/* Copyright (c) 2001-2009, The HSQL Development Group
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the HSQL Development Group nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.hsqldb;
import org.hsqldb.lib.ArrayUtil;
import org.hsqldb.lib.HashMappedList;
import org.hsqldb.lib.HashSet;
import org.hsqldb.lib.HsqlArrayList;
import org.hsqldb.lib.LongDeque;
import org.hsqldb.navigator.RangeIterator;
import org.hsqldb.store.ValuePool;
/*
* Session execution context and temporary data structures
*
* @author Fred Toussi (fredt@users dot sourceforge.net)
* @version 1.9.0
* @since 1.9.0
*/
public class SessionContext {
Session session;
//
HashMappedList sessionVariables;
RangeVariable[] sessionVariablesRange;
//
private HsqlArrayList stack;
public Object[] routineArguments = ValuePool.emptyObjectArray;
public Object[] routineVariables = ValuePool.emptyObjectArray;
Object[] dynamicArguments = ValuePool.emptyObjectArray;
public int depth;
//
HashMappedList savepoints;
LongDeque savepointTimestamps;
// range variable data
RangeIterator[] rangeIterators;
/**
* Reusable set of all FK constraints that have so far been enforced while
* a cascading insert or delete is in progress. This is emptied and passed
* with the first call to checkCascadeDelete or checkCascadeUpdate. During
* recursion, if an FK constraint is encountered and is already present
* in the set, the recursion stops.
*/
HashSet constraintPath;
/**
* Current list of all cascading updates on all table. This is emptied once
* a cascading operation is over.
*/
HashMappedList tableUpdateList;
//
StatementResultUpdate rowUpdateStatement = new StatementResultUpdate();
/**
* Creates a new instance of CompiledStatementExecutor.
*
* @param session the context in which to perform the execution
*/
SessionContext(Session session) {
this.session = session;
rangeIterators = new RangeIterator[4];
savepoints = new HashMappedList(4);
savepointTimestamps = new LongDeque();
sessionVariables = new HashMappedList();
sessionVariablesRange = new RangeVariable[1];
sessionVariablesRange[0] = new RangeVariable(sessionVariables, true);
}
public void push() {
if (stack == null) {
stack = new HsqlArrayList(true);
}
stack.add(dynamicArguments);
stack.add(routineArguments);
stack.add(routineVariables);
stack.add(rangeIterators);
stack.add(savepoints);
stack.add(savepointTimestamps);
rangeIterators = new RangeIterator[4];
savepoints = new HashMappedList(4);
savepointTimestamps = new LongDeque();
String name =
HsqlNameManager.getAutoSavepointNameString(session.actionTimestamp,
depth);
session.savepoint(name);
depth++;
}
public void pop() {
savepointTimestamps = (LongDeque) stack.remove(stack.size() - 1);
savepoints = (HashMappedList) stack.remove(stack.size() - 1);
rangeIterators = (RangeIterator[]) stack.remove(stack.size() - 1);
routineVariables = (Object[]) stack.remove(stack.size() - 1);
routineArguments = (Object[]) stack.remove(stack.size() - 1);
dynamicArguments = (Object[]) stack.remove(stack.size() - 1);
depth--;
}
public void pushDynamicArguments(Object[] args) {
if (stack == null) {
stack = new HsqlArrayList(true);
}
stack.add(dynamicArguments);
dynamicArguments = args;
}
public void popDynamicArguments() {
dynamicArguments = (Object[]) stack.remove(stack.size() - 1);
}
void clearStructures(StatementDMQL cs) {
if (cs.type == StatementTypes.UPDATE_WHERE
|| cs.type == StatementTypes.DELETE_WHERE
|| cs.type == StatementTypes.MERGE) {
if (constraintPath != null) {
constraintPath.clear();
}
if (tableUpdateList != null) {
for (int i = 0; i < tableUpdateList.size(); i++) {
HashMappedList updateList =
(HashMappedList) tableUpdateList.get(i);
updateList.clear();
}
}
}
if (cs.type == StatementTypes.INSERT) {
//
}
int count = cs.rangeIteratorCount;
if (count > rangeIterators.length) {
count = rangeIterators.length;
}
for (int i = 0; i < count; i++) {
if (rangeIterators[i] != null) {
rangeIterators[i].reset();
rangeIterators[i] = null;
}
}
}
public RangeIterator getCheckIterator() {
return rangeIterators[1];
}
public void setCheckIterator(RangeIterator iterator) {
rangeIterators[iterator.getRangePosition()] = iterator;
}
public void setRangeIterator(RangeIterator iterator) {
int position = iterator.getRangePosition();
if (position >= rangeIterators.length) {
rangeIterators =
(RangeIterator[]) ArrayUtil.resizeArray(rangeIterators,
position + 1);
}
rangeIterators[iterator.getRangePosition()] = iterator;
}
/**
* For cascade operations
*/
public HashMappedList getTableUpdateList() {
if (tableUpdateList == null) {
tableUpdateList = new HashMappedList();
}
return tableUpdateList;
}
/**
* For cascade operations
*/
public HashSet getConstraintPath() {
if (constraintPath == null) {
constraintPath = new HashSet();
}
return constraintPath;
}
public void addSessionVariable(ColumnSchema variable) {
int index = sessionVariables.size();
sessionVariables.add(variable.getName().name, variable);
Object[] vars = new Object[sessionVariables.size()];
ArrayUtil.copyArray(routineVariables, vars, routineVariables.length);
routineVariables = vars;
routineVariables[index] = variable.getDefaultValue(session);
}
}