How to fetch the last saved value?

[AntyaDev]

• How to fetch the last saved value?
• Does FASTER support some offset value as Kafka does? If it does, how can I get it?

[badrishc]

How to fetch the last saved value?

I assume you are talking about FasterLog and want to get the last committed value. FasterLog is committed until log.CommitedUntilAddress. One option is to scan that last committed page and find the last committed record.

var PageSize = 1L << logSettings.PageSizeBits;
var committedUntilAddress = log.CommittedUntilAddress;
var committedPageStart = committedUntilAddress & ~(PageSize - 1);
if (committedPageStart == committedUntilAddress) // corner case: committed until page boundary
   committedPageStart -= PageSize;

using (var iter = log.Scan(committedPageStart, committedUntilAddress))
{
   // skip to the last record of this scan
}

Does FASTER support some offset value as Kafka does? If it does, how can I get it?

Every enqueue is associated with an offset. TryEnqueue returns this logical address as an out param.

[AntyaDev]

Thanks @badrishc

[fdcastel]

@badrishc -- Does #861 improves this answer in any way?