Summary:
SimulatedHybridFileSystem now takes a more thorough simualtion of an HDD:
1. cover writes too, not just read
2. Latency and throughput is now simulated as seek + read time, using a rate limiter
This implementation can be modified to simulate full HDD behavior, which is not yet done.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9259
Test Plan: Run db_bench and observe the desired behavior.
Reviewed By: jay-zhuang
Differential Revision: D32903039
fbshipit-source-id: a83f5d72143e114d5e75edf39d647bf0b71978e1