protected virtual SecondaryKeyGenDelegate GetForeignKeyGenerator(SecondaryKeyAttribute secondaryKey)
{
return((pKey, pData) => {
var entity = pData.Data.FromBytes();
object foreingKey;
if (!entity.TryGet(secondaryKey.Name, out foreingKey))
{
throw new InvalidOperationException();
}
return new DatabaseEntry(foreingKey.ToBinnary());
});
}
public virtual SecondaryDatabase GetSecondaryDb(Database primaryDb, SecondaryKeyAttribute secondaryKey, Database foreignDb = null)
{
var dbName = SecondaryKeyDbName(primaryDb, secondaryKey);
SecondaryDatabase database;
if (_secondaryDbs.TryGetValue(dbName, out database))
{
return(database);
}
database = OpenWritableSecondaryDatabase(primaryDb, secondaryKey, dbName, foreignDb);
if (_secondaryDbs.TryAdd(dbName, database))
{
return(database);
}
database.Close();
database = _secondaryDbs[dbName];
return(database);
}
public virtual IEnumerable <DatabaseEntry> GetFromSecondaryDb(DatabaseEntry key, string entityName, SecondaryKeyAttribute secondaryKey)
{
Cursor cursor = null;
try {
var primaryDb = _schema.GetPrimaryDb(entityName);
var secondaryDb = _schema.GetSecondaryDb(primaryDb, secondaryKey);
cursor = secondaryDb.Cursor();
if (!cursor.Move(key, exact: true))
{
yield break;
}
if (secondaryKey.DuplicatesPolicy == DuplicatesPolicy.NONE)
{
yield return(cursor.Current.Value);
}
else
{
yield return(cursor.Current.Value);
while (cursor.MoveNextDuplicate())
{
yield return(cursor.Current.Value);
}
}
}
finally {
cursor?.Close();
}
}
protected virtual string SecondaryKeyDbName(Database primaryDb, SecondaryKeyAttribute secondaryKey)
{
return($"{primaryDb.DatabaseName}-->{secondaryKey.Name}");
}
protected virtual SecondaryDatabase OpenWritableSecondaryDatabase(Database primaryDb, SecondaryKeyAttribute secondaryForeingKey, string dbName, [CanBeNull] Database foreignDb = null)
{
var config = new SecondaryBTreeDatabaseConfig(primaryDb, GetForeignKeyGenerator(secondaryForeingKey))
{
Env = Environment,
Encrypted = IsEncrypted,
Duplicates = (BerkeleyDB.DuplicatesPolicy)secondaryForeingKey.DuplicatesPolicy,
Creation = CreatePolicy.IF_NEEDED,
ReadUncommitted = true,
FreeThreaded = IsFreeThreaded,
AutoCommit = true,
};
if (foreignDb != null)
{
config.SetForeignKeyConstraint(foreignDb, ForeignKeyDeleteAction.ABORT);
}
return(SecondaryBTreeDatabase.Open(_dbPath, dbName, config));
}
