a42324e370
Summary: Prior to this change, "make check" would always waste a lot of time relinking 60+ binaries. With this change, it does that only when the generated file, util/build_version.cc, changes, and that happens only when the date changes or when the current git SHA changes. This change makes some other improvements: before, there was no rule to build a deleted util/build_version.cc. If it was somehow removed, any attempt to link a program would fail. There is no longer any need for the separate file, build_tools/build_detect_version. Its functionality is now in the Makefile. * Makefile (DEPFILES): Don't filter-out util/build_version.cc. No need, and besides, removing that dependency was wrong. (date, git_sha, gen_build_version): New helper variables. (util/build_version.cc): New rule, to create this file and update it only if it would contain new information. * build_tools/build_detect_platform: Remove file. * db/db_impl.cc: Now, print only date (not the time). * util/build_version.h (rocksdb_build_compile_time): Remove declaration. No longer used. Test Plan: - Run "make check" twice, and note that the second time no linking is performed. - Remove util/build_version.cc and ensure that any "make" command regenerates it before doing anything else. - Run this: strings librocksdb.a|grep _build_. That prints output including the following: rocksdb_build_git_date:2015-02-19 rocksdb_build_git_sha:2.8.fb-1792-g3cb6cc0 Reviewers: ljin, sdong, igor Reviewed By: igor Subscribers: dhruba Differential Revision: https://reviews.facebook.net/D33591
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/