0712d541d1
Summary: Cleanable objects will perform the registered cleanups when they are destructed. We however rather to delay this cleaning like when we are gathering the merge operands. Current approach is to create the Cleanable object on heap (instead of on stack) and delay deleting it. By allowing Cleanables to delegate their cleanups to another cleanable object we can delay the cleaning without however the need to craete the cleanable object on heap and keeping it around. This patch applies this technique for the cleanups of BlockIter and shows improved performance for some in-memory benchmarks: +1.8% for merge worklaod, +6.4% for non-merge workload when the merge operator is specified. https://our.intern.facebook.com/intern/tasks?t=15168163 Non-merge benchmark: TEST_TMPDIR=/dev/shm/v100nocomp/ ./db_bench --benchmarks=fillrandom --num=1000000 -value_size=100 -compression_type=none Reading random with no merge operator specified: TEST_TMPDIR=/dev/shm/v100nocomp/ ./db_bench --benchmarks="read Closes https://github.com/facebook/rocksdb/pull/1711 Differential Revision: D4361163 Pulled By: maysamyabandeh fbshipit-source-id: 9801e07
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/