a3c1832e86
Summary: Crc32c Parallel computation optimization: Algorithm comes from Intel whitepaper: [crc-iscsi-polynomial-crc32-instruction-paper](https://www.intel.com/content/dam/www/public/us/en/documents/white-papers/crc-iscsi-polynomial-crc32-instruction-paper.pdf) Input data is divided into three equal-sized blocks Three parallel blocks (crc0, crc1, crc2) for 1024 Bytes One Block: 42(BLK_LENGTH) * 8(step length: crc32c_u64) bytes 1. crc32c_test: ``` [==========] Running 4 tests from 1 test case. [----------] Global test environment set-up. [----------] 4 tests from CRC [ RUN ] CRC.StandardResults [ OK ] CRC.StandardResults (1 ms) [ RUN ] CRC.Values [ OK ] CRC.Values (0 ms) [ RUN ] CRC.Extend [ OK ] CRC.Extend (0 ms) [ RUN ] CRC.Mask [ OK ] CRC.Mask (0 ms) [----------] 4 tests from CRC (1 ms total) [----------] Global test environment tear-down [==========] 4 tests from 1 test case ran. (1 ms total) [ PASSED ] 4 tests. ``` 2. RocksDB benchmark: db_bench --benchmarks="crc32c" ``` Linear Arm crc32c: crc32c: 1.005 micros/op 995133 ops/sec; 3887.2 MB/s (4096 per op) ``` ``` Parallel optimization with Armv8 crypto extension: crc32c: 0.419 micros/op 2385078 ops/sec; 9316.7 MB/s (4096 per op) ``` It gets ~2.4x speedup compared to linear Arm crc32c instructions. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5494 Differential Revision: D16340806 fbshipit-source-id: 95dae9a5b646fd20a8303671d82f17b2e162e945
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/
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.