/// <summary>
/// Private constructor
/// </summary>
/// <param name="command"></param>
/// <param name="groupAggregateVarInfoManager"></param>
private GroupAggregateVarComputationTranslator(
Command command,
GroupAggregateVarInfoManager groupAggregateVarInfoManager)
{
_command = command;
_groupAggregateVarInfoManager = groupAggregateVarInfoManager;
}
/// <summary>
/// Private constructor
/// </summary>
/// <param name="command"></param>
/// <param name="groupAggregateVarInfoManager"></param>
private GroupAggregateVarComputationTranslator(
Command command,
GroupAggregateVarInfoManager groupAggregateVarInfoManager)
{
this._command = command;
this._groupAggregateVarInfoManager = groupAggregateVarInfoManager;
}
/// <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>
/// 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)
{
GroupAggregateVarComputationTranslator handler = new GroupAggregateVarComputationTranslator(command, groupAggregateVarInfoManager);
Node 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);
}