[IMPROVED] Consumer create performance in some circumstances. #3901
+142
−17
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In cases where we had a large subject space, a filestore with many msg blocks, and a filtered consumer with a wildcard filtered subject, creating a consumer could take more memory and time then we wanted. This improvement works when the consumer is DeliverAll and we used the upper layer in memory psim structure to scan but only in memory and avoid a file read for each msg block.
Signed-off-by: Derek Collison derek@nats.io
/cc @nats-io/core