/**************************************************************************************
* Copyright (C) 2008 EsperTech, Inc. All rights reserved. *
* http://esper.codehaus.org *
* http://www.espertech.com *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the GPL license *
* a copy of which has been included with this distribution in the license.txt file. *
**************************************************************************************/
package com.espertech.esper.epl.core;
import com.espertech.esper.client.soda.ForClauseKeyword;
import com.espertech.esper.core.StatementResultService;
import com.espertech.esper.epl.expression.*;
import com.espertech.esper.epl.spec.*;
import com.espertech.esper.epl.variable.VariableService;
import com.espertech.esper.event.EventAdapterService;
import com.espertech.esper.event.EventTypeMetadata;
import com.espertech.esper.event.EventTypeSPI;
import com.espertech.esper.event.vaevent.ValueAddEventService;
import com.espertech.esper.schedule.TimeProvider;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.lang.annotation.Annotation;
import java.util.*;
/**
* Factory for select expression processors.
*/
public class SelectExprProcessorFactory
{
private static final Log log = LogFactory.getLog(SelectExprProcessorFactory.class);
/**
* Returns the processor to use for a given select-clause.
* @param selectionList - the list of select clause elements/items, which are expected to have been validated
* @param isUsingWildcard - true if the wildcard (*) occurs in the select clause
* @param insertIntoDesc - contains column names for the optional insert-into clause (if supplied)
* @param typeService - serves stream type information
* @param eventAdapterService - for generating wrapper instances for events
* @param statementResultService handles listeners/subscriptions awareness to reduce output result generation
* @param valueAddEventService - service that handles update events and variant events
* @param selectExprEventTypeRegistry - registry for event type to statements
* @param methodResolutionService - for resolving write methods
* @param exprEvaluatorContext context for expression evalauation
* @return select-clause expression processor
* @throws ExprValidationException to indicate the select expression cannot be validated
*/
public static SelectExprProcessor getProcessor(List<SelectClauseElementCompiled> selectionList,
boolean isUsingWildcard,
InsertIntoDesc insertIntoDesc,
ForClauseSpec forClauseSpec,
StreamTypeService typeService,
EventAdapterService eventAdapterService,
StatementResultService statementResultService,
ValueAddEventService valueAddEventService,
SelectExprEventTypeRegistry selectExprEventTypeRegistry,
MethodResolutionService methodResolutionService,
ExprEvaluatorContext exprEvaluatorContext,
VariableService variableService,
TimeProvider timeProvider,
String engineURI,
String statementId,
String statementName,
Annotation[] annotations)
throws ExprValidationException
{
SelectExprProcessor synthetic = getProcessorInternal(selectionList, isUsingWildcard, insertIntoDesc, typeService, eventAdapterService, valueAddEventService, selectExprEventTypeRegistry, methodResolutionService, exprEvaluatorContext, statementId);
// Handle binding as an optional service
if (statementResultService != null)
{
// Handle for-clause delivery contract checking
ExprNode[] groupedDeliveryExpr = null;
boolean forDelivery = false;
if (forClauseSpec != null) {
for (ForClauseItemSpec item : forClauseSpec.getClauses()) {
if (item.getKeyword() == null) {
throw new ExprValidationException("Expected any of the " + Arrays.toString(ForClauseKeyword.values()).toLowerCase() + " for-clause keywords after reserved keyword 'for'");
}
try {
ForClauseKeyword keyword = ForClauseKeyword.valueOf(item.getKeyword().toUpperCase());
if ((keyword == ForClauseKeyword.GROUPED_DELIVERY) && (item.getExpressions().isEmpty())) {
throw new ExprValidationException("The for-clause with the " + ForClauseKeyword.GROUPED_DELIVERY.getName() + " keyword requires one or more grouping expressions");
}
if ((keyword == ForClauseKeyword.DISCRETE_DELIVERY) && (!item.getExpressions().isEmpty())) {
throw new ExprValidationException("The for-clause with the " + ForClauseKeyword.DISCRETE_DELIVERY.getName() + " keyword does not allow grouping expressions");
}
if (forDelivery) {
throw new ExprValidationException("The for-clause with delivery keywords may only occur once in a statement");
}
}
catch (RuntimeException ex) {
throw new ExprValidationException("Expected any of the " + Arrays.toString(ForClauseKeyword.values()).toLowerCase() + " for-clause keywords after reserved keyword 'for'");
}
StreamTypeService type = new StreamTypeServiceImpl(synthetic.getResultEventType(), null, false, engineURI);
groupedDeliveryExpr = new ExprNode[item.getExpressions().size()];
ExprValidationContext validationContext = new ExprValidationContext(type, methodResolutionService, null, timeProvider, variableService, exprEvaluatorContext, eventAdapterService, statementName, annotations);
for (int i = 0; i < item.getExpressions().size(); i++) {
groupedDeliveryExpr[i] = ExprNodeUtil.getValidatedSubtree(item.getExpressions().get(i), validationContext);
}
forDelivery = true;
}
}
BindProcessor bindProcessor = new BindProcessor(selectionList, typeService.getEventTypes(), typeService.getStreamNames());
statementResultService.setSelectClause(bindProcessor.getExpressionTypes(), bindProcessor.getColumnNamesAssigned(), forDelivery, ExprNodeUtility.getEvaluators(groupedDeliveryExpr), exprEvaluatorContext);
return new SelectExprResultProcessor(statementResultService, synthetic, bindProcessor, exprEvaluatorContext);
}
return synthetic;
}
private static SelectExprProcessor getProcessorInternal(
List<SelectClauseElementCompiled> selectionList,
boolean isUsingWildcard,
InsertIntoDesc insertIntoDesc,
StreamTypeService typeService,
EventAdapterService eventAdapterService,
ValueAddEventService valueAddEventService,
SelectExprEventTypeRegistry selectExprEventTypeRegistry,
MethodResolutionService methodResolutionService,
ExprEvaluatorContext exprEvaluatorContext,
String statementId)
throws ExprValidationException
{
// Wildcard not allowed when insert into specifies column order
if(isUsingWildcard && insertIntoDesc != null && !insertIntoDesc.getColumnNames().isEmpty())
{
throw new ExprValidationException("Wildcard not allowed when insert-into specifies column order");
}
// Determine wildcard processor (select *)
if (isWildcardsOnly(selectionList))
{
// For joins
if (typeService.getStreamNames().length > 1)
{
log.debug(".getProcessor Using SelectExprJoinWildcardProcessor");
return new SelectExprJoinWildcardProcessor(typeService.getStreamNames(), typeService.getEventTypes(), eventAdapterService, insertIntoDesc, selectExprEventTypeRegistry, methodResolutionService, exprEvaluatorContext);
}
// Single-table selects with no insert-into
// don't need extra processing
else if (insertIntoDesc == null)
{
log.debug(".getProcessor Using wildcard processor");
return new SelectExprWildcardProcessor(typeService.getEventTypes()[0]);
}
}
// Verify the assigned or name used is unique
verifyNameUniqueness(selectionList);
// Construct processor
List<SelectClauseExprCompiledSpec> expressionList = getExpressions(selectionList);
List<SelectClauseStreamCompiledSpec> streamWildcards = getStreamWildcards(selectionList);
SelectExprProcessorHelper factory = new SelectExprProcessorHelper(expressionList, streamWildcards, insertIntoDesc, isUsingWildcard, typeService, eventAdapterService, valueAddEventService, selectExprEventTypeRegistry, methodResolutionService, exprEvaluatorContext, statementId);
SelectExprProcessor processor = factory.getEvaluator();
// add reference to the type obtained
EventTypeSPI type = (EventTypeSPI) processor.getResultEventType();
if (type.getMetadata().getTypeClass() != EventTypeMetadata.TypeClass.ANONYMOUS) {
selectExprEventTypeRegistry.add(processor.getResultEventType());
}
return processor;
}
/**
* Verify that each given name occurs exactly one.
* @param selectionList is the list of select items to verify names
* @throws com.espertech.esper.epl.expression.ExprValidationException thrown if a name occured more then once
*/
protected static void verifyNameUniqueness(List<SelectClauseElementCompiled> selectionList) throws ExprValidationException
{
Set<String> names = new HashSet<String>();
for (SelectClauseElementCompiled element : selectionList)
{
if (element instanceof SelectClauseExprCompiledSpec)
{
SelectClauseExprCompiledSpec expr = (SelectClauseExprCompiledSpec) element;
if (names.contains(expr.getAssignedName()))
{
throw new ExprValidationException("Column name '" + expr.getAssignedName() + "' appears more then once in select clause");
}
names.add(expr.getAssignedName());
}
else if (element instanceof SelectClauseStreamCompiledSpec)
{
SelectClauseStreamCompiledSpec stream = (SelectClauseStreamCompiledSpec) element;
if (stream.getOptionalName() == null)
{
continue; // ignore no-name stream selectors
}
if (names.contains(stream.getOptionalName()))
{
throw new ExprValidationException("Column name '" + stream.getOptionalName() + "' appears more then once in select clause");
}
names.add(stream.getOptionalName());
}
}
}
private static boolean isWildcardsOnly(List<SelectClauseElementCompiled> elements)
{
for (SelectClauseElementCompiled element : elements)
{
if (!(element instanceof SelectClauseElementWildcard))
{
return false;
}
}
return true;
}
private static List<SelectClauseExprCompiledSpec> getExpressions(List<SelectClauseElementCompiled> elements)
{
List<SelectClauseExprCompiledSpec> result = new ArrayList<SelectClauseExprCompiledSpec>();
for (SelectClauseElementCompiled element : elements)
{
if (element instanceof SelectClauseExprCompiledSpec)
{
result.add((SelectClauseExprCompiledSpec)element);
}
}
return result;
}
private static List<SelectClauseStreamCompiledSpec> getStreamWildcards(List<SelectClauseElementCompiled> elements)
{
List<SelectClauseStreamCompiledSpec> result = new ArrayList<SelectClauseStreamCompiledSpec>();
for (SelectClauseElementCompiled element : elements)
{
if (element instanceof SelectClauseStreamCompiledSpec)
{
result.add((SelectClauseStreamCompiledSpec)element);
}
}
return result;
}
}