Yu Zhang
32dd657bad
Summary: This PR added some optimizations for the per key handling for SST file for the user-defined timestamps in Memtable only feature. CPU profiling shows this part is a big culprit for regression. This optimization saves some string construction/destruction/appending/copying. vector operations like reserve/emplace_back. When iterating keys in a block, we need to copy some shared bytes from previous key, put it together with the non shared bytes and find a right location to pad the min timestamp. Previously, we create a tmp local string buffer to first construct the key from its pieces, and then copying this local string's content into `IterKey`'s buffer. To avoid having this local string and to avoid this extra copy. Instead of piecing together the key in a local string first, we just track all the pieces that make this key in a reused Slice array. And then copy the pieces in order into `IterKey`'s buffer. Since the previous key should be kept intact while we are copying some shared bytes from it, we added a secondary buffer in `IterKey` and alternate between primary buffer and secondary buffer. Pull Request resolved: https://github.com/facebook/rocksdb/pull/13031 Test Plan: Existing tests. Reviewed By: ltamasi Differential Revision: D63416531 Pulled By: jowlyzhang fbshipit-source-id: 9819b0e02301a2dbc90621b2fe4f651bc912113c
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/main/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.
Questions and discussions are welcome on the RocksDB Developers Public Facebook group and email list on Google Groups.
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.