public object GetValue(Transaction transaction)
{
lock (this)
{
if (transaction == this.pending)
{
return(this.pendingvalue);
}
// TODO review snapshots
if (this.snapshots.Count == 0)
{
return(this.value);
}
long?selected = null;
foreach (long ts in this.snapshots.Keys)
{
if (!Transaction.IsPrevious(transaction.Id, ts))
{
if (!selected.HasValue || Transaction.IsPrevious(selected.Value, ts))
{
selected = ts;
}
}
}
if (selected.HasValue)
{
return(this.snapshots[selected.Value]);
}
return(this.value);
}
}
public void ClearSnapshots(long timestamp)
{
lock (this)
{
long? previous = null;
IList <long> toforgot = new List <long>();
foreach (long ts in this.snapshots.Keys)
{
if (Transaction.IsPrevious(ts, timestamp))
{
if (previous.HasValue)
{
if (Transaction.IsPrevious(previous.Value, ts))
{
toforgot.Add(previous.Value);
previous = ts;
}
else
{
toforgot.Add(ts);
}
}
else
{
previous = ts;
}
}
}
foreach (long ts in toforgot)
{
this.snapshots.Remove(ts);
}
}
}