/// <exception cref="InvalidOperationException">Missed secondary key for some criterion.</exception>
public virtual IEnumerable <DatabaseEntry> GetByJoin(IBDbEntityInfo info, ICollection <IDataCriterion> criteria)
{
var cursorsLength = 0;
var secondaryCursors = new SecondaryCursor[criteria.Count];
JoinCursor joinCursor = null;
try {
var primaryDb = _schema.GetPrimaryDb(info.EntityName);
foreach (var criterion in criteria)
{
SecondaryKeyAttribute secondaryKey;
if (!info.SecondaryKeys.TryGetValue(criterion.Name, out secondaryKey))
{
var msg = $"Missed secondaty key '{criterion.Name}' for entity {info.EntityName} ({info.EntityType}).";
Log.TraceEvent(TraceEventType.Critical, msg);
throw new InvalidOperationException(msg);
}
var secondaryDb = _schema.GetSecondaryDb(primaryDb, secondaryKey);
var cursor = secondaryDb.SecondaryCursor();
secondaryCursors[cursorsLength++] = cursor;
var key = new DatabaseEntry(criterion.Value.ToBinnary());
if (!cursor.Move(key, exact:true))
{
yield break;
}
}
joinCursor = primaryDb.Join(secondaryCursors, true);
while (joinCursor.MoveNext())
{
yield return(joinCursor.Current.Value);
}
}
finally {
joinCursor?.Close();
for (var i = 0; i < cursorsLength; i++)
{
secondaryCursors[i].Close();
}
}
}
public void TestMoveJoinCursor()
{
testName = "TestMoveJoinCursor";
SetUpTest(true);
string dbFileName = testHome + "/" + testName + ".db";
string secFileName1 = testHome + "/" + "sec_" + testName + "1.db";
string secFileName2 = testHome + "/" + "sec_" + testName + "2.db";
// Open a primary database.
BTreeDatabaseConfig dbCfg = new BTreeDatabaseConfig();
dbCfg.Creation = CreatePolicy.IF_NEEDED;
BTreeDatabase db = BTreeDatabase.Open(dbFileName, dbCfg);
/*
* Open a secondary database on high byte of
* its data and another secondary database on
* little byte of its data.
*/
SecondaryBTreeDatabase secDB1, secDB2;
SecondaryCursor[] cursors = new SecondaryCursor[2];
byte[] byteValue = new byte[1];
byteValue[0] = 0;
GetSecCursor(db, secFileName1,
new SecondaryKeyGenDelegate(KeyGenOnBigByte),
out secDB1, out cursors[0], false,
new DatabaseEntry(byteValue));
byteValue[0] = 1;
GetSecCursor(db, secFileName2,
new SecondaryKeyGenDelegate(KeyGenOnLittleByte),
out secDB2, out cursors[1], true,
new DatabaseEntry(byteValue));
// Get join cursor.
JoinCursor joinCursor = db.Join(cursors, true);
/*
* MoveNextJoinItem do not use data value found
* in all of the cursor so the data in Current won't be
* changed.
*/
Assert.IsTrue(joinCursor.MoveNextItem());
Assert.AreEqual(0, joinCursor.Current.Key.Data[
joinCursor.Current.Key.Data.Length - 1]);
Assert.AreEqual(1, joinCursor.Current.Key.Data[0]);
Assert.IsNull(joinCursor.Current.Value.Data);
// Iterate on join cursor.
foreach (KeyValuePair <DatabaseEntry, DatabaseEntry> pair in joinCursor)
{
/*
* Confirm that the key got by join cursor has 0 at
* its highest byte and 1 at its lowest byte.
*/
Assert.AreEqual(0, pair.Key.Data[pair.Key.Data.Length - 1]);
Assert.AreEqual(1, pair.Key.Data[0]);
}
Assert.IsFalse(joinCursor.MoveNext());
// Close all.
joinCursor.Close();
cursors[0].Close();
cursors[1].Close();
secDB1.Close();
secDB2.Close();
db.Close();
}