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//---------------------------------------------------------------------
// <copyright file="ExtractorMetadata.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//
// @owner Microsoft
// @backupOwner Microsoft
//---------------------------------------------------------------------
namespace System.Data.Mapping.Update.Internal
{
using System.Data.Common;
using System.Data.Common.Utils;
using System.Data.Entity;
using System.Data.Metadata.Edm;
using System.Data.Objects;
using System.Diagnostics;
using System.Linq;
internal enum ModifiedPropertiesBehavior
{
/// <summary>
/// Indicates that all properties are modified. Used for added and deleted entities and for
/// modified complex type sub-records.
/// </summary>
AllModified,
/// <summary>
/// Indicates that no properties are modified. Used for unmodified complex type sub-records.
/// </summary>
NoneModified,
/// <summary>
/// Indicates that some properties are modified. Used for modified entities.
/// </summary>
SomeModified,
}
/// <summary>
/// Encapsulates metadata information relevant to update for records extracted from
/// the entity state manager, such as concurrency flags and key information.
/// </summary>
internal class ExtractorMetadata
{
internal ExtractorMetadata(EntitySetBase entitySetBase, StructuralType type, UpdateTranslator translator)
{
EntityUtil.CheckArgumentNull(entitySetBase, "entitySetBase");
m_type = EntityUtil.CheckArgumentNull(type, "type");
m_translator = EntityUtil.CheckArgumentNull(translator, "translator");
EntityType entityType = null;
Set<EdmMember> keyMembers;
Set<EdmMember> foreignKeyMembers;
switch (type.BuiltInTypeKind)
{
case BuiltInTypeKind.RowType:
// for row types (which are actually association end key records in disguise), all members
// are keys
keyMembers = new Set<EdmMember>(((RowType)type).Properties).MakeReadOnly();
foreignKeyMembers = Set<EdmMember>.Empty;
break;
case BuiltInTypeKind.EntityType:
entityType = (EntityType)type;
keyMembers = new Set<EdmMember>(entityType.KeyMembers).MakeReadOnly();
foreignKeyMembers = new Set<EdmMember>(((EntitySet)entitySetBase).ForeignKeyDependents
.SelectMany(fk => fk.Item2.ToProperties)).MakeReadOnly();
break;
default:
keyMembers = Set<EdmMember>.Empty;
foreignKeyMembers = Set<EdmMember>.Empty;
break;
}
IBaseList<EdmMember> members = TypeHelpers.GetAllStructuralMembers(type);
m_memberMap = new MemberInformation[members.Count];
// for each member, cache expensive to compute metadata information
for (int ordinal = 0; ordinal < members.Count; ordinal++)
{
EdmMember member = members[ordinal];
// figure out flags for this member
PropagatorFlags flags = PropagatorFlags.NoFlags;
int? entityKeyOrdinal = default(int?);
if (keyMembers.Contains(member))
{
flags |= PropagatorFlags.Key;
if (null != entityType)
{
entityKeyOrdinal = entityType.KeyMembers.IndexOf(member);
}
}
if (foreignKeyMembers.Contains(member))
{
flags |= PropagatorFlags.ForeignKey;
}
if (MetadataHelper.GetConcurrencyMode(member) == ConcurrencyMode.Fixed)
{
flags |= PropagatorFlags.ConcurrencyValue;
}
// figure out whether this member is mapped to any server generated
// columns in the store
bool isServerGenerated = m_translator.ViewLoader.IsServerGen(entitySetBase, m_translator.MetadataWorkspace, member);
// figure out whether member nullability is used as a condition in mapping
bool isNullConditionMember = m_translator.ViewLoader.IsNullConditionMember(entitySetBase, m_translator.MetadataWorkspace, member);
// add information about this member
m_memberMap[ordinal] = new MemberInformation(ordinal, entityKeyOrdinal, flags, member, isServerGenerated, isNullConditionMember);
}
}
private readonly MemberInformation[] m_memberMap;
private readonly StructuralType m_type;
private readonly UpdateTranslator m_translator;
/// <summary>
/// Requires: record must have correct type for this metadata instance.
/// Populates a new <see cref="PropagatorResult"/> object representing a member of a record matching the
/// type of this extractor. Given a record and a member, this method wraps the value of the member
/// in a PropagatorResult. This operation can be performed efficiently by this class, which knows
/// important stuff about the type being extracted.
/// </summary>
/// <param name="stateEntry">state manager entry containing value (used for error reporting)</param>
/// <param name="record">Record containing value (used to find the actual value)</param>
/// <param name="currentValues">Indicates whether we are reading current or original values.</param>
/// <param name="key">Entity key for the state entry. Must be set for entity records.</param>
/// <param name="ordinal">Ordinal of Member for which to retrieve a value.</param>
/// modified (must be ordinally aligned with the type). Null indicates all members are modified.</param>
/// <param name="modifiedPropertiesBehavior">Indicates how to determine whether a property is modified.</param>
/// <returns>Propagator result describing this member value.</returns>
internal PropagatorResult RetrieveMember(IEntityStateEntry stateEntry, IExtendedDataRecord record, bool useCurrentValues,
EntityKey key, int ordinal, ModifiedPropertiesBehavior modifiedPropertiesBehavior)
{
MemberInformation memberInformation = m_memberMap[ordinal];
// get identifier value
int identifier;
if (memberInformation.IsKeyMember)
{
// retrieve identifier for this key member
Debug.Assert(null != (object)key, "entities must have keys, and only entity members are marked IsKeyMember by " +
"the metadata wrapper");
int keyOrdinal = memberInformation.EntityKeyOrdinal.Value;
identifier = m_translator.KeyManager.GetKeyIdentifierForMemberOffset(key, keyOrdinal, ((EntityType)m_type).KeyMembers.Count);
}
else if (memberInformation.IsForeignKeyMember)
{
identifier = m_translator.KeyManager.GetKeyIdentifierForMember(key, record.GetName(ordinal), useCurrentValues);
}
else
{
identifier = PropagatorResult.NullIdentifier;
}
// determine if the member is modified
bool isModified = modifiedPropertiesBehavior == ModifiedPropertiesBehavior.AllModified ||
(modifiedPropertiesBehavior == ModifiedPropertiesBehavior.SomeModified &&
stateEntry.ModifiedProperties != null &&
stateEntry.ModifiedProperties[memberInformation.Ordinal]);
// determine member value
Debug.Assert(record.GetName(ordinal) == memberInformation.Member.Name, "expect record to present properties in metadata order");
if (memberInformation.CheckIsNotNull && record.IsDBNull(ordinal))
{
throw EntityUtil.Update(Strings.Update_NullValue(record.GetName(ordinal)), null, stateEntry);
}
object value = record.GetValue(ordinal);
// determine what kind of member this is
// entityKey (association end)
EntityKey entityKey = value as EntityKey;
if (null != (object)entityKey)
{
return CreateEntityKeyResult(stateEntry, entityKey);
}
// record (nested complex type)
IExtendedDataRecord nestedRecord = value as IExtendedDataRecord;
if (null != nestedRecord)
{
// for structural types, we track whether the entire complex type value is modified or not
var nestedModifiedPropertiesBehavior = isModified
? ModifiedPropertiesBehavior.AllModified
: ModifiedPropertiesBehavior.NoneModified;
UpdateTranslator translator = m_translator;
return ExtractResultFromRecord(stateEntry, isModified, nestedRecord, useCurrentValues, translator, nestedModifiedPropertiesBehavior);
}
// simple value (column/property value)
return CreateSimpleResult(stateEntry, record, memberInformation, identifier, isModified, ordinal, value);
}
// 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);
}
private PropagatorResult CreateSimpleResult(IEntityStateEntry stateEntry, IExtendedDataRecord record, MemberInformation memberInformation,
int identifier, bool isModified, int recordOrdinal, object value)
{
CurrentValueRecord updatableRecord = record as CurrentValueRecord;
// construct flags for the value, which is needed for complex type and simple members
PropagatorFlags flags = memberInformation.Flags;
if (!isModified) { flags |= PropagatorFlags.Preserve; }
if (PropagatorResult.NullIdentifier != identifier)
{
// construct a key member
PropagatorResult result;
if ((memberInformation.IsServerGenerated || memberInformation.IsForeignKeyMember) && null != updatableRecord)
{
result = PropagatorResult.CreateServerGenKeyValue(flags, value, stateEntry, identifier, recordOrdinal);
}
else
{
result = PropagatorResult.CreateKeyValue(flags, value, stateEntry, identifier);
}
// we register the entity as the "owner" of an identity so that back-propagation can succeed
// (keys can only be back-propagated to entities, not association ends). It also allows us
// to walk to the entity state entry in case of exceptions, since the state entry propagated
// through the stack may be eliminated in a project above a join.
m_translator.KeyManager.RegisterIdentifierOwner(result);
return result;
}
else
{
if ((memberInformation.IsServerGenerated || memberInformation.IsForeignKeyMember) && null != updatableRecord)
{
// note: we only produce a server gen result when
return PropagatorResult.CreateServerGenSimpleValue(flags, value, updatableRecord, recordOrdinal);
}
else
{
return PropagatorResult.CreateSimpleValue(flags, value);
}
}
}
/// <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);
}
private class MemberInformation
{
/// <summary>
/// Gets ordinal of the member.
/// </summary>
internal readonly int Ordinal;
/// <summary>
/// Gets key ordinal for primary key member (null if not a primary key).
/// </summary>
internal readonly int? EntityKeyOrdinal;
/// <summary>
/// Gets propagator flags for the member, excluding the 'Preserve' flag
/// which can only be set in context.
/// </summary>
internal readonly PropagatorFlags Flags;
/// <summary>
/// Indicates whether this is a key member.
/// </summary>
internal bool IsKeyMember
{
get
{
return PropagatorFlags.Key == (Flags & PropagatorFlags.Key);
}
}
/// <summary>
/// Indicates whether this is a foreign key member.
/// </summary>
internal bool IsForeignKeyMember
{
get
{
return PropagatorFlags.ForeignKey == (Flags & PropagatorFlags.ForeignKey);
}
}
/// <summary>
/// Indicates whether this value is server generated.
/// </summary>
internal readonly bool IsServerGenerated;
/// <summary>
/// Indicates whether non-null values are supported for this member.
/// </summary>
internal readonly bool CheckIsNotNull;
/// <summary>
/// Gets the member described by this wrapper.
/// </summary>
internal readonly EdmMember Member;
internal MemberInformation(int ordinal, int? entityKeyOrdinal, PropagatorFlags flags, EdmMember member, bool isServerGenerated, bool isNullConditionMember)
{
Debug.Assert(entityKeyOrdinal.HasValue ==
(member.DeclaringType.BuiltInTypeKind == BuiltInTypeKind.EntityType && (flags & PropagatorFlags.Key) == PropagatorFlags.Key),
"key ordinal should only be provided if this is an entity key property");
this.Ordinal = ordinal;
this.EntityKeyOrdinal = entityKeyOrdinal;
this.Flags = flags;
this.Member = member;
this.IsServerGenerated = isServerGenerated;
// in two cases, we must check that a member value is not null:
// - where the type participates in an isnull condition, nullability constraints must be honored
// - for complex types, mapping relies on nullability constraint
// - in other cases, nullability does not impact round trippability so we don't check
this.CheckIsNotNull = !TypeSemantics.IsNullable(member) &&
(isNullConditionMember || member.TypeUsage.EdmType.BuiltInTypeKind == BuiltInTypeKind.ComplexType);
}
}
}
}
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