Summary:
I recently discovered the confusing, undocumented semantics of
Read() functions in the FileSystem and Env APIs. I have added
clarification to the best of my reverse-engineered understanding, and
made a note in HISTORY.md for implementors to check their
implementations, as a subtly non-adherent implementation could lead to
RocksDB quietly ignoring some portion of a file.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8029
Test Plan: no code changes
Reviewed By: anand1976
Differential Revision: D26831698
Pulled By: pdillinger
fbshipit-source-id: 208f97ff6037bc13bb2ef360b987c2640c79bd03
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 especially 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.