Summary:
RangeDelAggregatorV2 now supports ShouldDelete calls on
snapshot stripes and creation of range tombstone compaction iterators.
RangeDelAggregator is no longer used on any non-test code path, and will
be removed in a future commit.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4758
Differential Revision: D13439254
Pulled By: abhimadan
fbshipit-source-id: fe105bcf8e3d4a2df37a622d5510843cd71b0401
Summary:
Expose common stats min,max,count,sum via statistics JNI. These stats are not fully exposed on the Java side as is, but are available on the native side.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4742
Differential Revision: D13403766
Pulled By: ajkr
fbshipit-source-id: 5b70f7bd3fb7490aab73dcbd09f13490fce5c773
Summary:
The test fails sporadically expecting the DB to be empty after DeleteFilesInRange(..., nullptr, nullptr) call which is not. Debugging shows cases where the files are skipped since they are being compacted. The patch fixes the test by waiting for the last CompactRange to finish before calling DeleteFilesInRange.
Verified by
```
~/gtest-parallel/gtest-parallel ./db_compaction_test --gtest_filter=DBCompactionTest.DeleteFileRange --repeat=10000
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4784
Differential Revision: D13469402
Pulled By: maysamyabandeh
fbshipit-source-id: 3d8f44abe205b82c69f01e7edf27e1f8098248e1
Summary:
Updating the `HistogramType.java` and `TickerType.java` to expose and correct metrics for statistics callbacks.
Moved `NO_ITERATOR_CREATED` to the proper stat name and deprecated `NO_ITERATORS`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4733
Differential Revision: D13466936
Pulled By: sagar0
fbshipit-source-id: a58d1edcc07c7b68c3525b1aa05828212c89c6c7
Summary:
Separate flag for enabling option from flag for enabling dedicated atomic stress test. I have found setting the former without setting the latter can detect different problems.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4781
Differential Revision: D13463211
Pulled By: ajkr
fbshipit-source-id: 054f777885b2dc7d5ea99faafa21d6537eee45fd
Summary:
options_file_number_ must be written under db::mutex_ sine its read is protected by mutex_ in ::GetLiveFiles(). However currently it is written in ::RenameTempFileToOptionsFile() which according to its contract must be called without holding db::mutex_. The patch fixes the race condition by also acquitting the mutex_ before writing options_file_number_. Also it does that only if the rename of option file is successful.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4780
Differential Revision: D13461411
Pulled By: maysamyabandeh
fbshipit-source-id: 2d5bae96a1f3e969ef2505b737cf2d7ae749787b
Summary:
If one column family is dropped, we should simply skip it and continue to flush
other active ones.
Currently we use Status::ShutdownInProgress to notify caller of column families
being dropped. In the future, we should consider using a different Status code.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4708
Differential Revision: D13378954
Pulled By: riversand963
fbshipit-source-id: 42f248cdf2d32d4c0f677cd39012694b8f1328ca
Summary:
It sometimes times out with it is run with TSAN. The patch reduces the iteration from 50 to 30. This reduces the normal runtime from 5.2 to 3.1 seconds and should similarly address the TSAN timeout problem.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4779
Differential Revision: D13456862
Pulled By: maysamyabandeh
fbshipit-source-id: fdc0ad7d781b1c33b771d2415ff5fa2f1b5e2537
Summary:
The PR is targeting to resolve the issue of:
https://github.com/facebook/rocksdb/issues/3972#issue-330771918
We have a rocksdb created with leveled-compaction with multiple column families (CFs), some of CFs are using HDD to store big and less frequently accessed data and others are using SSD.
When there are continuously write traffics going on to all CFs, the compaction thread pool is mostly occupied by those slow HDD compactions, which blocks fully utilize SSD bandwidth.
Since atomic write and transaction is needed across CFs, so splitting it to multiple rocksdb instance is not an option for us.
With the compaction thread control, we got 30%+ HDD write throughput gain, and also a lot smooth SSD write since less write stall happening.
ConcurrentTaskLimiter can be shared with multi-CFs across rocksdb instances, so the feature does not only work for multi-CFs scenarios, but also for multi-rocksdbs scenarios, who need disk IO resource control per tenant.
The usage is straight forward:
e.g.:
//
// Enable compaction thread limiter thru ColumnFamilyOptions
//
std::shared_ptr<ConcurrentTaskLimiter> ctl(NewConcurrentTaskLimiter("foo_limiter", 4));
Options options;
ColumnFamilyOptions cf_opt(options);
cf_opt.compaction_thread_limiter = ctl;
...
//
// Compaction thread limiter can be tuned or disabled on-the-fly
//
ctl->SetMaxOutstandingTask(12); // enlarge to 12 tasks
...
ctl->ResetMaxOutstandingTask(); // disable (bypass) thread limiter
ctl->SetMaxOutstandingTask(-1); // Same as above
...
ctl->SetMaxOutstandingTask(0); // full throttle (0 task)
//
// Sharing compaction thread limiter among CFs (to resolve multiple storage perf issue)
//
std::shared_ptr<ConcurrentTaskLimiter> ctl_ssd(NewConcurrentTaskLimiter("ssd_limiter", 8));
std::shared_ptr<ConcurrentTaskLimiter> ctl_hdd(NewConcurrentTaskLimiter("hdd_limiter", 4));
Options options;
ColumnFamilyOptions cf_opt_ssd1(options);
ColumnFamilyOptions cf_opt_ssd2(options);
ColumnFamilyOptions cf_opt_hdd1(options);
ColumnFamilyOptions cf_opt_hdd2(options);
ColumnFamilyOptions cf_opt_hdd3(options);
// SSD CFs
cf_opt_ssd1.compaction_thread_limiter = ctl_ssd;
cf_opt_ssd2.compaction_thread_limiter = ctl_ssd;
// HDD CFs
cf_opt_hdd1.compaction_thread_limiter = ctl_hdd;
cf_opt_hdd2.compaction_thread_limiter = ctl_hdd;
cf_opt_hdd3.compaction_thread_limiter = ctl_hdd;
...
//
// The limiter is disabled by default (or set to nullptr explicitly)
//
Options options;
ColumnFamilyOptions cf_opt(options);
cf_opt.compaction_thread_limiter = nullptr;
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4332
Differential Revision: D13226590
Pulled By: siying
fbshipit-source-id: 14307aec55b8bd59c8223d04aa6db3c03d1b0c1d
Summary:
The test has been failing sporadically probably because the configured compaction options were actually unused. Verified that by the following:
```
~/gtest-parallel/gtest-parallel ./db_compaction_test --gtest_filter=DBCompactionTest.DeleteFileRange --repeat=1000
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4776
Differential Revision: D13441052
Pulled By: maysamyabandeh
fbshipit-source-id: d35075b9e6cef9b9c9d0d571f9cd72ade8eda55d
Summary:
In Direct I/O case, WritableFileWriter::Close() rewrites the last block again, even if there is nothing new. The reason is that, Close() flushes the buffer. For non-direct I/O case, the buffer is empty in this case so it is a no-op. However, in direct I/O case, the partial data in the last block is kept in the buffer because it needs to be rewritten for the next write. This piece of data is flushed again. This commit fixes it by skipping this write out if `pending_sync_` flag shows that there isn't new data sync last sync.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4771
Differential Revision: D13420426
Pulled By: siying
fbshipit-source-id: 9d39ec9a215b1425d4ed40d85e0eba1f5daa75c6
Summary:
This PR fixes#4721. When an exception is caught and thrown as a different exception, then the original exception should be inserted as a cause of the new exception. This bug in RocksDB was swallowing the underlying exception from `NativeLibraryLoader` and throwing the following exception
```
...
Caused by: java.lang.RuntimeException: Unable to load the RocksDB shared libraryjava.nio.channels.ClosedByInterruptException
at org.rocksdb.RocksDB.loadLibrary(RocksDB.java:67)
at org.rocksdb.RocksDB.<clinit>(RocksDB.java:35)
... 73 more
```
The fix is simple and self-explanatory.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4728
Differential Revision: D13418371
Pulled By: sagar0
fbshipit-source-id: d76c25af2a83a0f8ba62cc8d7b721bfddc85fdf1
Summary:
To support the flush/compaction use cases of RangeDelAggregator
in v2, FragmentedRangeTombstoneIterator now supports dropping tombstones
that cannot be read in the compaction output file. Furthermore,
FragmentedRangeTombstoneIterator supports the "snapshot striping" use
case by allowing an iterator to be split by a list of snapshots.
RangeDelAggregatorV2 will use these changes in a follow-up change.
In the process of making these changes, other miscellaneous cleanups
were also done in these files.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4740
Differential Revision: D13287382
Pulled By: abhimadan
fbshipit-source-id: f5aeb03e1b3058049b80c02a558ee48f723fa48c
Summary:
Fixes some RocksJava regressions recently introduced, whereby RocksJava would not build on JDK 7.
These should have been visible on Travis-CI!
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4768
Differential Revision: D13418173
Pulled By: sagar0
fbshipit-source-id: 57bf223188887f84d9e072031af2e0d2c8a69c30
Summary:
Change the directory where ExternalSSTFileBasicTest* tests run.
**Problem:**
Without this change, I spent considerable time chasing around a non-existent issue as ExternalSSTFileTest.* and ExternalSSTFileBasicTest.* create similar directories.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4766
Differential Revision: D13409384
Pulled By: sagar0
fbshipit-source-id: c33e1f4d505dfa6efbc788d6c57cdb680053ded3
Summary:
When adding CompactionFilter and CompactionFilterFactory settings to the Java layer, ColumnFamilyOptions was modified directly instead of ColumnFamilyOptionsInterface. This meant that the old-stye Options monolith was left behind.
This patch fixes that, by:
- promoting the CompactionFilter + CompactionFilterFactory setters from ColumnFamilyOptions -> ColumnFamilyOptionsInterface
- adding getters in ColumnFamilyOptionsInterface
- implementing setters in Options
- implementing getters in both ColumnFamilyOptions and Options
- adding testcases
- reusing a test CompactionFilterFactory by moving it to a common location
Pull Request resolved: https://github.com/facebook/rocksdb/pull/3461
Differential Revision: D13278788
Pulled By: sagar0
fbshipit-source-id: 72602c6eb97dc80734e718abb5e2e9958d3c753b
Summary:
It is possible to see a situation like the following when
subcompactions are enabled:
1. A subcompaction boundary is set to `[b, e)`.
2. The first output file in a subcompaction has `c@20` as its smallest key
3. The range tombstone `[a, d)30` is encountered.
4. The tombstone is written to the range-del meta block and the new
smallest key is set to `b@0` (since no keys in this subcompaction's
output can be smaller than `b`).
5. A key `b@10` in a lower level will now reappear, since it is not
covered by the truncated start key `b@0`.
In general, unless the smallest data key in a file has a seqnum of 0, it
is not safe to truncate a tombstone at the start key to have a seqnum of
0, since it can expose keys with a seqnum greater than 0 but less than
the tombstone's actual seqnum.
To fix this, when the lower bound of a file is from the subcompaction
boundaries, we now set the seqnum of an artificially extended smallest
key to the tombstone's seqnum. This is safe because subcompactions
operate over disjoint sets of keys, and the subcompactions that can
experience this problem are not the first subcompaction (which is
unbounded on the left).
Furthermore, there is now an assertion to detect the described anomalous
case.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4723
Differential Revision: D13236188
Pulled By: abhimadan
fbshipit-source-id: a6da6a113f2de1e2ff307ca72e055300c8fe5692
Summary:
Compile logs have a bit of noise due to missing javadoc annotations. Updating docs to reduce.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4764
Differential Revision: D13400193
Pulled By: sagar0
fbshipit-source-id: 65c7efb70747cc3bb35a336a6881ea6536ae5ff4
Summary:
Fix the definition of assumed_tracked in Transaction that was introduced in #4680
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4762
Differential Revision: D13399150
Pulled By: maysamyabandeh
fbshipit-source-id: 2a30fe49e3c44adacd7e45cd48eae95023ca9dca
Summary:
1. DBImplReadOnly::GetLiveFiles should not return NotSupported. Instead, it
should call DBImpl::GetLiveFiles(flush_memtable=false).
2. In DBImp::Recover, we should also recover the OPTIONS file name and/or
number so that an immediate subsequent GetLiveFiles will get the correct
OPTIONS name.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4681
Differential Revision: D13069205
Pulled By: riversand963
fbshipit-source-id: 3e6a0174307d06db5a01feb099b306cea1f7f88a
Summary:
Add counters to track block cache index/filter hits and misses. We currently count aggregate hits and misses, which includes index/filter/data blocks.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4540
Differential Revision: D10459652
Pulled By: anand1976
fbshipit-source-id: 0c59eee7f12f5103dcb6686f0e7995babe63d425
Summary:
Uses a newer build toolchain but the same old GLIBC when building releases of RocksJava for Linux x64 in the Docker Container.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4756
Differential Revision: D13383575
Pulled By: sagar0
fbshipit-source-id: 27c58814876e434d5fa61395e6664cfc5f6830b1
Summary:
Refactored and simplified `BlockBasedTable::Open` to be similar to `BlockBasedTableBuilder::Finish` as both these functions complement each other. Also added `BlockBasedTableBuilder::WriteFooter` along the way.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4636
Differential Revision: D12933319
Pulled By: sagar0
fbshipit-source-id: 1ff1d02f6d80a63b5ba720a1fc75e71c7344137b
Summary:
the original test does not give enough time difference between tombstone write time and the expire time point, which make test flaky.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4755
Reviewed By: maysamyabandeh
Differential Revision: D13369681
Pulled By: wpc
fbshipit-source-id: 22576f354c63cd0b39d8b35c3913303707503ea9
Summary:
Transaction::GetForUpdate is extended with a do_validate parameter with default value of true. If false it skips validating the snapshot (if there is any) before doing the read. After the read it also returns the latest value (expects the ReadOptions::snapshot to be nullptr). This allows RocksDB applications to use GetForUpdate similarly to how InnoDB does. Similarly ::Merge, ::Put, ::Delete, and ::SingleDelete are extended with assume_exclusive_tracked with default value of false. It true it indicates that call is assumed to be after a ::GetForUpdate(do_validate=false).
The Java APIs are accordingly updated.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4680
Differential Revision: D13068508
Pulled By: maysamyabandeh
fbshipit-source-id: f0b59db28f7f6a078b60844d902057140765e67d
Summary:
As titled. Update history to include a recent bug fix in
9be3e6b488.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4753
Differential Revision: D13350286
Pulled By: riversand963
fbshipit-source-id: b6324780dee4cb1757bc2209403a08531c150c08
Summary:
When write stall has already been triggered due to number of L0 files reaching
threshold, file ingestion must proceed with its flush without waiting for the
write stall condition to cleared by the compaction because compaction can wait
for ingestion to finish (circular wait).
In order to avoid this wait, we can set `FlushOptions.allow_write_stall` to be
true (default is false). Setting it to false can cause deadlock.
This can happen when the number of compaction threads is low.
Considere the following
```
Time compaction_thread ingestion_thread
| num_running_ingest_file_++
| while(num_running_ingest_file_>0){wait}
| flush
V
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4751
Differential Revision: D13343037
Pulled By: riversand963
fbshipit-source-id: d3b95938814af46ec4c463feff0b50c70bd8b23f
Summary:
Don't enable ROCKSDB_JEMALLOC unless the build mode is opt and default
allocator is jemalloc. In dev mode, this is causing compile/link errors such as -
```
stderr: buck-out/dev/gen/rocksdb/src/rocksdb_lib#compile-pic-malloc_stats.cc.o4768b59e,gcc-5-glibc-2.23-clang/db/malloc_stats.cc.o:malloc_stats.cc:function rocksdb::DumpMallocStats(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*): error: undefined reference to 'malloc_stats_print'
clang-7.0: error: linker command failed with exit code 1
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4747
Differential Revision: D13324840
Pulled By: anand1976
fbshipit-source-id: 45ffbd4f63fe4d9e8a0473d8f066155e4ef64a14
Summary:
Current implementation of `current_over_upper_bound_` fails to take into consideration that keys might be invalid in either base iterator or delta iterator. Calling key() in such scenario will lead to assertion failure and runtime errors.
This PR addresses the bug by adding check for valid keys before calling `IsOverUpperBound()`, also added test coverage for iterate_upper_bound usage in BaseDeltaIterator
Also recommit https://github.com/facebook/rocksdb/pull/4656 (It was reverted earlier due to bugs)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4702
Differential Revision: D13146643
Pulled By: miasantreble
fbshipit-source-id: 6d136929da12d0f2e2a5cea474a8038ec5cdf1d0
Summary:
Full block (use_block_based_builder=false) Bloom filter has clear CPU saving benefits but with limitation of using temp memory when building an SST file proportional to the SST file size. We reduced the chance of having large SST files with multi-level universal compaction. Now we change to a default with better performance.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4735
Differential Revision: D13266674
Pulled By: siying
fbshipit-source-id: 7594a4c3e32568a5a2adce22bb0e46553e55c602
Summary:
Currently tests are failing on master with the following message:
> util/jemalloc_nodump_allocator.cc:132:8: error: unused parameter ‘options’ [-Werror=unused-parameter]
Status NewJemallocNodumpAllocator(
This PR attempts to fix the issue
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4738
Differential Revision: D13278804
Pulled By: miasantreble
fbshipit-source-id: 64a6204aa685bd85d8b5080655cafef9980fac2f
Summary:
The fix in #4727 for double snapshot release was incomplete since it does not properly remove the duplicate entires in the snapshot list after finding that a snapshot is still valid. The patch does that and also improves the unit test to show the issue.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4734
Differential Revision: D13266260
Pulled By: maysamyabandeh
fbshipit-source-id: 351e2c40cca45a87b757774c11af74182314911e
Summary:
Add option to limit tcache usage by allocation size. This is to reduce total tcache size in case there are many user threads accessing the allocator and incur non-trivial memory usage.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4736
Differential Revision: D13269305
Pulled By: yiwu-arbug
fbshipit-source-id: 95a9b7fc67facd66837c849137e30e137112e19d
Summary:
**Summary:**
Simplified the code layout by moving FIFOCompactionPicker to a separate file.
**Why?:**
While trying to add ttl functionality to universal compaction, I found that `FIFOCompactionPicker` class and its impl methods to be interspersed between `LevelCompactionPicker` methods which kind-of made the code a little hard to traverse. So I moved `FIFOCompactionPicker` to a separate compaction_picker_fifo.h/cc file, similar to `UniversalCompactionPicker`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4724
Differential Revision: D13227914
Pulled By: sagar0
fbshipit-source-id: 89471766ea67fa4d87664a41c057dd7df4b3d4e3
Summary:
There is a race condition in DBFlushTest.SyncFail, as illustrated below.
```
time thread1 bg_flush_thread
| Flush(wait=false, cfd)
| refs_before=cfd->current()->TEST_refs() PickMemtable calls cfd->current()->Ref()
V
```
The race condition between thread1 getting the ref count of cfd's current
version and bg_flush_thread incrementing the cfd's current version makes it
possible for later assertion on refs_before to fail. Therefore, we add test
sync points to enforce the order and assert on the ref count before and after
PickMemtable is called in bg_flush_thread.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4633
Differential Revision: D12967131
Pulled By: riversand963
fbshipit-source-id: a99d2bacb7869ec5d8d03b24ef2babc0e6ae1a3b
Summary:
there is chance that
* the caller tries to repair the db when holding the db_lock, in
that case the env implementation might not set the `lock`
parameter of Repairer::Run().
* the caller somehow never calls Repairer::Run().
either way, the desctructor of Repair will compare the uninitialized
db_lock_ with nullptr, and tries to unlock it. there is good chance
that the db_lock_ is not nullptr, then boom.
Signed-off-by: Kefu Chai <tchaikov@gmail.com>
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4683
Differential Revision: D13260287
Pulled By: riversand963
fbshipit-source-id: 878a119d2e9f10a0fa17ee62cf3fb24b33d49fa5
Summary:
Add a dummy main() in sst_file_reader_test for ROCKSDB_LITE to fix link failure in regression
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4725
Differential Revision: D13252885
Pulled By: anand1976
fbshipit-source-id: 0e22b964815e2bf01aff7d03ed4ae59d44fa86f1
Summary:
Currently the garbage collection of items in old_commit_map_ was done upon ::ReleaseSnapshot. The assumption behind this method was that the sequence number of snapshots are unique, which is incorrect. In the very rare cases that two consecutive snapshot have the same sequence number this could lead the release of the first snapshot affect the old_commit_map_ that is necessary to service the reads of the second snapshot. The bug would be triggered only if i) two snapshot have the same seq, ii) both of them are very old (older than the last ~4m transactions), and iii) there is commit entry overlapping with the snapshot seq number.
It is fixed by doing the cleanup of old_commit_map_ in UpdateSnapshot: the new list of snapshots are compared with the old one and the missing sequence numbers are concluded released. If two snapshots have the same seq number, after the release of one of them, the seq number still appears in the snapshot least and thus not cleaned up prematurely.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4727
Differential Revision: D13246495
Pulled By: maysamyabandeh
fbshipit-source-id: 93b87a5042afd8060889df245526d3f5d29de9fe
Summary:
Fix block based table reader not using memory_allocator when allocating index blocks and compression dictionary blocks.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4678
Differential Revision: D13054594
Pulled By: yiwu-arbug
fbshipit-source-id: 379f25bcc665395662511c4f873f4b7b55104ce2
Summary:
Removed `one_time_use` flag, which removed the need for some
tests, and changed all `NewRangeTombstoneIterator` methods to return
`FragmentedRangeTombstoneIterators`.
These changes also led to removing `RangeDelAggregatorV2::AddUnfragmentedTombstones`
and one of the `MemTableListVersion::AddRangeTombstoneIterators` methods.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4692
Differential Revision: D13106570
Pulled By: abhimadan
fbshipit-source-id: cbab5432d7fc2d9cdfd8d9d40361a1bffaa8f845
Summary:
If user do not end the trace manually, the tracing will continue which can potential use up all the storage space and cause problem. In this PR, the max trace file size is added to the TraceOptions and user can set the value if they need or the default is 64GB.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4610
Differential Revision: D12893400
Pulled By: zhichao-cao
fbshipit-source-id: acf4b5a6076bb691778bdfbac4864e1006758953
Summary:
A user friendly sst file reader is useful when we want to access sst
files outside of RocksDB. For example, we can generate an sst file
with SstFileWriter and send it to other places, then use SstFileReader
to read the file and process the entries in other ways.
Also rename the original SstFileReader to SstFileDumper because of
name conflict, and seems SstFileDumper is more appropriate for tools.
TODO: there is only a very simple test now, because I want to get some feedback first.
If the changes look good, I will add more tests soon.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4717
Differential Revision: D13212686
Pulled By: ajkr
fbshipit-source-id: 737593383264c954b79e63edaf44aaae0d947e56
