internal TransactionLogEntry <T> GetObject <T>(StmObject <T> stmObject)
{
ITransactionLogEntry tle;
if (_entries.TryGetValue(stmObject.UniqueId, out tle))
{
return((TransactionLogEntry <T>)tle);
}
return(null);
}
internal void LogWrite <T>(StmObject <T> stmObject, T newValue)
{
var newStmObject = new StmObject <T>(newValue);
var txEntry = _txLog.GetObject(stmObject);
if (txEntry == null)
{
txEntry = TransactionLogEntry <T> .LogWriteEntry(stmObject, newStmObject);
_txLog.Add(txEntry);
return;
}
txEntry.UpdateNewStmObject(newStmObject);
}
private TransactionLogEntry(StmObject <T> originalObject, StmObject <T> newObject, bool incrementVersionId)
{
OriginalObject = originalObject;
NewObject = newObject;
var versionId = originalObject.Element.Version;
if (versionId is int)
{
OriginalVersionId = versionId;
newObject.Element.Version = incrementVersionId ? (int)versionId + 1 : (int)versionId;
}
else
{
// this object is being updated. wait until the update is complete or error out.
bool waitMore;
do
{
waitMore = OriginalObject.ResetEvent.Wait(1000);
versionId = originalObject.Element.Version;
} while (!(versionId is int) && waitMore);
if (versionId is int)
{
OriginalVersionId = versionId;
newObject.Element.Version = incrementVersionId ? (int)versionId + 1 : (int)versionId;
}
else
{
throw new InvalidStmObjectStateException("StmObject is not in valid state.");
}
}
}
internal T LogRead <T>(StmObject <T> stmObject)
{
var txEntry = _txLog.GetObject(stmObject);
if (txEntry == null)
{
// first read on object: create txlog entry...
var newStmObject = stmObject.Clone();
txEntry = TransactionLogEntry <T> .LogReadEntry(stmObject, newStmObject);
_txLog.Add(txEntry);
// return new value
return(newStmObject.Value);
}
if (IsValidVersion(txEntry))
{
return(txEntry.NewObject.Value);
}
throw new StmObjectValueChangedException("StmObject value has been changed by another transaction since it was last read. (Use isolation level 'ReadCommitted' to allow such changes to happen.)");
}
internal void UpdateNewStmObject(StmObject <T> newStmObject)
{
newStmObject.Element.Version = (int)OriginalVersionId + 1;
NewObject = newStmObject;
}
internal static TransactionLogEntry <T> LogWriteEntry(StmObject <T> originalObject, StmObject <T> newObject)
{
return(new TransactionLogEntry <T>(originalObject, newObject, true));
}
internal static TransactionLogEntry <T> LogReadEntry(StmObject <T> originalObject, StmObject <T> newObject)
{
return(new TransactionLogEntry <T>(originalObject, newObject, false));
}
