Code:
/ 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / DataEntity / System / Data / Query / PlanCompiler / NominalTypeEliminator.cs / 1305376 / NominalTypeEliminator.cs
//----------------------------------------------------------------------
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
//
// @owner [....]
// @backupOwner [....]
//---------------------------------------------------------------------
using System;
using System.Collections;
using System.Collections.Generic;
//using System.Diagnostics; // Please use PlanCompiler.Assert instead of Debug.Assert in this class...
using System.Globalization;
using System.Linq;
using System.Data.Common;
using md = System.Data.Metadata.Edm;
using System.Data.Query.InternalTrees;
using System.Data.Query.PlanCompiler;
namespace System.Data.Query.PlanCompiler
{
///
/// The goal of this module is to eliminate all references to nominal types
/// in the tree. Additionally, all structured types are replaced by "flat"
/// record types - where every field of the structured type is a scalar type.
/// Note that UDTs are not considered to be structured types.
///
/// At the end of this phase,
/// * there are no more nominal types in the tree
/// * there are no more nested record types in the tree
/// * No Var in the tree is of an structured type
/// * Additionally (and these follow from the statements above)
/// * There are no NewInstanceOp constructors in the tree
/// * There are no PropertyOp operators where the result is a structured type
///
/// This module uses information from the PropertyPushdown phase to "optimize"
/// structured type elimination. Essentially, if we can avoid producing pieces
/// of information that will be discarded later, then lets do that.
///
/// The general mechanism of type elimination is as follows. We walk up the tree
/// in a bottom up fashion, and try to convert all structured types into flattened
/// record types - type constructors are first converted into flat record constructors
/// and then dismantled etc. The barrier points - Vars - are all converted into
/// scalar types, and all intermediate stages will be eliminated in transition.
///
/// The output from this phase includes a ColumnMap - which is used later by
/// the execution model to produce results in the right form from an otherwise
/// flat query
///
/// Notes: This phase could be combined later with the PropertyPushdown phase
///
///
internal class NominalTypeEliminator : BasicOpVisitorOfNode
{
#region Nested Classes
///
/// Describes an operation kind - for various property extractions
///
internal enum OperationKind
{
///
/// Comparing two instances for equality
///
Equality,
///
/// Checking to see if an instance is null
///
IsNull,
///
/// Getting the "identity" of an entity
///
GetIdentity,
///
/// Getting the keys of an entity
///
GetKeys,
///
/// All properties of an entity
///
All
}
#endregion
#region private state
private Dictionary m_varPropertyMap;
private Dictionary m_nodePropertyMap;
private VarInfoMap m_varInfoMap;
private PlanCompiler m_compilerState;
private Command m_command { get { return m_compilerState.Command; } }
private StructuredTypeInfo m_typeInfo;
private Dictionary m_typeToNewTypeMap;
private const string PrefixMatchCharacter = "%"; // This is ANSI-SQL defined, but it should probably be configurable.
#endregion
#region constructors
private NominalTypeEliminator(PlanCompiler compilerState,
StructuredTypeInfo typeInfo,
Dictionary varPropertyMap,
Dictionary nodePropertyMap)
{
m_compilerState = compilerState;
m_typeInfo = typeInfo;
m_varPropertyMap = varPropertyMap;
m_nodePropertyMap = nodePropertyMap;
m_varInfoMap = new VarInfoMap();
m_typeToNewTypeMap = new Dictionary(TypeUsageEqualityComparer.Instance);
}
#endregion
#region Process Driver
///
/// Eliminates all structural types from the query
///
/// current compiler state
/// list of all referenced types
/// list of referenced entitysets
internal static void Process(PlanCompiler compilerState,
StructuredTypeInfo structuredTypeInfo)
{
#if DEBUG
//string phase0 = Dump.ToXml(compilerState.Command);
Validator.Validate(compilerState);
#endif
// Phase 1: Top-down property pushdown
Dictionary varPropertyMap;
Dictionary nodePropertyMap;
PropertyPushdownHelper.Process(compilerState.Command, structuredTypeInfo, out varPropertyMap, out nodePropertyMap);
#if DEBUG
//string phase1 = Dump.ToXml(compilerState.Command);
Validator.Validate(compilerState);
#endif
// Phase 2: actually eliminate nominal types
NominalTypeEliminator nte = new NominalTypeEliminator(compilerState, structuredTypeInfo,
varPropertyMap, nodePropertyMap);
nte.Process();
#if DEBUG
//string phase2 = Dump.ToXml(compilerState.Command);
Validator.Validate(compilerState);
#endif
#if DEBUG
//To avoid garbage collection
//int size = phase0.Length;
//size = phase1.Length;
//size = phase2.Length;
#endif
}
///
/// The real driver. Invokes the visitor to traverse the tree bottom-up,
/// and modifies the tree along the way.
///
private void Process()
{
Node rootNode = m_command.Root;
PlanCompiler.Assert(rootNode.Op.OpType == OpType.PhysicalProject, "root node is not PhysicalProjectOp?");
// invoke the visitor on the root node
rootNode.Op.Accept(this, rootNode);
}
#endregion
#region type utilities
///
/// The datatype of the typeid property
///
private md.TypeUsage DefaultTypeIdType
{
get { return m_command.StringType; }
}
///
/// Get the "new" type corresponding to the input type.
/// For structured types, we simply look up the typeInfoMap
/// For collection types, we create a new collection type based on the
/// "new" element type.
/// For all other types, we simply return the input type
///
///
/// (type, out collectionType))
{
// If this is a collection type, then clone a new collection type
md.TypeUsage newElementType = GetNewType(collectionType.TypeUsage);
newType = TypeUtils.CreateCollectionType(newElementType);
}
else if (TypeUtils.IsStructuredType(type))
{
// structured type => we've already calculated the input
newType = m_typeInfo.GetTypeInfo(type).FlattenedTypeUsage;
}
else
{
// "simple" type => return the input type
newType = type;
}
// Add this information to the map
m_typeToNewTypeMap[type] = newType;
return newType;
}
#endregion
#region misc utilities
///
/// This function builds a "property accessor" over the input expression. It
/// can produce one of three results:
///
/// - It can return "null", if it is convinced that the input has no
/// such expression
/// - It can return a subnode of the input, if that subnode represents
/// the property
/// - Or, it can build a PropertyOp explicitly
///
/// Assertion: the property is not a structured type
///
/// The input expression
/// The desired property
///
/// A BuildAccessor variant. If the appropriate property was not found, then
/// build up a null constant instead
///
///
///
///
/// Builds up an accessor to the typeid property. If the type has no typeid
/// property, then we simply create a constantOp with the corresponding
/// typeid value for the type
///
/// the input expression
/// the original type of the input expression
///
/// Builds a SoftCast operator over the input - if one is necessary.
///
/// the input expression to "cast"
/// the target type
/// the "cast"ed expression
private Node BuildSoftCast(Node node, md.TypeUsage targetType)
{
PlanCompiler.Assert(node.Op.IsScalarOp, "Attempting SoftCast around non-ScalarOp?");
if (Command.EqualTypes(node.Op.Type, targetType))
{
return node;
}
// Skip any castOps we may have created already
while (node.Op.OpType == OpType.SoftCast)
{
node = node.Child0;
}
Node newNode = m_command.CreateNode(m_command.CreateSoftCastOp(targetType), node);
return newNode;
}
///
/// Clones a subtree.
/// This is used by the "BuildAccessor" routines to build a property-accessor
/// over some input. If we're reusing the input, the input must be cloned.
///
/// The subtree to copy
///
/// Returns a node for a null constant of the desired type
///
///
///
/// Create a node to represent nullability.
///
/// Node for the typeid constant
private Node CreateNullSentinelConstant()
{
NullSentinelOp op = m_command.CreateNullSentinelOp();
return m_command.CreateNode(op);
}
///
/// Create a node to represent the exact value of the typeid constant
///
/// The current type
/// Node for the typeid constant
private Node CreateTypeIdConstant(TypeInfo typeInfo)
{
object value = typeInfo.TypeId;
md.TypeUsage typeIdType;
if (typeInfo.RootType.DiscriminatorMap != null)
{
typeIdType = md.Helper.GetModelTypeUsage(typeInfo.RootType.DiscriminatorMap.DiscriminatorProperty);
}
else
{
typeIdType = DefaultTypeIdType;
}
InternalConstantOp op = m_command.CreateInternalConstantOp(typeIdType, value);
return m_command.CreateNode(op);
}
///
/// Create a node to represent a typeid constant for a prefix match.
/// If the typeid value were "123X", then we would generate a constant
/// like "123X%"
///
/// the current type
/// Node for the typeid constant
private Node CreateTypeIdConstantForPrefixMatch(TypeInfo typeInfo)
{
string value = typeInfo.TypeId + PrefixMatchCharacter;
InternalConstantOp op = m_command.CreateInternalConstantOp(DefaultTypeIdType, value);
return m_command.CreateNode(op);
}
///
/// Identify the list of property refs for comparison and isnull semantics
///
///
///
/// GetPropertyRefsForComparisonAndIsNull(TypeInfo typeInfo, OperationKind opKind)
{
PlanCompiler.Assert(opKind == OperationKind.IsNull || opKind == OperationKind.Equality,
"Unexpected opKind: " + opKind + "; Can only handle IsNull and Equality");
md.TypeUsage currentType = typeInfo.Type;
md.RowType recordType = null;
if (TypeHelpers.TryGetEdmType(currentType, out recordType))
{
if (opKind == OperationKind.IsNull && typeInfo.HasNullSentinelProperty)
{
yield return NullSentinelPropertyRef.Instance;
}
else
foreach (md.EdmProperty m in recordType.Properties)
{
if (!TypeUtils.IsStructuredType(md.Helper.GetModelTypeUsage(m)))
{
yield return new SimplePropertyRef(m);
}
else
{
TypeInfo nestedTypeInfo = m_typeInfo.GetTypeInfo(md.Helper.GetModelTypeUsage(m));
foreach (PropertyRef p in GetPropertyRefs(nestedTypeInfo, opKind))
{
PropertyRef nestedPropertyRef = p.CreateNestedPropertyRef(m);
yield return nestedPropertyRef;
}
}
}
yield break;
}
md.EntityType entityType = null;
if (TypeHelpers.TryGetEdmType(currentType, out entityType))
{
if (opKind == OperationKind.Equality ||
(opKind == OperationKind.IsNull && !typeInfo.HasTypeIdProperty))
{
foreach (PropertyRef p in typeInfo.GetIdentityPropertyRefs())
{
yield return p;
}
}
else
{
yield return TypeIdPropertyRef.Instance;
}
yield break;
}
md.ComplexType complexType = null;
if (TypeHelpers.TryGetEdmType(currentType, out complexType))
{
PlanCompiler.Assert(opKind == OperationKind.IsNull, "complex types not equality-comparable");
PlanCompiler.Assert(typeInfo.HasNullSentinelProperty, "complex type with no null sentinel property: can't handle isNull");
yield return NullSentinelPropertyRef.Instance;
yield break;
}
md.RefType refType = null;
if (TypeHelpers.TryGetEdmType(currentType, out refType))
{
foreach (PropertyRef p in typeInfo.GetAllPropertyRefs())
{
yield return p;
}
yield break;
}
PlanCompiler.Assert(false, "Unknown type");
}
///
/// Get the list of "desired" propertyrefs for the specified type and operation
///
///
///
/// GetPropertyRefs(TypeInfo typeInfo, OperationKind opKind)
{
PlanCompiler.Assert(opKind != OperationKind.All, "unexpected attempt to GetPropertyRefs(...,OperationKind.All)");
if (opKind == OperationKind.GetKeys)
{
return typeInfo.GetKeyPropertyRefs();
}
else if (opKind == OperationKind.GetIdentity)
{
return typeInfo.GetIdentityPropertyRefs();
}
else
{
return GetPropertyRefsForComparisonAndIsNull(typeInfo, opKind);
}
}
///
/// Get a list of "desired" properties for each operationKind (specified by the opKind
/// parameter). The OpKinds we support are
///
/// * GetKeys
/// Applies only to entity and ref types - gets the key properties (more specifically
/// the flattened equivalents)
/// * GetIdentity
/// Applies only to entity and ref types - gets the entityset id property first, and then the
/// the Key properties
/// * All
/// Gets all properties of the flattened type
///
/// * Equality
/// Scalar types - the entire instance
/// Entity - the identity properties
/// Ref - all properties (= identity properties)
/// Complex/Collection - Not supported
/// Record - recurse over each property
///
/// * IsNull
/// Scalar types - entire instance
/// Entity - typeid property, if it exists; otherwise, the key properties
/// ComplexType - typeid property
/// Ref - all properties
/// Collection - not supported
/// Record - recurse over each property
///
/// Type information for the current op
/// Current operation kind
/// List of desired properties
private IEnumerable GetProperties(TypeInfo typeInfo, OperationKind opKind)
{
if (opKind == OperationKind.All)
{
foreach (md.EdmProperty p in typeInfo.GetAllProperties())
{
yield return p;
}
}
else
{
foreach (PropertyRef p in GetPropertyRefs(typeInfo, opKind))
{
yield return typeInfo.GetNewProperty(p);
}
}
}
///
/// Get a list of properties and value (expressions) for each desired property of the
/// input. The list of desired properties is based on the opKind parameter.
/// The ignoreMissingProperties indicates if we should create a null constant, in case
/// the input cannot produce the specified property
///
/// typeinfo for the input
/// Current operation kind
/// The input expression tree
/// Should we ignore missing properties
/// Output: list of properties
/// Output: correspondng list of values
private void GetPropertyValues(TypeInfo typeInfo, OperationKind opKind, Node input, bool ignoreMissingProperties,
out List properties, out List values)
{
values = new List();
properties = new List();
foreach (md.EdmProperty prop in GetProperties(typeInfo, opKind))
{
KeyValuePair kv = GetPropertyValue(input, prop, ignoreMissingProperties);
if (kv.Value != null)
{
properties.Add(kv.Key);
values.Add(kv.Value);
}
}
}
///
/// Build up a key-value pair of (property, expression) to represent
/// the extraction of the appropriate property from the input expression
///
/// The input (structured type) expression
/// The property in question
/// should we ignore missing properties
/// GetPropertyValue(Node input, md.EdmProperty property, bool ignoreMissingProperties)
{
Node n = null;
if (!ignoreMissingProperties)
{
n = BuildAccessorWithNulls(input, property);
}
else
{
n = BuildAccessor(input, property);
}
return new KeyValuePair(property, n);
}
///
/// Walk the SortKeys, and expand out
/// any Structured type Var references
/// If any of the sort keys is expanded to include a var representing a null sentinel,
/// set PlanCompiler.HasSortingOnNullSentinels to true.
///
/// The list of input keys
/// An expanded list of keys. If there is nothing to expand it returns the original list.
private List HandleSortKeys(List keys)
{
List newSortKeys = new List();
bool modified = false;
foreach (InternalTrees.SortKey k in keys)
{
VarInfo varInfo;
if (!m_varInfoMap.TryGetVarInfo(k.Var, out varInfo))
{
newSortKeys.Add(k);
}
else
{
StructuredVarInfo structuredVarInfo = varInfo as StructuredVarInfo;
if (structuredVarInfo != null && structuredVarInfo.NewVarsIncludeNullSentinelVar)
{
m_compilerState.HasSortingOnNullSentinels = true;
}
foreach (Var v in varInfo.NewVars)
{
InternalTrees.SortKey newKey = Command.CreateSortKey(v, k.AscendingSort, k.Collation);
newSortKeys.Add(newKey);
}
modified = true;
}
}
List result = modified ? newSortKeys : keys;
return result;
}
#endregion
#region Visitor methods
#region AncillaryOp Visitors
///
/// VarDefListOp
///
/// Walks each VarDefOp child, and "expands" it out if the Var is a
/// structured type.
///
/// For each Var that is expanded, a new expression is created to compute
/// its value (from the original computed expression)
/// A new VarDefListOp is created to hold all the "expanded" Varlist
///
///
///
/// newChildren = new List();
foreach (Node chi in n.Children)
{
VarDefOp varDefOp = chi.Op as VarDefOp;
if (TypeUtils.IsStructuredType(varDefOp.Var.Type)
|| TypeUtils.IsCollectionType(varDefOp.Var.Type))
{
List newChiList;
md.TypeUsage x;
FlattenComputedVar((ComputedVar)varDefOp.Var, chi, out newChiList, out x);
foreach (Node newChi in newChiList)
{
newChildren.Add(newChi);
}
}
else
{
newChildren.Add(chi);
}
}
Node newVarDefListNode = m_command.CreateNode(n.Op, newChildren);
return newVarDefListNode;
}
///
/// Helps flatten out a computedVar expression
///
/// The Var
/// Subtree rooted at the VarDefOp expression
/// list of new nodes produced
///
/// VarInfo for this var
private void FlattenComputedVar(ComputedVar v, Node node, out List newNodes, out md.TypeUsage newType)
{
newNodes = new List();
Node definingExprNode = node.Child0; // defining expression for the VarDefOp
newType = null;
if (TypeUtils.IsCollectionType(v.Type))
{
newType = GetNewType(v.Type);
Var newVar;
Node newVarDefNode = m_command.CreateVarDefNode(definingExprNode, out newVar);
newNodes.Add(newVarDefNode);
m_varInfoMap.CreateCollectionVarInfo(v, newVar);
return;
}
// Get the "new" type for the Var
TypeInfo typeInfo = m_typeInfo.GetTypeInfo(v.Type);
// Get a list of properties that we think are necessary
PropertyRefList desiredProperties = m_varPropertyMap[v];
List newVars = new List();
List newProps = new List();
newNodes = new List();
var hasNullSentinelVar = false;
foreach (PropertyRef p in typeInfo.PropertyRefList)
{
// do I care for this property?
if (!desiredProperties.Contains(p))
{
continue;
}
md.EdmProperty newProperty = typeInfo.GetNewProperty(p);
//
// #479467 - Make sure that we build Vars for all properties - if
// we are asked to produce all properties. This is extremely important
// for the top-level Vars
//
Node propAccessor = null;
if (desiredProperties.AllProperties)
{
propAccessor = BuildAccessorWithNulls(definingExprNode, newProperty);
}
else
{
propAccessor = BuildAccessor(definingExprNode, newProperty);
if (propAccessor == null)
{
continue;
}
}
// Add the new property
newProps.Add(newProperty);
// Create a new VarDefOp.
Var newVar;
Node newVarDefNode = m_command.CreateVarDefNode(propAccessor, out newVar);
newNodes.Add(newVarDefNode);
newVars.Add(newVar);
// Check if it is a null sentinel var
if (!hasNullSentinelVar && IsNullSentinelPropertyRef(p))
{
hasNullSentinelVar = true;
}
}
m_varInfoMap.CreateStructuredVarInfo(v, typeInfo.FlattenedType, newVars, newProps, hasNullSentinelVar);
return;
}
///
/// Is the given propertyRef representing a null sentinel
/// It is if:
/// - it is a NullSentinelPropertyRef
/// - it is a NestedPropertyRef with the outer property being a NullSentinelPropertyRef
///
///
///
/// PhysicalProjectOp
///
///
///
///
/// Walk the input var sequence, flatten each var, and return the new sequence of
/// Vars
///
/// input Var sequence
/// flattened output var sequence
private IEnumerable FlattenVars(IEnumerable vars)
{
foreach (Var v in vars)
{
VarInfo varInfo;
if (!m_varInfoMap.TryGetVarInfo(v, out varInfo))
{
yield return v;
}
else
{
foreach (Var newVar in varInfo.NewVars)
{
yield return newVar;
}
}
}
}
///
/// Probe the current VarSet for "structured" Vars - replace these with the
/// corresponding sets of flattened Vars
///
/// current set of vars
/// an "expanded" varset
private VarVec FlattenVarSet(VarVec varSet)
{
VarVec newVarSet = m_command.CreateVarVec(FlattenVars(varSet));
return newVarSet;
}
///
/// Build up a new varlist, where each structured var has been replaced by its
/// corresponding flattened vars
///
/// the varlist to flatten
/// the new flattened varlist
private VarList FlattenVarList(VarList varList)
{
VarList newVarList = Command.CreateVarList(FlattenVars(varList));
return newVarList;
}
///
/// Simply flatten out every var in the keys, and return a new DistinctOp
///
/// DistinctOp
/// Current subtree
///
/// GroupBy
///
/// Again, VisitChildren - for the Keys and Properties VarDefList nodes - does
/// the real work.
///
/// The "Keys" and the "OutputVars" varsets are updated to flatten out
/// references to any structured Vars.
///
///
///
///
/// GroupByInto
///
/// Again, VisitChildren - for the Keys and Properties VarDefList nodes - does
/// the real work.
///
/// The "Keys", "InputVars" and "OutputVars" varsets are updated to flatten out
/// references to any structured Vars.
///
///
///
///
/// ProjectOp
///
/// The computedVars (the VarDefList) are processed via the VisitChildren() call
/// We then try to update the "Vars" property to flatten out any structured
/// type Vars - if a new VarSet is produced, then the ProjectOp is cloned
///
///
///
/// new subtree
public override Node Visit(ProjectOp op, Node n)
{
VisitChildren(n);
// update the output Vars with the right set of information
VarVec newVars = FlattenVarSet(op.Outputs);
if (op.Outputs != newVars)
{
// If the set of vars is empty, that means we didn;t need any of the Vars
if (newVars.IsEmpty)
{
return n.Child0;
}
n.Op = m_command.CreateProjectOp(newVars);
}
return n;
}
///
/// ScanTableOp
///
/// Visit a scanTable Op. Flatten out the table's record into one column
/// for each field. Additionally, set up the VarInfo map appropriately
///
///
///
/// new subtree
public override Node Visit(ScanTableOp op, Node n)
{
Var columnVar = op.Table.Columns[0];
TypeInfo typeInfo = m_typeInfo.GetTypeInfo(columnVar.Type);
md.RowType newRowType = typeInfo.FlattenedType;
List properties = new List();
List keyProperties = new List();
HashSet declaredProps = new HashSet();
foreach (md.EdmProperty p in TypeHelpers.GetAllStructuralMembers(columnVar.Type.EdmType))
{
declaredProps.Add(p.Name);
}
foreach (md.EdmProperty p in newRowType.Properties)
{
if (declaredProps.Contains(p.Name))
{
properties.Add(p);
}
}
foreach (PropertyRef pref in typeInfo.GetKeyPropertyRefs())
{
md.EdmProperty p = typeInfo.GetNewProperty(pref);
keyProperties.Add(p);
}
//
// Create a flattened table definition, and a table with that definiton;
//
TableMD newTableMD = m_command.CreateFlatTableDefinition(properties, keyProperties, op.Table.TableMetadata.Extent);
Table newTable = m_command.CreateTableInstance(newTableMD);
VarInfo varInfo = m_varInfoMap.CreateStructuredVarInfo(columnVar, newRowType, newTable.Columns, properties);
n.Op = m_command.CreateScanTableOp(newTable);
return n;
}
///
/// Get the *single" var produced by the subtree rooted at this node.
/// Returns null, if the node produces more than one var, or less than one
///
/// the node
/// the single var produced by the node
internal static Var GetSingletonVar(Node n)
{
switch (n.Op.OpType)
{
case OpType.Project:
{
ProjectOp projectOp = (ProjectOp)n.Op;
return (projectOp.Outputs.Count == 1) ? projectOp.Outputs.First : null;
}
case OpType.ScanTable:
{
ScanTableOp tableOp = (ScanTableOp)n.Op;
return (tableOp.Table.Columns.Count == 1) ? tableOp.Table.Columns[0] : null;
}
case OpType.Filter:
case OpType.SingleRow:
case OpType.Sort:
case OpType.ConstrainedSort:
return GetSingletonVar(n.Child0);
case OpType.UnionAll:
case OpType.Intersect:
case OpType.Except:
{
SetOp setOp = (SetOp)n.Op;
return (setOp.Outputs.Count == 1) ? setOp.Outputs.First : null;
}
case OpType.Unnest:
{
UnnestOp unnestOp = (UnnestOp)n.Op;
return unnestOp.Table.Columns.Count == 1 ? unnestOp.Table.Columns[0] : null;
}
case OpType.Distinct:
{
DistinctOp distinctOp = (DistinctOp)n.Op;
return (distinctOp.Keys.Count == 1) ? distinctOp.Keys.First : null;
}
default:
return null;
}
}
///
/// ScanViewOp
///
/// Flatten out the view definition, and return that after
/// the appropriate remapping
///
/// the ScanViewOp
/// current subtree
/// the flattened view definition
public override Node Visit(ScanViewOp op, Node n)
{
//
// Get the "single" var produced by the input
//
Var inputVar = GetSingletonVar(n.Child0);
PlanCompiler.Assert(inputVar != null, "cannot identify Var for the input node to the ScanViewOp");
// and the table should have exactly one column
PlanCompiler.Assert(op.Table.Columns.Count == 1, "table for scanViewOp has more than on column?");
Var columnVar = op.Table.Columns[0];
Node definingNode = VisitNode(n.Child0);
VarInfo varInfo;
if (!m_varInfoMap.TryGetVarInfo(inputVar, out varInfo))
{
PlanCompiler.Assert(false, "didn't find inputVar for scanViewOp?");
}
// we must be dealing with a structured column here
StructuredVarInfo svarInfo = (StructuredVarInfo)varInfo;
TypeInfo typeInfo = m_typeInfo.GetTypeInfo(columnVar.Type);
// if this view does not represent an entityset, then we're pretty much
// done. We simply add a mapping from the columnVar to the list of flattened
// vars produced by the underlying projectOp
m_varInfoMap.CreateStructuredVarInfo(columnVar, svarInfo.NewType, svarInfo.NewVars, svarInfo.Fields);
return definingNode;
}
///
/// Convert a SortOp. Specifically, walk the SortKeys, and expand out
/// any Structured type Var references
///
/// the sortOp
/// the current node
/// new subtree
public override Node Visit(SortOp op, Node n)
{
VisitChildren(n);
List newSortKeys = HandleSortKeys(op.Keys);
if (newSortKeys != op.Keys)
{
n.Op = m_command.CreateSortOp(newSortKeys);
}
return n;
}
///
/// UnnestOp
///
/// Converts an UnnestOp to the right shape.
/// Flattens out the Table instance, and updates
///
///
///
/// new subtree
public override Node Visit(UnnestOp op, Node n)
{
// Visit the children first
VisitChildren(n);
md.TypeUsage newType;
if (n.HasChild0)
{
Node chi = n.Child0;
VarDefOp varDefOp = chi.Op as VarDefOp;
if (null != varDefOp)
{
if (TypeUtils.IsStructuredType(varDefOp.Var.Type)
|| TypeUtils.IsCollectionType(varDefOp.Var.Type))
{
List newChildren = new List();
FlattenComputedVar((ComputedVar)varDefOp.Var, chi, out newChildren, out newType);
PlanCompiler.Assert(newChildren.Count == 1, "Flattening unnest var produced more than one Var");
n.Child0 = newChildren[0];
}
}
}
// Create a new unnestVar
VarInfo unnestVarInfo;
Var newUnnestVar;
if (!m_varInfoMap.TryGetVarInfo(op.Var, out unnestVarInfo))
{
throw EntityUtil.InternalError(EntityUtil.InternalErrorCode.WrongVarType);
}
else if (!unnestVarInfo.IsCollectionType)
{
throw EntityUtil.InternalError(EntityUtil.InternalErrorCode.WrongVarType);
}
else
{
newUnnestVar = ((CollectionVarInfo)unnestVarInfo).NewVar;
}
//
// Flatten out the table
// Create a flattened table definition, and a table with that definiton;
//
Table newTable = op.Table;
Var columnVar = op.Table.Columns[0];
if (TypeUtils.IsStructuredType(columnVar.Type))
{
TypeInfo typeInfo = m_typeInfo.GetTypeInfo(columnVar.Type);
md.RowType newRowType = typeInfo.FlattenedType;
TableMD newTableMD = m_command.CreateFlatTableDefinition(newRowType);
newTable = m_command.CreateTableInstance(newTableMD);
VarInfo outputVarInfo = m_varInfoMap.CreateStructuredVarInfo(columnVar, newRowType, newTable.Columns, newRowType.Properties.ToList());
}
// Create a new UnnestOp
n.Op = m_command.CreateUnnestOp(newUnnestVar, newTable);
return n;
}
#region SetOps
///
/// SetOp
///
/// Converts all SetOps - union/intersect/except.
/// Calls VisitChildren() to do the bulk of the work. After that, the VarMaps
/// need to be updated to reflect the removal of any structured Vars
///
///
///
/// new subtree
protected override Node VisitSetOp(SetOp op, Node n)
{
VisitChildren(n);
// Now walk through the first VarMap, and identify the Vars that are needed
for (int i = 0; i < op.VarMap.Length; i++)
{
List newComputedVars;
op.VarMap[i] = FlattenVarMap(op.VarMap[i], out newComputedVars);
if (newComputedVars != null)
{
n.Children[i] = FixupSetOpChild(n.Children[i], op.VarMap[i], newComputedVars);
}
}
// now get the set of Vars that we will actually need
op.Outputs.Clear();
foreach (Var v in op.VarMap[0].Keys)
{
op.Outputs.Set(v);
}
return n;
}
///
/// Fixes up a SetOp child.
/// As part of Var flattening, it may so happen that the outer var in the VarMap
/// may require a property that has no corresponding analog in the inner Var
/// This logically implies that the corresponding inner property is null. H
/// What we do here is to throw an additional projectOp over the setOp child to
/// add computed Vars (whose defining expressions are null constants) for each
/// of those missing properties
///
/// one child of the setop
/// the varmap for this child
/// list of new Vars produced
/// new node for the setOpchild (if any)
private Node FixupSetOpChild(Node setOpChild, VarMap varMap, List newComputedVars)
{
PlanCompiler.Assert(null != setOpChild, "null setOpChild?");
PlanCompiler.Assert(null != varMap, "null varMap?");
PlanCompiler.Assert(null != newComputedVars, "null newComputedVars?");
// Walk through the list of Vars that have no inner analog, and create
// a computed Var for each of them
VarVec newVarSet = m_command.CreateVarVec();
foreach (KeyValuePair kv in varMap)
{
newVarSet.Set(kv.Value);
}
List varDefOpNodes = new List();
foreach (Var v in newComputedVars)
{
VarDefOp varDefOp = m_command.CreateVarDefOp(v);
Node varDefOpNode = m_command.CreateNode(varDefOp, CreateNullConstantNode(v.Type));
varDefOpNodes.Add(varDefOpNode);
}
Node varDefListNode = m_command.CreateNode(m_command.CreateVarDefListOp(), varDefOpNodes);
ProjectOp projectOp = m_command.CreateProjectOp(newVarSet);
Node projectNode = m_command.CreateNode(projectOp, setOpChild, varDefListNode);
return projectNode;
}
///
/// Flattens out a VarMap.
///
/// Any structured type Vars are expanded out; and collection type Vars
/// are replaced by new Vars that reflect the new collection types.
///
/// There is one special case when dealing with Structured type Vars -
/// the output and input vars may no longer be 1-1; specifically, there
/// may be no input Var corresponding to an output var. In such cases, we
/// build up a new ComputedVar (with an expected value of null), and use that
/// in place of the inner var. A subsequent stage will inspect the list of
/// new ComputedVars, and perform the appropriate fixups
///
/// The VarMap to fixup
/// list of any new computedVars that are created
/// a new VarMap
private VarMap FlattenVarMap(VarMap varMap, out List newComputedVars)
{
newComputedVars = null;
VarMap newVarMap = new VarMap();
foreach (KeyValuePair kv in varMap)
{
VarInfo innerVarInfo;
VarInfo outerVarInfo;
// Does the inner var have a Varinfo - if not, simply add it
// to the VarMap, and continue.
// Otherwise, the Outer var must have a VarInfo too
if (!m_varInfoMap.TryGetVarInfo(kv.Value, out innerVarInfo))
{
newVarMap.Add(kv.Key, kv.Value);
}
else
{
// get my own var info
if (!m_varInfoMap.TryGetVarInfo(kv.Key, out outerVarInfo))
{
outerVarInfo = FlattenSetOpVar((SetOpVar)kv.Key);
}
// If this Var represents a collection type, then simply
// replace the singleton Var
if (outerVarInfo.IsCollectionType)
{
newVarMap.Add(((CollectionVarInfo)outerVarInfo).NewVar, ((CollectionVarInfo)innerVarInfo).NewVar);
}
else
{ // structured type
StructuredVarInfo outerSvarInfo = (StructuredVarInfo)outerVarInfo;
StructuredVarInfo innerSvarInfo = (StructuredVarInfo)innerVarInfo;
// walk through each property, and find the innerVar corresponding
// to that property
foreach (md.EdmProperty prop in outerSvarInfo.Fields)
{
Var outerVar;
Var innerVar;
bool ret = outerSvarInfo.TryGetVar(prop, out outerVar);
PlanCompiler.Assert(ret, "Could not find VarInfo for prop " + prop.Name);
if (!innerSvarInfo.TryGetVar(prop, out innerVar))
{
// we didn't find a corresponding innerVar.
innerVar = m_command.CreateComputedVar(outerVar.Type);
if (newComputedVars == null)
{
newComputedVars = new List();
}
newComputedVars.Add((ComputedVar)innerVar);
}
newVarMap.Add(outerVar, innerVar);
}
}
}
}
return newVarMap;
}
///
/// Flattens a SetOpVar (used in SetOps). Simply produces a list of
/// properties corresponding to each desired property
///
///
/// newProps = new List();
bool hasNullSentinelVar = false;
foreach (PropertyRef p in typeInfo.PropertyRefList)
{
if (!desiredProperties.Contains(p))
{
continue;
}
md.EdmProperty newProperty = typeInfo.GetNewProperty(p);
newProps.Add(newProperty);
SetOpVar newVar = m_command.CreateSetOpVar(md.Helper.GetModelTypeUsage(newProperty));
newVars.Add(newVar);
// Check if it is a null sentinel var
if (!hasNullSentinelVar && IsNullSentinelPropertyRef(p))
{
hasNullSentinelVar = true;
}
}
VarInfo varInfo = m_varInfoMap.CreateStructuredVarInfo(v, typeInfo.FlattenedType, newVars, newProps, hasNullSentinelVar);
return varInfo;
}
#endregion
#region DML RelOps
//
// DML RelOps are technically very simple - we should simply visit the
// children. However, I will defer this to when we actually support DML
// so for now, the default implementation in the basicVisitor is to throw
// unimplemented and that's good enough.
//
#endregion
#endregion
#region ScalarOp Visitors
///
/// SoftCastOp
///
/// Visit the children first.
///
/// If this is an entity type, complextype or ref type, simply return the
/// visited child. (Rationale: These must be in the same type hierarchy; or
/// the earlier stages of query would have barfed. And, we end up
/// using the same "flat" type for every type in the hierarchy)
///
/// If this is a scalar type, then simply return the current node
///
/// If this is a collection type, then create a new softcastOp over the input
/// (the collection type may have changed)
///
/// Otherwise, we're dealing with a record type. Since our earlier
/// definitions of equivalence required that equivalent record types must
/// have the same number of fields, with "promotable" types, and in the same
/// order; *and* since we asked for all properties (see PropertyPushdownHelper),
/// the input must be a NewRecordOp, whose fields line up 1-1 with our fields.
/// Build up a new NewRecordOp based on the arguments to the input NewRecordOp,
/// and build up SoftCastOps for any field whose type does not match
///
///
///
/// newArgs = new List();
// We have to adjust for when we're supposed to add/remove null sentinels;
// it is entirely possible that we may need to add multiple null sentinel
// columns (See SQLBUDT #549068 for an example).
IEnumerator outputs = newOp.Properties.GetEnumerator();
int outputPropertyCount = newOp.Properties.Count;
outputs.MoveNext();
IEnumerator inputs = n.Child0.Children.GetEnumerator();
int inputPropertyCount = n.Child0.Children.Count;
inputs.MoveNext();
// We know that all Null Sentinels are added on the left side, so we'll
// just keep adding them until we have the same number of properties on
// both the input and the output...
while (inputPropertyCount < outputPropertyCount)
{
PlanCompiler.Assert(outputTypeInfo.HasNullSentinelProperty && !inputTypeInfo.HasNullSentinelProperty, "NullSentinelProperty mismatch on input?");
// make up a null sentinel; the output requires it.
newArgs.Add(CreateNullSentinelConstant());
outputs.MoveNext();
outputPropertyCount--;
}
// Likewise, we'll just drop any null sentinel columns from the input until
// we have the same number of columns...
while (inputPropertyCount > outputPropertyCount)
{
PlanCompiler.Assert(!outputTypeInfo.HasNullSentinelProperty && inputTypeInfo.HasNullSentinelProperty, "NullSentinelProperty mismatch on output?");
// remove the null sentinel; the output doesn't require it.
inputs.MoveNext();
inputPropertyCount--;
}
do
{
md.EdmProperty p = outputs.Current;
Node arg = BuildSoftCast(inputs.Current, md.Helper.GetModelTypeUsage(p));
newArgs.Add(arg);
outputs.MoveNext();
}
while (inputs.MoveNext());
Node newNode = m_command.CreateNode(newOp, newArgs);
return newNode;
}
else if (md.TypeSemantics.IsCollectionType(oldType))
{
//
// Our collection type may have changed - 'coz the
// element type of the collection may have changed.
// Simply build up a new castOp (if necessary)
//
return BuildSoftCast(n.Child0, newType);
}
else if (md.TypeSemantics.IsPrimitiveType(oldType))
{
// How primitive! Well, the Prime Directive prohibits me
// from doing much with these.
return n;
}
else
{
PlanCompiler.Assert(md.TypeSemantics.IsNominalType(oldType) ||
md.TypeSemantics.IsReferenceType(oldType),
"Gasp! Not a nominal type or even a reference type");
// I'm dealing with a nominal type (entity, complex type) or
// a reference type here. Every type in the same hierarchy
// must have been rationalized into the same type, and so, we
// won't need to do anything special
PlanCompiler.Assert(Command.EqualTypes(newType, n.Child0.Op.Type),
"Types are not equal");
return n.Child0;
}
}
///
/// CaseOp
///
/// Special handling
///
/// If the case statement is of one of the following two shapes:
/// (1) case when X then NULL else Y, or
/// (2) case when X then Y else NULL,
/// where Y is of row type and the types of the input CaseOp, the NULL and Y are the same,
/// it gets rewritten into: Y', where Y's null sentinel N' is:
/// (1) case when X then NULL else N, or
/// where N is Y's null sentinel.
///
/// the CaseOp
/// corresponding node
/// new subtree
public override Node Visit(CaseOp op, Node n)
{
// Before visiting the children, check whether the case statment can be optimized
bool thenClauseIsNull;
bool canSimplifyPrecheck = PlanCompilerUtil.IsRowTypeCaseOpWithNullability(op, n, out thenClauseIsNull);
VisitChildren(n);
if (canSimplifyPrecheck)
{
Node rewrittenNode;
if (TryRewriteCaseOp(n, thenClauseIsNull, out rewrittenNode))
{
return rewrittenNode;
}
}
//
// If the CaseOp returns a simple type, then we don't need to do
// anything special.
//
// Bug 480780: We must perform further processing, if the result
// type is not a scalar
//
// If the CaseOp returns a collection, then we need to create a
// new CaseOp of the new and improved collection type.
if (TypeUtils.IsCollectionType(op.Type))
{
md.TypeUsage newType = GetNewType(op.Type);
n.Op = m_command.CreateCaseOp(newType);
return n;
}
else if (TypeUtils.IsStructuredType(op.Type))
{
// We've got a structured type, so the CaseOp is flattened out into
// a NewRecordOp via the FlattenCaseOp method.
PropertyRefList desiredProperties = m_nodePropertyMap[n];
Node newNode = FlattenCaseOp(op, n, m_typeInfo.GetTypeInfo(op.Type), desiredProperties);
return newNode;
}
else
{
return n;
}
}
///
/// Given a case statement of one of the following two shapes:
/// (1) case when X then NULL else Y, or
/// (2) case when X then Y else NULL,
/// where Y is of row type and the types of the input CaseOp, the NULL and Y are the same,
/// it rewrittes into: Y', where Y's null sentinel N' is:
/// (1) case when X then NULL else N, or
/// where N is Y's null sentinel.
///
/// The rewrite only happens if:
/// (1) Y has null sentinel, and
/// (2) Y is a NewRecordOp.
///
///
///
///
/// Whether a rewrite was done
private bool TryRewriteCaseOp(Node n, bool thenClauseIsNull, out Node rewrittenNode)
{
rewrittenNode = n;
//If the type of the case op does not have a null sentinel, we can't do the rewrite.
if (!m_typeInfo.GetTypeInfo(n.Op.Type).HasNullSentinelProperty)
{
return false;
}
Node resultNode = thenClauseIsNull ? n.Child2 : n.Child1;
if (resultNode.Op.OpType != OpType.NewRecord)
{
return false;
}
//Rewrite the null sentinel, which is the first child of the resultNode
Node currentNullSentinel = resultNode.Child0;
md.TypeUsage integerType = this.m_command.IntegerType;
PlanCompiler.Assert(currentNullSentinel.Op.Type.EdmEquals(integerType), "Column that is expected to be a null sentinel is not of Integer type.");
CaseOp newCaseOp = m_command.CreateCaseOp(integerType);
List children = new List(3);
//The the 'when' from the case statement
children.Add(n.Child0);
Node nullSentinelNullNode = m_command.CreateNode(m_command.CreateNullOp(integerType));
Node nullSentinelThenNode = thenClauseIsNull ? nullSentinelNullNode : currentNullSentinel;
Node nullSentinelElseNode = thenClauseIsNull ? currentNullSentinel : nullSentinelNullNode;
children.Add(nullSentinelThenNode);
children.Add(nullSentinelElseNode);
//Use the case op as a new null sentinel
resultNode.Child0 = m_command.CreateNode(newCaseOp, children);
rewrittenNode = resultNode;
return true;
}
///
/// Flattens a CaseOp - Specifically, if the CaseOp returns a structuredtype,
/// then the CaseOp is broken up so that we build up a "flat" record constructor
/// for that structured type, with each argument to the record constructor being
/// a (scalar) CaseOp. For example:
///
/// Case when b1 then e1 else e2 end
///
/// gets translated into:
///
/// RecordOp(case when b1 then e1.a else e2.a end,
/// case when b1 then e1.b else e2.b end,
/// ...)
///
/// The property extraction is optimized by producing only those properties
/// that have actually been requested.
///
/// the CaseOp
/// Node corresponding to the CaseOp
/// Information about the type
/// Set of properties desired
/// fieldTypes = new List();
List fieldValues = new List();
foreach (PropertyRef pref in typeInfo.PropertyRefList)
{
// Is this property desired later?
if (!desiredProperties.Contains(pref))
{
continue;
}
md.EdmProperty property = typeInfo.GetNewProperty(pref);
// Build up an accessor for this property across each when/then clause
List caseChildren = new List();
for (int i = 0; i < n.Children.Count - 1; )
{
Node whenNode = Copy(n.Children[i]);
caseChildren.Add(whenNode);
i++;
Node propNode = BuildAccessorWithNulls(n.Children[i], property);
caseChildren.Add(propNode);
i++;
}
Node elseNode = BuildAccessorWithNulls(n.Children[n.Children.Count - 1], property);
caseChildren.Add(elseNode);
Node caseNode = m_command.CreateNode(m_command.CreateCaseOp(md.Helper.GetModelTypeUsage(property)), caseChildren);
fieldTypes.Add(property);
fieldValues.Add(caseNode);
}
NewRecordOp newRec = m_command.CreateNewRecordOp(typeInfo.FlattenedTypeUsage, fieldTypes);
return m_command.CreateNode(newRec, fieldValues);
}
///
/// CollectOp
///
/// Nothing much to do - simply update the result type
///
/// the NestOp
/// corresponding node
/// new subtree
public override Node Visit(CollectOp op, Node n)
{
VisitChildren(n);
// simply update the desired type
n.Op = m_command.CreateCollectOp(GetNewType(op.Type));
return n;
}
///
/// ComparisonOp
///
/// If the inputs to the comparisonOp are Refs/records/entitytypes, then
/// we need to flatten these out. Of course, the only reasonable comparisons
/// should be EQ and NE
///
///
///
/// properties1;
List properties2;
List values1;
List values2;
// get a list of the relevant properties and values from each of the children
GetPropertyValues(child0TypeInfo, OperationKind.Equality, n.Child0, false, out properties1, out values1);
GetPropertyValues(child1TypeInfo, OperationKind.Equality, n.Child1, false, out properties2, out values2);
PlanCompiler.Assert((properties1.Count == properties2.Count) && (values1.Count == values2.Count), "different shaped structured types?");
// Build up an and-chain of comparison ops on the property values
Node andNode = null;
for (int i = 0; i < values1.Count; i++)
{
ComparisonOp newCompOp = m_command.CreateComparisonOp(op.OpType);
Node newCompNode = m_command.CreateNode(newCompOp, values1[i], values2[i]);
if (null == andNode)
andNode = newCompNode;
else
andNode = m_command.CreateNode(m_command.CreateConditionalOp(OpType.And), andNode, newCompNode);
}
return andNode;
}
///
/// ConditionalOp
///
/// IsNull requires special handling.
///
///
///
/// properties = null;
List values = null;
GetPropertyValues(typeInfo, OperationKind.IsNull, n.Child0, false, out properties, out values);
PlanCompiler.Assert(properties.Count == values.Count && properties.Count > 0, "No properties returned from GetPropertyValues(IsNull)?");
Node andNode = null;
foreach (Node propertyValue in values)
{
Node isNullNode = m_command.CreateNode(m_command.CreateConditionalOp(OpType.IsNull), propertyValue);
if (andNode == null)
andNode = isNullNode;
else
andNode = m_command.CreateNode(m_command.CreateConditionalOp(OpType.And), andNode, isNullNode);
}
return andNode;
}
///
/// Convert a ConstrainedSortOp. Specifically, walk the SortKeys, and expand out
/// any Structured type Var references
///
/// the constrainedSortOp
/// the current node
/// new subtree
public override Node Visit(ConstrainedSortOp op, Node n)
{
VisitChildren(n);
List newSortKeys = HandleSortKeys(op.Keys);
if (newSortKeys != op.Keys)
{
n.Op = m_command.CreateConstrainedSortOp(newSortKeys, op.WithTies);
}
return n;
}
///
/// GetEntityKeyOp
///
///
///
///
/// GetRefKeyOp
///
///
///
///
/// GetEntityKeyOp/GetRefKeyOp common handling
///
/// In either case, get the "key" properties from the input entity/ref, and
/// build up a record constructor from these values
///
/// the GetRefKey/GetEntityKey op
/// current subtree
/// new expression subtree
private Node FlattenGetKeyOp(ScalarOp op, Node n)
{
PlanCompiler.Assert(op.OpType == OpType.GetEntityRef || op.OpType == OpType.GetRefKey, "Expecting GetEntityRef or GetRefKey ops");
TypeInfo inputTypeInfo = m_typeInfo.GetTypeInfo(((ScalarOp)n.Child0.Op).Type);
TypeInfo outputTypeInfo = m_typeInfo.GetTypeInfo(op.Type);
// Visit the child - will flatten out the input ref/entity
VisitChildren(n);
// Get "key" properties (and the corresponding values) from the input
List inputFieldTypes;
List inputFieldValues;
// Get the key properties for GetRefKey; get the Identity properties
// for GetEntityRef
if (op.OpType == OpType.GetRefKey)
{
GetPropertyValues(inputTypeInfo, OperationKind.GetKeys, n.Child0, false /* ignore missing props */, out inputFieldTypes, out inputFieldValues);
}
else
{
PlanCompiler.Assert(op.OpType == OpType.GetEntityRef,
"Expected OpType.GetEntityRef: Found " + op.OpType);
GetPropertyValues(inputTypeInfo, OperationKind.GetIdentity, n.Child0, false, out inputFieldTypes, out inputFieldValues);
}
if (outputTypeInfo.HasNullSentinelProperty && !inputTypeInfo.HasNullSentinelProperty)
{
// Add a null sentinel column, the input doesn't have one but the output requires it.
inputFieldValues.Insert(0, CreateNullSentinelConstant());
}
// create an appropriate record constructor
List outputFieldTypes = new List(outputTypeInfo.FlattenedType.Properties);
PlanCompiler.Assert(inputFieldValues.Count == outputFieldTypes.Count, "fieldTypes.Count mismatch?");
NewRecordOp rec = m_command.CreateNewRecordOp(outputTypeInfo.FlattenedTypeUsage, outputFieldTypes);
Node newNode = m_command.CreateNode(rec, inputFieldValues);
return newNode;
}
///
/// Common handler for PropertyOp and RelPropertyOp
///
///
///
///
/// fieldTypes = new List();
List fieldValues = new List();
PropertyRefList expectedProperties = m_nodePropertyMap[n];
foreach (PropertyRef npr in outputTypeInfo.PropertyRefList)
{
// Is this a property that's desired by my consumers?
if (expectedProperties.Contains(npr))
{
PropertyRef newPropRef = npr.CreateNestedPropertyRef(propertyRef);
md.EdmProperty outputNestedProp = outputTypeInfo.GetNewProperty(npr);
md.EdmProperty newNestedProp = inputTypeInfo.GetNewProperty(newPropRef);
Node field = BuildAccessor(n.Child0, newNestedProp);
if (null != field)
{
fieldTypes.Add(outputNestedProp);
fieldValues.Add(field);
}
}
}
Op newRecordOp = m_command.CreateNewRecordOp(outputTypeInfo.FlattenedTypeUsage, fieldTypes);
newNode = m_command.CreateNode(newRecordOp, fieldValues);
}
else
{
md.EdmProperty newProp = inputTypeInfo.GetNewProperty(propertyRef);
// Build an accessor over the new property
newNode = this.BuildAccessorWithNulls(n.Child0, newProp);
}
return newNode;
}
///
/// PropertyOp
///
/// If this is a scalar/collection property, then simply get the appropriate
/// field out.
///
/// Otherwise, build up a record constructor corresponding to the result
/// type - optimize this by only getting those properties that are needed
///
/// If the instance is not a structured type (ie) it is a UDT, then simply return
///
///
/// the PropertyOp
/// the corresponding node
/// new subtree
public override Node Visit(PropertyOp op, Node n)
{
return VisitPropertyOp(op, n, new SimplePropertyRef(op.PropertyInfo));
}
///
/// RelPropertyOp. Pick out the appropriate property from the child
///
///
///
///
/// RefOp
///
/// Simply convert this into the corresponding record type - with one
/// field for each key, and one for the entitysetid
///
///
///
/// inputFields;
List inputFieldValues;
GetPropertyValues(inputTypeInfo, OperationKind.All, n.Child0, false, out inputFields, out inputFieldValues);
// Get my property list
List outputFields = new List(outputTypeInfo.FlattenedType.Properties);
if (outputTypeInfo.HasEntitySetIdProperty)
{
PlanCompiler.Assert(outputFields[0] == outputTypeInfo.EntitySetIdProperty, "OutputField0 must be the entitySetId property");
if (inputTypeInfo.HasNullSentinelProperty && !outputTypeInfo.HasNullSentinelProperty)
{ // realistically, REFs can't have null sentinels, but I'm being pedantic...
PlanCompiler.Assert(outputFields.Count == inputFields.Count, "Mismatched field count: Expected " + inputFields.Count + "; Got " + outputFields.Count);
RemoveNullSentinel(inputTypeInfo, inputFields, inputFieldValues, outputFields);
}
else
{
PlanCompiler.Assert(outputFields.Count == inputFields.Count + 1, "Mismatched field count: Expected " + (inputFields.Count + 1) + "; Got " + outputFields.Count);
}
// Now prepend a value for the entitysetid property and a value for this property
int entitySetId = m_typeInfo.GetEntitySetId(op.EntitySet);
inputFieldValues.Insert(0, m_command.CreateNode(m_command.CreateInternalConstantOp(md.Helper.GetModelTypeUsage(outputTypeInfo.EntitySetIdProperty), entitySetId)));
}
else
{
if (inputTypeInfo.HasNullSentinelProperty && !outputTypeInfo.HasNullSentinelProperty)
{ // realistically, REFs can't have null sentinels, but I'm being pedantic...
RemoveNullSentinel(inputTypeInfo, inputFields, inputFieldValues, outputFields);
}
PlanCompiler.Assert(outputFields.Count == inputFields.Count, "Mismatched field count: Expected " + inputFields.Count + "; Got " + outputFields.Count);
}
// now build up a NewRecordConstructor with the appropriate info
NewRecordOp recOp = m_command.CreateNewRecordOp(outputTypeInfo.FlattenedTypeUsage, outputFields);
Node newNode = m_command.CreateNode(recOp, inputFieldValues);
return newNode;
}
// We have to adjust for when we're supposed to remove null sentinels;
// columns (See SQLBUDT #553534 for an example). Note that we shouldn't
// have to add null sentinels here, since reference types won't be expecting
// them (the fact that the key is null is good enough...)
private static void RemoveNullSentinel(TypeInfo inputTypeInfo, List inputFields, List inputFieldValues, List outputFields)
{
PlanCompiler.Assert(inputFields[0] == inputTypeInfo.NullSentinelProperty, "InputField0 must be the null sentinel property");
inputFields.RemoveAt(0);
inputFieldValues.RemoveAt(0);
}
///
/// VarRefOp
///
/// Replace a VarRef with a copy of the corresponding "Record" constructor
///
/// the VarRefOp
/// the node
/// new subtree
public override Node Visit(VarRefOp op, Node n)
{
// Lookup my VarInfo
VarInfo varInfo;
if (!m_varInfoMap.TryGetVarInfo(op.Var, out varInfo))
{
PlanCompiler.Assert(!TypeUtils.IsStructuredType(op.Type),
"No varInfo for a structured type var: Id = " + op.Var.Id + " Type = " + op.Type);
return n;
}
if (varInfo.IsCollectionType)
{
n.Op = m_command.CreateVarRefOp(((CollectionVarInfo)varInfo).NewVar);
return n;
}
else
{
// A very specialized record constructor mechanism for structured type Vars.
// We look up the VarInfo corresponding to the Var - which has a set of fields
// and the corresponding properties that we need to produce
StructuredVarInfo structuredVarInfo = (StructuredVarInfo)varInfo;
NewRecordOp newOp = m_command.CreateNewRecordOp(structuredVarInfo.NewTypeUsage, structuredVarInfo.Fields);
List newNodeChildren = new List();
foreach (Var v in varInfo.NewVars)
{
VarRefOp newVarRefOp = m_command.CreateVarRefOp(v);
newNodeChildren.Add(m_command.CreateNode(newVarRefOp));
}
Node newNode = m_command.CreateNode(newOp, newNodeChildren);
return newNode;
}
}
#region record construction ops
///
/// Handler for NewEntity
///
///
///
///
/// NewInstanceOp
///
/// the NewInstanceOp
/// corresponding node
/// new subtree
public override Node Visit(NewInstanceOp op, Node n)
{
return FlattenConstructor(op, n);
}
///
/// DiscriminatedNewInstanceOp
///
/// the DiscriminatedNewInstanceOp
/// corresponding node
/// new subtree
public override Node Visit(DiscriminatedNewEntityOp op, Node n)
{
return FlattenConstructor(op, n);
}
///
/// Given an explicit discriminator value, map to normalized values. Essentially, this allows
/// a discriminated new instance to coexist with free-floating entities, MEST, etc. which use
/// general purpose ordpath type ids (e.g. '0X0X')
///
/// An example of the normalization is given:
///
/// CASE
/// WHEN discriminator = 'Base' THEN '0X'
/// WHEN discriminator = 'Derived1' THEN '0X0X'
/// WHEN discriminator = 'Derived2' THEN '0X1X'
/// ELSE '0X2X' -- default case for 'Derived3'
///
private Node NormalizeTypeDiscriminatorValues(DiscriminatedNewEntityOp op, Node discriminator)
{
TypeInfo typeInfo = m_typeInfo.GetTypeInfo(op.Type);
CaseOp normalizer = m_command.CreateCaseOp(typeInfo.RootType.TypeIdProperty.TypeUsage);
List children = new List(op.DiscriminatorMap.TypeMap.Count * 2 - 1);
for (int i = 0; i < op.DiscriminatorMap.TypeMap.Count; i++)
{
object discriminatorValue = op.DiscriminatorMap.TypeMap[i].Key;
md.EntityType type = op.DiscriminatorMap.TypeMap[i].Value;
TypeInfo currentTypeInfo = m_typeInfo.GetTypeInfo(md.TypeUsage.Create(type));
Node normalizedDiscriminatorConstant = CreateTypeIdConstant(currentTypeInfo);
// for the last type, return the 'then' value
if (i == op.DiscriminatorMap.TypeMap.Count - 1)
{
// ELSE normalizedDiscriminatorValue
children.Add(normalizedDiscriminatorConstant);
}
else
{
// WHEN discriminator = discriminatorValue THEN normalizedDiscriminatorValue
ConstantBaseOp discriminatorValueOp = m_command.CreateConstantOp(md.Helper.GetModelTypeUsage(op.DiscriminatorMap.DiscriminatorProperty.TypeUsage),
discriminatorValue);
Node discriminatorConstant = m_command.CreateNode(discriminatorValueOp);
ComparisonOp discriminatorPredicateOp = m_command.CreateComparisonOp(OpType.EQ);
Node discriminatorPredicate = m_command.CreateNode(discriminatorPredicateOp, discriminator, discriminatorConstant);
children.Add(discriminatorPredicate);
children.Add(normalizedDiscriminatorConstant);
}
}
// swap discriminator with case op normalizing the discriminator
discriminator = m_command.CreateNode(normalizer, children);
return discriminator;
}
///
/// NewRecordOp
///
/// the newRecordOp
/// corresponding node
/// new subtree
public override Node Visit(NewRecordOp op, Node n)
{
return FlattenConstructor(op, n);
}
///
/// Build out an expression corresponding to the entitysetid
///
/// the property corresponding to the entitysetid
/// the *NewEntity op
///
/// Flattens out a constructor into a "flat" record constructor.
/// The "flat" record type is looked up for the current constructor's type,
/// and each property is filled out from the current constructor's fields
///
/// The NewRecordOp/NewInstanceOp
/// The current subtree
/// the new subtree
private Node FlattenConstructor(ScalarOp op, Node n)
{
PlanCompiler.Assert(op.OpType == OpType.NewInstance || op.OpType == OpType.NewRecord || op.OpType == OpType.DiscriminatedNewEntity || op.OpType == OpType.NewEntity,
"unexpected op: " + op.OpType + "?");
// First visit all my children
VisitChildren(n);
// Find the new type corresponding to the type
TypeInfo typeInfo = m_typeInfo.GetTypeInfo(op.Type);
md.RowType flatType = typeInfo.FlattenedType;
NewEntityBaseOp newEntityOp = op as NewEntityBaseOp;
// Identify the fields
IEnumerable opFields = null;
DiscriminatedNewEntityOp discriminatedNewInstanceOp = null;
if (op.OpType == OpType.NewRecord)
{
// Get only those fields that I have values for
opFields = ((NewRecordOp)op).Properties;
}
else if (op.OpType == OpType.DiscriminatedNewEntity)
{
// Get all properties projected by the discriminated new instance op
discriminatedNewInstanceOp = (DiscriminatedNewEntityOp)op;
opFields = discriminatedNewInstanceOp.DiscriminatorMap.Properties;
}
else
{
// Children align with structural members of type for a standard NewInstanceOp
opFields = TypeHelpers.GetAllStructuralMembers(op.Type);
}
// Next, walk through each of my field, and flatten out any field
// that is structured.
List newFields = new List();
List newFieldValues = new List();
//
// NOTE: we expect the type id property and the entityset id properties
// to be at the start of the properties collection.
//
// Add a typeid property if we need one
//
if (typeInfo.HasTypeIdProperty)
{
newFields.Add(typeInfo.TypeIdProperty);
if (null == discriminatedNewInstanceOp)
{
newFieldValues.Add(CreateTypeIdConstant(typeInfo));
}
else
{
// first child in DiscriminatedNewInstanceOp is discriminator/typeid
Node discriminator = n.Children[0];
if (null == typeInfo.RootType.DiscriminatorMap)
{
// if there are multiple sets (or free-floating constructors) for this type
// hierarchy, normalize the discriminator value to expose the standard
// '0X' style values
discriminator = NormalizeTypeDiscriminatorValues(discriminatedNewInstanceOp, discriminator);
}
newFieldValues.Add(discriminator);
}
}
//
// Add an entitysetid property if we need one
//
if (typeInfo.HasEntitySetIdProperty)
{
newFields.Add(typeInfo.EntitySetIdProperty);
PlanCompiler.Assert(newEntityOp != null, "unexpected optype:" + op.OpType);
Node entitySetIdNode = GetEntitySetIdExpr(typeInfo.EntitySetIdProperty, newEntityOp);
// Get the entity-set-id of the "current" entityset
newFieldValues.Add(entitySetIdNode);
}
// Add a nullability property if we need one
if (typeInfo.HasNullSentinelProperty)
{
newFields.Add(typeInfo.NullSentinelProperty);
newFieldValues.Add(CreateNullSentinelConstant());
}
//
// first child of discriminatedNewInstanceOp is the typeId; otherwise, the first child is the first property
//
int childrenIndex = null == discriminatedNewInstanceOp ? 0 : 1;
foreach (md.EdmMember opField in opFields)
{
Node fieldValue = n.Children[childrenIndex];
if (TypeUtils.IsStructuredType(md.Helper.GetModelTypeUsage(opField)))
{
// Flatten out nested type
md.RowType nestedFlatType = m_typeInfo.GetTypeInfo(md.Helper.GetModelTypeUsage(opField)).FlattenedType;
// Find offset of opField in top-level flat type
int nestedPropertyOffset = typeInfo.RootType.GetNestedStructureOffset(new SimplePropertyRef(opField));
foreach (md.EdmProperty nestedProperty in nestedFlatType.Properties)
{
// Try to build up an accessor for this property from the input
Node nestedPropertyValue = BuildAccessor(fieldValue, nestedProperty);
if (null != nestedPropertyValue)
{
newFields.Add(flatType.Properties[nestedPropertyOffset]);
newFieldValues.Add(nestedPropertyValue);
}
nestedPropertyOffset++;
}
}
else
{
PropertyRef propRef = new SimplePropertyRef(opField);
md.EdmProperty outputTypeProp = typeInfo.GetNewProperty(propRef);
newFields.Add(outputTypeProp);
newFieldValues.Add(fieldValue);
}
childrenIndex++;
}
//
// We've now handled all the regular properties. Now, walk through all the rel properties -
// obviously, this only applies for the *NewEntityOps
//
if (newEntityOp != null)
{
foreach (RelProperty relProp in newEntityOp.RelationshipProperties)
{
Node fieldValue = n.Children[childrenIndex];
md.RowType nestedFlatType = m_typeInfo.GetTypeInfo(relProp.ToEnd.TypeUsage).FlattenedType;
// Find offset of opField in top-level flat type
int nestedPropertyOffset = typeInfo.RootType.GetNestedStructureOffset(new RelPropertyRef(relProp));
foreach (md.EdmProperty nestedProperty in nestedFlatType.Properties)
{
// Try to build up an accessor for this property from the input
Node nestedPropertyValue = BuildAccessor(fieldValue, nestedProperty);
if (null != nestedPropertyValue)
{
newFields.Add(flatType.Properties[nestedPropertyOffset]);
newFieldValues.Add(nestedPropertyValue);
}
nestedPropertyOffset++;
}
childrenIndex++;
}
}
//
// So, now we have the list of all fields that should make up the
// flat type. Create a new node with them.
//
NewRecordOp newOp = m_command.CreateNewRecordOp(typeInfo.FlattenedTypeUsage, newFields);
Node newNode = m_command.CreateNode(newOp, newFieldValues);
return newNode;
}
///
/// NullOp
///
/// If the node represents a null of an entity type it 'flattens' it into a new record,
/// with at most one non-null value: for the typeIdProperty, if one is needed.
/// If the node represents an null of a non-entity type, no special work is done.
///
/// The NullOp
/// The current subtree
/// the new subtree
public override Node Visit(NullOp op, Node n)
{
if (!TypeUtils.IsStructuredType(op.Type))
{
return n;
}
// Find the new type corresponding to the type
TypeInfo typeInfo = m_typeInfo.GetTypeInfo(op.Type);
List newFields = new List();
List newFieldValues = new List();
// Add a typeid property if we need one
if (typeInfo.HasTypeIdProperty)
{
newFields.Add(typeInfo.TypeIdProperty);
var typeIdType = md.Helper.GetModelTypeUsage(typeInfo.TypeIdProperty);
newFieldValues.Add(CreateNullConstantNode(typeIdType));
}
NewRecordOp newRecordOp = new NewRecordOp(typeInfo.FlattenedTypeUsage, newFields);
return m_command.CreateNode(newRecordOp, newFieldValues);
}
#endregion
#region type comparison ops
///
/// IsOf
///
/// Convert an IsOf operator into a typeid comparison:
///
/// IsOfOnly(e, T) => e.TypeId == TypeIdValue(T)
/// IsOf(e, T) => e.TypeId like TypeIdValue(T)% escape null
///
///
/// The IsOfOp to handle
/// current isof subtree
/// new subtree
public override Node Visit(IsOfOp op, Node n)
{
// First visit all my children
VisitChildren(n);
if (!TypeUtils.IsStructuredType(op.IsOfType))
{
return n;
}
TypeInfo typeInfo = m_typeInfo.GetTypeInfo(op.IsOfType);
Node newNode = CreateTypeComparisonOp(n.Child0, typeInfo, op.IsOfOnly);
return newNode;
}
///
/// TreatOp
///
/// TreatOp(e, T) => case when e.TypeId like TypeIdValue(T) then T else null end
///
/// the TreatOp
/// the node
/// new subtree
public override Node Visit(TreatOp op, Node n)
{
// First visit all my children
VisitChildren(n);
//
// filter out useless treat operations
// Treat(subtype-instance as superType)
//
ScalarOp arg = (ScalarOp)n.Child0.Op;
if (op.IsFakeTreat ||
md.TypeSemantics.IsStructurallyEqual(arg.Type, op.Type) ||
md.TypeSemantics.IsSubTypeOf(arg.Type, op.Type))
{
return n.Child0;
}
// When we support UDTs
if (!TypeUtils.IsStructuredType(op.Type))
{
return n;
}
//
// First, convert this into a CaseOp:
// case when e.TypeId like TypeIdValue then e else null end
//
TypeInfo typeInfo = m_typeInfo.GetTypeInfo(op.Type);
Node likeNode = CreateTypeComparisonOp(n.Child0, typeInfo, false);
CaseOp caseOp = m_command.CreateCaseOp(typeInfo.FlattenedTypeUsage);
Node caseNode = m_command.CreateNode(caseOp, likeNode, n.Child0, CreateNullConstantNode(caseOp.Type));
//
// Now "flatten" out this Op into a constructor. But only get the
// desired properties
//
PropertyRefList desiredProperties = m_nodePropertyMap[n];
Node flattenedCaseNode = FlattenCaseOp(caseOp, caseNode, typeInfo, desiredProperties);
return flattenedCaseNode;
}
///
/// Create a typeid-comparison operator - more specifically, create an
/// operator that compares a typeid value with the typeid property of an
/// input structured type.
/// The comparison may be "exact" - in which case we're looking for the exact
/// type; otherwise, we're looking for any possible subtypes.
/// The "exact" variant is used by the IsOfOp (only); the other variant is
/// used by IsOfOp and TreatOp
///
/// The input structured type expression
/// Augmented type information for the type
/// Exact comparison?
/// New comparison expression
private Node CreateTypeComparisonOp(Node input, TypeInfo typeInfo, bool isExact)
{
Node typeIdProperty = BuildTypeIdAccessor(input, typeInfo);
Node newNode = null;
if (isExact)
{
newNode = CreateTypeEqualsOp(typeInfo, typeIdProperty);
}
else
{
if (typeInfo.RootType.DiscriminatorMap != null)
{
// where there are explicit discriminator values, LIKE '0X%' pattern does not work...
newNode = CreateDisjunctiveTypeComparisonOp(typeInfo, typeIdProperty);
}
else
{
Node typeIdConstantNode = CreateTypeIdConstantForPrefixMatch(typeInfo);
LikeOp likeOp = m_command.CreateLikeOp();
newNode = m_command.CreateNode(likeOp, typeIdProperty, typeIdConstantNode, CreateNullConstantNode(DefaultTypeIdType));
}
}
return newNode;
}
///
/// Create a filter matching all types in the given hierarchy (typeIdProperty IN typeInfo.Hierarchy) e.g.:
///
/// typeIdProperty = 'Base' OR typeIdProperty = 'Derived1' ...
///
/// This is called only for types using DiscriminatorMap (explicit discriminator values)
///
///
///
/// type hierarchy check
private Node CreateDisjunctiveTypeComparisonOp(TypeInfo typeInfo, Node typeIdProperty)
{
PlanCompiler.Assert(typeInfo.RootType.DiscriminatorMap != null, "should be used only for DiscriminatorMap type checks");
// collect all non-abstract types in the given hierarchy
IEnumerable types = typeInfo.GetTypeHierarchy().Where(t => !t.Type.EdmType.Abstract);
// generate a disjunction
Node current = null;
foreach (TypeInfo type in types)
{
Node typeComparisonNode = CreateTypeEqualsOp(type, typeIdProperty);
if (null == current)
{
current = typeComparisonNode;
}
else
{
current = m_command.CreateNode(m_command.CreateConditionalOp(OpType.Or), current, typeComparisonNode);
}
}
if (null == current)
{
// only abstract types in this hierarchy... no values possible
current = m_command.CreateNode(m_command.CreateFalseOp());
}
return current;
}
///
/// Generates a node of the form typeIdProperty = typeInfo.TypeId
///
///
///
/// type equality check
private Node CreateTypeEqualsOp(TypeInfo typeInfo, Node typeIdProperty)
{
Node typeIdConstantNode = CreateTypeIdConstant(typeInfo);
ComparisonOp eqCompOp = m_command.CreateComparisonOp(OpType.EQ);
Node result = m_command.CreateNode(eqCompOp, typeIdProperty, typeIdConstantNode);
return result;
}
#endregion
#endregion
#endregion
}
}
// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
//----------------------------------------------------------------------
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
//
// @owner [....]
// @backupOwner [....]
//---------------------------------------------------------------------
using System;
using System.Collections;
using System.Collections.Generic;
//using System.Diagnostics; // Please use PlanCompiler.Assert instead of Debug.Assert in this class...
using System.Globalization;
using System.Linq;
using System.Data.Common;
using md = System.Data.Metadata.Edm;
using System.Data.Query.InternalTrees;
using System.Data.Query.PlanCompiler;
namespace System.Data.Query.PlanCompiler
{
///
/// The goal of this module is to eliminate all references to nominal types
/// in the tree. Additionally, all structured types are replaced by "flat"
/// record types - where every field of the structured type is a scalar type.
/// Note that UDTs are not considered to be structured types.
///
/// At the end of this phase,
/// * there are no more nominal types in the tree
/// * there are no more nested record types in the tree
/// * No Var in the tree is of an structured type
/// * Additionally (and these follow from the statements above)
/// * There are no NewInstanceOp constructors in the tree
/// * There are no PropertyOp operators where the result is a structured type
///
/// This module uses information from the PropertyPushdown phase to "optimize"
/// structured type elimination. Essentially, if we can avoid producing pieces
/// of information that will be discarded later, then lets do that.
///
/// The general mechanism of type elimination is as follows. We walk up the tree
/// in a bottom up fashion, and try to convert all structured types into flattened
/// record types - type constructors are first converted into flat record constructors
/// and then dismantled etc. The barrier points - Vars - are all converted into
/// scalar types, and all intermediate stages will be eliminated in transition.
///
/// The output from this phase includes a ColumnMap - which is used later by
/// the execution model to produce results in the right form from an otherwise
/// flat query
///
/// Notes: This phase could be combined later with the PropertyPushdown phase
///
///
internal class NominalTypeEliminator : BasicOpVisitorOfNode
{
#region Nested Classes
///
/// Describes an operation kind - for various property extractions
///
internal enum OperationKind
{
///
/// Comparing two instances for equality
///
Equality,
///
/// Checking to see if an instance is null
///
IsNull,
///
/// Getting the "identity" of an entity
///
GetIdentity,
///
/// Getting the keys of an entity
///
GetKeys,
///
/// All properties of an entity
///
All
}
#endregion
#region private state
private Dictionary m_varPropertyMap;
private Dictionary m_nodePropertyMap;
private VarInfoMap m_varInfoMap;
private PlanCompiler m_compilerState;
private Command m_command { get { return m_compilerState.Command; } }
private StructuredTypeInfo m_typeInfo;
private Dictionary m_typeToNewTypeMap;
private const string PrefixMatchCharacter = "%"; // This is ANSI-SQL defined, but it should probably be configurable.
#endregion
#region constructors
private NominalTypeEliminator(PlanCompiler compilerState,
StructuredTypeInfo typeInfo,
Dictionary varPropertyMap,
Dictionary nodePropertyMap)
{
m_compilerState = compilerState;
m_typeInfo = typeInfo;
m_varPropertyMap = varPropertyMap;
m_nodePropertyMap = nodePropertyMap;
m_varInfoMap = new VarInfoMap();
m_typeToNewTypeMap = new Dictionary(TypeUsageEqualityComparer.Instance);
}
#endregion
#region Process Driver
///
/// Eliminates all structural types from the query
///
/// current compiler state
/// list of all referenced types
/// list of referenced entitysets
internal static void Process(PlanCompiler compilerState,
StructuredTypeInfo structuredTypeInfo)
{
#if DEBUG
//string phase0 = Dump.ToXml(compilerState.Command);
Validator.Validate(compilerState);
#endif
// Phase 1: Top-down property pushdown
Dictionary varPropertyMap;
Dictionary nodePropertyMap;
PropertyPushdownHelper.Process(compilerState.Command, structuredTypeInfo, out varPropertyMap, out nodePropertyMap);
#if DEBUG
//string phase1 = Dump.ToXml(compilerState.Command);
Validator.Validate(compilerState);
#endif
// Phase 2: actually eliminate nominal types
NominalTypeEliminator nte = new NominalTypeEliminator(compilerState, structuredTypeInfo,
varPropertyMap, nodePropertyMap);
nte.Process();
#if DEBUG
//string phase2 = Dump.ToXml(compilerState.Command);
Validator.Validate(compilerState);
#endif
#if DEBUG
//To avoid garbage collection
//int size = phase0.Length;
//size = phase1.Length;
//size = phase2.Length;
#endif
}
///
/// The real driver. Invokes the visitor to traverse the tree bottom-up,
/// and modifies the tree along the way.
///
private void Process()
{
Node rootNode = m_command.Root;
PlanCompiler.Assert(rootNode.Op.OpType == OpType.PhysicalProject, "root node is not PhysicalProjectOp?");
// invoke the visitor on the root node
rootNode.Op.Accept(this, rootNode);
}
#endregion
#region type utilities
///
/// The datatype of the typeid property
///
private md.TypeUsage DefaultTypeIdType
{
get { return m_command.StringType; }
}
///
/// Get the "new" type corresponding to the input type.
/// For structured types, we simply look up the typeInfoMap
/// For collection types, we create a new collection type based on the
/// "new" element type.
/// For all other types, we simply return the input type
///
///
/// (type, out collectionType))
{
// If this is a collection type, then clone a new collection type
md.TypeUsage newElementType = GetNewType(collectionType.TypeUsage);
newType = TypeUtils.CreateCollectionType(newElementType);
}
else if (TypeUtils.IsStructuredType(type))
{
// structured type => we've already calculated the input
newType = m_typeInfo.GetTypeInfo(type).FlattenedTypeUsage;
}
else
{
// "simple" type => return the input type
newType = type;
}
// Add this information to the map
m_typeToNewTypeMap[type] = newType;
return newType;
}
#endregion
#region misc utilities
///
/// This function builds a "property accessor" over the input expression. It
/// can produce one of three results:
///
/// - It can return "null", if it is convinced that the input has no
/// such expression
/// - It can return a subnode of the input, if that subnode represents
/// the property
/// - Or, it can build a PropertyOp explicitly
///
/// Assertion: the property is not a structured type
///
/// The input expression
/// The desired property
///
/// A BuildAccessor variant. If the appropriate property was not found, then
/// build up a null constant instead
///
///
///
///
/// Builds up an accessor to the typeid property. If the type has no typeid
/// property, then we simply create a constantOp with the corresponding
/// typeid value for the type
///
/// the input expression
/// the original type of the input expression
///
/// Builds a SoftCast operator over the input - if one is necessary.
///
/// the input expression to "cast"
/// the target type
/// the "cast"ed expression
private Node BuildSoftCast(Node node, md.TypeUsage targetType)
{
PlanCompiler.Assert(node.Op.IsScalarOp, "Attempting SoftCast around non-ScalarOp?");
if (Command.EqualTypes(node.Op.Type, targetType))
{
return node;
}
// Skip any castOps we may have created already
while (node.Op.OpType == OpType.SoftCast)
{
node = node.Child0;
}
Node newNode = m_command.CreateNode(m_command.CreateSoftCastOp(targetType), node);
return newNode;
}
///
/// Clones a subtree.
/// This is used by the "BuildAccessor" routines to build a property-accessor
/// over some input. If we're reusing the input, the input must be cloned.
///
/// The subtree to copy
///
/// Returns a node for a null constant of the desired type
///
///
///
/// Create a node to represent nullability.
///
/// Node for the typeid constant
private Node CreateNullSentinelConstant()
{
NullSentinelOp op = m_command.CreateNullSentinelOp();
return m_command.CreateNode(op);
}
///
/// Create a node to represent the exact value of the typeid constant
///
/// The current type
/// Node for the typeid constant
private Node CreateTypeIdConstant(TypeInfo typeInfo)
{
object value = typeInfo.TypeId;
md.TypeUsage typeIdType;
if (typeInfo.RootType.DiscriminatorMap != null)
{
typeIdType = md.Helper.GetModelTypeUsage(typeInfo.RootType.DiscriminatorMap.DiscriminatorProperty);
}
else
{
typeIdType = DefaultTypeIdType;
}
InternalConstantOp op = m_command.CreateInternalConstantOp(typeIdType, value);
return m_command.CreateNode(op);
}
///
/// Create a node to represent a typeid constant for a prefix match.
/// If the typeid value were "123X", then we would generate a constant
/// like "123X%"
///
/// the current type
/// Node for the typeid constant
private Node CreateTypeIdConstantForPrefixMatch(TypeInfo typeInfo)
{
string value = typeInfo.TypeId + PrefixMatchCharacter;
InternalConstantOp op = m_command.CreateInternalConstantOp(DefaultTypeIdType, value);
return m_command.CreateNode(op);
}
///
/// Identify the list of property refs for comparison and isnull semantics
///
///
///
/// GetPropertyRefsForComparisonAndIsNull(TypeInfo typeInfo, OperationKind opKind)
{
PlanCompiler.Assert(opKind == OperationKind.IsNull || opKind == OperationKind.Equality,
"Unexpected opKind: " + opKind + "; Can only handle IsNull and Equality");
md.TypeUsage currentType = typeInfo.Type;
md.RowType recordType = null;
if (TypeHelpers.TryGetEdmType(currentType, out recordType))
{
if (opKind == OperationKind.IsNull && typeInfo.HasNullSentinelProperty)
{
yield return NullSentinelPropertyRef.Instance;
}
else
foreach (md.EdmProperty m in recordType.Properties)
{
if (!TypeUtils.IsStructuredType(md.Helper.GetModelTypeUsage(m)))
{
yield return new SimplePropertyRef(m);
}
else
{
TypeInfo nestedTypeInfo = m_typeInfo.GetTypeInfo(md.Helper.GetModelTypeUsage(m));
foreach (PropertyRef p in GetPropertyRefs(nestedTypeInfo, opKind))
{
PropertyRef nestedPropertyRef = p.CreateNestedPropertyRef(m);
yield return nestedPropertyRef;
}
}
}
yield break;
}
md.EntityType entityType = null;
if (TypeHelpers.TryGetEdmType(currentType, out entityType))
{
if (opKind == OperationKind.Equality ||
(opKind == OperationKind.IsNull && !typeInfo.HasTypeIdProperty))
{
foreach (PropertyRef p in typeInfo.GetIdentityPropertyRefs())
{
yield return p;
}
}
else
{
yield return TypeIdPropertyRef.Instance;
}
yield break;
}
md.ComplexType complexType = null;
if (TypeHelpers.TryGetEdmType(currentType, out complexType))
{
PlanCompiler.Assert(opKind == OperationKind.IsNull, "complex types not equality-comparable");
PlanCompiler.Assert(typeInfo.HasNullSentinelProperty, "complex type with no null sentinel property: can't handle isNull");
yield return NullSentinelPropertyRef.Instance;
yield break;
}
md.RefType refType = null;
if (TypeHelpers.TryGetEdmType(currentType, out refType))
{
foreach (PropertyRef p in typeInfo.GetAllPropertyRefs())
{
yield return p;
}
yield break;
}
PlanCompiler.Assert(false, "Unknown type");
}
///
/// Get the list of "desired" propertyrefs for the specified type and operation
///
///
///
/// GetPropertyRefs(TypeInfo typeInfo, OperationKind opKind)
{
PlanCompiler.Assert(opKind != OperationKind.All, "unexpected attempt to GetPropertyRefs(...,OperationKind.All)");
if (opKind == OperationKind.GetKeys)
{
return typeInfo.GetKeyPropertyRefs();
}
else if (opKind == OperationKind.GetIdentity)
{
return typeInfo.GetIdentityPropertyRefs();
}
else
{
return GetPropertyRefsForComparisonAndIsNull(typeInfo, opKind);
}
}
///
/// Get a list of "desired" properties for each operationKind (specified by the opKind
/// parameter). The OpKinds we support are
///
/// * GetKeys
/// Applies only to entity and ref types - gets the key properties (more specifically
/// the flattened equivalents)
/// * GetIdentity
/// Applies only to entity and ref types - gets the entityset id property first, and then the
/// the Key properties
/// * All
/// Gets all properties of the flattened type
///
/// * Equality
/// Scalar types - the entire instance
/// Entity - the identity properties
/// Ref - all properties (= identity properties)
/// Complex/Collection - Not supported
/// Record - recurse over each property
///
/// * IsNull
/// Scalar types - entire instance
/// Entity - typeid property, if it exists; otherwise, the key properties
/// ComplexType - typeid property
/// Ref - all properties
/// Collection - not supported
/// Record - recurse over each property
///
/// Type information for the current op
/// Current operation kind
/// List of desired properties
private IEnumerable GetProperties(TypeInfo typeInfo, OperationKind opKind)
{
if (opKind == OperationKind.All)
{
foreach (md.EdmProperty p in typeInfo.GetAllProperties())
{
yield return p;
}
}
else
{
foreach (PropertyRef p in GetPropertyRefs(typeInfo, opKind))
{
yield return typeInfo.GetNewProperty(p);
}
}
}
///
/// Get a list of properties and value (expressions) for each desired property of the
/// input. The list of desired properties is based on the opKind parameter.
/// The ignoreMissingProperties indicates if we should create a null constant, in case
/// the input cannot produce the specified property
///
/// typeinfo for the input
/// Current operation kind
/// The input expression tree
/// Should we ignore missing properties
/// Output: list of properties
/// Output: correspondng list of values
private void GetPropertyValues(TypeInfo typeInfo, OperationKind opKind, Node input, bool ignoreMissingProperties,
out List properties, out List values)
{
values = new List();
properties = new List();
foreach (md.EdmProperty prop in GetProperties(typeInfo, opKind))
{
KeyValuePair kv = GetPropertyValue(input, prop, ignoreMissingProperties);
if (kv.Value != null)
{
properties.Add(kv.Key);
values.Add(kv.Value);
}
}
}
///
/// Build up a key-value pair of (property, expression) to represent
/// the extraction of the appropriate property from the input expression
///
/// The input (structured type) expression
/// The property in question
/// should we ignore missing properties
/// GetPropertyValue(Node input, md.EdmProperty property, bool ignoreMissingProperties)
{
Node n = null;
if (!ignoreMissingProperties)
{
n = BuildAccessorWithNulls(input, property);
}
else
{
n = BuildAccessor(input, property);
}
return new KeyValuePair(property, n);
}
///
/// Walk the SortKeys, and expand out
/// any Structured type Var references
/// If any of the sort keys is expanded to include a var representing a null sentinel,
/// set PlanCompiler.HasSortingOnNullSentinels to true.
///
/// The list of input keys
/// An expanded list of keys. If there is nothing to expand it returns the original list.
private List HandleSortKeys(List keys)
{
List newSortKeys = new List();
bool modified = false;
foreach (InternalTrees.SortKey k in keys)
{
VarInfo varInfo;
if (!m_varInfoMap.TryGetVarInfo(k.Var, out varInfo))
{
newSortKeys.Add(k);
}
else
{
StructuredVarInfo structuredVarInfo = varInfo as StructuredVarInfo;
if (structuredVarInfo != null && structuredVarInfo.NewVarsIncludeNullSentinelVar)
{
m_compilerState.HasSortingOnNullSentinels = true;
}
foreach (Var v in varInfo.NewVars)
{
InternalTrees.SortKey newKey = Command.CreateSortKey(v, k.AscendingSort, k.Collation);
newSortKeys.Add(newKey);
}
modified = true;
}
}
List result = modified ? newSortKeys : keys;
return result;
}
#endregion
#region Visitor methods
#region AncillaryOp Visitors
///
/// VarDefListOp
///
/// Walks each VarDefOp child, and "expands" it out if the Var is a
/// structured type.
///
/// For each Var that is expanded, a new expression is created to compute
/// its value (from the original computed expression)
/// A new VarDefListOp is created to hold all the "expanded" Varlist
///
///
///
/// newChildren = new List();
foreach (Node chi in n.Children)
{
VarDefOp varDefOp = chi.Op as VarDefOp;
if (TypeUtils.IsStructuredType(varDefOp.Var.Type)
|| TypeUtils.IsCollectionType(varDefOp.Var.Type))
{
List newChiList;
md.TypeUsage x;
FlattenComputedVar((ComputedVar)varDefOp.Var, chi, out newChiList, out x);
foreach (Node newChi in newChiList)
{
newChildren.Add(newChi);
}
}
else
{
newChildren.Add(chi);
}
}
Node newVarDefListNode = m_command.CreateNode(n.Op, newChildren);
return newVarDefListNode;
}
///
/// Helps flatten out a computedVar expression
///
/// The Var
/// Subtree rooted at the VarDefOp expression
/// list of new nodes produced
///
/// VarInfo for this var
private void FlattenComputedVar(ComputedVar v, Node node, out List newNodes, out md.TypeUsage newType)
{
newNodes = new List();
Node definingExprNode = node.Child0; // defining expression for the VarDefOp
newType = null;
if (TypeUtils.IsCollectionType(v.Type))
{
newType = GetNewType(v.Type);
Var newVar;
Node newVarDefNode = m_command.CreateVarDefNode(definingExprNode, out newVar);
newNodes.Add(newVarDefNode);
m_varInfoMap.CreateCollectionVarInfo(v, newVar);
return;
}
// Get the "new" type for the Var
TypeInfo typeInfo = m_typeInfo.GetTypeInfo(v.Type);
// Get a list of properties that we think are necessary
PropertyRefList desiredProperties = m_varPropertyMap[v];
List newVars = new List();
List newProps = new List();
newNodes = new List();
var hasNullSentinelVar = false;
foreach (PropertyRef p in typeInfo.PropertyRefList)
{
// do I care for this property?
if (!desiredProperties.Contains(p))
{
continue;
}
md.EdmProperty newProperty = typeInfo.GetNewProperty(p);
//
// #479467 - Make sure that we build Vars for all properties - if
// we are asked to produce all properties. This is extremely important
// for the top-level Vars
//
Node propAccessor = null;
if (desiredProperties.AllProperties)
{
propAccessor = BuildAccessorWithNulls(definingExprNode, newProperty);
}
else
{
propAccessor = BuildAccessor(definingExprNode, newProperty);
if (propAccessor == null)
{
continue;
}
}
// Add the new property
newProps.Add(newProperty);
// Create a new VarDefOp.
Var newVar;
Node newVarDefNode = m_command.CreateVarDefNode(propAccessor, out newVar);
newNodes.Add(newVarDefNode);
newVars.Add(newVar);
// Check if it is a null sentinel var
if (!hasNullSentinelVar && IsNullSentinelPropertyRef(p))
{
hasNullSentinelVar = true;
}
}
m_varInfoMap.CreateStructuredVarInfo(v, typeInfo.FlattenedType, newVars, newProps, hasNullSentinelVar);
return;
}
///
/// Is the given propertyRef representing a null sentinel
/// It is if:
/// - it is a NullSentinelPropertyRef
/// - it is a NestedPropertyRef with the outer property being a NullSentinelPropertyRef
///
///
///
/// PhysicalProjectOp
///
///
///
///
/// Walk the input var sequence, flatten each var, and return the new sequence of
/// Vars
///
/// input Var sequence
/// flattened output var sequence
private IEnumerable FlattenVars(IEnumerable vars)
{
foreach (Var v in vars)
{
VarInfo varInfo;
if (!m_varInfoMap.TryGetVarInfo(v, out varInfo))
{
yield return v;
}
else
{
foreach (Var newVar in varInfo.NewVars)
{
yield return newVar;
}
}
}
}
///
/// Probe the current VarSet for "structured" Vars - replace these with the
/// corresponding sets of flattened Vars
///
/// current set of vars
/// an "expanded" varset
private VarVec FlattenVarSet(VarVec varSet)
{
VarVec newVarSet = m_command.CreateVarVec(FlattenVars(varSet));
return newVarSet;
}
///
/// Build up a new varlist, where each structured var has been replaced by its
/// corresponding flattened vars
///
/// the varlist to flatten
/// the new flattened varlist
private VarList FlattenVarList(VarList varList)
{
VarList newVarList = Command.CreateVarList(FlattenVars(varList));
return newVarList;
}
///
/// Simply flatten out every var in the keys, and return a new DistinctOp
///
/// DistinctOp
/// Current subtree
///
/// GroupBy
///
/// Again, VisitChildren - for the Keys and Properties VarDefList nodes - does
/// the real work.
///
/// The "Keys" and the "OutputVars" varsets are updated to flatten out
/// references to any structured Vars.
///
///
///
///
/// GroupByInto
///
/// Again, VisitChildren - for the Keys and Properties VarDefList nodes - does
/// the real work.
///
/// The "Keys", "InputVars" and "OutputVars" varsets are updated to flatten out
/// references to any structured Vars.
///
///
///
///
/// ProjectOp
///
/// The computedVars (the VarDefList) are processed via the VisitChildren() call
/// We then try to update the "Vars" property to flatten out any structured
/// type Vars - if a new VarSet is produced, then the ProjectOp is cloned
///
///
///
/// new subtree
public override Node Visit(ProjectOp op, Node n)
{
VisitChildren(n);
// update the output Vars with the right set of information
VarVec newVars = FlattenVarSet(op.Outputs);
if (op.Outputs != newVars)
{
// If the set of vars is empty, that means we didn;t need any of the Vars
if (newVars.IsEmpty)
{
return n.Child0;
}
n.Op = m_command.CreateProjectOp(newVars);
}
return n;
}
///
/// ScanTableOp
///
/// Visit a scanTable Op. Flatten out the table's record into one column
/// for each field. Additionally, set up the VarInfo map appropriately
///
///
///
/// new subtree
public override Node Visit(ScanTableOp op, Node n)
{
Var columnVar = op.Table.Columns[0];
TypeInfo typeInfo = m_typeInfo.GetTypeInfo(columnVar.Type);
md.RowType newRowType = typeInfo.FlattenedType;
List properties = new List();
List keyProperties = new List();
HashSet declaredProps = new HashSet();
foreach (md.EdmProperty p in TypeHelpers.GetAllStructuralMembers(columnVar.Type.EdmType))
{
declaredProps.Add(p.Name);
}
foreach (md.EdmProperty p in newRowType.Properties)
{
if (declaredProps.Contains(p.Name))
{
properties.Add(p);
}
}
foreach (PropertyRef pref in typeInfo.GetKeyPropertyRefs())
{
md.EdmProperty p = typeInfo.GetNewProperty(pref);
keyProperties.Add(p);
}
//
// Create a flattened table definition, and a table with that definiton;
//
TableMD newTableMD = m_command.CreateFlatTableDefinition(properties, keyProperties, op.Table.TableMetadata.Extent);
Table newTable = m_command.CreateTableInstance(newTableMD);
VarInfo varInfo = m_varInfoMap.CreateStructuredVarInfo(columnVar, newRowType, newTable.Columns, properties);
n.Op = m_command.CreateScanTableOp(newTable);
return n;
}
///
/// Get the *single" var produced by the subtree rooted at this node.
/// Returns null, if the node produces more than one var, or less than one
///
/// the node
/// the single var produced by the node
internal static Var GetSingletonVar(Node n)
{
switch (n.Op.OpType)
{
case OpType.Project:
{
ProjectOp projectOp = (ProjectOp)n.Op;
return (projectOp.Outputs.Count == 1) ? projectOp.Outputs.First : null;
}
case OpType.ScanTable:
{
ScanTableOp tableOp = (ScanTableOp)n.Op;
return (tableOp.Table.Columns.Count == 1) ? tableOp.Table.Columns[0] : null;
}
case OpType.Filter:
case OpType.SingleRow:
case OpType.Sort:
case OpType.ConstrainedSort:
return GetSingletonVar(n.Child0);
case OpType.UnionAll:
case OpType.Intersect:
case OpType.Except:
{
SetOp setOp = (SetOp)n.Op;
return (setOp.Outputs.Count == 1) ? setOp.Outputs.First : null;
}
case OpType.Unnest:
{
UnnestOp unnestOp = (UnnestOp)n.Op;
return unnestOp.Table.Columns.Count == 1 ? unnestOp.Table.Columns[0] : null;
}
case OpType.Distinct:
{
DistinctOp distinctOp = (DistinctOp)n.Op;
return (distinctOp.Keys.Count == 1) ? distinctOp.Keys.First : null;
}
default:
return null;
}
}
///
/// ScanViewOp
///
/// Flatten out the view definition, and return that after
/// the appropriate remapping
///
/// the ScanViewOp
/// current subtree
/// the flattened view definition
public override Node Visit(ScanViewOp op, Node n)
{
//
// Get the "single" var produced by the input
//
Var inputVar = GetSingletonVar(n.Child0);
PlanCompiler.Assert(inputVar != null, "cannot identify Var for the input node to the ScanViewOp");
// and the table should have exactly one column
PlanCompiler.Assert(op.Table.Columns.Count == 1, "table for scanViewOp has more than on column?");
Var columnVar = op.Table.Columns[0];
Node definingNode = VisitNode(n.Child0);
VarInfo varInfo;
if (!m_varInfoMap.TryGetVarInfo(inputVar, out varInfo))
{
PlanCompiler.Assert(false, "didn't find inputVar for scanViewOp?");
}
// we must be dealing with a structured column here
StructuredVarInfo svarInfo = (StructuredVarInfo)varInfo;
TypeInfo typeInfo = m_typeInfo.GetTypeInfo(columnVar.Type);
// if this view does not represent an entityset, then we're pretty much
// done. We simply add a mapping from the columnVar to the list of flattened
// vars produced by the underlying projectOp
m_varInfoMap.CreateStructuredVarInfo(columnVar, svarInfo.NewType, svarInfo.NewVars, svarInfo.Fields);
return definingNode;
}
///
/// Convert a SortOp. Specifically, walk the SortKeys, and expand out
/// any Structured type Var references
///
/// the sortOp
/// the current node
/// new subtree
public override Node Visit(SortOp op, Node n)
{
VisitChildren(n);
List newSortKeys = HandleSortKeys(op.Keys);
if (newSortKeys != op.Keys)
{
n.Op = m_command.CreateSortOp(newSortKeys);
}
return n;
}
///
/// UnnestOp
///
/// Converts an UnnestOp to the right shape.
/// Flattens out the Table instance, and updates
///
///
///
/// new subtree
public override Node Visit(UnnestOp op, Node n)
{
// Visit the children first
VisitChildren(n);
md.TypeUsage newType;
if (n.HasChild0)
{
Node chi = n.Child0;
VarDefOp varDefOp = chi.Op as VarDefOp;
if (null != varDefOp)
{
if (TypeUtils.IsStructuredType(varDefOp.Var.Type)
|| TypeUtils.IsCollectionType(varDefOp.Var.Type))
{
List newChildren = new List();
FlattenComputedVar((ComputedVar)varDefOp.Var, chi, out newChildren, out newType);
PlanCompiler.Assert(newChildren.Count == 1, "Flattening unnest var produced more than one Var");
n.Child0 = newChildren[0];
}
}
}
// Create a new unnestVar
VarInfo unnestVarInfo;
Var newUnnestVar;
if (!m_varInfoMap.TryGetVarInfo(op.Var, out unnestVarInfo))
{
throw EntityUtil.InternalError(EntityUtil.InternalErrorCode.WrongVarType);
}
else if (!unnestVarInfo.IsCollectionType)
{
throw EntityUtil.InternalError(EntityUtil.InternalErrorCode.WrongVarType);
}
else
{
newUnnestVar = ((CollectionVarInfo)unnestVarInfo).NewVar;
}
//
// Flatten out the table
// Create a flattened table definition, and a table with that definiton;
//
Table newTable = op.Table;
Var columnVar = op.Table.Columns[0];
if (TypeUtils.IsStructuredType(columnVar.Type))
{
TypeInfo typeInfo = m_typeInfo.GetTypeInfo(columnVar.Type);
md.RowType newRowType = typeInfo.FlattenedType;
TableMD newTableMD = m_command.CreateFlatTableDefinition(newRowType);
newTable = m_command.CreateTableInstance(newTableMD);
VarInfo outputVarInfo = m_varInfoMap.CreateStructuredVarInfo(columnVar, newRowType, newTable.Columns, newRowType.Properties.ToList());
}
// Create a new UnnestOp
n.Op = m_command.CreateUnnestOp(newUnnestVar, newTable);
return n;
}
#region SetOps
///
/// SetOp
///
/// Converts all SetOps - union/intersect/except.
/// Calls VisitChildren() to do the bulk of the work. After that, the VarMaps
/// need to be updated to reflect the removal of any structured Vars
///
///
///
/// new subtree
protected override Node VisitSetOp(SetOp op, Node n)
{
VisitChildren(n);
// Now walk through the first VarMap, and identify the Vars that are needed
for (int i = 0; i < op.VarMap.Length; i++)
{
List newComputedVars;
op.VarMap[i] = FlattenVarMap(op.VarMap[i], out newComputedVars);
if (newComputedVars != null)
{
n.Children[i] = FixupSetOpChild(n.Children[i], op.VarMap[i], newComputedVars);
}
}
// now get the set of Vars that we will actually need
op.Outputs.Clear();
foreach (Var v in op.VarMap[0].Keys)
{
op.Outputs.Set(v);
}
return n;
}
///
/// Fixes up a SetOp child.
/// As part of Var flattening, it may so happen that the outer var in the VarMap
/// may require a property that has no corresponding analog in the inner Var
/// This logically implies that the corresponding inner property is null. H
/// What we do here is to throw an additional projectOp over the setOp child to
/// add computed Vars (whose defining expressions are null constants) for each
/// of those missing properties
///
/// one child of the setop
/// the varmap for this child
/// list of new Vars produced
/// new node for the setOpchild (if any)
private Node FixupSetOpChild(Node setOpChild, VarMap varMap, List newComputedVars)
{
PlanCompiler.Assert(null != setOpChild, "null setOpChild?");
PlanCompiler.Assert(null != varMap, "null varMap?");
PlanCompiler.Assert(null != newComputedVars, "null newComputedVars?");
// Walk through the list of Vars that have no inner analog, and create
// a computed Var for each of them
VarVec newVarSet = m_command.CreateVarVec();
foreach (KeyValuePair kv in varMap)
{
newVarSet.Set(kv.Value);
}
List varDefOpNodes = new List();
foreach (Var v in newComputedVars)
{
VarDefOp varDefOp = m_command.CreateVarDefOp(v);
Node varDefOpNode = m_command.CreateNode(varDefOp, CreateNullConstantNode(v.Type));
varDefOpNodes.Add(varDefOpNode);
}
Node varDefListNode = m_command.CreateNode(m_command.CreateVarDefListOp(), varDefOpNodes);
ProjectOp projectOp = m_command.CreateProjectOp(newVarSet);
Node projectNode = m_command.CreateNode(projectOp, setOpChild, varDefListNode);
return projectNode;
}
///
/// Flattens out a VarMap.
///
/// Any structured type Vars are expanded out; and collection type Vars
/// are replaced by new Vars that reflect the new collection types.
///
/// There is one special case when dealing with Structured type Vars -
/// the output and input vars may no longer be 1-1; specifically, there
/// may be no input Var corresponding to an output var. In such cases, we
/// build up a new ComputedVar (with an expected value of null), and use that
/// in place of the inner var. A subsequent stage will inspect the list of
/// new ComputedVars, and perform the appropriate fixups
///
/// The VarMap to fixup
/// list of any new computedVars that are created
/// a new VarMap
private VarMap FlattenVarMap(VarMap varMap, out List newComputedVars)
{
newComputedVars = null;
VarMap newVarMap = new VarMap();
foreach (KeyValuePair kv in varMap)
{
VarInfo innerVarInfo;
VarInfo outerVarInfo;
// Does the inner var have a Varinfo - if not, simply add it
// to the VarMap, and continue.
// Otherwise, the Outer var must have a VarInfo too
if (!m_varInfoMap.TryGetVarInfo(kv.Value, out innerVarInfo))
{
newVarMap.Add(kv.Key, kv.Value);
}
else
{
// get my own var info
if (!m_varInfoMap.TryGetVarInfo(kv.Key, out outerVarInfo))
{
outerVarInfo = FlattenSetOpVar((SetOpVar)kv.Key);
}
// If this Var represents a collection type, then simply
// replace the singleton Var
if (outerVarInfo.IsCollectionType)
{
newVarMap.Add(((CollectionVarInfo)outerVarInfo).NewVar, ((CollectionVarInfo)innerVarInfo).NewVar);
}
else
{ // structured type
StructuredVarInfo outerSvarInfo = (StructuredVarInfo)outerVarInfo;
StructuredVarInfo innerSvarInfo = (StructuredVarInfo)innerVarInfo;
// walk through each property, and find the innerVar corresponding
// to that property
foreach (md.EdmProperty prop in outerSvarInfo.Fields)
{
Var outerVar;
Var innerVar;
bool ret = outerSvarInfo.TryGetVar(prop, out outerVar);
PlanCompiler.Assert(ret, "Could not find VarInfo for prop " + prop.Name);
if (!innerSvarInfo.TryGetVar(prop, out innerVar))
{
// we didn't find a corresponding innerVar.
innerVar = m_command.CreateComputedVar(outerVar.Type);
if (newComputedVars == null)
{
newComputedVars = new List();
}
newComputedVars.Add((ComputedVar)innerVar);
}
newVarMap.Add(outerVar, innerVar);
}
}
}
}
return newVarMap;
}
///
/// Flattens a SetOpVar (used in SetOps). Simply produces a list of
/// properties corresponding to each desired property
///
///
/// newProps = new List();
bool hasNullSentinelVar = false;
foreach (PropertyRef p in typeInfo.PropertyRefList)
{
if (!desiredProperties.Contains(p))
{
continue;
}
md.EdmProperty newProperty = typeInfo.GetNewProperty(p);
newProps.Add(newProperty);
SetOpVar newVar = m_command.CreateSetOpVar(md.Helper.GetModelTypeUsage(newProperty));
newVars.Add(newVar);
// Check if it is a null sentinel var
if (!hasNullSentinelVar && IsNullSentinelPropertyRef(p))
{
hasNullSentinelVar = true;
}
}
VarInfo varInfo = m_varInfoMap.CreateStructuredVarInfo(v, typeInfo.FlattenedType, newVars, newProps, hasNullSentinelVar);
return varInfo;
}
#endregion
#region DML RelOps
//
// DML RelOps are technically very simple - we should simply visit the
// children. However, I will defer this to when we actually support DML
// so for now, the default implementation in the basicVisitor is to throw
// unimplemented and that's good enough.
//
#endregion
#endregion
#region ScalarOp Visitors
///
/// SoftCastOp
///
/// Visit the children first.
///
/// If this is an entity type, complextype or ref type, simply return the
/// visited child. (Rationale: These must be in the same type hierarchy; or
/// the earlier stages of query would have barfed. And, we end up
/// using the same "flat" type for every type in the hierarchy)
///
/// If this is a scalar type, then simply return the current node
///
/// If this is a collection type, then create a new softcastOp over the input
/// (the collection type may have changed)
///
/// Otherwise, we're dealing with a record type. Since our earlier
/// definitions of equivalence required that equivalent record types must
/// have the same number of fields, with "promotable" types, and in the same
/// order; *and* since we asked for all properties (see PropertyPushdownHelper),
/// the input must be a NewRecordOp, whose fields line up 1-1 with our fields.
/// Build up a new NewRecordOp based on the arguments to the input NewRecordOp,
/// and build up SoftCastOps for any field whose type does not match
///
///
///
/// newArgs = new List();
// We have to adjust for when we're supposed to add/remove null sentinels;
// it is entirely possible that we may need to add multiple null sentinel
// columns (See SQLBUDT #549068 for an example).
IEnumerator outputs = newOp.Properties.GetEnumerator();
int outputPropertyCount = newOp.Properties.Count;
outputs.MoveNext();
IEnumerator inputs = n.Child0.Children.GetEnumerator();
int inputPropertyCount = n.Child0.Children.Count;
inputs.MoveNext();
// We know that all Null Sentinels are added on the left side, so we'll
// just keep adding them until we have the same number of properties on
// both the input and the output...
while (inputPropertyCount < outputPropertyCount)
{
PlanCompiler.Assert(outputTypeInfo.HasNullSentinelProperty && !inputTypeInfo.HasNullSentinelProperty, "NullSentinelProperty mismatch on input?");
// make up a null sentinel; the output requires it.
newArgs.Add(CreateNullSentinelConstant());
outputs.MoveNext();
outputPropertyCount--;
}
// Likewise, we'll just drop any null sentinel columns from the input until
// we have the same number of columns...
while (inputPropertyCount > outputPropertyCount)
{
PlanCompiler.Assert(!outputTypeInfo.HasNullSentinelProperty && inputTypeInfo.HasNullSentinelProperty, "NullSentinelProperty mismatch on output?");
// remove the null sentinel; the output doesn't require it.
inputs.MoveNext();
inputPropertyCount--;
}
do
{
md.EdmProperty p = outputs.Current;
Node arg = BuildSoftCast(inputs.Current, md.Helper.GetModelTypeUsage(p));
newArgs.Add(arg);
outputs.MoveNext();
}
while (inputs.MoveNext());
Node newNode = m_command.CreateNode(newOp, newArgs);
return newNode;
}
else if (md.TypeSemantics.IsCollectionType(oldType))
{
//
// Our collection type may have changed - 'coz the
// element type of the collection may have changed.
// Simply build up a new castOp (if necessary)
//
return BuildSoftCast(n.Child0, newType);
}
else if (md.TypeSemantics.IsPrimitiveType(oldType))
{
// How primitive! Well, the Prime Directive prohibits me
// from doing much with these.
return n;
}
else
{
PlanCompiler.Assert(md.TypeSemantics.IsNominalType(oldType) ||
md.TypeSemantics.IsReferenceType(oldType),
"Gasp! Not a nominal type or even a reference type");
// I'm dealing with a nominal type (entity, complex type) or
// a reference type here. Every type in the same hierarchy
// must have been rationalized into the same type, and so, we
// won't need to do anything special
PlanCompiler.Assert(Command.EqualTypes(newType, n.Child0.Op.Type),
"Types are not equal");
return n.Child0;
}
}
///
/// CaseOp
///
/// Special handling
///
/// If the case statement is of one of the following two shapes:
/// (1) case when X then NULL else Y, or
/// (2) case when X then Y else NULL,
/// where Y is of row type and the types of the input CaseOp, the NULL and Y are the same,
/// it gets rewritten into: Y', where Y's null sentinel N' is:
/// (1) case when X then NULL else N, or
/// where N is Y's null sentinel.
///
/// the CaseOp
/// corresponding node
/// new subtree
public override Node Visit(CaseOp op, Node n)
{
// Before visiting the children, check whether the case statment can be optimized
bool thenClauseIsNull;
bool canSimplifyPrecheck = PlanCompilerUtil.IsRowTypeCaseOpWithNullability(op, n, out thenClauseIsNull);
VisitChildren(n);
if (canSimplifyPrecheck)
{
Node rewrittenNode;
if (TryRewriteCaseOp(n, thenClauseIsNull, out rewrittenNode))
{
return rewrittenNode;
}
}
//
// If the CaseOp returns a simple type, then we don't need to do
// anything special.
//
// Bug 480780: We must perform further processing, if the result
// type is not a scalar
//
// If the CaseOp returns a collection, then we need to create a
// new CaseOp of the new and improved collection type.
if (TypeUtils.IsCollectionType(op.Type))
{
md.TypeUsage newType = GetNewType(op.Type);
n.Op = m_command.CreateCaseOp(newType);
return n;
}
else if (TypeUtils.IsStructuredType(op.Type))
{
// We've got a structured type, so the CaseOp is flattened out into
// a NewRecordOp via the FlattenCaseOp method.
PropertyRefList desiredProperties = m_nodePropertyMap[n];
Node newNode = FlattenCaseOp(op, n, m_typeInfo.GetTypeInfo(op.Type), desiredProperties);
return newNode;
}
else
{
return n;
}
}
///
/// Given a case statement of one of the following two shapes:
/// (1) case when X then NULL else Y, or
/// (2) case when X then Y else NULL,
/// where Y is of row type and the types of the input CaseOp, the NULL and Y are the same,
/// it rewrittes into: Y', where Y's null sentinel N' is:
/// (1) case when X then NULL else N, or
/// where N is Y's null sentinel.
///
/// The rewrite only happens if:
/// (1) Y has null sentinel, and
/// (2) Y is a NewRecordOp.
///
///
///
///
/// Whether a rewrite was done
private bool TryRewriteCaseOp(Node n, bool thenClauseIsNull, out Node rewrittenNode)
{
rewrittenNode = n;
//If the type of the case op does not have a null sentinel, we can't do the rewrite.
if (!m_typeInfo.GetTypeInfo(n.Op.Type).HasNullSentinelProperty)
{
return false;
}
Node resultNode = thenClauseIsNull ? n.Child2 : n.Child1;
if (resultNode.Op.OpType != OpType.NewRecord)
{
return false;
}
//Rewrite the null sentinel, which is the first child of the resultNode
Node currentNullSentinel = resultNode.Child0;
md.TypeUsage integerType = this.m_command.IntegerType;
PlanCompiler.Assert(currentNullSentinel.Op.Type.EdmEquals(integerType), "Column that is expected to be a null sentinel is not of Integer type.");
CaseOp newCaseOp = m_command.CreateCaseOp(integerType);
List children = new List(3);
//The the 'when' from the case statement
children.Add(n.Child0);
Node nullSentinelNullNode = m_command.CreateNode(m_command.CreateNullOp(integerType));
Node nullSentinelThenNode = thenClauseIsNull ? nullSentinelNullNode : currentNullSentinel;
Node nullSentinelElseNode = thenClauseIsNull ? currentNullSentinel : nullSentinelNullNode;
children.Add(nullSentinelThenNode);
children.Add(nullSentinelElseNode);
//Use the case op as a new null sentinel
resultNode.Child0 = m_command.CreateNode(newCaseOp, children);
rewrittenNode = resultNode;
return true;
}
///
/// Flattens a CaseOp - Specifically, if the CaseOp returns a structuredtype,
/// then the CaseOp is broken up so that we build up a "flat" record constructor
/// for that structured type, with each argument to the record constructor being
/// a (scalar) CaseOp. For example:
///
/// Case when b1 then e1 else e2 end
///
/// gets translated into:
///
/// RecordOp(case when b1 then e1.a else e2.a end,
/// case when b1 then e1.b else e2.b end,
/// ...)
///
/// The property extraction is optimized by producing only those properties
/// that have actually been requested.
///
/// the CaseOp
/// Node corresponding to the CaseOp
/// Information about the type
/// Set of properties desired
/// fieldTypes = new List();
List fieldValues = new List();
foreach (PropertyRef pref in typeInfo.PropertyRefList)
{
// Is this property desired later?
if (!desiredProperties.Contains(pref))
{
continue;
}
md.EdmProperty property = typeInfo.GetNewProperty(pref);
// Build up an accessor for this property across each when/then clause
List caseChildren = new List();
for (int i = 0; i < n.Children.Count - 1; )
{
Node whenNode = Copy(n.Children[i]);
caseChildren.Add(whenNode);
i++;
Node propNode = BuildAccessorWithNulls(n.Children[i], property);
caseChildren.Add(propNode);
i++;
}
Node elseNode = BuildAccessorWithNulls(n.Children[n.Children.Count - 1], property);
caseChildren.Add(elseNode);
Node caseNode = m_command.CreateNode(m_command.CreateCaseOp(md.Helper.GetModelTypeUsage(property)), caseChildren);
fieldTypes.Add(property);
fieldValues.Add(caseNode);
}
NewRecordOp newRec = m_command.CreateNewRecordOp(typeInfo.FlattenedTypeUsage, fieldTypes);
return m_command.CreateNode(newRec, fieldValues);
}
///
/// CollectOp
///
/// Nothing much to do - simply update the result type
///
/// the NestOp
/// corresponding node
/// new subtree
public override Node Visit(CollectOp op, Node n)
{
VisitChildren(n);
// simply update the desired type
n.Op = m_command.CreateCollectOp(GetNewType(op.Type));
return n;
}
///
/// ComparisonOp
///
/// If the inputs to the comparisonOp are Refs/records/entitytypes, then
/// we need to flatten these out. Of course, the only reasonable comparisons
/// should be EQ and NE
///
///
///
/// properties1;
List properties2;
List values1;
List values2;
// get a list of the relevant properties and values from each of the children
GetPropertyValues(child0TypeInfo, OperationKind.Equality, n.Child0, false, out properties1, out values1);
GetPropertyValues(child1TypeInfo, OperationKind.Equality, n.Child1, false, out properties2, out values2);
PlanCompiler.Assert((properties1.Count == properties2.Count) && (values1.Count == values2.Count), "different shaped structured types?");
// Build up an and-chain of comparison ops on the property values
Node andNode = null;
for (int i = 0; i < values1.Count; i++)
{
ComparisonOp newCompOp = m_command.CreateComparisonOp(op.OpType);
Node newCompNode = m_command.CreateNode(newCompOp, values1[i], values2[i]);
if (null == andNode)
andNode = newCompNode;
else
andNode = m_command.CreateNode(m_command.CreateConditionalOp(OpType.And), andNode, newCompNode);
}
return andNode;
}
///
/// ConditionalOp
///
/// IsNull requires special handling.
///
///
///
/// properties = null;
List values = null;
GetPropertyValues(typeInfo, OperationKind.IsNull, n.Child0, false, out properties, out values);
PlanCompiler.Assert(properties.Count == values.Count && properties.Count > 0, "No properties returned from GetPropertyValues(IsNull)?");
Node andNode = null;
foreach (Node propertyValue in values)
{
Node isNullNode = m_command.CreateNode(m_command.CreateConditionalOp(OpType.IsNull), propertyValue);
if (andNode == null)
andNode = isNullNode;
else
andNode = m_command.CreateNode(m_command.CreateConditionalOp(OpType.And), andNode, isNullNode);
}
return andNode;
}
///
/// Convert a ConstrainedSortOp. Specifically, walk the SortKeys, and expand out
/// any Structured type Var references
///
/// the constrainedSortOp
/// the current node
/// new subtree
public override Node Visit(ConstrainedSortOp op, Node n)
{
VisitChildren(n);
List newSortKeys = HandleSortKeys(op.Keys);
if (newSortKeys != op.Keys)
{
n.Op = m_command.CreateConstrainedSortOp(newSortKeys, op.WithTies);
}
return n;
}
///
/// GetEntityKeyOp
///
///
///
///
/// GetRefKeyOp
///
///
///
///
/// GetEntityKeyOp/GetRefKeyOp common handling
///
/// In either case, get the "key" properties from the input entity/ref, and
/// build up a record constructor from these values
///
/// the GetRefKey/GetEntityKey op
/// current subtree
/// new expression subtree
private Node FlattenGetKeyOp(ScalarOp op, Node n)
{
PlanCompiler.Assert(op.OpType == OpType.GetEntityRef || op.OpType == OpType.GetRefKey, "Expecting GetEntityRef or GetRefKey ops");
TypeInfo inputTypeInfo = m_typeInfo.GetTypeInfo(((ScalarOp)n.Child0.Op).Type);
TypeInfo outputTypeInfo = m_typeInfo.GetTypeInfo(op.Type);
// Visit the child - will flatten out the input ref/entity
VisitChildren(n);
// Get "key" properties (and the corresponding values) from the input
List inputFieldTypes;
List inputFieldValues;
// Get the key properties for GetRefKey; get the Identity properties
// for GetEntityRef
if (op.OpType == OpType.GetRefKey)
{
GetPropertyValues(inputTypeInfo, OperationKind.GetKeys, n.Child0, false /* ignore missing props */, out inputFieldTypes, out inputFieldValues);
}
else
{
PlanCompiler.Assert(op.OpType == OpType.GetEntityRef,
"Expected OpType.GetEntityRef: Found " + op.OpType);
GetPropertyValues(inputTypeInfo, OperationKind.GetIdentity, n.Child0, false, out inputFieldTypes, out inputFieldValues);
}
if (outputTypeInfo.HasNullSentinelProperty && !inputTypeInfo.HasNullSentinelProperty)
{
// Add a null sentinel column, the input doesn't have one but the output requires it.
inputFieldValues.Insert(0, CreateNullSentinelConstant());
}
// create an appropriate record constructor
List outputFieldTypes = new List(outputTypeInfo.FlattenedType.Properties);
PlanCompiler.Assert(inputFieldValues.Count == outputFieldTypes.Count, "fieldTypes.Count mismatch?");
NewRecordOp rec = m_command.CreateNewRecordOp(outputTypeInfo.FlattenedTypeUsage, outputFieldTypes);
Node newNode = m_command.CreateNode(rec, inputFieldValues);
return newNode;
}
///
/// Common handler for PropertyOp and RelPropertyOp
///
///
///
///
/// fieldTypes = new List();
List fieldValues = new List();
PropertyRefList expectedProperties = m_nodePropertyMap[n];
foreach (PropertyRef npr in outputTypeInfo.PropertyRefList)
{
// Is this a property that's desired by my consumers?
if (expectedProperties.Contains(npr))
{
PropertyRef newPropRef = npr.CreateNestedPropertyRef(propertyRef);
md.EdmProperty outputNestedProp = outputTypeInfo.GetNewProperty(npr);
md.EdmProperty newNestedProp = inputTypeInfo.GetNewProperty(newPropRef);
Node field = BuildAccessor(n.Child0, newNestedProp);
if (null != field)
{
fieldTypes.Add(outputNestedProp);
fieldValues.Add(field);
}
}
}
Op newRecordOp = m_command.CreateNewRecordOp(outputTypeInfo.FlattenedTypeUsage, fieldTypes);
newNode = m_command.CreateNode(newRecordOp, fieldValues);
}
else
{
md.EdmProperty newProp = inputTypeInfo.GetNewProperty(propertyRef);
// Build an accessor over the new property
newNode = this.BuildAccessorWithNulls(n.Child0, newProp);
}
return newNode;
}
///
/// PropertyOp
///
/// If this is a scalar/collection property, then simply get the appropriate
/// field out.
///
/// Otherwise, build up a record constructor corresponding to the result
/// type - optimize this by only getting those properties that are needed
///
/// If the instance is not a structured type (ie) it is a UDT, then simply return
///
///
/// the PropertyOp
/// the corresponding node
/// new subtree
public override Node Visit(PropertyOp op, Node n)
{
return VisitPropertyOp(op, n, new SimplePropertyRef(op.PropertyInfo));
}
///
/// RelPropertyOp. Pick out the appropriate property from the child
///
///
///
///
/// RefOp
///
/// Simply convert this into the corresponding record type - with one
/// field for each key, and one for the entitysetid
///
///
///
/// inputFields;
List inputFieldValues;
GetPropertyValues(inputTypeInfo, OperationKind.All, n.Child0, false, out inputFields, out inputFieldValues);
// Get my property list
List outputFields = new List(outputTypeInfo.FlattenedType.Properties);
if (outputTypeInfo.HasEntitySetIdProperty)
{
PlanCompiler.Assert(outputFields[0] == outputTypeInfo.EntitySetIdProperty, "OutputField0 must be the entitySetId property");
if (inputTypeInfo.HasNullSentinelProperty && !outputTypeInfo.HasNullSentinelProperty)
{ // realistically, REFs can't have null sentinels, but I'm being pedantic...
PlanCompiler.Assert(outputFields.Count == inputFields.Count, "Mismatched field count: Expected " + inputFields.Count + "; Got " + outputFields.Count);
RemoveNullSentinel(inputTypeInfo, inputFields, inputFieldValues, outputFields);
}
else
{
PlanCompiler.Assert(outputFields.Count == inputFields.Count + 1, "Mismatched field count: Expected " + (inputFields.Count + 1) + "; Got " + outputFields.Count);
}
// Now prepend a value for the entitysetid property and a value for this property
int entitySetId = m_typeInfo.GetEntitySetId(op.EntitySet);
inputFieldValues.Insert(0, m_command.CreateNode(m_command.CreateInternalConstantOp(md.Helper.GetModelTypeUsage(outputTypeInfo.EntitySetIdProperty), entitySetId)));
}
else
{
if (inputTypeInfo.HasNullSentinelProperty && !outputTypeInfo.HasNullSentinelProperty)
{ // realistically, REFs can't have null sentinels, but I'm being pedantic...
RemoveNullSentinel(inputTypeInfo, inputFields, inputFieldValues, outputFields);
}
PlanCompiler.Assert(outputFields.Count == inputFields.Count, "Mismatched field count: Expected " + inputFields.Count + "; Got " + outputFields.Count);
}
// now build up a NewRecordConstructor with the appropriate info
NewRecordOp recOp = m_command.CreateNewRecordOp(outputTypeInfo.FlattenedTypeUsage, outputFields);
Node newNode = m_command.CreateNode(recOp, inputFieldValues);
return newNode;
}
// We have to adjust for when we're supposed to remove null sentinels;
// columns (See SQLBUDT #553534 for an example). Note that we shouldn't
// have to add null sentinels here, since reference types won't be expecting
// them (the fact that the key is null is good enough...)
private static void RemoveNullSentinel(TypeInfo inputTypeInfo, List inputFields, List inputFieldValues, List outputFields)
{
PlanCompiler.Assert(inputFields[0] == inputTypeInfo.NullSentinelProperty, "InputField0 must be the null sentinel property");
inputFields.RemoveAt(0);
inputFieldValues.RemoveAt(0);
}
///
/// VarRefOp
///
/// Replace a VarRef with a copy of the corresponding "Record" constructor
///
/// the VarRefOp
/// the node
/// new subtree
public override Node Visit(VarRefOp op, Node n)
{
// Lookup my VarInfo
VarInfo varInfo;
if (!m_varInfoMap.TryGetVarInfo(op.Var, out varInfo))
{
PlanCompiler.Assert(!TypeUtils.IsStructuredType(op.Type),
"No varInfo for a structured type var: Id = " + op.Var.Id + " Type = " + op.Type);
return n;
}
if (varInfo.IsCollectionType)
{
n.Op = m_command.CreateVarRefOp(((CollectionVarInfo)varInfo).NewVar);
return n;
}
else
{
// A very specialized record constructor mechanism for structured type Vars.
// We look up the VarInfo corresponding to the Var - which has a set of fields
// and the corresponding properties that we need to produce
StructuredVarInfo structuredVarInfo = (StructuredVarInfo)varInfo;
NewRecordOp newOp = m_command.CreateNewRecordOp(structuredVarInfo.NewTypeUsage, structuredVarInfo.Fields);
List newNodeChildren = new List();
foreach (Var v in varInfo.NewVars)
{
VarRefOp newVarRefOp = m_command.CreateVarRefOp(v);
newNodeChildren.Add(m_command.CreateNode(newVarRefOp));
}
Node newNode = m_command.CreateNode(newOp, newNodeChildren);
return newNode;
}
}
#region record construction ops
///
/// Handler for NewEntity
///
///
///
///
/// NewInstanceOp
///
/// the NewInstanceOp
/// corresponding node
/// new subtree
public override Node Visit(NewInstanceOp op, Node n)
{
return FlattenConstructor(op, n);
}
///
/// DiscriminatedNewInstanceOp
///
/// the DiscriminatedNewInstanceOp
/// corresponding node
/// new subtree
public override Node Visit(DiscriminatedNewEntityOp op, Node n)
{
return FlattenConstructor(op, n);
}
///
/// Given an explicit discriminator value, map to normalized values. Essentially, this allows
/// a discriminated new instance to coexist with free-floating entities, MEST, etc. which use
/// general purpose ordpath type ids (e.g. '0X0X')
///
/// An example of the normalization is given:
///
/// CASE
/// WHEN discriminator = 'Base' THEN '0X'
/// WHEN discriminator = 'Derived1' THEN '0X0X'
/// WHEN discriminator = 'Derived2' THEN '0X1X'
/// ELSE '0X2X' -- default case for 'Derived3'
///
private Node NormalizeTypeDiscriminatorValues(DiscriminatedNewEntityOp op, Node discriminator)
{
TypeInfo typeInfo = m_typeInfo.GetTypeInfo(op.Type);
CaseOp normalizer = m_command.CreateCaseOp(typeInfo.RootType.TypeIdProperty.TypeUsage);
List children = new List(op.DiscriminatorMap.TypeMap.Count * 2 - 1);
for (int i = 0; i < op.DiscriminatorMap.TypeMap.Count; i++)
{
object discriminatorValue = op.DiscriminatorMap.TypeMap[i].Key;
md.EntityType type = op.DiscriminatorMap.TypeMap[i].Value;
TypeInfo currentTypeInfo = m_typeInfo.GetTypeInfo(md.TypeUsage.Create(type));
Node normalizedDiscriminatorConstant = CreateTypeIdConstant(currentTypeInfo);
// for the last type, return the 'then' value
if (i == op.DiscriminatorMap.TypeMap.Count - 1)
{
// ELSE normalizedDiscriminatorValue
children.Add(normalizedDiscriminatorConstant);
}
else
{
// WHEN discriminator = discriminatorValue THEN normalizedDiscriminatorValue
ConstantBaseOp discriminatorValueOp = m_command.CreateConstantOp(md.Helper.GetModelTypeUsage(op.DiscriminatorMap.DiscriminatorProperty.TypeUsage),
discriminatorValue);
Node discriminatorConstant = m_command.CreateNode(discriminatorValueOp);
ComparisonOp discriminatorPredicateOp = m_command.CreateComparisonOp(OpType.EQ);
Node discriminatorPredicate = m_command.CreateNode(discriminatorPredicateOp, discriminator, discriminatorConstant);
children.Add(discriminatorPredicate);
children.Add(normalizedDiscriminatorConstant);
}
}
// swap discriminator with case op normalizing the discriminator
discriminator = m_command.CreateNode(normalizer, children);
return discriminator;
}
///
/// NewRecordOp
///
/// the newRecordOp
/// corresponding node
/// new subtree
public override Node Visit(NewRecordOp op, Node n)
{
return FlattenConstructor(op, n);
}
///
/// Build out an expression corresponding to the entitysetid
///
/// the property corresponding to the entitysetid
/// the *NewEntity op
///
/// Flattens out a constructor into a "flat" record constructor.
/// The "flat" record type is looked up for the current constructor's type,
/// and each property is filled out from the current constructor's fields
///
/// The NewRecordOp/NewInstanceOp
/// The current subtree
/// the new subtree
private Node FlattenConstructor(ScalarOp op, Node n)
{
PlanCompiler.Assert(op.OpType == OpType.NewInstance || op.OpType == OpType.NewRecord || op.OpType == OpType.DiscriminatedNewEntity || op.OpType == OpType.NewEntity,
"unexpected op: " + op.OpType + "?");
// First visit all my children
VisitChildren(n);
// Find the new type corresponding to the type
TypeInfo typeInfo = m_typeInfo.GetTypeInfo(op.Type);
md.RowType flatType = typeInfo.FlattenedType;
NewEntityBaseOp newEntityOp = op as NewEntityBaseOp;
// Identify the fields
IEnumerable opFields = null;
DiscriminatedNewEntityOp discriminatedNewInstanceOp = null;
if (op.OpType == OpType.NewRecord)
{
// Get only those fields that I have values for
opFields = ((NewRecordOp)op).Properties;
}
else if (op.OpType == OpType.DiscriminatedNewEntity)
{
// Get all properties projected by the discriminated new instance op
discriminatedNewInstanceOp = (DiscriminatedNewEntityOp)op;
opFields = discriminatedNewInstanceOp.DiscriminatorMap.Properties;
}
else
{
// Children align with structural members of type for a standard NewInstanceOp
opFields = TypeHelpers.GetAllStructuralMembers(op.Type);
}
// Next, walk through each of my field, and flatten out any field
// that is structured.
List newFields = new List();
List newFieldValues = new List();
//
// NOTE: we expect the type id property and the entityset id properties
// to be at the start of the properties collection.
//
// Add a typeid property if we need one
//
if (typeInfo.HasTypeIdProperty)
{
newFields.Add(typeInfo.TypeIdProperty);
if (null == discriminatedNewInstanceOp)
{
newFieldValues.Add(CreateTypeIdConstant(typeInfo));
}
else
{
// first child in DiscriminatedNewInstanceOp is discriminator/typeid
Node discriminator = n.Children[0];
if (null == typeInfo.RootType.DiscriminatorMap)
{
// if there are multiple sets (or free-floating constructors) for this type
// hierarchy, normalize the discriminator value to expose the standard
// '0X' style values
discriminator = NormalizeTypeDiscriminatorValues(discriminatedNewInstanceOp, discriminator);
}
newFieldValues.Add(discriminator);
}
}
//
// Add an entitysetid property if we need one
//
if (typeInfo.HasEntitySetIdProperty)
{
newFields.Add(typeInfo.EntitySetIdProperty);
PlanCompiler.Assert(newEntityOp != null, "unexpected optype:" + op.OpType);
Node entitySetIdNode = GetEntitySetIdExpr(typeInfo.EntitySetIdProperty, newEntityOp);
// Get the entity-set-id of the "current" entityset
newFieldValues.Add(entitySetIdNode);
}
// Add a nullability property if we need one
if (typeInfo.HasNullSentinelProperty)
{
newFields.Add(typeInfo.NullSentinelProperty);
newFieldValues.Add(CreateNullSentinelConstant());
}
//
// first child of discriminatedNewInstanceOp is the typeId; otherwise, the first child is the first property
//
int childrenIndex = null == discriminatedNewInstanceOp ? 0 : 1;
foreach (md.EdmMember opField in opFields)
{
Node fieldValue = n.Children[childrenIndex];
if (TypeUtils.IsStructuredType(md.Helper.GetModelTypeUsage(opField)))
{
// Flatten out nested type
md.RowType nestedFlatType = m_typeInfo.GetTypeInfo(md.Helper.GetModelTypeUsage(opField)).FlattenedType;
// Find offset of opField in top-level flat type
int nestedPropertyOffset = typeInfo.RootType.GetNestedStructureOffset(new SimplePropertyRef(opField));
foreach (md.EdmProperty nestedProperty in nestedFlatType.Properties)
{
// Try to build up an accessor for this property from the input
Node nestedPropertyValue = BuildAccessor(fieldValue, nestedProperty);
if (null != nestedPropertyValue)
{
newFields.Add(flatType.Properties[nestedPropertyOffset]);
newFieldValues.Add(nestedPropertyValue);
}
nestedPropertyOffset++;
}
}
else
{
PropertyRef propRef = new SimplePropertyRef(opField);
md.EdmProperty outputTypeProp = typeInfo.GetNewProperty(propRef);
newFields.Add(outputTypeProp);
newFieldValues.Add(fieldValue);
}
childrenIndex++;
}
//
// We've now handled all the regular properties. Now, walk through all the rel properties -
// obviously, this only applies for the *NewEntityOps
//
if (newEntityOp != null)
{
foreach (RelProperty relProp in newEntityOp.RelationshipProperties)
{
Node fieldValue = n.Children[childrenIndex];
md.RowType nestedFlatType = m_typeInfo.GetTypeInfo(relProp.ToEnd.TypeUsage).FlattenedType;
// Find offset of opField in top-level flat type
int nestedPropertyOffset = typeInfo.RootType.GetNestedStructureOffset(new RelPropertyRef(relProp));
foreach (md.EdmProperty nestedProperty in nestedFlatType.Properties)
{
// Try to build up an accessor for this property from the input
Node nestedPropertyValue = BuildAccessor(fieldValue, nestedProperty);
if (null != nestedPropertyValue)
{
newFields.Add(flatType.Properties[nestedPropertyOffset]);
newFieldValues.Add(nestedPropertyValue);
}
nestedPropertyOffset++;
}
childrenIndex++;
}
}
//
// So, now we have the list of all fields that should make up the
// flat type. Create a new node with them.
//
NewRecordOp newOp = m_command.CreateNewRecordOp(typeInfo.FlattenedTypeUsage, newFields);
Node newNode = m_command.CreateNode(newOp, newFieldValues);
return newNode;
}
///
/// NullOp
///
/// If the node represents a null of an entity type it 'flattens' it into a new record,
/// with at most one non-null value: for the typeIdProperty, if one is needed.
/// If the node represents an null of a non-entity type, no special work is done.
///
/// The NullOp
/// The current subtree
/// the new subtree
public override Node Visit(NullOp op, Node n)
{
if (!TypeUtils.IsStructuredType(op.Type))
{
return n;
}
// Find the new type corresponding to the type
TypeInfo typeInfo = m_typeInfo.GetTypeInfo(op.Type);
List newFields = new List();
List newFieldValues = new List();
// Add a typeid property if we need one
if (typeInfo.HasTypeIdProperty)
{
newFields.Add(typeInfo.TypeIdProperty);
var typeIdType = md.Helper.GetModelTypeUsage(typeInfo.TypeIdProperty);
newFieldValues.Add(CreateNullConstantNode(typeIdType));
}
NewRecordOp newRecordOp = new NewRecordOp(typeInfo.FlattenedTypeUsage, newFields);
return m_command.CreateNode(newRecordOp, newFieldValues);
}
#endregion
#region type comparison ops
///
/// IsOf
///
/// Convert an IsOf operator into a typeid comparison:
///
/// IsOfOnly(e, T) => e.TypeId == TypeIdValue(T)
/// IsOf(e, T) => e.TypeId like TypeIdValue(T)% escape null
///
///
/// The IsOfOp to handle
/// current isof subtree
/// new subtree
public override Node Visit(IsOfOp op, Node n)
{
// First visit all my children
VisitChildren(n);
if (!TypeUtils.IsStructuredType(op.IsOfType))
{
return n;
}
TypeInfo typeInfo = m_typeInfo.GetTypeInfo(op.IsOfType);
Node newNode = CreateTypeComparisonOp(n.Child0, typeInfo, op.IsOfOnly);
return newNode;
}
///
/// TreatOp
///
/// TreatOp(e, T) => case when e.TypeId like TypeIdValue(T) then T else null end
///
/// the TreatOp
/// the node
/// new subtree
public override Node Visit(TreatOp op, Node n)
{
// First visit all my children
VisitChildren(n);
//
// filter out useless treat operations
// Treat(subtype-instance as superType)
//
ScalarOp arg = (ScalarOp)n.Child0.Op;
if (op.IsFakeTreat ||
md.TypeSemantics.IsStructurallyEqual(arg.Type, op.Type) ||
md.TypeSemantics.IsSubTypeOf(arg.Type, op.Type))
{
return n.Child0;
}
// When we support UDTs
if (!TypeUtils.IsStructuredType(op.Type))
{
return n;
}
//
// First, convert this into a CaseOp:
// case when e.TypeId like TypeIdValue then e else null end
//
TypeInfo typeInfo = m_typeInfo.GetTypeInfo(op.Type);
Node likeNode = CreateTypeComparisonOp(n.Child0, typeInfo, false);
CaseOp caseOp = m_command.CreateCaseOp(typeInfo.FlattenedTypeUsage);
Node caseNode = m_command.CreateNode(caseOp, likeNode, n.Child0, CreateNullConstantNode(caseOp.Type));
//
// Now "flatten" out this Op into a constructor. But only get the
// desired properties
//
PropertyRefList desiredProperties = m_nodePropertyMap[n];
Node flattenedCaseNode = FlattenCaseOp(caseOp, caseNode, typeInfo, desiredProperties);
return flattenedCaseNode;
}
///
/// Create a typeid-comparison operator - more specifically, create an
/// operator that compares a typeid value with the typeid property of an
/// input structured type.
/// The comparison may be "exact" - in which case we're looking for the exact
/// type; otherwise, we're looking for any possible subtypes.
/// The "exact" variant is used by the IsOfOp (only); the other variant is
/// used by IsOfOp and TreatOp
///
/// The input structured type expression
/// Augmented type information for the type
/// Exact comparison?
/// New comparison expression
private Node CreateTypeComparisonOp(Node input, TypeInfo typeInfo, bool isExact)
{
Node typeIdProperty = BuildTypeIdAccessor(input, typeInfo);
Node newNode = null;
if (isExact)
{
newNode = CreateTypeEqualsOp(typeInfo, typeIdProperty);
}
else
{
if (typeInfo.RootType.DiscriminatorMap != null)
{
// where there are explicit discriminator values, LIKE '0X%' pattern does not work...
newNode = CreateDisjunctiveTypeComparisonOp(typeInfo, typeIdProperty);
}
else
{
Node typeIdConstantNode = CreateTypeIdConstantForPrefixMatch(typeInfo);
LikeOp likeOp = m_command.CreateLikeOp();
newNode = m_command.CreateNode(likeOp, typeIdProperty, typeIdConstantNode, CreateNullConstantNode(DefaultTypeIdType));
}
}
return newNode;
}
///
/// Create a filter matching all types in the given hierarchy (typeIdProperty IN typeInfo.Hierarchy) e.g.:
///
/// typeIdProperty = 'Base' OR typeIdProperty = 'Derived1' ...
///
/// This is called only for types using DiscriminatorMap (explicit discriminator values)
///
///
///
/// type hierarchy check
private Node CreateDisjunctiveTypeComparisonOp(TypeInfo typeInfo, Node typeIdProperty)
{
PlanCompiler.Assert(typeInfo.RootType.DiscriminatorMap != null, "should be used only for DiscriminatorMap type checks");
// collect all non-abstract types in the given hierarchy
IEnumerable types = typeInfo.GetTypeHierarchy().Where(t => !t.Type.EdmType.Abstract);
// generate a disjunction
Node current = null;
foreach (TypeInfo type in types)
{
Node typeComparisonNode = CreateTypeEqualsOp(type, typeIdProperty);
if (null == current)
{
current = typeComparisonNode;
}
else
{
current = m_command.CreateNode(m_command.CreateConditionalOp(OpType.Or), current, typeComparisonNode);
}
}
if (null == current)
{
// only abstract types in this hierarchy... no values possible
current = m_command.CreateNode(m_command.CreateFalseOp());
}
return current;
}
///
/// Generates a node of the form typeIdProperty = typeInfo.TypeId
///
///
///
/// type equality check
private Node CreateTypeEqualsOp(TypeInfo typeInfo, Node typeIdProperty)
{
Node typeIdConstantNode = CreateTypeIdConstant(typeInfo);
ComparisonOp eqCompOp = m_command.CreateComparisonOp(OpType.EQ);
Node result = m_command.CreateNode(eqCompOp, typeIdProperty, typeIdConstantNode);
return result;
}
#endregion
#endregion
#endregion
}
}
// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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