6083bc79f8
Summary: Introducing blob_db::TTLExtractor to replace extract_ttl_fn. The TTL extractor can be use to extract TTL from keys insert with Put or WriteBatch. Change over existing extract_ttl_fn are: * If value is changed, it will be return via std::string* (rather than Slice*). With Slice* the new value has to be part of the existing value. With std::string* the limitation is removed. * It can optionally return TTL or expiration. Other changes in this PR: * replace `std::chrono::system_clock` with `Env::NowMicros` so that I can mock time in tests. * add several TTL tests. * other minor naming change. Closes https://github.com/facebook/rocksdb/pull/2659 Differential Revision: D5512627 Pulled By: yiwu-arbug fbshipit-source-id: 0dfcb00d74d060b8534c6130c808e4d5d0a54440
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.
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/