_LEVEL		
		java.sql.Connection.TRANSACTION_SERIALIZABLE		// SERIALIZABLE_ISOLATION_LEVEL
	};

	public static final String[][] CS_TO_SQL_ISOLATION_MAP = {
		{ "  "},					// UNSPECIFIED_ISOLATION_LEVEL
		{ "UR", "DIRTY READ", "READ UNCOMMITTED"},
		{ "CS", "CURSOR STABILITY", "READ COMMITTED"},
		{ "RS"},		// read stability	
		{ "RR", "REPEATABLE READ", "SERIALIZABLE"}
	};

	/**
	 * Get the ResultSetFactory from this ExecutionContext.
	 *
	 * @return	The result set factory associated with this
	 *		ExecutionContext
	 */
	ResultSetFactory getResultSetFactory();

	/**
	 * Get the ResultSetStatisticsFactory from this ExecutionContext.
	 *
	 * @return	The result set statistics factory associated with this
	 *		ExecutionContext
	 *
	 * @exception StandardException		Thrown on error
	 */
	ResultSetStatisticsFactory getResultSetStatisticsFactory()
								throws StandardException;

	/**
	 * Get the ExecutionFactory from this ExecutionContext.
	 *
	 * @return	The Execution factory associated with this
	 *		ExecutionContext
	 */
	ExecutionFactory getExecutionFactory();

	/**
	 * Mark the beginning of a statement (INSERT, UPDATE, DELETE)
	 *
	 * @param sourceRS	Source ResultSet for the statement.
	 * @exception StandardException Thrown on error
	 */
	void beginStatement(ResultSet sourceRS) throws StandardException;

	/**
	 * The end of a statement (INSERT, UPDATE, DELETE)
	 * @exception StandardException Thrown on error
	 */
	void endStatement() throws StandardException;

	/**
	  *	Sifts the array of foreign key constraints for the ones
	  *	which apply in the current context. In certain contexts
	  *	(e.g., when applying the COPY file or when tearing-off
	  *	a new table during REFRESH), we don't want to not bother
	  *	enforcing some foreign keys.
	  *
	  *	@param	fullList	the full list of foreign keys that
	  *						apply for the current statement
	  *
	  *	@return	a pruned back list, which we will actually bother
	  *			enforcing.
	  *
	  * @exception StandardException Thrown on error
	  */
	public	Object[]	siftForeignKeys( Object[] fullList ) throws StandardException;

	/**
	 * Sifts the triggers for the ones which apply in the current context. 
	 * In certain contexts (e.g., when applying the COPY file or 
	 * when tearing-off a new table during REFRESH), we don't want to 
	 * not bother firing triggers.
	 * 
	 *	@param	triggerInfo	the original trigger info
	 *
	 *	@return	a pruned back triggerInfo, which we will actually bother
	 *			enforcing.
	 *
	 * @exception StandardException Thrown on error
	 */
	public Object siftTriggers(Object triggerInfo) throws StandardException;
}