public IEnumerable <TKey> GetReverseEnumerator()
{
long prevProtectionCounter = 0;
var prevModificationCounter = 0;
var pos = long.MaxValue;
while (true)
{
if (pos == long.MaxValue)
{
prevModificationCounter = _modificationCounter;
if (!_keyValueTr.FindLastKey(_prefix))
{
break;
}
pos = _keyValueTr.GetKeyIndex();
}
else
{
if (_keyValueTr.CursorMovedCounter != prevProtectionCounter)
{
if (prevModificationCounter != _modificationCounter)
{
ThrowModifiedDuringEnum();
}
if (!_keyValueTr.SetKeyIndex(_prefix, pos))
{
break;
}
}
else
{
if (!_keyValueTr.FindPreviousKey(_prefix))
{
break;
}
}
}
prevProtectionCounter = _keyValueTr.CursorMovedCounter;
var key = CurrentToKey();
yield return(key);
pos--;
}
}
public IEnumerable <KeyValuePair <TKey, TValue> > GetReverseEnumerator()
{
long prevProtectionCounter = 0;
var prevModificationCounter = 0;
var pos = long.MaxValue;
while (true)
{
_keyValueTrProtector.Start();
if (pos == long.MaxValue)
{
prevModificationCounter = _modificationCounter;
_keyValueTr.SetKeyPrefix(_prefix);
if (!_keyValueTr.FindLastKey())
{
break;
}
pos = _keyValueTr.GetKeyIndex();
}
else
{
if (_keyValueTrProtector.WasInterupted(prevProtectionCounter))
{
if (prevModificationCounter != _modificationCounter)
{
ThrowModifiedDuringEnum();
}
_keyValueTr.SetKeyPrefix(_prefix);
if (!_keyValueTr.SetKeyIndex(pos))
{
break;
}
}
else
{
if (!_keyValueTr.FindPreviousKey())
{
break;
}
}
}
prevProtectionCounter = _keyValueTrProtector.ProtectionCounter;
var keyBytes = _keyValueTr.GetKeyAsByteArray();
var valueBytes = _keyValueTr.GetValueAsByteArray();
var key = ByteArrayToKey(keyBytes);
var value = ByteArrayToValue(valueBytes);
yield return(new KeyValuePair <TKey, TValue>(key, value));
pos--;
}
}
internal static ByteBuffer FindLastKeyWithPrefix(ByteBuffer keyBytes, ByteBuffer endKeyBytes,
IKeyValueDBTransaction keyValueTr, KeyValueDBTransactionProtector keyValueTrProtector)
{
var buffer = ByteBuffer.NewEmpty();
buffer = buffer.ResizingAppend(keyBytes).ResizingAppend(endKeyBytes);
keyValueTrProtector.Start();
keyValueTr.SetKeyPrefix(buffer);
if (!keyValueTr.FindLastKey())
{
return(endKeyBytes);
}
var key = keyValueTr.GetKeyIncludingPrefix();
return(key.Slice(keyBytes.Length));
}
public AdvancedEnumerator(ODBSet <TKey> owner, AdvancedEnumeratorParam <TKey> param)
{
_owner = owner;
_keyValueTr = _owner._keyValueTr;
_ascending = param.Order == EnumerationOrder.Ascending;
_prevModificationCounter = _owner._modificationCounter;
_prevProtectionCounter = _keyValueTr.CursorMovedCounter;
_keyValueTr.FindFirstKey(_owner._prefix);
var prefixIndex = _keyValueTr.GetKeyIndex();
long startIndex;
long endIndex;
if (param.EndProposition == KeyProposition.Ignored)
{
_keyValueTr.FindLastKey(_owner._prefix);
endIndex = _keyValueTr.GetKeyIndex() - prefixIndex - 1;
}
else
{
var keyBytes = _owner.KeyToByteArray(param.End);
switch (_keyValueTr.Find(keyBytes, (uint)_owner._prefix.Length))
{
case FindResult.Exact:
endIndex = _keyValueTr.GetKeyIndex() - prefixIndex;
if (param.EndProposition == KeyProposition.Excluded)
{
endIndex--;
}
break;
case FindResult.Previous:
endIndex = _keyValueTr.GetKeyIndex() - prefixIndex;
break;
case FindResult.Next:
endIndex = _keyValueTr.GetKeyIndex() - prefixIndex - 1;
break;
case FindResult.NotFound:
endIndex = -1;
break;
default:
throw new ArgumentOutOfRangeException();
}
}
if (param.StartProposition == KeyProposition.Ignored)
{
startIndex = 0;
}
else
{
var keyBytes = _owner.KeyToByteArray(param.Start);
switch (_keyValueTr.Find(keyBytes, (uint)_owner._prefix.Length))
{
case FindResult.Exact:
startIndex = _keyValueTr.GetKeyIndex() - prefixIndex;
if (param.StartProposition == KeyProposition.Excluded)
{
startIndex++;
}
break;
case FindResult.Previous:
startIndex = _keyValueTr.GetKeyIndex() - prefixIndex + 1;
break;
case FindResult.Next:
startIndex = _keyValueTr.GetKeyIndex() - prefixIndex;
break;
case FindResult.NotFound:
startIndex = 0;
break;
default:
throw new ArgumentOutOfRangeException();
}
}
_count = (uint)Math.Max(0, endIndex - startIndex + 1);
_startPos = (uint)(_ascending ? startIndex : endIndex);
_pos = 0;
_seekState = SeekState.Undefined;
}
public bool FindLastKey()
{
LogSimpleOperation(KVReplayOperation.FindLastKey);
return(_tr.FindLastKey());
}
public bool FindLastKey()
{
return(_keyValueDBTransaction.FindLastKey());
}
