Could we enable hived to pretend to reach livesync at lower block numbers for HAF testing
Motivation: faster testing of HAF, especially during transition from replay/sync mode to live sync.
How it could work: we specify a cmd-line option that indicates the blocknumber at which to pretend to reach livesync. Let's assume replay case for simplicity. When we replay to the specified block, hived would continue to process blocks from the block_log, but the option would cause sql_serializer to enter live mode and add a delay time to the thread that reads the haf_wal and sends them to haf db. At this point, sql_serializer would quickly fill up the wal, causing hived to block until queries get removed from the wal. So the delay in the haf_wal reader thread would effectively slow hived replay down so it runs at livesync speed.
Need to think about this more to see if any problems, just saving this idea off so it is not forgotten.