internal override void Visit(UploadVersionRequest req)
{
VersionList versionList = req.RemoteVerList as VersionList;
if (versionList == null)
{
if (!this.dict.TryGetValue(req.RecordKey, out versionList))
{
throw new TransactionException("The specified record does not exist.");
}
}
if (versionList.TryAdd(req.VersionEntry, out VersionEntry remoteEntry))
{
req.RemoteVerEntry = remoteEntry;
req.Result = true;
req.Finished = true;
return;
}
else
{
// The same version key has been added before or by a concurrent tx.
// The new version cannot be inserted.
req.RemoteVerEntry = req.VersionEntry;
req.Result = false;
req.Finished = true;
}
}
internal override void Visit(DeleteVersionRequest req)
{
VersionList versionList = req.RemoteVerList as VersionList;
// Only get the version list location when version list is null
if (versionList == null)
{
if (!this.dict.TryGetValue(req.RecordKey, out versionList))
{
req.Result = true;
req.Finished = true;
return;
}
}
versionList.TryRemove(req.SenderId, req.VersionKey);
req.Result = true;
req.Finished = true;
}
internal override void Visit(InitiGetVersionListRequest req)
{
if (!this.dict.TryGetValue(req.RecordKey, out VersionList versionList))
{
VersionList newVersionList = new VersionList();
if (this.dict.TryAdd(req.RecordKey, newVersionList))
{
// The version list is newly created by this tx.
// No meaningful versions exist, except for the artificial entry as a tail pointer.
req.RemoteVerList = newVersionList;
req.Result = true;
req.Finished = true;
return;
}
}
else
{
req.RemoteVerList = null;
req.Result = false;
req.Finished = true;
}
}