25a0d0ca30
Summary: Although RocksDB falls over in various other ways with KVs around 4GB or more, this change fixes how XXH32 and XXH64 were being called by the block checksum code to support >= 4GB in case that should ever happen, or the code copied for other uses. This change is not a schema compatibility issue because the checksum verification code would checksum the first (block_size + 1) mod 2^32 bytes while the checksum construction code would checksum the first block_size mod 2^32 plus the compression type byte, meaning the XXH32/64 checksums for >=4GB block would not match about 255/256 times. While touching this code, I refactored to consolidate redundant implementations, improving diagnostics and performance tracking in some cases. Also used less confusing language in those diagnostics. Makes https://github.com/facebook/rocksdb/issues/6875 obsolete. Pull Request resolved: https://github.com/facebook/rocksdb/pull/6978 Test Plan: I was able to write a test for this using an SST file writer and VerifyChecksum in a reader. The test fails before the fix, though I'm leaving the test disabled because I don't think it's worth the expense of running regularly. Reviewed By: gg814 Differential Revision: D22143260 Pulled By: pdillinger fbshipit-source-id: 982993d16134e8c50bea2269047f901c1783726e
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.
Start with example usage here: https://github.com/facebook/rocksdb/tree/master/examples
See the github wiki for more explanation.
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.
Design discussions are conducted in https://www.facebook.com/groups/rocksdb.dev/ and https://rocksdb.slack.com/
License
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.