Commit Graph

8043 Commits

Author SHA1 Message Date
haoyuhuang 349db90497 Make GetEntryFromCache a member function. (#5394)
Summary:
The commit makes GetEntryFromCache become a member function. It also makes all its callers become member functions.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5394

Differential Revision: D15579222

Pulled By: HaoyuHuang

fbshipit-source-id: 07509c42ee9022dcded54950012bd3bd562aa1ae
2019-06-03 12:34:59 -07:00
Siying Dong 000b9ec217 Move some logging related files to logging/ (#5387)
Summary:
Many logging related source files are under util/. It will be more structured if they are together.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5387

Differential Revision: D15579036

Pulled By: siying

fbshipit-source-id: 3850134ed50b8c0bb40a0c8ae1f184fa4081303f
2019-05-31 17:23:59 -07:00
Yuan Zhou 79edf0a7a8 util: fix log_write_bench (#5335)
Summary:
log_write_bench doesn't compile due to some recent API changes.
This patch fixes the compile by adding the missing params for
OptimizeForLogWrite() and WritableFileWriter().

Signed-off-by: Yuan Zhou <yuan.zhou@intel.com>
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5335

Differential Revision: D15588875

Pulled By: miasantreble

fbshipit-source-id: 726ff4dc227733e915c3b796df25bd3ab0b431ac
2019-05-31 17:17:57 -07:00
Zhongyi Xie d7d8605f56 Fix a clang analyze warning (#5398)
Summary:
Clang analyzer is reporting a false positive warning thinking `type` is uninitialized. The variable is initialized by `ParseFileName` by reference so assigning a default value to keep clang happy.
Current failure:
```
file/filename.cc:435:15: warning: The left operand of '==' is a garbage value
        (type == kInfoLogFile)) {
         ~~~~ ^
1 warning generated.
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5398

Differential Revision: D15588421

Pulled By: miasantreble

fbshipit-source-id: fb121c270300f3a659e68bc7f6674ff4ddf2df9a
2019-05-31 17:02:51 -07:00
Vijay Nadimpalli cae22c53fb Make format
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5395

Differential Revision: D15581698

Pulled By: vjnadimpalli

fbshipit-source-id: f415972f16e784b1361714c202b97defcab46767
2019-05-31 15:24:43 -07:00
Vijay Nadimpalli 49c5a12dbe Organizing rocksdb/db directory
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5390

Differential Revision: D15579388

Pulled By: vjnadimpalli

fbshipit-source-id: 5bfc95e31554b8ff05b97b76d6534113f527f366
2019-05-31 11:57:01 -07:00
Levi Tamasi a3609b7dde Improve const correctness in BlockBasedTableReader (#5383)
Summary:
Many methods are passing around pointers to non-const objects when in fact
they do not/should not modify said objects. The patch makes the semantics
clearer and also helps from a thread safety point-of-view by changing some
pointers to pointers-to-const and marking some instance methods as const.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5383

Differential Revision: D15562770

Pulled By: ltamasi

fbshipit-source-id: 89361dadbb8b25bbe54d17e8da28fee24a2419af
2019-05-31 11:41:35 -07:00
Siying Dong cb094e13bb Auto roll logger to enforce options.keep_log_file_num immediately after a new file is created (#5370)
Summary:
Right now, with auto roll logger, options.keep_log_file_num enforcement is triggered by events like DB reopen or full obsolete scan happens. In the mean time, the size and number of log files can grow without a limit. We put a stronger enforcement to the option, so that the number of log files can always under control.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5370

Differential Revision: D15570413

Pulled By: siying

fbshipit-source-id: 0916c3c4d42ab8fdd29389ee7fd7e1557b03176e
2019-05-31 10:50:19 -07:00
qinzuoyan 0834bbd0b1 Configure ccache in CMakeLists.txt to speed up compilation
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5388

Differential Revision: D15579052

Pulled By: siying

fbshipit-source-id: ee58770fe023f40b9aa189a225e4c7ef50613ea9
2019-05-31 10:45:11 -07:00
Yanqin Jin 83f7a8eed0 Fix compilation error in LITE mode (#5391)
Summary:
Add macro ROCKSDB_LITE to fix compilation.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5391

Differential Revision: D15574522

Pulled By: riversand963

fbshipit-source-id: 95aea83c5d9b2bf98a3ba0ef9167b63c9be2988b
2019-05-31 08:32:22 -07:00
Zhongyi Xie ab8f6c01a6 move LevelCompactionPicker to a separate file (#5369)
Summary:
In order to improve code readability, this PR moves LevelCompactionBuilder and LevelCompactionPicker to compaction_picker_level.h and .cc
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5369

Differential Revision: D15540172

Pulled By: miasantreble

fbshipit-source-id: c1a578b93f127cd63661b53f32b356e6edd349af
2019-05-30 21:38:24 -07:00
Sagar Vemuri ff9d286877 Reorder DBImpl's private section (#5385)
Summary:
The methods and fields in the private section of DBImpl were all intermingled, making it hard to figure out where the fields/methods start and where they end. I cleaned up the code a little so that all the type declaration are at the beginning, followed by methods, and all the data fields are at the end. This follows
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5385

Differential Revision: D15566978

Pulled By: sagar0

fbshipit-source-id: 4618a7d819ad4e2d7cc9ae1af2c59f400140bb1b
2019-05-30 21:32:46 -07:00
Yanqin Jin b9f5900658 Fix WAL replay by skipping old write batches (#5170)
Summary:
1. Fix a bug in WAL replay in which write batches with old sequence numbers are mistakenly inserted into memtables.
2. Add support for benchmarking secondary instance to db_bench_tool.
With changes made in this PR, we can start benchmarking secondary instance
using two processes. It is also possible to vary the frequency at which the
secondary instance tries to catch up with the primary. The info log of the
secondary can be found in a directory whose path can be specified with
'-secondary_path'.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5170

Differential Revision: D15564608

Pulled By: riversand963

fbshipit-source-id: ce97688ed3d33f69d3a0b9266ebbbbf887aa0ec8
2019-05-30 19:33:33 -07:00
Siying Dong 8843129ece Move some memory related files from util/ to memory/ (#5382)
Summary:
Move arena, allocator, and memory tools under util to a separate memory/ directory.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5382

Differential Revision: D15564655

Pulled By: siying

fbshipit-source-id: 9cd6b5d0d3d52b39606e19221fa154596e5852a5
2019-05-30 17:44:09 -07:00
Yanqin Jin f1302ebab8 Add class-level comments to version-related classes (#5348)
Summary:
As title.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5348

Differential Revision: D15564595

Pulled By: riversand963

fbshipit-source-id: dd45aa86a70e0343c2e9ef702fad165163f548e6
2019-05-30 16:18:33 -07:00
Sagar Vemuri 1b59a490ef Fix flaky DBTest2.PresetCompressionDict test (#5378)
Summary:
Fix flaky DBTest2.PresetCompressionDict test.

This PR fixes two issues with the test:
1. Replaces `GetSstFiles` with `TotalSize`, which is based on `DB::GetColumnFamilyMetaData` so that only the size of the live SST files is taken into consideration when computing the total size of all sst files. Earlier, with `GetSstFiles`, even obsolete files were getting picked up.
1. In ZSTD compression, it is sometimes possible that using a trained dictionary is not better than using an untrained one. Using a trained dictionary performs well in 99% of the cases, but still in the remaining ~1% of the cases (out of 10000 runs) using an untrained dictionary gets better compression results.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5378

Differential Revision: D15559100

Pulled By: sagar0

fbshipit-source-id: c35adbf13871f520a2cec48f8bad9ff27ff7a0b4
2019-05-30 16:11:27 -07:00
Vijay Nadimpalli 50e470791d Organizing rocksdb/table directory by format
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5373

Differential Revision: D15559425

Pulled By: vjnadimpalli

fbshipit-source-id: 5d6d6d615582bedd96a4b879bb25d429a6de8b55
2019-05-30 14:51:11 -07:00
Sagar Vemuri e62986260f Fix env_options_for_read spelling in CompactionJob
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5380

Differential Revision: D15563386

Pulled By: sagar0

fbshipit-source-id: 8b26aef47cfc40ff8016daf815582f21cdd40df2
2019-05-30 14:04:53 -07:00
Levi Tamasi 1e35584251 Move the index readers out of the block cache (#5298)
Summary:
Currently, when the block cache is used for index blocks as well, it is
not really the index block that is stored in the cache but an
IndexReader object. Since this object is not pure data (it has, for
instance, pointers that might dangle), it's not really sharable. To
avoid the issues around this, the current code uses a dummy unique cache
key for each TableReader to store the IndexReader, and erases the
IndexReader entry when the TableReader is closed. Instead of doing this,
the new code moves the IndexReader out of the cache altogether. In
particular, instead of the TableReader owning, or caching/pinning the
IndexReader based on the customer's settings, the TableReader
unconditionally owns the IndexReader, which in turn owns/caches/pins
the index block (which is itself sharable and thus can be safely put in
the cache without any hacks).

Note: the change has two side effects:
1) Partitions of partitioned indexes no longer affect the read
amplification statistics.
2) Eviction statistics for index blocks are temporarily broken. We plan to fix
this in a separate phase.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5298

Differential Revision: D15303203

Pulled By: ltamasi

fbshipit-source-id: 935a69ba59d87d5e44f42e2310619b790c366e47
2019-05-30 11:53:27 -07:00
anand76 bd44ec2006 Fix reopen voting logic in db_stress when using MultiGet (#5374)
Summary:
When the --reopen option is non-zero, the DB is reopened after every ops_per_thread/(reopen+1) ops, with the check being done after every op. With MultiGet, we might do multiple ops in one iteration, which broke the logic that checked when to synchronize among the threads and reopen the DB. This PR fixes that logic.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5374

Differential Revision: D15559780

Pulled By: anand1976

fbshipit-source-id: ee6563a68045df7f367eca3cbc2500d3e26359ef
2019-05-30 11:41:08 -07:00
Siying Dong e9e0101ca4 Move test related files under util/ to test_util/ (#5377)
Summary:
There are too many types of files under util/. Some test related files don't belong to there or just are just loosely related. Mo
ve them to a new directory test_util/, so that util/ is cleaner.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5377

Differential Revision: D15551366

Pulled By: siying

fbshipit-source-id: 0f5c8653832354ef8caa31749c0143815d719e2c
2019-05-30 11:25:51 -07:00
anand76 a984040f0b Increase Trash/DB size ratio in DBSSTTest.RateLimitedWALDelete (#5366)
Summary:
By increasing the ratio, we ensure that all files go through background deletion and eliminate flakiness due to timing of deletions.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5366

Differential Revision: D15549992

Pulled By: anand1976

fbshipit-source-id: d137375cd791fc1a802841412755d6e2b8fd7688
2019-05-30 11:12:59 -07:00
Zhongyi Xie 87fe4bcab8 Fix FIFO dynamic options sanitization (#5367)
Summary:
When dynamically setting options, we check the option type info and skip options that are marked deprecated. However this check is only done at top level, which results in bugs where SetOptions will corrupt option values and cause unexpected system behavior iff a deprecated second level option is set dynamically.
For exmaple, the following call:
```
dbfull()->SetOptions(
    {{"compaction_options_fifo",
        "{allow_compaction=true;max_table_files_size=1024;ttl=731;}"}});
```
was from pre 6.0 release when `ttl` was part of `compaction_options_fifo`. Now that it got moved out of `compaction_options_fifo`, this call will incorrectly set `compaction_options_fifo.max_table_files_size` to 731 (as `max_table_files_size` is the first one in `OptionsHelper::fifo_compaction_options_type_info` struct) and cause files to gett evicted much faster than expected.

This PR adds verification to second level options like `compaction_options_fifo.ttl` or `compaction_options_fifo.max_table_files_size` when set dynamically, and filter out those marked as deprecated.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5367

Differential Revision: D15530998

Pulled By: miasantreble

fbshipit-source-id: 818258be5c3abe09cd82d62f3c083572d70fecdd
2019-05-30 10:46:28 -07:00
Siying Dong 545d206040 Move some file related files outside util/ (#5375)
Summary:
util/ means for lower level libraries, so it's a good idea to move the files which requires knowledge to DB out. Create a file/ and move some files there.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5375

Differential Revision: D15550935

Pulled By: siying

fbshipit-source-id: 61a9715dcde5386eebfb43e93f847bba1ae0d3f2
2019-05-29 20:47:06 -07:00
Maysam Yabandeh eab4f49a2c WritePrepared: skip_concurrency_control option (#5330)
Summary:
This enables the user to set TransactionDBOptions::skip_concurrency_control so the standard `DB::Write(const WriteOptions& opts, WriteBatch* updates)` would skip the concurrency control. This would give higher throughput to the users who know their use case doesn't need concurrency control.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5330

Differential Revision: D15525932

Pulled By: maysamyabandeh

fbshipit-source-id: 68421ac1ba34f549a4a8de9ce4c2dccf6fb4b06b
2019-05-28 16:29:45 -07:00
Maysam Yabandeh f5576c3317 WritePrepared: disableWAL in commit without prepare (#5327)
Summary:
When committing a transaction without prepare, WritePrepared simply writes the batch to db and add the commit entry to CommitCache. When two_write_queues=true, following the rule of committing only from 2nd write queue, the first write, writes the batch and the only thing the 2nd write does is to write the commit entry to CommitCache. Currently the write batch in 2nd write is set to an empty LogData entry, while the write to the WAL could simply be entirely disabled.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5327

Differential Revision: D15424546

Pulled By: maysamyabandeh

fbshipit-source-id: 3d9ea3922d5196984c584d62a3ed57e1f7ca7b9f
2019-05-28 14:21:52 -07:00
Siying Dong 4d0c3b1f96 Add comments in compaction_picker.h
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5357

Differential Revision: D15522825

Pulled By: siying

fbshipit-source-id: d775386b9d10c7179f5d3af2c821ed213abfacdf
2019-05-28 12:24:38 -07:00
Yanqin Jin b5e4ee2e76 Fix a clang analyze error (#5365)
Summary:
The analyzer thinks max_allowed_ space can be 0. In that case, free_space will
be assigned as free_space. It fails to realize that the function call
GetFreeSpace actually sets the free_space variable properly, which is possibly
due to lack of inter-function call analysis.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5365

Differential Revision: D15521790

Pulled By: riversand963

fbshipit-source-id: 839d0a285a1c8773a28a385f0c3be4bb7fbe32cb
2019-05-28 12:19:41 -07:00
Sagar Vemuri e264eebcd7 Add comments in file_reader_writer.h (#5355)
Summary:
Add file and class level comments in file_reader_writer.h
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5355

Differential Revision: D15499020

Pulled By: sagar0

fbshipit-source-id: 925b2326885cdb4357e6a139ac65ee5e2ce1d613
2019-05-24 20:31:45 -07:00
Yanqin Jin bd9f1d2d0f Fix RocksDB auto-recovery from SpaceLimit err (#5334)
Summary:
If RocksDB is configured with a positive max_allowed_space (via sst file manager),
then the sst file manager should use this value instead of total free disk
space to determine whether to clear the background error of space limit
reached.

In DBSSTTest.DBWithMaxSpaceAllowed, we configure a low space limit that is very
likely lower than the free disk space of the test machine. Therefore, once the
test db encounters a Status::SpaceLimit, error handler will call into sst file
manager to start error recovery which may clear the bg error since disk free
space is larger than reserved_disk_buffer_.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5334

Differential Revision: D15501622

Pulled By: riversand963

fbshipit-source-id: 58035efc450b062d6b28c78c322005ec3705fb47
2019-05-24 18:38:12 -07:00
Sagar Vemuri b09c018b4d Add comments to trace_replay.h (#5359)
Summary:
Add file, class, and function level comments in trace_replay.h
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5359

Differential Revision: D15505318

Pulled By: sagar0

fbshipit-source-id: 181e3d4ea805fd9a33f91b89e123bbd0c1ead2ce
2019-05-24 16:59:54 -07:00
Zhongyi Xie a466120cd5 improve comments in db_impl_secondary
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5360

Differential Revision: D15502973

Pulled By: miasantreble

fbshipit-source-id: 15b7f9d7928e771a6fac0643861173be8ba6b37a
2019-05-24 15:32:03 -07:00
anand76 029b98984e Add some comments in table_cache.h
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5343

Differential Revision: D15485831

Pulled By: anand1976

fbshipit-source-id: 8735ccfba90d7ecb3559e63f792e34527f04ed29
2019-05-24 14:26:43 -07:00
anand76 eb7647ee6c Add comments t get_context.h
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5353

Differential Revision: D15497912

Pulled By: anand1976

fbshipit-source-id: 72cff2465ca342aa810f925be5a7016b938aa416
2019-05-24 13:31:05 -07:00
Siying Dong 6267ed251a Improve comment in db_impl.h (#5338)
Summary:
Add some comments in db_impl.h. Also reordered function order a little bit so that I can add a comment to flag the area of functions implementing DB interface.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5338

Differential Revision: D15498284

Pulled By: siying

fbshipit-source-id: 3d7c59c8303577fe44d13c74ae84c7ce05164f77
2019-05-24 13:09:55 -07:00
Vijay Nadimpalli f66026c8c7 Comments for BlockBasedTable
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5352

Differential Revision: D15498477

Pulled By: vjnadimpalli

fbshipit-source-id: 08a981521848433362a56ac521c7fb83c7dd7b2a
2019-05-24 12:35:25 -07:00
Siying Dong f69e63dc5f Improve comments in compaction.h
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5356

Differential Revision: D15499033

Pulled By: siying

fbshipit-source-id: 069ae48669484beaf668dd90389b8743b3309dc3
2019-05-24 12:24:28 -07:00
Siying Dong 596cc1547a Update comments in column_family.h (#5347)
Summary:
Document relationships of data structures declared in column_family.h
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5347

Differential Revision: D15496941

Pulled By: siying

fbshipit-source-id: 47b37835abba26aa31a94fabea6b2775483e0ccb
2019-05-24 12:07:15 -07:00
Zhongyi Xie 767d1f3ff1 Improve comments for StatsHistoryIterator and InMemoryStatsHistoryIterator
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5346

Differential Revision: D15497679

Pulled By: miasantreble

fbshipit-source-id: c10caf10293c3d9663bfb398a0d331326d1e9e67
2019-05-24 11:40:05 -07:00
Levi Tamasi 98094f6cac Add some comments for BlockContents
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5354

Differential Revision: D15496645

Pulled By: ltamasi

fbshipit-source-id: 1282b1ce11fbc412d3d87b2688fd0586e7bb6b85
2019-05-24 11:20:09 -07:00
Zhongyi Xie 88ff80780b improve comment for WalManager (#5350)
Summary:
att
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5350

Differential Revision: D15496467

Pulled By: miasantreble

fbshipit-source-id: c29c0b143bf4df2040695a82be0feb9814ddb641
2019-05-24 10:40:30 -07:00
Zhongyi Xie 94c78b11e4 improve comments for statistics.h
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5351

Differential Revision: D15496346

Pulled By: miasantreble

fbshipit-source-id: eeb619e6bd8616003ba35b0cd4bb8050e6a8cb4d
2019-05-24 10:33:57 -07:00
Sagar Vemuri 5d359fc337 Document AlignedBuffer (#5345)
Summary:
Add comments to util/aligned_buffer.h
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5345

Differential Revision: D15496004

Pulled By: sagar0

fbshipit-source-id: 31bc6f35e88dedd74cff55febe02c9e761304f76
2019-05-24 10:05:40 -07:00
haoyuhuang 74a334a2eb Provide an option so that SST ingestion won't fall back to copy after hard linking fails (#5333)
Summary:
RocksDB always tries to perform a hard link operation on the external SST file to ingest. This operation can fail if the external SST resides on a different device/FS, or the underlying FS does not support hard link. Currently RocksDB assumes that if the link fails, the user is willing to perform file copy, which is not true according to the post. This commit provides an option named  'failed_move_fall_back_to_copy' for users to choose which behavior they want.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5333

Differential Revision: D15457597

Pulled By: HaoyuHuang

fbshipit-source-id: f3626e13f845db4f7ed970a53ec8a2b1f0d62214
2019-05-23 21:58:52 -07:00
Zhongyi Xie 6a54278b4a add class level comment for RepeatableThread
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5344

Differential Revision: D15485431

Pulled By: miasantreble

fbshipit-source-id: 9c0f6cf0d826743e743012549976705ceb8cc0c4
2019-05-23 17:03:23 -07:00
Zhongyi Xie 09b534cc2f improve comments for CompactionJob (#5341)
Summary:
add class/function level comments to the header file
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5341

Differential Revision: D15485442

Pulled By: miasantreble

fbshipit-source-id: 9f11e2a1cd3ce0f4990f01353d0a6f4b050615cf
2019-05-23 16:57:46 -07:00
Siying Dong 38a06aa225 Improve comments of classes for PlainTable (#5339)
Summary:
Simply add some comments.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5339

Differential Revision: D15485315

Pulled By: siying

fbshipit-source-id: 4594b1c4c967e6bd08aa7fa08a37df3481df1938
2019-05-23 16:51:44 -07:00
Siying Dong 02830a20f8 Add comments in db/dbformat.h
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5342

Differential Revision: D15485238

Pulled By: siying

fbshipit-source-id: a56b374584cb1d815c1173907a807d90b37d4dd6
2019-05-23 16:44:20 -07:00
Siying Dong dc30a9b69b Add comments to db/db_iter.h (#5340)
Summary:
Add file comment in db/db_iter.h and minor changes in other parts.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5340

Differential Revision: D15484605

Pulled By: siying

fbshipit-source-id: 173771f9d5bd51303de5410ee5afd0a4af9d6572
2019-05-23 16:11:38 -07:00
Levi Tamasi 40aa520a51 Add class comment for BlockFetcher
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5337

Differential Revision: D15482289

Pulled By: ltamasi

fbshipit-source-id: 8639ca78c1b8dfcc337a742d4d81d5752f12545f
2019-05-23 14:22:26 -07:00