26293c89a6
Summary: Crc32c Parallel computation coding optimization: Macro unfolding removes the "for" loop and is good to decrease branch-miss in arm64 micro architecture 1024 Bytes is divided into 8(head) + 1008( 6 * 7 * 3 * 8 ) + 8(tail) three parts Macro unfolding 42 loops to 6 CRC32C7X24BYTESs 1 CRC32C7X24BYTES containing 7 CRC32C24BYTESs 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, db_bench --benchmarks="crc32c" crc32c : 0.218 micros/op 4595390 ops/sec; 17950.7 MB/s (4096 per op) 3, repeated crc32c_test case 60000 times perf stat -e branch-miss -- ./crc32c_test before optimization: 739,426,504 branch-miss after optimization: 1,128,572 branch-miss Pull Request resolved: https://github.com/facebook/rocksdb/pull/5675 Differential Revision: D16989210 fbshipit-source-id: 7204e6069bb6ed066d49c2d1b3ac385065a98557 |
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| file | ||
| hdfs | ||
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| java | ||
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| DEFAULT_OPTIONS_HISTORY.md | ||
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| LANGUAGE-BINDINGS.md | ||
| LICENSE.Apache | ||
| LICENSE.leveldb | ||
| Makefile | ||
| README.md | ||
| ROCKSDB_LITE.md | ||
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README.md
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.