/// <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);
}
/// <summary>
/// See <see cref="LeftPlaceholder"></see>
/// </summary>
/// <param name="key"></param>
/// <param name="mode"></param>
/// <returns></returns>
private PropagatorResult RightPlaceholder(CompositeKey key, PopulateMode mode)
{
return(PlaceholderPopulator.Populate(m_right.Placeholder, key, m_rightPlaceholderKey, mode, m_parent.UpdateTranslator));
}
/// <summary>
/// Construct a new placeholder with the shape of the given placeholder. Key values are
/// injected into the resulting place holder and default values are substituted with
/// either propagator constants or progagator nulls depending on the mode established
/// by the <paramref name="mode"/> flag.
/// </summary>
/// <remarks>
/// The key is essentially an array of values. The key map indicates that for a particular
/// placeholder an expression (keyMap.Keys) corresponds to some ordinal in the key array.
/// </remarks>
/// <param name="placeholder">Placeholder to clone</param>
/// <param name="key">Key to substitute</param>
/// <param name="placeholderKey">Key elements in the placeholder (ordinally aligned with 'key')</param>
/// <param name="mode">Mode of operation.</param>
/// <param name="translator">Translator context.</param>
/// <returns>Cloned placeholder with key values</returns>
internal static PropagatorResult Populate(PropagatorResult placeholder, CompositeKey key,
CompositeKey placeholderKey, PopulateMode mode, UpdateTranslator translator)
{
EntityUtil.CheckArgumentNull(placeholder, "placeholder");
EntityUtil.CheckArgumentNull(key, "key");
EntityUtil.CheckArgumentNull(placeholderKey, "placeholderKey");
EntityUtil.CheckArgumentNull(translator, "translator");
// Figure out which flags to apply to generated elements.
bool isNull = mode == PopulateMode.NullModified || mode == PopulateMode.NullPreserve;
bool preserve = mode == PopulateMode.NullPreserve || mode == PopulateMode.Unknown;
PropagatorFlags flags = PropagatorFlags.NoFlags;
if (!isNull)
{
flags |= PropagatorFlags.Unknown;
} // only null values are known
if (preserve)
{
flags |= PropagatorFlags.Preserve;
}
PropagatorResult result = placeholder.Replace(node =>
{
// See if this is a key element
int keyIndex = -1;
for (int i = 0; i < placeholderKey.KeyComponents.Length; i++)
{
if (placeholderKey.KeyComponents[i] == node)
{
keyIndex = i;
break;
}
}
if (keyIndex != -1)
{
// Key value.
return(key.KeyComponents[keyIndex]);
}
else
{
// for simple entries, just return using the markup context for this
// populator
object value = isNull ? null : node.GetSimpleValue();
return(PropagatorResult.CreateSimpleValue(flags, value));
}
});
return(result);
}
/// <summary>
/// Propagate all changes associated with a particular join key.
/// </summary>
/// <param name="key">Key.</param>
/// <param name="result">Resulting changes are added to this result.</param>
private void Propagate(CompositeKey key, ChangeNode result, JoinDictionary leftDeletes, JoinDictionary leftInserts,
JoinDictionary rightDeletes, JoinDictionary rightInserts)
{
// Retrieve changes associates with this join key
Tuple <CompositeKey, PropagatorResult> leftInsert = null;
Tuple <CompositeKey, PropagatorResult> leftDelete = null;
Tuple <CompositeKey, PropagatorResult> rightInsert = null;
Tuple <CompositeKey, PropagatorResult> rightDelete = null;
Ops input = Ops.Nothing;
if (leftInserts.TryGetValue(key, out leftInsert))
{
input |= Ops.LeftInsert;
}
if (leftDeletes.TryGetValue(key, out leftDelete))
{
input |= Ops.LeftDelete;
}
if (rightInserts.TryGetValue(key, out rightInsert))
{
input |= Ops.RightInsert;
}
if (rightDeletes.TryGetValue(key, out rightDelete))
{
input |= Ops.RightDelete;
}
// Get propagation rules for the changes
Ops insertRule = m_insertRules[input];
Ops deleteRule = m_deleteRules[input];
if (Ops.Unsupported == insertRule || Ops.Unsupported == deleteRule)
{
// If no propagation rules are defined, it suggests an invalid workload (e.g.
// a required entity or relationship is missing). In general, such exceptions
// should be caught by the RelationshipConstraintValidator, but we defensively
// check for problems here regardless. For instance, a 0..1:1..1 self-assocation
// implied a stronger constraint that cannot be checked by RelationshipConstraintValidator.
// First gather state entries contributing to the problem
List <IEntityStateEntry> stateEntries = new List <IEntityStateEntry>();
Action <Tuple <CompositeKey, PropagatorResult> > addStateEntries = (r) =>
{
if (r != null)
{
stateEntries.AddRange(SourceInterpreter.GetAllStateEntries(r.Item2, this.m_parent.m_updateTranslator,
this.m_parent.m_table));
}
};
addStateEntries(leftInsert);
addStateEntries(leftDelete);
addStateEntries(rightInsert);
addStateEntries(rightDelete);
throw EntityUtil.Update(Strings.Update_InvalidChanges, null, stateEntries);
}
// Where needed, substitute null/unknown placeholders. In some of the join propagation
// rules, we handle the case where a side of the join is 'unknown', or where one side
// of a join is comprised of an record containing only nulls. For instance, we may update
// only one extent appearing in a row of a table (unknown), or; we may insert only
// the left hand side of a left outer join, in which case the right hand side is 'null'.
if (0 != (Ops.LeftUnknown & insertRule))
{
leftInsert = Tuple.Create(key, LeftPlaceholder(key, PopulateMode.Unknown));
}
if (0 != (Ops.LeftUnknown & deleteRule))
{
leftDelete = Tuple.Create(key, LeftPlaceholder(key, PopulateMode.Unknown));
}
if (0 != (Ops.RightNullModified & insertRule))
{
rightInsert = Tuple.Create(key, RightPlaceholder(key, PopulateMode.NullModified));
}
else if (0 != (Ops.RightNullPreserve & insertRule))
{
rightInsert = Tuple.Create(key, RightPlaceholder(key, PopulateMode.NullPreserve));
}
else if (0 != (Ops.RightUnknown & insertRule))
{
rightInsert = Tuple.Create(key, RightPlaceholder(key, PopulateMode.Unknown));
}
if (0 != (Ops.RightNullModified & deleteRule))
{
rightDelete = Tuple.Create(key, RightPlaceholder(key, PopulateMode.NullModified));
}
else if (0 != (Ops.RightNullPreserve & deleteRule))
{
rightDelete = Tuple.Create(key, RightPlaceholder(key, PopulateMode.NullPreserve));
}
else if (0 != (Ops.RightUnknown & deleteRule))
{
rightDelete = Tuple.Create(key, RightPlaceholder(key, PopulateMode.Unknown));
}
// Populate elements in join output
if (null != leftInsert && null != rightInsert)
{
result.Inserted.Add(CreateResultTuple(leftInsert, rightInsert, result));
}
if (null != leftDelete && null != rightDelete)
{
result.Deleted.Add(CreateResultTuple(leftDelete, rightDelete, result));
}
}
private void DiagnoseKeyCollision(UpdateCompiler compiler, PropagatorResult change, CompositeKey key, PropagatorResult other)
{
KeyManager keyManager = compiler.m_translator.KeyManager;
CompositeKey otherKey = new CompositeKey(GetKeyConstants(other));
// determine if the conflict is due to shared principal key values
bool sharedPrincipal = true;
for (int i = 0; sharedPrincipal && i < key.KeyComponents.Length; i++)
{
int identifier1 = key.KeyComponents[i].Identifier;
int identifier2 = otherKey.KeyComponents[i].Identifier;
if (!keyManager.GetPrincipals(identifier1).Intersect(keyManager.GetPrincipals(identifier2)).Any())
{
sharedPrincipal = false;
}
}
if (sharedPrincipal)
{
// if the duplication is due to shared principals, there is a duplicate key exception
var stateEntries = SourceInterpreter.GetAllStateEntries(change, compiler.m_translator, m_table)
.Concat(SourceInterpreter.GetAllStateEntries(other, compiler.m_translator, m_table));
throw EntityUtil.Update(Strings.Update_DuplicateKeys, null, stateEntries);
}
else
{
// if there are no shared principals, it implies that common dependents are the problem
HashSet <IEntityStateEntry> commonDependents = null;
foreach (PropagatorResult keyValue in key.KeyComponents.Concat(otherKey.KeyComponents))
{
var dependents = new HashSet <IEntityStateEntry>();
foreach (int dependentId in keyManager.GetDependents(keyValue.Identifier))
{
PropagatorResult dependentResult;
if (keyManager.TryGetIdentifierOwner(dependentId, out dependentResult) &&
null != dependentResult.StateEntry)
{
dependents.Add(dependentResult.StateEntry);
}
}
if (null == commonDependents)
{
commonDependents = new HashSet <IEntityStateEntry>(dependents);
}
else
{
commonDependents.IntersectWith(dependents);
}
}
// to ensure the exception shape is consistent with constraint violations discovered while processing
// commands (a more conventional scenario in which different tables are contributing principal values)
// wrap a DataConstraintException in an UpdateException
throw EntityUtil.Update(Strings.Update_GeneralExecutionException,
EntityUtil.Constraint(Strings.Update_ReferentialConstraintIntegrityViolation), commonDependents);
}
}
