// Return true iff EPG is modified by this method.
public bool RewriteOne(int idx)
{
QueryNodeInfo curNode = this.m_nodeInfos[idx];
if (curNode.OperatorName == "Where" && !curNode.Children[0].Child.IsForked)
{
LambdaExpression lambda = DryadLinqExpression.GetLambda(((MethodCallExpression)curNode.QueryExpression).Arguments[1]);
if (lambda.Type.GetGenericArguments().Length == 2)
{
QueryNodeInfo child = curNode.Children[0].Child;
string[] names = new string[] { "OrderBy", "Distinct", "RangePartition", "HashPartition" };
if (names.Contains(child.OperatorName))
{
curNode.Swap(child);
return true;
}
if (child.OperatorName == "Concat")
{
curNode.Delete();
for (int i = 0; i < child.Children.Count; i++)
{
NodeInfoEdge edge = child.Children[i];
QueryNodeInfo node = curNode.Clone();
this.m_nodeInfos.Add(node);
edge.Insert(node);
}
return true;
}
}
}
else if ((curNode.OperatorName == "Select" || curNode.OperatorName == "SelectMany") &&
!curNode.Children[0].Child.IsForked)
{
LambdaExpression lambda = DryadLinqExpression.GetLambda(((MethodCallExpression)curNode.QueryExpression).Arguments[1]);
if (lambda.Type.GetGenericArguments().Length == 2)
{
QueryNodeInfo child = curNode.Children[0].Child;
if (child.OperatorName == "Concat")
{
curNode.Delete();
for (int i = 0; i < child.Children.Count; i++)
{
NodeInfoEdge edge = child.Children[i];
QueryNodeInfo node = curNode.Clone();
this.m_nodeInfos.Add(node);
edge.Insert(node);
}
return true;
}
}
}
else if (curNode.OperatorName == "Take" && !curNode.Children[0].Child.IsForked)
{
QueryNodeInfo child = curNode.Children[0].Child;
if (child.OperatorName == "Select")
{
QueryNodeInfo cchild = child.Children[0].Child;
if (cchild.OperatorName != "GroupBy")
{
curNode.Swap(child);
return true;
}
}
}
else if ((curNode.OperatorName == "Contains" ||
curNode.OperatorName == "ContainsAsQuery" ||
curNode.OperatorName == "All" ||
curNode.OperatorName == "AllAsQuery" ||
curNode.OperatorName == "Any" ||
curNode.OperatorName == "AnyAsQuery") &&
!curNode.Children[0].Child.IsForked)
{
QueryNodeInfo child = curNode.Children[0].Child;
string[] names = new string[] { "OrderBy", "Distinct", "RangePartition", "HashPartition" };
if (names.Contains(child.OperatorName))
{
child.Delete();
return true;
}
}
return false;
}
