private LinearAggregationFactoryDesc HandleTableAccessWindow(
ExprNode[] childNodes,
AggregationStateType stateType,
ExprValidationContext validationContext,
TableMetadataColumnAggregation tableAccess)
{
var original = (ExprAggMultiFunctionLinearAccessNodeFactoryAccess) tableAccess.Factory;
if (childNodes.Length == 0 ||
childNodes.Length == 1 && childNodes[0] is ExprWildcard)
{
var componentType = original.ContainedEventType.UnderlyingType;
var accessor = new AggregationAccessorWindowNoEval(componentType);
var factory = new ExprAggMultiFunctionLinearAccessNodeFactoryAccess(this, accessor,
TypeHelper.GetArrayType(componentType), original.ContainedEventType, null, null, null);
return new LinearAggregationFactoryDesc(factory, factory.ContainedEventType, null);
}
if (childNodes.Length == 1)
{
// Expressions apply to events held, thereby validate in terms of event value expressions
var paramNode = childNodes[0];
var streams = TableServiceUtil.StreamTypeFromTableColumn(tableAccess,
validationContext.StreamTypeService.EngineURIQualifier);
var localValidationContext = new ExprValidationContext(streams, validationContext);
paramNode = ExprNodeUtility.GetValidatedSubtree(ExprNodeOrigin.AGGPARAM, paramNode,
localValidationContext);
var paramNodeEval = paramNode.ExprEvaluator;
var factory = new ExprAggMultiFunctionLinearAccessNodeFactoryAccess(this,
new AggregationAccessorWindowWEval(0, paramNodeEval, paramNodeEval.ReturnType),
TypeHelper.GetArrayType(paramNodeEval.ReturnType), original.ContainedEventType, null, null, null);
return new LinearAggregationFactoryDesc(factory, null, paramNodeEval.ReturnType);
}
throw new ExprValidationException("Invalid number of parameters");
}
private LinearAggregationFactoryDesc HandleTableAccessFirstLast(
ExprNode[] childNodes,
AggregationStateType stateType,
ExprValidationContext validationContext,
TableMetadataColumnAggregation tableAccess)
{
var original = (ExprAggMultiFunctionLinearAccessNodeFactoryAccess) tableAccess.Factory;
var resultType = original.ContainedEventType.UnderlyingType;
var defaultAccessor = stateType == AggregationStateType.FIRST
? AggregationAccessorFirstNoEval.INSTANCE
: (AggregationAccessor) AggregationAccessorLastNoEval.INSTANCE;
if (childNodes.Length == 0)
{
var factoryAccess = new ExprAggMultiFunctionLinearAccessNodeFactoryAccess(this, defaultAccessor,
resultType, original.ContainedEventType, null, null, null);
return new LinearAggregationFactoryDesc(factoryAccess, factoryAccess.ContainedEventType, null);
}
if (childNodes.Length == 1)
{
if (childNodes[0] is ExprWildcard)
{
var factoryAccess = new ExprAggMultiFunctionLinearAccessNodeFactoryAccess(this, defaultAccessor,
resultType, original.ContainedEventType, null, null, null);
return new LinearAggregationFactoryDesc(factoryAccess, factoryAccess.ContainedEventType, null);
}
if (childNodes[0] is ExprStreamUnderlyingNode)
throw new ExprValidationException("Stream-wildcard is not allowed for table column access");
// Expressions apply to events held, thereby validate in terms of event value expressions
var paramNode = childNodes[0];
var streams = TableServiceUtil.StreamTypeFromTableColumn(tableAccess,
validationContext.StreamTypeService.EngineURIQualifier);
var localValidationContext = new ExprValidationContext(streams, validationContext);
paramNode = ExprNodeUtility.GetValidatedSubtree(ExprNodeOrigin.AGGPARAM, paramNode,
localValidationContext);
var paramNodeEval = paramNode.ExprEvaluator;
AggregationAccessor accessor;
if (stateType == AggregationStateType.FIRST)
accessor = new AggregationAccessorFirstWEval(0, paramNodeEval);
else
accessor = new AggregationAccessorLastWEval(0, paramNodeEval);
var factory = new ExprAggMultiFunctionLinearAccessNodeFactoryAccess(
this, accessor, paramNodeEval.ReturnType, original.ContainedEventType, null, null, null);
return new LinearAggregationFactoryDesc(factory, factory.ContainedEventType, null);
}
if (childNodes.Length == 2)
{
var isFirst = stateType == AggregationStateType.FIRST;
var constant = -1;
var indexEvalNode = childNodes[1];
if (indexEvalNode.IsConstantResult)
constant = indexEvalNode.ExprEvaluator.Evaluate(EvaluateParams.EmptyTrue).AsInt();
var evaluatorIndex = indexEvalNode.ExprEvaluator;
if (evaluatorIndex.ReturnType.IsInt32()) {
throw new ExprValidationException(
GetErrorPrefix(stateType) +
" requires a constant index expression that returns an integer value");
}
var accessor = new AggregationAccessorFirstLastIndexNoEval(evaluatorIndex, constant, isFirst);
var factory = new ExprAggMultiFunctionLinearAccessNodeFactoryAccess(this, accessor, resultType,
original.ContainedEventType, null, null, null);
return new LinearAggregationFactoryDesc(factory, factory.ContainedEventType, null);
}
throw new ExprValidationException("Invalid number of parameters");
}
