Summary:
MyRocks testing found an issue that while iterating over keys
that are outside the prefix, sometimes wrong results were seen for keys
outside the prefix. We now tighten the range of keys seen with a new
read option called prefix_seen_at_start. This remembers the starting
prefix and then compares it on a Next for equality of prefix. If they
are from a different prefix, it sets valid to false.
Test Plan: PrefixTest.PrefixValid
Reviewers: IslamAbdelRahman, sdong, yhchiang, anthony
Reviewed By: anthony
Subscribers: spetrunia, hermanlee4, yoshinorim, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D50211
9d50afc3b9