Summary: This PR continues https://github.com/facebook/rocksdb/issues/12153 by implementing the missing `Iterator` APIs - `Seek()`, `SeekForPrev()`, `SeekToLast()`, and `Prev`. A MaxHeap Implementation has been added to handle the reverse direction. The current implementation does not include upper/lower bounds yet. These will be added in subsequent PRs. The API is still marked as under construction and will be lifted after being added to the stress test. Please note that changing the iterator direction in the middle of iteration is expensive, as it requires seeking the element in each iterator again in the opposite direction and rebuilding the heap along the way. The first `Next()` after `SeekForPrev()` requires changing the direction under the current implementation. We may optimize this in later PRs. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12422 Test Plan: The `multi_cf_iterator_test` has been extended to cover the API implementations. Reviewed By: pdillinger Differential Revision: D54820754 Pulled By: jaykorean fbshipit-source-id: 9eb741508df0f7bad598fb8e6bd5cdffc39e81d1
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.