Summary:
This PR adds a ghost cache for admission control. Specifically, it admits an entry on its second access.
It also adds a hybrid row-block cache that caches the referenced key-value pairs of a Get/MultiGet request instead of its blocks.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5534
Test Plan: make clean && COMPILE_WITH_ASAN=1 make check -j32
Differential Revision: D16101124
Pulled By: HaoyuHuang
fbshipit-source-id: b99edda6418a888e94eb40f71ece45d375e234b1
RocksDB: A Persistent Key-Value Store for Flash and RAM Storage
RocksDB is developed and maintained by Facebook Database Engineering Team.
It is built on earlier work on LevelDB by Sanjay Ghemawat (sanjay@google.com)
and Jeff Dean (jeff@google.com)
This code is a library that forms the core building block for a fast
key value server, especially suited for storing data on flash drives.
It has a Log-Structured-Merge-Database (LSM) design with flexible tradeoffs
between Write-Amplification-Factor (WAF), Read-Amplification-Factor (RAF)
and Space-Amplification-Factor (SAF). It has multi-threaded compactions,
making it specially suitable for storing multiple terabytes of data in a
single database.
The public interface is in include/. Callers should not include or
rely on the details of any other header files in this package. Those
internal APIs may be changed without warning.
RocksDB is dual-licensed under both the GPLv2 (found in the COPYING file in the root directory) and Apache 2.0 License (found in the LICENSE.Apache file in the root directory). You may select, at your option, one of the above-listed licenses.