Summary:
The PR fixes a Java test for Merge operator `uint64add`.
The current implementation uses wrong byte order for long serialization, but fails to catch this error because the merge sum is lower than `256`.
The PR makes this test case more representative (i.e. it fails with wrong byte order) and changes the byte order to little endian.
Some background: RocksDB uses LittleEndian byte order for integer serialization across all platforms. `MergeTest` uses `ByteBuffer` that defaults to BigEndian byte order.
This test case might probably be used as a sample of `MergeOperator` usage in Java.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7243
Reviewed By: ajkr
Differential Revision: D23079593
Pulled By: pdillinger
fbshipit-source-id: 82e8e166901d66733e96a0116f88d0ec4761ddf1
Summary:
A new option `std::shared_ptr<FileChecksumGenFactory> backup_checksum_gen_factory` is added to `BackupableDBOptions`. This allows custom checksum functions to be used for creating, verifying, or restoring backups.
Tests are added.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7085
Test Plan: Passed make check
Reviewed By: pdillinger
Differential Revision: D22390756
Pulled By: gg814
fbshipit-source-id: 3b7756ca444c2129844536b91c3ca09f53b6248f
Summary:
```
int* value = new int;
ASSERT_NE(nullptr, value);
```
`ASSERT_NE` can expand the expression such that a memory leak is
reported by clang analyzer.
We can remove this ASSERT_NE since we can assume the memory allocation
must succeed. Otherwise a bad alloc exception will be thrown and the
process will be killed anyway.
Test plan (dev server):
```
USE_CLANG=1 make analyze
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7245
Reviewed By: jay-zhuang
Differential Revision: D23079641
Pulled By: riversand963
fbshipit-source-id: a6739a903f90f8715f6f1ef3e5c8a329245b8e78
Summary:
The patch updates github-pages to the latest version. Dependencies were
updated using `bundle update`. Also, the deprecated option `gems` is replaced
with `plugins` in the Jekyll config.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7235
Test Plan: `bundle exec jekyll serve`
Reviewed By: pdillinger
Differential Revision: D23034419
Pulled By: ltamasi
fbshipit-source-id: a3f6df1c33281bdfd33aa61c6dc92162d9b7f079
Summary:
Timer (defined in timer.h) schedules and runs user-specified fuctions
regularly. Current implementation holds the mutex while running user
function, which will lead to contention and waiting.
To fix, Timer::Run releases mutex before running user function, and
re-acquires it afterwards.
This fix will impact how we can cancel a task. If the task is running,
it is not holding the mutex. The thread calling Cancel() should wait
until the current task finishes.
Test Plan (devserver):
make check
COMPILE_WITH_ASAN=1 make check
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7228
Reviewed By: jay-zhuang
Differential Revision: D23065487
Pulled By: riversand963
fbshipit-source-id: 07cb59741f506d3eb875c8ab90f73437568d3724
Summary:
We have a number of tests hanging on MacOS and windows due to
mishandling of code for mock sleeps. In addition, the code was in
terrible shape because the same variable (addon_time_) would sometimes
refer to microseconds and sometimes to seconds. One test even assumed it
was nanoseconds but was written to pass anyway.
This has been cleaned up so that DB tests generally use a SpecialEnv
function to mock sleep, for either some number of microseconds or seconds
depending on the function called. But to call one of these, the test must first
call SetMockSleep (precondition enforced with assertion), which also turns
sleeps in RocksDB into mock sleeps. To also removes accounting for actual
clock time, call SetTimeElapseOnlySleepOnReopen, which implies
SetMockSleep (on DB re-open). This latter setting only works by applying
on DB re-open, otherwise havoc can ensue if Env goes back in time with
DB open.
More specifics:
Removed some unused test classes, and updated comments on the general
problem.
Fixed DBSSTTest.GetTotalSstFilesSize using a sync point callback instead
of mock time. For this we have the only modification to production code,
inserting a sync point callback in flush_job.cc, which is not a change to
production behavior.
Removed unnecessary resetting of mock times to 0 in many tests. RocksDB
deals in relative time. Any behaviors relying on absolute date/time are likely
a bug. (The above test DBSSTTest.GetTotalSstFilesSize was the only one
clearly injecting a specific absolute time for actual testing convenience.) Just
in case I misunderstood some test, I put this note in each replacement:
// NOTE: Presumed unnecessary and removed: resetting mock time in env
Strengthened some tests like MergeTestTime, MergeCompactionTimeTest, and
FilterCompactionTimeTest in db_test.cc
stats_history_test and blob_db_test are each their own beast, rather deeply
dependent on MockTimeEnv. Each gets its own variant of a work-around for
TimedWait in a mock time environment. (Reduces redundancy and
inconsistency in stats_history_test.)
Intended follow-up:
Remove TimedWait from the public API of InstrumentedCondVar, and only
make that accessible through Env by passing in an InstrumentedCondVar and
a deadline. Then the Env implementations mocking time can fix this problem
without using sync points. (Test infrastructure using sync points interferes
with individual tests' control over sync points.)
With that change, we can simplify/consolidate the scattered work-arounds.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7101
Test Plan: make check on Linux and MacOS
Reviewed By: zhichao-cao
Differential Revision: D23032815
Pulled By: pdillinger
fbshipit-source-id: 7f33967ada8b83011fb54e8279365c008bd6610b
Summary:
`VersionStorageInfo::AddFile` currently has a debug-mode consistency
check to make sure the newly added file does not overlap with the
previous one (for levels below L0). Considering that
`VersionBuilder::CheckConsistency` also performs similar checks (in
fact, those checks are more comprehensive and cover L0 as well), this
check is redundant. The patch removes it and also cleans up `AddFile` a
little.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7237
Test Plan: `make check`
Reviewed By: riversand963
Differential Revision: D23041937
Pulled By: ltamasi
fbshipit-source-id: e00665f3b83bfd17f86c54c238800f3d77d739bd
Summary:
The mechanism to mark files for compaction is most commonly used in
delete-triggered compaction. This PR adds an option to exercise the
marking mechanism on random files created by db_stress. This PR also
enables that option in db_crashtest.py on its db_stress runs at random.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7231
Test Plan:
- ran some minified crash tests; verified they succeed and we see `"compaction_reason": "FilesMarkedForCompaction"` regularly in the logs.
```
$ TEST_TMPDIR=/dev/shm python tools/db_crashtest.py blackbox --duration=600 --interval=30 --max_key=10000000 --write_buffer_size=1048576 --target_file_size_base=1048576 --max_bytes_for_level_base=4194304 --value_size_mult=33
$ TEST_TMPDIR=/dev/shm python tools/db_crashtest.py whitebox --duration=600 --interval=30 --max_key=1000000 --write_buffer_size=1048576 --target_file_size_base=1048576 --max_bytes_for_level_base=4194304 --value_size_mult=33 --random_kill_odd=8887
```
Reviewed By: anand1976
Differential Revision: D23025156
Pulled By: ajkr
fbshipit-source-id: a404c467ebc12afa94dae35956ea9b372f592a96
Summary:
Delete triggered compaction (DTC) for universal compaction style with ```num_levels = 1``` has been disabled for sometime due to a data correctness bug. This PR re-enables it with a bug fix. A file marked for compaction can be picked, along with all L0 files after it as the compaction input. We stop adding files to the input once we encounter a file already being compacted (the original bug failed to check the compaction status of the files).
Tests:
Add unit tests to ```compaction_picker_test.cc```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7224
Reviewed By: ajkr
Differential Revision: D23031845
Pulled By: anand1976
fbshipit-source-id: 9de3cab5f9774cede666c2c48d309a7d9b88a505
Summary:
`-O3` is already adopted widely, so we should make it easier to configure
for development/open source. This PR adds an `OPTIMIZE_LEVEL` variable
that users can set to override the `-O` flag chosen in the Makefile.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7202
Test Plan: built a few different ways and verified correct value is passed for `-O` flag
Reviewed By: pdillinger
Differential Revision: D22845291
Pulled By: ajkr
fbshipit-source-id: 84471362e7d627dd606b25bf5f6a3d796817fa1c
Summary:
Trying to fix issue that caused two failures out of eight most
recent master builds
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7234
Test Plan: Watch CircleCI
Reviewed By: riversand963
Differential Revision: D23032184
Pulled By: pdillinger
fbshipit-source-id: dae403f63c0e4f6ab8a3e8e49a49069a532b8f4a
Summary:
The debug is supposed to print out two keys to show the value mismatch, which was compared just a few lines above.
However, the actual print-out is the same values (so they obviously won't be mismatched)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6587
Reviewed By: riversand963
Differential Revision: D23025279
Pulled By: ajkr
fbshipit-source-id: 4c6c35bc60b273f13c08b5464b6f690d8a5cfe41
Summary:
Introduce io_timeout in ReadOptions and enabled deadline/io_timeout for
Iterators.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7161
Test Plan: New unit tests in db_basic_test
Reviewed By: riversand963
Differential Revision: D22687352
Pulled By: anand1976
fbshipit-source-id: 67bbb0e6d7ae80b256589244468494292538c6ec
Summary:
Pointed out by https://github.com/facebook/rocksdb/issues/7197 , there is a double lock in WriteImplWALOnly.
Also find another deadlock in UnorderedWriteMemtable. Move the check after switch_all_.notify_all().
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7199
Test Plan: pass make check
Reviewed By: anand1976
Differential Revision: D22961714
Pulled By: zhichao-cao
fbshipit-source-id: 0707922dc50d28ea141a15a8cdcbd1c8993ea0d8
Summary:
A colon will be added after 'msg' automatically when invoke function Status(Code _code, const Slice& msg, const Slice& msg2),
it's not needed to append a colon explicitly to 'msg'.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7041
Reviewed By: ajkr
Differential Revision: D22292801
fbshipit-source-id: 8f2d69065bb779d2613468bf9fc9169f32c3f1ec
Summary:
Improvements to the RocksJava release process:
* Generates the Maven artifact version number as part of the release step
* Also generates appropriate checksum files to speed the deploy and publish step
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7219
Reviewed By: ltamasi
Differential Revision: D22983481
Pulled By: pdillinger
fbshipit-source-id: 7b8ffaf46471cd3cda181eb830c962b317d2e688
Summary:
We're going to support more locking protocols such as range lock in transaction.
However, in current design, `TransactionBase` has a member `tracked_keys` which assumes that point lock (lock a single key) is used, and is used in snapshot checking (isolation protocol). When using range lock, we may use read committed instead of snapshot checking as the isolation protocol.
The most significant usage scenarios of `tracked_keys` are:
1. pessimistic transaction uses it to track the locked keys, and unlock these keys when commit or rollback.
2. optimistic transaction does not lock keys upfront, it only tracks the lock intentions in tracked_keys, and do write conflict checking when commit.
3. each `SavePoint` tracks the keys that are locked since the `SavePoint`, `RollbackToSavePoint` or `PopSavePoint` relies on both the tracked keys in `SavePoint`s and `tracked_keys`.
Based on these scenarios, if we can abstract out a `LockTracker` interface to hold a set of tracked locks (can be keys or key ranges), and have methods that can be composed together to implement the scenarios, then `tracked_keys` can be an internal data structure of one implementation of `LockTracker`. See `utilities/transactions/lock/lock_tracker.h` for the detailed interface design, and `utilities/transactions/lock/point_lock_tracker.cc` for the implementation.
In the future, a `RangeLockTracker` can be implemented to track range locks without affecting other components.
After this PR, a clean interface for lock manager should be possible, and then ideally, we can have pluggable locking protocols.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7013
Test Plan: Run `transaction_test` and `optimistic_transaction_test`.
Reviewed By: ajkr
Differential Revision: D22163706
Pulled By: cheng-chang
fbshipit-source-id: f2860577b5334e31dd2994f5bc6d7c40d502b1b4
Summary:
`WalAddition`, `WalDeletion` are defined in `wal_version.h` and used in `VersionEdit`.
`WalAddition` is used to represent events of creating a new WAL (no size, just log number), or closing a WAL (with size).
`WalDeletion` is used to represent events of deleting or archiving a WAL, it means the WAL is no longer alive (won't be replayed during recovery).
`WalSet` is the set of alive WALs kept in `VersionSet`.
1. Why use `WalDeletion` instead of relying on `MinLogNumber` to identify outdated WALs
On recovery, we can compute `MinLogNumber()` based on the log numbers kept in MANIFEST, any log with number < MinLogNumber can be ignored. So it seems that we don't need to persist `WalDeletion` to MANIFEST, since we can ignore the WALs based on MinLogNumber.
But the `MinLogNumber()` is actually a lower bound, it does not exactly mean that logs starting from MinLogNumber must exist. This is because in a corner case, when a column family is empty and never flushed, its log number is set to the largest log number, but not persisted in MANIFEST. So let's say there are 2 column families, when creating the DB, the first WAL has log number 1, so it's persisted to MANIFEST for both column families. Then CF 0 is empty and never flushed, CF 1 is updated and flushed, so a new WAL with log number 2 is created and persisted to MANIFEST for CF 1. But CF 0's log number in MANIFEST is still 1. So on recovery, MinLogNumber is 1, but since log 1 only contains data for CF 1, and CF 1 is flushed, log 1 might have already been deleted from disk.
We can make `MinLogNumber()` be the exactly minimum log number that must exist, by persisting the most recent log number for empty column families that are not flushed. But if there are N such column families, then every time a new WAL is created, we need to add N records to MANIFEST.
In current design, a record is persisted to MANIFEST only when WAL is created, closed, or deleted/archived, so the number of WAL related records are bounded to 3x number of WALs.
2. Why keep `WalSet` in `VersionSet` instead of applying the `VersionEdit`s to `VersionStorageInfo`
`VersionEdit`s are originally designed to track the addition and deletion of SST files. The SST files are related to column families, each column family has a list of `Version`s, and each `Version` keeps the set of active SST files in `VersionStorageInfo`.
But WALs are a concept of DB, they are not bounded to specific column families. So logically it does not make sense to store WALs in a column family's `Version`s.
Also, `Version`'s purpose is to keep reference to SST / blob files, so that they are not deleted until there is no version referencing them. But a WAL is deleted regardless of version references.
So we keep the WALs in `VersionSet` for the purpose of writing out the DB state's snapshot when creating new MANIFESTs.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7164
Test Plan:
make version_edit_test && ./version_edit_test
make wal_edit_test && ./wal_edit_test
Reviewed By: ltamasi
Differential Revision: D22677936
Pulled By: cheng-chang
fbshipit-source-id: 5a3b6890140e572ffd79eb37e6e4c3c32361a859
Summary:
FaultInjectionTestFS::NewDirectory currently asserts that the directory
creation on the target filesystem succeeds. This is actually not
guaranteed since there might be a legitimate I/O error when creating the
directory. The patch removes this assertion.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7220
Test Plan: `make check`
Reviewed By: zhichao-cao
Differential Revision: D22957990
Pulled By: ltamasi
fbshipit-source-id: b2e221320d8ce7235cb4897ef5936072412a25b6
Summary:
IteratorIterator::IsOutOfBound() and IteratorIterator::MayBeOutOfUpperBound() are two functions that related to upper bound check. It is hard for users to reason about this complexity. Consolidate the two functions into one and assign an enum as results to improve readability.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7200
Test Plan: Run all existing test. Would run crash test with atomic for a while.
Reviewed By: anand1976
Differential Revision: D22833181
fbshipit-source-id: a0c724267056adbd0476bde74650e6c7226077e6
Summary:
as title.
When ReadOptions.iter_start_ts is not nullptr, DBIter::key() should
return internal keys including value type.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7178
Test Plan: make check
Reviewed By: ltamasi
Differential Revision: D22935879
Pulled By: riversand963
fbshipit-source-id: 7508d962cf11ebcfa6386d2529b4f3606b47ccfd
Summary:
https://github.com/facebook/rocksdb/pull/5289 introduces a performance regression that caused an upper bound check within every BlockBasedTableIterator::Next(). This is unnecessary if we've checked the boundary key for current block and it is within upper bound.
Fix the bug. Also rename the boolean to a enum so that the code is slightly better readable. The original regression was probably to fix a bug that the block upper bound check status is not reset after a new block is created. Fix it bug so that the regression can be avoided without hitting the bug.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7209
Test Plan: Run all existing tests. Will run atomic black box crash test for a while.
Reviewed By: anand1976
Differential Revision: D22859246
fbshipit-source-id: cbdad1f5e656c55fd8b71726d5a4f6cb53ff9140
Summary:
The patch moves `CompressionType` to its own header file and makes sure
all other public headers include this new header directly, as opposed to
relying on transitive includes or forward declarations.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7162
Test Plan: `make check`
Reviewed By: riversand963
Differential Revision: D22676545
Pulled By: ltamasi
fbshipit-source-id: 01d7a232377a229cbbc373d0ec1bf01dc0b0ce02
Summary:
Previously, a `ReadOptions` object was stored in every `BlockBasedTableIterator`
and every `LevelIterator`. This redundancy consumes extra memory,
resulting in the `Arena` making more allocations, and iteration
observing worse cache performance.
This PR migrates callers of `NewInternalIterator()` and
`MakeInputIterator()` to provide a `ReadOptions` object guaranteed to
outlive the returned iterator. When the iterator's lifetime will be managed by the
user, this lifetime guarantee is achieved by storing the `ReadOptions`
value in `ArenaWrappedDBIter`. Then, sub-iterators of `NewInternalIterator()` and
`MakeInputIterator()` can hold a reference-to-const `ReadOptions`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7210
Test Plan:
- `make check` under ASAN and valgrind
- benchmark: on a DB with 2 L0 files and 3 L1+ levels, this PR reduced `Arena` allocation 4792 -> 4160 bytes.
Reviewed By: anand1976
Differential Revision: D22861323
Pulled By: ajkr
fbshipit-source-id: 54aebb3e89c872eeab0f5793b4b6e42878d093ce
Summary:
Very small improvements to document the defaults.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7215
Reviewed By: zhichao-cao
Differential Revision: D22902286
fbshipit-source-id: a754d172a0d8e4c03754f6f1771d4a693d60a770
Summary:
Adds compaction statistics (total bytes read and written) for compactions that occur for delete-triggered, periodic, and TTL compaction reasons.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7165
Test Plan:
TTL and periodic can be checked by runnning db_bench with the options activated:
/db_bench --benchmarks="fillrandom,stats" --statistics --num=10000000 -base_background_compactions=16 -periodic_compaction_seconds=1
./db_bench --benchmarks="fillrandom,stats" --statistics --num=10000000 -base_background_compactions=16 -fifo_compaction_ttl=1
Setting the time to one second causes non-zero bytes read/written for those compaction reasons. Disabling them or setting them to times longer than the test run length causes the stats to return to zero as expected.
Delete-triggered compaction counting is tested in DBTablePropertiesTest.DeletionTriggeredCompactionMarking
Reviewed By: ajkr
Differential Revision: D22693050
Pulled By: akabcenell
fbshipit-source-id: d15cef4d94576f703015c8942d5f0d492f69401d
Summary:
NextAndGetResult() is not implemented in memtable and is very simply implemented in level iterator. The result is that for a normal leveled iterator, performance regression will be observed for calling PrepareValue() for most iterator Next(). Mitigate the problem by implementing the function for both iterators. In level iterator, the implementation cannot be perfect as when calling file iterator's SeekToFirst() we don't have information about whether the value is prepared. Fortunately, the first key should not cause a big portion of the CPu.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7179
Test Plan: Run normal crash test for a while.
Reviewed By: anand1976
Differential Revision: D22783840
fbshipit-source-id: c19f45cdf21b756190adef97a3b66ccde3936e05
Summary:
Make (most of) the env*_test pass when ASSERT_STATUS_CHECKED is enabled.
One test that opens a database is currently disabled in this mode, as there are many errors that need revisited for DB tests and status checks.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7176
Reviewed By: cheng-chang
Differential Revision: D22799278
Pulled By: ajkr
fbshipit-source-id: 16d8a02eaeecd6df1060249b6a5811292801f2ed
Summary:
`USE_LTO=1` in `make` commands now enables LTO. The archiver (`ar`) needed
to change in this PR to use a wrapper that enables the LTO plugin.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7181
Test Plan:
build a few ways
```
$ make clean && USE_LTO=1 make -j48 db_bench
$ make clean && USE_CLANG=1 USE_LTO=1 make -j48 db_bench
$ make clean && ROCKSDB_NO_FBCODE=1 USE_LTO=1 make -j48 db_bench
```
Reviewed By: cheng-chang
Differential Revision: D22784994
Pulled By: ajkr
fbshipit-source-id: 9c45333bd49bf4615aa04c85b7c6fd3925421152
Summary:
Fix the data race warning by removing an unnecessary variable that causes the warning.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7177
Test Plan:
`COMPILE_WITH_TSAN=1 make backupable_db_test`
`./backupable_db_test --gtest_filter=*TableFileWithDbChecksumCorruptedDuringBackup*`
Reviewed By: riversand963
Differential Revision: D22774430
Pulled By: gg814
fbshipit-source-id: 3b0b1ac344d0375c64da564cc97f98745c289959
Summary:
On Travis, the old `alignment()` returned by `RandomAccessFileReaderTest` is inconsistent with the `GetRequiredBufferAlignment` returned in `RandomAccessFileReader`. This PR removes `alignment()` and consistently use `GetRequiredBufferAlignment` as page size.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7173
Test Plan:
make random_access_file_reader_test && ./random_access_file_reader_test
Watch Travis
Reviewed By: siying
Differential Revision: D22741606
Pulled By: cheng-chang
fbshipit-source-id: f28f29a7c993bbc3594ae70ecd186fa8bab9c4f2
Summary:
BackupableDBTest.RateLimiting test is failing due to timed out
on our test server. It might be because of nested loops run sequentially that test different type of combinations of parameters. This patch converts the test into parameterized test so that all combinations can be tested out.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7167
Test Plan: make check -j64
Reviewed By: zhichao-cao
Differential Revision: D22709531
Pulled By: akankshamahajan15
fbshipit-source-id: 95518153e87b3b5311a6c1960a191bca58898786
Summary:
SST Partitioner interface that allows to split SST files during compactions.
It basically instruct compaction to create a new file when needed. When one is using well defined prefixes and prefixed way of defining tables it is good to define also partitioning so that promotion of some SST file does not cover huge key space on next level (worst case complete space).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6957
Reviewed By: ajkr
Differential Revision: D22461239
fbshipit-source-id: 9ce07bba08b3ba89c2d45630520368f704d1316e
Summary:
There is a typo in TryMerge which may cause MultiRead to internally read more data than expected, but won't affect MultiRead results' correctness.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7157
Test Plan: make random_access_file_reader_test && ./random_access_file_reader_test
Reviewed By: siying
Differential Revision: D22670257
Pulled By: cheng-chang
fbshipit-source-id: d261289455a65aa496b348c6e5582b48b12963b7
Arkady Dyakonov