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);
}
}
internal override PropagatorResult Merge(KeyManager keyManager, PropagatorResult other)
{
KeyValue otherKey = other as KeyValue;
if (null == otherKey)
{
EntityUtil.InternalError(EntityUtil.InternalErrorCode.UpdatePipelineResultRequestInvalid, 0, "KeyValue.Merge");
}
// Determine which key (this or otherKey) is first in the chain. Principal keys take
// precedence over dependent keys and entities take precedence over relationships.
if (this.Identifier != otherKey.Identifier)
{
// Find principal (if any)
if (keyManager.GetPrincipals(otherKey.Identifier).Contains(this.Identifier))
{
return(this.ReplicateResultWithNewNext(otherKey));
}
else
{
return(otherKey.ReplicateResultWithNewNext(this));
}
}
else
{
// Entity takes precedence of relationship
if (null == m_stateEntry || m_stateEntry.IsRelationship)
{
return(otherKey.ReplicateResultWithNewNext(this));
}
else
{
return(this.ReplicateResultWithNewNext(otherKey));
}
}
}