/// <summary>
/// Try to produce an equivalent tree to the input subtree, over a single group aggregate variable.
/// Such translation can only be produced if all external references of the input subtree are to a
/// single group aggregate var, or to vars that are can be translated over that single group
/// aggregate var
/// </summary>
/// <param name="subtree"> The input subtree </param>
/// <param name="isVarDefinition"> </param>
/// <param name="command"> </param>
/// <param name="groupAggregateVarInfoManager"> </param>
/// <param name="groupAggregateVarInfo"> The groupAggregateVarInfo over which the input subtree can be translated </param>
/// <param name="templateNode"> A tree that is equvalent to the input tree, but over the group aggregate variable represented by the groupAggregetVarInfo </param>
/// <param name="isUnnested"> </param>
/// <returns> True, if the translation can be done, false otherwise </returns>
public static bool TryTranslateOverGroupAggregateVar(
Node subtree,
bool isVarDefinition,
Command command,
GroupAggregateVarInfoManager groupAggregateVarInfoManager,
out GroupAggregateVarInfo groupAggregateVarInfo,
out Node templateNode,
out bool isUnnested)
{
var handler = new GroupAggregateVarComputationTranslator(command, groupAggregateVarInfoManager);
var inputNode = subtree;
SoftCastOp softCastOp = null;
bool isCollect;
if (inputNode.Op.OpType
== OpType.SoftCast)
{
softCastOp = (SoftCastOp)inputNode.Op;
inputNode = inputNode.Child0;
}
if (inputNode.Op.OpType
== OpType.Collect)
{
templateNode = handler.VisitCollect(inputNode);
isCollect = true;
}
else
{
templateNode = handler.VisitNode(inputNode);
isCollect = false;
}
groupAggregateVarInfo = handler._targetGroupAggregateVarInfo;
isUnnested = handler._isUnnested;
if (handler._targetGroupAggregateVarInfo == null
|| templateNode == null)
{
return false;
}
if (softCastOp != null)
{
SoftCastOp newSoftCastOp;
//
// The type needs to be fixed only if the unnesting happened during this translation.
// That can be recognized by these two cases:
// 1) if the input node was a collect, or
// 2) if the input did not represent a var definition, but a function aggregate argument and
// the template is VarRef of a group aggregate var.
//
if (isCollect
||
!isVarDefinition
&& AggregatePushdownUtil.IsVarRefOverGivenVar(templateNode, handler._targetGroupAggregateVarInfo.GroupAggregateVar))
{
newSoftCastOp = command.CreateSoftCastOp(TypeHelpers.GetEdmType<CollectionType>(softCastOp.Type).TypeUsage);
}
else
{
newSoftCastOp = softCastOp;
}
templateNode = command.CreateNode(newSoftCastOp, templateNode);
}
return true;
}
// <summary>
// Copies a SoftCastOp
// </summary>
// <param name="op"> The Op to Copy </param>
// <param name="n"> The Node that references the Op </param>
// <returns> A copy of the original Node that references a copy of the original Op </returns>
public override Node Visit(SoftCastOp op, Node n)
{
return(CopyDefault(m_destCmd.CreateSoftCastOp(op.Type), n));
}
internal Node GetInternalTree(Command targetIqtCommand, IList<Node> targetIqtArguments)
{
if (m_internalTreeNode == null)
{
var viewGenErrors = new List<EdmSchemaError>();
DiscriminatorMap discriminatorMap;
var tree = GenerateFunctionView(out discriminatorMap);
if (viewGenErrors.Count > 0)
{
throw new MappingException(Helper.CombineErrorMessage(viewGenErrors));
}
Debug.Assert(tree != null, "tree != null");
// Convert this into an ITree first
var itree = ITreeGenerator.Generate(tree, discriminatorMap);
var rootProject = itree.Root; // PhysicalProject(RelInput)
PlanCompiler.Assert(
rootProject.Op.OpType == OpType.PhysicalProject,
"Expected a physical projectOp at the root of the tree - found " + rootProject.Op.OpType);
var rootProjectOp = (PhysicalProjectOp)rootProject.Op;
Debug.Assert(rootProjectOp.Outputs.Count == 1, "rootProjectOp.Outputs.Count == 1");
var rootInput = rootProject.Child0; // the RelInput in PhysicalProject(RelInput)
// #554756: VarVec enumerators are not cached on the shared Command instance.
itree.DisableVarVecEnumCaching();
// Function import returns a collection, so convert it to a scalar by wrapping into CollectOp.
var relNode = rootInput;
var relVar = rootProjectOp.Outputs[0];
// ProjectOp does not implement Type property, so get the type from the column map.
var functionViewType = rootProjectOp.ColumnMap.Type;
if (!Command.EqualTypes(functionViewType, FunctionImport.ReturnParameter.TypeUsage))
{
Debug.Assert(
TypeSemantics.IsPromotableTo(functionViewType, FunctionImport.ReturnParameter.TypeUsage),
"Mapping expression result type must be promotable to the c-space function return type.");
// Build "relNode = Project(relNode, SoftCast(relVar))"
var expectedCollectionType = (CollectionType)FunctionImport.ReturnParameter.TypeUsage.EdmType;
var expectedElementType = expectedCollectionType.TypeUsage;
var varRefNode = itree.CreateNode(itree.CreateVarRefOp(relVar));
var castNode = itree.CreateNode(itree.CreateSoftCastOp(expectedElementType), varRefNode);
var varDefListNode = itree.CreateVarDefListNode(castNode, out relVar);
var projectOp = itree.CreateProjectOp(relVar);
relNode = itree.CreateNode(projectOp, relNode, varDefListNode);
}
// Build "Collect(PhysicalProject(relNode))
m_internalTreeNode = itree.BuildCollect(relNode, relVar);
}
Debug.Assert(m_internalTreeNode != null, "m_internalTreeNode != null");
// Prepare argument replacement dictionary
Debug.Assert(m_commandParameters.Length == targetIqtArguments.Count, "m_commandParameters.Length == targetIqtArguments.Count");
var viewArguments = new Dictionary<string, Node>(m_commandParameters.Length);
for (var i = 0; i < m_commandParameters.Length; ++i)
{
var commandParam = m_commandParameters[i];
var argumentNode = targetIqtArguments[i];
// If function import parameter is of enum type, the argument value for it will be of enum type. We however have
// converted enum types to underlying types for m_commandParameters. So we now need to softcast the argument
// expression to the underlying type as well.
if (TypeSemantics.IsEnumerationType(argumentNode.Op.Type))
{
argumentNode = targetIqtCommand.CreateNode(
targetIqtCommand.CreateSoftCastOp(TypeHelpers.CreateEnumUnderlyingTypeUsage(argumentNode.Op.Type)),
argumentNode);
}
Debug.Assert(
TypeSemantics.IsPromotableTo(argumentNode.Op.Type, commandParam.ResultType),
"Argument type must be promotable to parameter type.");
viewArguments.Add(commandParam.ParameterName, argumentNode);
}
return FunctionViewOpCopier.Copy(targetIqtCommand, m_internalTreeNode, viewArguments);
}
