/// <summary>
/// Performs projection for a single row. Evaluates each projection argument against the specified
/// row, returning a result with the specified type.
/// </summary>
/// <param name="node">Projection expression.</param>
/// <param name="row">Row to project.</param>
/// <param name="resultType">Type of the projected row.</param>
/// <returns>Projected row.</returns>
private PropagatorResult Project(DbProjectExpression node, PropagatorResult row, TypeUsage resultType)
{
EntityUtil.CheckArgumentNull(node, "node");
Debug.Assert(null != node.Projection, "CQT validates DbProjectExpression.Projection property");
DbNewInstanceExpression projection = node.Projection as DbNewInstanceExpression;
if (null == projection)
{
throw EntityUtil.NotSupported(System.Data.Entity.Strings.Update_UnsupportedProjection(node.Projection.ExpressionKind));
}
// Initialize empty structure containing space for every element of the projection.
PropagatorResult[] projectedValues = new PropagatorResult[projection.Arguments.Count];
// Extract value from the input row for every projection argument requested.
for (int ordinal = 0; ordinal < projectedValues.Length; ordinal++)
{
projectedValues[ordinal] = Evaluator.Evaluate(projection.Arguments[ordinal], row, this);
}
// Return a new row containing projected values.
PropagatorResult projectedRow = PropagatorResult.CreateStructuralValue(projectedValues, (StructuralType)resultType.EdmType, false);
return(projectedRow);
}
/// <summary>
/// Given default values for children members, produces a new default expression for the requested (parent) member.
/// </summary>
/// <param name="node">Parent member</param>
/// <returns>Default value for parent member</returns>
internal PropagatorResult Visit(EdmMember node)
{
PropagatorResult result;
TypeUsage nodeType = Helper.GetModelTypeUsage(node);
if (Helper.IsScalarType(nodeType.EdmType))
{
GetPropagatorResultForPrimitiveType(Helper.AsPrimitive(nodeType.EdmType), out result);
}
else
{
// Construct a new 'complex type' (really any structural type) member.
StructuralType structuralType = (StructuralType)nodeType.EdmType;
IBaseList <EdmMember> members = TypeHelpers.GetAllStructuralMembers(structuralType);
PropagatorResult[] args = new PropagatorResult[members.Count];
for (int ordinal = 0; ordinal < members.Count; ordinal++)
// foreach (EdmMember member in members)
{
args[ordinal] = Visit(members[ordinal]);
}
result = PropagatorResult.CreateStructuralValue(args, structuralType, false);
}
return(result);
}
/// <summary>
/// Specialization of <see cref="CreatePlaceholder" /> for a relationship set extent.
/// </summary>
/// <param name="associationSet"></param>
/// <returns></returns>
private PropagatorResult CreateAssociationSetPlaceholder(AssociationSet associationSet)
{
Debug.Assert(null != associationSet, "Caller must verify parameters are not null");
var endMetadata = associationSet.ElementType.AssociationEndMembers;
PropagatorResult[] endReferenceValues = new PropagatorResult[endMetadata.Count];
// Create a reference expression for each end in the relationship
for (int endOrdinal = 0; endOrdinal < endMetadata.Count; endOrdinal++)
{
var end = endMetadata[endOrdinal];
EntityType entityType = (EntityType)((RefType)end.TypeUsage.EdmType).ElementType;
// Retrieve key values for this end
PropagatorResult[] keyValues = new PropagatorResult[entityType.KeyMembers.Count];
for (int memberOrdinal = 0; memberOrdinal < entityType.KeyMembers.Count; memberOrdinal++)
{
EdmMember keyMember = entityType.KeyMembers[memberOrdinal];
PropagatorResult keyValue = CreateMemberPlaceholder(keyMember);
keyValues[memberOrdinal] = keyValue;
}
RowType endType = entityType.GetKeyRowType(m_parent.MetadataWorkspace);
PropagatorResult refKeys = PropagatorResult.CreateStructuralValue(keyValues, endType, false);
endReferenceValues[endOrdinal] = refKeys;
}
PropagatorResult result = PropagatorResult.CreateStructuralValue(endReferenceValues, associationSet.ElementType, false);
return(result);
}
// Note that this is called only for association ends. Entities have key values inline.
private PropagatorResult CreateEntityKeyResult(IEntityStateEntry stateEntry, EntityKey entityKey)
{
// get metadata for key
EntityType entityType = entityKey.GetEntitySet(m_translator.MetadataWorkspace).ElementType;
RowType keyRowType = entityType.GetKeyRowType(m_translator.MetadataWorkspace);
ExtractorMetadata keyMetadata = m_translator.GetExtractorMetadata(stateEntry.EntitySet, keyRowType);
int keyMemberCount = keyRowType.Properties.Count;
PropagatorResult[] keyValues = new PropagatorResult[keyMemberCount];
for (int ordinal = 0; ordinal < keyRowType.Properties.Count; ordinal++)
{
EdmMember keyMember = keyRowType.Properties[ordinal];
// retrieve information about this key value
MemberInformation keyMemberInformation = keyMetadata.m_memberMap[ordinal];
int keyIdentifier = m_translator.KeyManager.GetKeyIdentifierForMemberOffset(entityKey, ordinal, keyRowType.Properties.Count);
object keyValue = null;
if (entityKey.IsTemporary)
{
// If the EntityKey is temporary, we need to retrieve the appropriate
// key value from the entity itself (or in this case, the IEntityStateEntry).
IEntityStateEntry entityEntry = stateEntry.StateManager.GetEntityStateEntry(entityKey);
Debug.Assert(entityEntry.State == EntityState.Added,
"The corresponding entry for a temp EntityKey should be in the Added State.");
keyValue = entityEntry.CurrentValues[keyMember.Name];
}
else
{
// Otherwise, we extract the value from within the EntityKey.
keyValue = entityKey.FindValueByName(keyMember.Name);
}
Debug.Assert(keyValue != null, "keyValue should've been retrieved.");
// construct propagator result
keyValues[ordinal] = PropagatorResult.CreateKeyValue(
keyMemberInformation.Flags,
keyValue,
stateEntry,
keyIdentifier);
// see UpdateTranslator.Identifiers for information on key identifiers and ordinals
}
return(PropagatorResult.CreateStructuralValue(keyValues, keyMetadata.m_type, false));
}
/// <summary>
/// Converts a record to a propagator result
/// </summary>
/// <param name="stateEntry">state manager entry containing the record</param>
/// <param name="isModified">Indicates whether the root element is modified (i.e., whether the type has changed)</param>
/// <param name="record">Record to convert</param>
/// <param name="useCurrentValues">Indicates whether we are retrieving current or original values.</param>
/// <param name="translator">Translator for session context; registers new metadata for the record type if none
/// exists</param>
/// <param name="modifiedPropertiesBehavior">Indicates how to determine whether a property is modified.</param>
/// <returns>Result corresponding to the given record</returns>
internal static PropagatorResult ExtractResultFromRecord(IEntityStateEntry stateEntry, bool isModified, IExtendedDataRecord record,
bool useCurrentValues, UpdateTranslator translator, ModifiedPropertiesBehavior modifiedPropertiesBehavior)
{
StructuralType structuralType = (StructuralType)record.DataRecordInfo.RecordType.EdmType;
ExtractorMetadata metadata = translator.GetExtractorMetadata(stateEntry.EntitySet, structuralType);
EntityKey key = stateEntry.EntityKey;
PropagatorResult[] nestedValues = new PropagatorResult[record.FieldCount];
for (int ordinal = 0; ordinal < nestedValues.Length; ordinal++)
{
nestedValues[ordinal] = metadata.RetrieveMember(stateEntry, record, useCurrentValues, key,
ordinal, modifiedPropertiesBehavior);
}
return(PropagatorResult.CreateStructuralValue(nestedValues, structuralType, isModified));
}
/// <summary>
/// Specialization of <see cref="CreatePlaceholder" /> for an entity set extent.
/// </summary>
/// <param name="entitySet"></param>
/// <returns></returns>
private PropagatorResult CreateEntitySetPlaceholder(EntitySet entitySet)
{
EntityUtil.CheckArgumentNull(entitySet, "entitySet");
ReadOnlyMetadataCollection <EdmProperty> members = entitySet.ElementType.Properties;
PropagatorResult[] memberValues = new PropagatorResult[members.Count];
for (int ordinal = 0; ordinal < members.Count; ordinal++)
{
PropagatorResult memberValue = CreateMemberPlaceholder(members[ordinal]);
memberValues[ordinal] = memberValue;
}
PropagatorResult result = PropagatorResult.CreateStructuralValue(memberValues, entitySet.ElementType, false);
return(result);
}
/// <summary>
/// Produce a tuple containing joined rows.
/// </summary>
/// <param name="left">Left row.</param>
/// <param name="right">Right row.</param>
/// <param name="leftKey">Key used to join left element.</param>
/// <param name="rightKey">Key used to join right element.</param>
/// <param name="result">Result change node; used for type information.</param>
/// <returns>Result of joining the input rows.</returns>
private PropagatorResult CreateResultTuple(Tuple <CompositeKey, PropagatorResult> left, Tuple <CompositeKey, PropagatorResult> right, ChangeNode result)
{
// using ref compare to avoid triggering value based
CompositeKey leftKey = left.Item1;
CompositeKey rightKey = right.Item1;
Dictionary <PropagatorResult, PropagatorResult> map = null;
if (!object.ReferenceEquals(null, leftKey) &&
!object.ReferenceEquals(null, rightKey) &&
!object.ReferenceEquals(leftKey, rightKey))
{
// Merge key values from the left and the right (since they're equal, there's a possibility we'll
// project values only from the left or the right hand side and lose important context.)
CompositeKey mergedKey = leftKey.Merge(m_parent.m_updateTranslator.KeyManager, rightKey);
// create a dictionary so that we can replace key values with merged key values (carrying context
// from both sides)
map = new Dictionary <PropagatorResult, PropagatorResult>();
for (int i = 0; i < leftKey.KeyComponents.Length; i++)
{
map[leftKey.KeyComponents[i]] = mergedKey.KeyComponents[i];
map[rightKey.KeyComponents[i]] = mergedKey.KeyComponents[i];
}
}
PropagatorResult[] joinRecordValues = new PropagatorResult[2];
joinRecordValues[0] = left.Item2;
joinRecordValues[1] = right.Item2;
PropagatorResult join = PropagatorResult.CreateStructuralValue(joinRecordValues, (StructuralType)result.ElementType.EdmType, false);
// replace with merged key values as appropriate
if (null != map)
{
PropagatorResult replacement;
join = join.Replace(original => map.TryGetValue(original, out replacement) ? replacement : original);
}
return(join);
}
