4e85b74790
Summary: Without this diff, this is what happens to compaction output file if it's a subclass of WritableFileWrapper: - during compaction, all `PrepareWrite()` calls update `last_preallocated_block_` of the `WritableFileWrapper` itself, not of `target_`, since `PrepareWrite()` is not virtual, - `PrepareWrite()` calls `Allocate()`, which is virtual; it does `fallocate()` on `target_`, - after writing data, `target_->Close()` calls `GetPreallocationStatus()` of `target_`; it returns `last_preallocated_block_` of `target_`, which is zero because it was never touched before, - `target_->Close()` doesn't call `ftruncate()`; file remains big. This diff fixes it in a straightforward way, by making the methods virtual. `WritableFileWrapper` ends up having the useless fields `last_preallocated_block_` and `preallocation_block_size_`. I think ideally the preallocation logic should be outside `WritableFile`, the same way as `log_writer.h` and `file_reader_writer.h` moved some non-platform-specific logic out of Env, but that's probably not worth the effort now. Test Plan: `make -j check`; I'm going to deploy it on our test tier and see if it fixes space reclamation problem there Reviewers: yhchiang, sdong Reviewed By: sdong Subscribers: andrewkr, dhruba, sdong Differential Revision: https://reviews.facebook.net/D54681 |
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| arcanist_util | ||
| build_tools | ||
| coverage | ||
| db | ||
| doc | ||
| examples | ||
| hdfs | ||
| include/rocksdb | ||
| java | ||
| memtable | ||
| port | ||
| table | ||
| third-party | ||
| tools | ||
| util | ||
| utilities | ||
| .arcconfig | ||
| .clang-format | ||
| .gitignore | ||
| .travis.yml | ||
| appveyor.yml | ||
| AUTHORS | ||
| CMakeLists.txt | ||
| CONTRIBUTING.md | ||
| DUMP_FORMAT.md | ||
| HISTORY.md | ||
| INSTALL.md | ||
| LICENSE | ||
| Makefile | ||
| PATENTS | ||
| README.md | ||
| ROCKSDB_LITE.md | ||
| src.mk | ||
| thirdparty.inc | ||
| USERS.md | ||
| Vagrantfile | ||
| WINDOWS_PORT.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/