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* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership. Some portions may be licensed
* to Red Hat, Inc. under one or more contributor license agreements.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA.
*/
package org.teiid.dqp.internal.process;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.teiid.common.buffer.BufferManager;
import org.teiid.common.buffer.BufferManager.TupleSourceType;
import org.teiid.common.buffer.TupleBuffer;
import org.teiid.common.buffer.TupleSource;
import org.teiid.core.TeiidComponentException;
import org.teiid.core.TeiidProcessingException;
import org.teiid.core.types.DataTypeManager;
import org.teiid.query.processor.ProcessorDataManager;
import org.teiid.query.processor.RegisterRequestParameter;
import org.teiid.query.sql.LanguageVisitor;
import org.teiid.query.sql.lang.Command;
import org.teiid.query.sql.lang.DependentSetCriteria;
import org.teiid.query.sql.symbol.Constant;
import org.teiid.query.util.CommandContext;
public class TupleSourceCache {
final static class CachableVisitor extends LanguageVisitor {
boolean cacheable = true;
List<Object> parameters;
@Override
public void visit(Constant c) {
if (c.isMultiValued()) {
notCachable();
} else if (DataTypeManager.isLOB(c.getType())) {
if (parameters == null) {
parameters = new ArrayList<Object>();
}
parameters.add(c.getValue());
}
}
private void notCachable() {
cacheable = false;
setAbort(true);
}
@Override
public void visit(DependentSetCriteria obj) {
notCachable();
}
}
private static class SharedState {
TupleBuffer tb;
TupleSource ts;
int id;
int expectedReaders;
private void remove() {
ts.closeSource();
tb.remove();
tb = null;
ts = null;
}
}
public abstract static class CopyOnReadTupleSource implements TupleSource {
int rowNumber = 1;
TupleBuffer tb;
TupleSource ts;
protected CopyOnReadTupleSource(TupleBuffer tb, TupleSource ts) {
this.tb = tb;
this.ts = ts;
}
@Override
public List<?> nextTuple() throws TeiidComponentException,
TeiidProcessingException {
synchronized (tb) {
if (rowNumber <= tb.getRowCount()) {
return tb.getBatch(rowNumber).getTuple(rowNumber++);
}
if (tb.isFinal()) {
return null;
}
List<?> row = ts.nextTuple();
if (row == null) {
tb.setFinal(true);
} else {
tb.addTuple(row);
rowNumber++;
}
return row;
}
}
}
private class SharedTupleSource extends CopyOnReadTupleSource {
private SharedState state;
private boolean closed = false;
public SharedTupleSource(SharedState state) {
super(state.tb, state.ts);
this.state = state;
}
@Override
public void closeSource() {
if (!closed && --state.expectedReaders == 0 && sharedStates != null && sharedStates.containsKey(state.id)) {
state.remove();
sharedStates.remove(state.id);
}
closed = true;
}
}
private Map<Integer, SharedState> sharedStates;
public void close() {
if (sharedStates != null) {
for (SharedState ss : sharedStates.values()) {
ss.remove();
}
sharedStates = null;
}
}
public TupleSource getSharedTupleSource(CommandContext context, Command command, String modelName, RegisterRequestParameter parameterObject, BufferManager bufferMgr, ProcessorDataManager pdm) throws TeiidComponentException, TeiidProcessingException {
if (sharedStates == null) {
sharedStates = new HashMap<Integer, SharedState>();
}
SharedState state = sharedStates.get(parameterObject.info.id);
if (state == null) {
state = new SharedState();
state.expectedReaders = parameterObject.info.sharingCount;
RegisterRequestParameter param = new RegisterRequestParameter(parameterObject.connectorBindingId, parameterObject.nodeID, -1);
param.fetchSize = parameterObject.fetchSize;
state.ts = pdm.registerRequest(context, command, modelName, param);
if (param.doNotCache) {
return state.ts;
}
state.tb = bufferMgr.createTupleBuffer(command.getProjectedSymbols(), context.getConnectionId(), TupleSourceType.PROCESSOR);
state.id = parameterObject.info.id;
sharedStates.put(parameterObject.info.id, state);
}
return new SharedTupleSource(state);
}
}