internal void UpgradeTransactionToWriteOne(KeyValueDBTransaction transaction, ReadTrLink link)
{
lock (_readLinkLock)
{
if (link == null && _writeTrInCreation)
{
_writeTrInCreation = false;
}
else
{
if (_writeTr != null || _writeTrInCreation) throw new BTDBTransactionRetryException("Write transaction already running");
if (link.TransactionNumber != _currentState.TransactionCounter)
throw new BTDBTransactionRetryException("Newer write transaction already finished");
}
_writeTr = transaction;
_currentTrCommited = false;
_commitNeeded = false;
_newState.TransactionCounter++;
_unallocatedCounter = 0;
Debug.Assert(_unallocatedSectorHeadLink == null);
Debug.Assert(_unallocatedSectorTailLink == null);
Debug.Assert(_dirtySectorHeadLink == null);
Debug.Assert(_dirtySectorTailLink == null);
Debug.Assert(_inTransactionSectorHeadLink == null);
Debug.Assert(_inTransactionSectorTailLink == null);
Debug.Assert(_spaceAllocatedInTransaction.Empty);
Debug.Assert(_spaceDeallocatedInTransaction.Empty);
}
}
internal void DisposeReadTransaction(ReadTrLink link)
{
DereferenceReadLink(link);
}
public IKeyValueDBTransaction StartTransaction()
{
ReadTrLink link;
lock (_readLinkLock)
{
if (_readTrLinkHead == null || _readTrLinkHead.TransactionNumber != _currentState.TransactionCounter)
{
link = new ReadTrLink
{
TransactionNumber = _currentState.TransactionCounter,
ReadTrRunningCount = 1,
RootBTree = _currentState.RootBTree,
KeyValuePairCount = _currentState.KeyValuePairCount,
UsedSize = _currentState.UsedSize,
WantedDatabaseLength = _currentState.WantedDatabaseLength
};
if (_readTrLinkHead != null)
{
_readTrLinkHead.Next = link;
}
else
{
_readTrLinkTail = link;
}
_readTrLinkHead = link;
}
else
{
link = _readTrLinkHead;
link.ReadTrRunningCount++;
}
}
try
{
return new KeyValueDBTransaction(this, link);
}
catch (Exception)
{
DereferenceReadLink(link);
throw;
}
}
internal KeyValueDBStats CalculateStats(ReadTrLink readLink)
{
var result = new KeyValueDBStats
{
DatabaseStreamSize = _positionLessStream.GetSize(),
TotalBytesRead = (ulong)_totalBytesRead,
TotalBytesWritten = _totalBytesWritten
};
if (readLink != null)
{
result.TransactionNumber = readLink.TransactionNumber;
result.KeyValuePairCount = readLink.KeyValuePairCount;
result.ReallyUsedSize = readLink.UsedSize;
result.WastedSize = readLink.WantedDatabaseLength - readLink.UsedSize;
}
else
{
result.TransactionNumber = _newState.TransactionCounter;
result.KeyValuePairCount = _newState.KeyValuePairCount;
result.ReallyUsedSize = _newState.UsedSize;
result.WastedSize = _newState.WantedDatabaseLength - _newState.UsedSize;
}
return result;
}
private void DereferenceReadLink(ReadTrLink link)
{
lock (_readLinkLock)
{
link.ReadTrRunningCount--;
if (link != _readTrLinkTail) return;
while (true)
{
if (link.ReadTrRunningCount > 0) return;
if (link.SpaceToReuse != null)
{
lock (_spaceSoonReusableLock)
{
if (_spaceSoonReusable == null) _spaceSoonReusable = link.SpaceToReuse;
else
{
_spaceSoonReusable.MergeInPlace(link.SpaceToReuse);
}
}
}
_readTrLinkTail = link.Next;
if (_readTrLinkHead == link)
{
_readTrLinkHead = null;
return;
}
link = _readTrLinkTail;
}
}
}
