Summary:
store a zero as the checksum when disabled since it's easier to keep block trailer a fixed length.
Closes https://github.com/facebook/rocksdb/pull/2781
Differential Revision: D5694702
Pulled By: ajkr
fbshipit-source-id: 69cea9da415778ba2b600dfd9d0dfc8cb5188ecd
Summary:
This reverts the previous commit 1d7048c598, which broke the build.
Did a `git revert 1d7048c`.
Closes https://github.com/facebook/rocksdb/pull/2627
Differential Revision: D5476473
Pulled By: sagar0
fbshipit-source-id: 4756ff5c0dfc88c17eceb00e02c36176de728d06
Summary: This uses `clang-tidy` to comment out unused parameters (in functions, methods and lambdas) in fbcode. Cases that the tool failed to handle are fixed manually.
Reviewed By: igorsugak
Differential Revision: D5454343
fbshipit-source-id: 5dee339b4334e25e963891b519a5aa81fbf627b2
Summary:
The casting seemed to cause a problem.
I think this might increase it to unsigned long.
Closes https://github.com/facebook/rocksdb/pull/2562
Differential Revision: D5406842
Pulled By: siying
fbshipit-source-id: 736adef31448229a58a1a48bdbe77792f36736e8
Summary:
Currently metadata_block_size controls only index partition size. With this patch a partition is cut after any of index or filter partitions reaches metadata_block_size.
Closes https://github.com/facebook/rocksdb/pull/2452
Differential Revision: D5275651
Pulled By: maysamyabandeh
fbshipit-source-id: 5057e4424b4c8902043782e6bf8c38f0c4f25160
Summary:
Introducing FIFO compactions with TTL.
FIFO compaction is based on size only which makes it tricky to enable in production as use cases can have organic growth. A user requested an option to drop files based on the time of their creation instead of the total size.
To address that request:
- Added a new TTL option to FIFO compaction options.
- Updated FIFO compaction score to take TTL into consideration.
- Added a new table property, creation_time, to keep track of when the SST file is created.
- Creation_time is set as below:
- On Flush: Set to the time of flush.
- On Compaction: Set to the max creation_time of all the files involved in the compaction.
- On Repair and Recovery: Set to the time of repair/recovery.
- Old files created prior to this code change will have a creation_time of 0.
- FIFO compaction with TTL is enabled when ttl > 0. All files older than ttl will be deleted during compaction. i.e. `if (file.creation_time < (current_time - ttl)) then delete(file)`. This will enable cases where you might want to delete all files older than, say, 1 day.
- FIFO compaction will fall back to the prior way of deleting files based on size if:
- the creation_time of all files involved in compaction is 0.
- the total size (of all SST files combined) does not drop below `compaction_options_fifo.max_table_files_size` even if the files older than ttl are deleted.
This feature is not supported if max_open_files != -1 or with table formats other than Block-based.
**Test Plan:**
Added tests.
**Benchmark results:**
Base: FIFO with max size: 100MB ::
```
svemuri@dev15905 ~/rocksdb (fifo-compaction) $ TEST_TMPDIR=/dev/shm ./db_bench --benchmarks=readwhilewriting --num=5000000 --threads=16 --compaction_style=2 --fifo_compaction_max_table_files_size_mb=100
readwhilewriting : 1.924 micros/op 519858 ops/sec; 13.6 MB/s (1176277 of 5000000 found)
```
With TTL (a low one for testing) ::
```
svemuri@dev15905 ~/rocksdb (fifo-compaction) $ TEST_TMPDIR=/dev/shm ./db_bench --benchmarks=readwhilewriting --num=5000000 --threads=16 --compaction_style=2 --fifo_compaction_max_table_files_size_mb=100 --fifo_compaction_ttl=20
readwhilewriting : 1.902 micros/op 525817 ops/sec; 13.7 MB/s (1185057 of 5000000 found)
```
Example Log lines:
```
2017/06/26-15:17:24.609249 7fd5a45ff700 (Original Log Time 2017/06/26-15:17:24.609177) [db/compaction_picker.cc:1471] [default] FIFO compaction: picking file 40 with creation time 1498515423 for deletion
2017/06/26-15:17:24.609255 7fd5a45ff700 (Original Log Time 2017/06/26-15:17:24.609234) [db/db_impl_compaction_flush.cc:1541] [default] Deleted 1 files
...
2017/06/26-15:17:25.553185 7fd5a61a5800 [DEBUG] [db/db_impl_files.cc:309] [JOB 0] Delete /dev/shm/dbbench/000040.sst type=2 #40 -- OK
2017/06/26-15:17:25.553205 7fd5a61a5800 EVENT_LOG_v1 {"time_micros": 1498515445553199, "job": 0, "event": "table_file_deletion", "file_number": 40}
```
SST Files remaining in the dbbench dir, after db_bench execution completed:
```
svemuri@dev15905 ~/rocksdb (fifo-compaction) $ ls -l /dev/shm//dbbench/*.sst
-rw-r--r--. 1 svemuri users 30749887 Jun 26 15:17 /dev/shm//dbbench/000042.sst
-rw-r--r--. 1 svemuri users 30768779 Jun 26 15:17 /dev/shm//dbbench/000044.sst
-rw-r--r--. 1 svemuri users 30757481 Jun 26 15:17 /dev/shm//dbbench/000046.sst
```
Closes https://github.com/facebook/rocksdb/pull/2480
Differential Revision: D5305116
Pulled By: sagar0
fbshipit-source-id: 3e5cfcf5dd07ed2211b5b37492eb235b45139174
Summary:
When Partitioning index/filter is enabled the user might need to check the index block size as well as the top-level index size via sst_dump. This patch records i) number of partitions, ii) top-level index size and make it accessible through sst_dump. The number of partitions for filters is the same as that of indexes. The top-level index for filters has a similar size to top-level index for indexes, so it is not repeated.
Closes https://github.com/facebook/rocksdb/pull/2437
Differential Revision: D5224225
Pulled By: maysamyabandeh
fbshipit-source-id: 5324598c75793523aef1bb7ee225a5475e95a9cb
Summary:
This is the second split of this pull request: https://github.com/facebook/rocksdb/pull/1891 which includes only the builder part. The testing will be included in the third split, where the reader is also included.
Closes https://github.com/facebook/rocksdb/pull/1952
Differential Revision: D4660272
Pulled By: maysamyabandeh
fbshipit-source-id: 36b3cf0
Summary:
This option is needed to be enabled for Direct IO
and I cannot think of a reason where we need to disable it
remove it and default it to true
Closes https://github.com/facebook/rocksdb/pull/1944
Differential Revision: D4641088
Pulled By: IslamAbdelRahman
fbshipit-source-id: d7085b9
Summary:
Partition Index blocks and use a Partition-index as a 2nd level index.
The two-level index can be used by setting
BlockBasedTableOptions::kTwoLevelIndexSearch as the index type and
configuring BlockBasedTableOptions::index_per_partition
t15539501
Closes https://github.com/facebook/rocksdb/pull/1814
Differential Revision: D4473535
Pulled By: maysamyabandeh
fbshipit-source-id: bffb87e
Summary:
The gcc-7 code for parsing comments (libcpp/lex.c) didn't match
the intentional fallthough in this comment.
table/block_based_table_builder.cc: In member function 'void rocksdb::BlockBasedTableBuilder::WriteRawBlock(const rocksdb::Slice&, rocksdb::CompressionType, rocksdb::BlockHandle*)':
table/block_based_table_builder.cc:754:22: error: this statement may fall through [-Werror=implicit-fallthrough=]
assert(false);
^
table/block_based_table_builder.cc:756:7: note: here
case kCRC32c: {
^~~~
cc1plus: all warnings being treated as errors
Closes https://github.com/facebook/rocksdb/pull/1661
Differential Revision: D4318817
Pulled By: yiwu-arbug
fbshipit-source-id: e67d171
Summary:
change ioptions.comparator to user_comparator instread of internal_comparator.
Also change Comparator* to InternalKeyComparator* to make its type explicitly.
Test Plan: make all check -j64
Reviewers: andrewkr, sdong, yiwu
Reviewed By: yiwu
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D65121
Summary:
reland https://reviews.facebook.net/D62523
- Update SstFileWriter to include a property for a global sequence number in the SST file `rocksdb.external_sst_file.global_seqno`
- Update TableProperties to be aware of the offset of each property in the file
- Update BlockBasedTableReader and Block to be able to honor the sequence number in `rocksdb.external_sst_file.global_seqno` property and use it to overwrite all sequence number in the file
Something worth mentioning is that we don't update the seqno in the index block since and when doing a binary search, the reason for that is that it's guaranteed that SST files with global seqno will have only one user_key and each key will have seqno=0 encoded in it, This mean that this key is greater than any other key with seqno> 0. That mean that we can actually keep the current logic for these blocks
Test Plan: unit tests
Reviewers: sdong, yhchiang
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D65211
Summary:
- Update SstFileWriter to include a property for a global sequence number in the SST file `rocksdb.external_sst_file.global_seqno`
- Update TableProperties to be aware of the offset of each property in the file
- Update BlockBasedTableReader and Block to be able to honor the sequence number in `rocksdb.external_sst_file.global_seqno` property and use it to overwrite all sequence number in the file
Something worth mentioning is that we don't update the seqno in the index block since and when doing a binary search, the reason for that is that it's guaranteed that SST files with global seqno will have only one user_key and each key will have seqno=0 encoded in it, This mean that this key is greater than any other key with seqno> 0. That mean that we can actually keep the current logic for these blocks
Test Plan: unit tests
Reviewers: andrewkr, yhchiang, yiwu, sdong
Reviewed By: sdong
Subscribers: hcz, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D62523
Summary:
- Store range tombstones in a separate MemTableRep instantiated with ColumnFamilyOptions::memtable_factory
- MemTable::NewRangeTombstoneIterator() returns a MemTableIterator over the separate MemTableRep
- Part of the read path is not implemented yet (i.e., MemTable::Get())
Test Plan: see unit tests
Reviewers: wanning
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D62217
Summary:
ZSTD 1.0.0 is coming. We can finally add a support of ZSTD without worrying about compatibility.
Still keep ZSTDNotFinal for compatibility reason.
Test Plan: Run all tests. Run db_bench with ZSTD version with RocksDB built with ZSTD 1.0 and older.
Reviewers: andrewkr, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: cyan, igor, IslamAbdelRahman, leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D63141
Summary:
Make sure prefix extractor name is stored in SST files and if DB is opened with a prefix extractor of a different name, prefix bloom is skipped when read the file.
Also add unit tests for that.
Test Plan:
before change:
```
Note: Google Test filter = BlockBasedTableTest.SkipPrefixBloomFilter
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from BlockBasedTableTest
[ RUN ] BlockBasedTableTest.SkipPrefixBloomFilter
table/table_test.cc:1421: Failure
Value of: db_iter->Valid()
Actual: false
Expected: true
[ FAILED ] BlockBasedTableTest.SkipPrefixBloomFilter (1 ms)
[----------] 1 test from BlockBasedTableTest (1 ms total)
[----------] Global test environment tear-down
[==========] 1 test from 1 test case ran. (1 ms total)
[ PASSED ] 0 tests.
[ FAILED ] 1 test, listed below:
[ FAILED ] BlockBasedTableTest.SkipPrefixBloomFilter
1 FAILED TEST
```
after:
```
Note: Google Test filter = BlockBasedTableTest.SkipPrefixBloomFilter
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from BlockBasedTableTest
[ RUN ] BlockBasedTableTest.SkipPrefixBloomFilter
[ OK ] BlockBasedTableTest.SkipPrefixBloomFilter (0 ms)
[----------] 1 test from BlockBasedTableTest (0 ms total)
[----------] Global test environment tear-down
[==========] 1 test from 1 test case ran. (0 ms total)
[ PASSED ] 1 test.
```
Reviewers: sdong, andrewkr, yiwu, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D61215
Summary: 1. Range Deletion Tombstone structure 2. Modify Add() in table_builder to make it usable for adding range del tombstones 3. Expose NewTombstoneIterator() API in table_reader
Test Plan: table_test.cc (now BlockBasedTableBuilder::Add() only accepts InternalKey. I make table_test only pass InternalKey to BlockBasedTableBuidler. Also test writing/reading range deletion tombstones in table_test )
Reviewers: sdong, IslamAbdelRahman, lightmark, andrewkr
Reviewed By: andrewkr
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D61473
Summary:
Experiments on column-aware encodings. Supported features: 1) extract data blocks from SST file and encode with specified encodings; 2) Decode encoded data back into row format; 3) Directly extract data blocks and write in row format (without prefix encoding); 4) Get column distribution statistics for column format; 5) Dump data blocks separated by columns in human-readable format.
There is still on-going work on this diff. More refactoring is necessary.
Test Plan: Wrote tests in `column_aware_encoding_test.cc`. More tests should be added.
Reviewers: sdong
Reviewed By: sdong
Subscribers: arahut, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D60027
* Added new statistics and refactored to allow ioptions to be passed around as required to access environment and statistics pointers (and, as a convenient side effect, info_log pointer).
* Prevent incrementing compression counter when compression is turned off in options.
* Prevent incrementing compression counter when compression is turned off in options.
* Added two more supported compression types to test code in db_test.cc
* Prevent incrementing compression counter when compression is turned off in options.
* Added new StatsLevel that excludes compression timing.
* Fixed casting error in coding.h
* Fixed CompressionStatsTest for new StatsLevel.
* Removed unused variable that was breaking the Linux build
Summary:
I was investigating performance issues in the SstFileWriter and found all of the following:
- The SstFileWriter::Add() function created a local InternalKey every time it was called generating a allocation and free each time. Changed to have an InternalKey member variable that can be reset with the new InternalKey::Set() function.
- In SstFileWriter::Add() the smallest_key and largest_key values were assigned the result of a ToString() call, but it is simpler to just assign them directly from the user's key.
- The Slice class had no move constructor so each time one was returned from a function a new one had to be allocated, the old data copied to the new, and the old one was freed. I added the move constructor which also required a copy constructor and assignment operator.
- The BlockBuilder::CurrentSizeEstimate() function calculates the current estimate size, but was being called 2 or 3 times for each key added. I changed the class to maintain a running estimate (equal to the original calculation) so that the function can return an already calculated value.
- The code in BlockBuilder::Add() that calculated the shared bytes between the last key and the new key duplicated what Slice::difference_offset does, so I replaced it with the standard function.
- BlockBuilder::Add() had code to copy just the changed portion into the last key value (and asserted that it now matched the new key). It is more efficient just to copy the whole new key over.
- Moved this same code up into the 'if (use_delta_encoding_)' since the last key value is only needed when delta encoding is on.
- FlushBlockBySizePolicy::BlockAlmostFull calculated a standard deviation value each time it was called, but this information would only change if block_size of block_size_deviation changed, so I created a member variable to hold the value to avoid the calculation each time.
- Each PutVarint??() function has a buffer and calls std::string::append(). Two or three calls in a row could share a buffer and a single call to std::string::append().
Some of these will be helpful outside of the SstFileWriter. I'm not 100% the addition of the move constructor is appropriate as I wonder why this wasn't done before - maybe because of compiler compatibility? I tried it on gcc 4.8 and 4.9.
Test Plan: The changes should not affect the results so the existing tests should all still work and no new tests were added. The value of the changes was seen by manually testing the SstFileWriter class through MyRocks and adding timing code to identify problem areas.
Reviewers: sdong, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D59607
Summary:
Try to decompress compressed blocks when a special flag is set.
assert and crash in debug builds if we can't decompress the just-compressed input.
Test Plan: Run unit-tests.
Reviewers: dhruba, andrewkr, sdong, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D59145
Summary: Store SST file compression algorithm as a TableProperty.
Test Plan: Modified and ran the table_test UT that checks for TableProperties
Reviewers: IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: lgalanis, andrewkr, dhruba, IslamAbdelRahman
Differential Revision: https://reviews.facebook.net/D58017
Summary:
This adds a new metablock containing a shared dictionary that is used
to compress all data blocks in the SST file. The size of the shared dictionary
is configurable in CompressionOptions and defaults to 0. It's currently only
used for zlib/lz4/lz4hc, but the block will be stored in the SST regardless of
the compression type if the user chooses a nonzero dictionary size.
During compaction, computes the dictionary by randomly sampling the first
output file in each subcompaction. It pre-computes the intervals to sample
by assuming the output file will have the maximum allowable length. In case
the file is smaller, some of the pre-computed sampling intervals can be beyond
end-of-file, in which case we skip over those samples and the dictionary will
be a bit smaller. After the dictionary is generated using the first file in a
subcompaction, it is loaded into the compression library before writing each
block in each subsequent file of that subcompaction.
On the read path, gets the dictionary from the metablock, if it exists. Then,
loads that dictionary into the compression library before reading each block.
Test Plan: new unit test
Reviewers: yhchiang, IslamAbdelRahman, cyan, sdong
Reviewed By: sdong
Subscribers: andrewkr, yoshinorim, kradhakrishnan, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D52287
Summary:
This is the original diff that I have landed and reverted and now I want to land again https://reviews.facebook.net/D34269
For old SST files we will show
```
comparator name: N/A
merge operator name: N/A
property collectors names: N/A
```
For new SST files with no merge operator name and with no property collectors
```
comparator name: leveldb.BytewiseComparator
merge operator name: nullptr
property collectors names: []
```
for new SST files with these properties
```
comparator name: leveldb.BytewiseComparator
merge operator name: UInt64AddOperator
property collectors names: [DummyPropertiesCollector1,DummyPropertiesCollector2]
```
Test Plan: unittests
Reviewers: andrewkr, yhchiang, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D56487
Comparable with Snappy on comp ratio.
Implemented using Windows API, does not require external package.
Avaiable since Windows 8 and server 2012.
Use -DXPRESS=1 with CMake to enable.
Summary:
Added the column family name to the properties block. This property
is omitted only if the property is unavailable, such as when RepairDB()
writes SST files.
In a next diff, I will change RepairDB to use this new property for
deciding to which column family an existing SST file belongs. If this
property is missing, it will add it to the "unknown" column family (same
as its existing behavior).
Test Plan:
New unit test:
$ ./db_table_properties_test --gtest_filter=DBTablePropertiesTest.GetColumnFamilyNameProperty
Reviewers: IslamAbdelRahman, yhchiang, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D55605
Summary:
Cache to have an option to fail Cache::Insert() when full. Update call sites to check status and handle error.
I totally have no idea what's correct behavior of all the call sites when they encounter error. Please let me know if you see something wrong or more unit test is needed.
Test Plan: make check -j32, see tests pass.
Reviewers: anthony, yhchiang, andrewkr, IslamAbdelRahman, kradhakrishnan, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D54705
Summary: Add a new option to BlockBasedTableOptions that will allow us to change the restart interval for the index block
Test Plan: unit tests
Reviewers: yhchiang, anthony, andrewkr, sdong
Reviewed By: sdong
Subscribers: march, dhruba
Differential Revision: https://reviews.facebook.net/D53721
Summary:
This patch update the Iterator API to introduce new functions that allow users to keep the Slices returned by key() valid as long as the Iterator is not deleted
ReadOptions::pin_data : If true keep loaded blocks in memory as long as the iterator is not deleted
Iterator::IsKeyPinned() : If true, this mean that the Slice returned by key() is valid as long as the iterator is not deleted
Also add a new option BlockBasedTableOptions::use_delta_encoding to allow users to disable delta_encoding if needed.
Benchmark results (using https://phabricator.fb.com/P20083553)
```
// $ du -h /home/tec/local/normal.4K.Snappy/db10077
// 6.1G /home/tec/local/normal.4K.Snappy/db10077
// $ du -h /home/tec/local/zero.8K.LZ4/db10077
// 6.4G /home/tec/local/zero.8K.LZ4/db10077
// Benchmarks for shard db10077
// _build/opt/rocks/benchmark/rocks_copy_benchmark \
// --normal_db_path="/home/tec/local/normal.4K.Snappy/db10077" \
// --zero_db_path="/home/tec/local/zero.8K.LZ4/db10077"
// First run
// ============================================================================
// rocks/benchmark/RocksCopyBenchmark.cpp relative time/iter iters/s
// ============================================================================
// BM_StringCopy 1.73s 576.97m
// BM_StringPiece 103.74% 1.67s 598.55m
// ============================================================================
// Match rate : 1000000 / 1000000
// Second run
// ============================================================================
// rocks/benchmark/RocksCopyBenchmark.cpp relative time/iter iters/s
// ============================================================================
// BM_StringCopy 611.99ms 1.63
// BM_StringPiece 203.76% 300.35ms 3.33
// ============================================================================
// Match rate : 1000000 / 1000000
```
Test Plan: Unit tests
Reviewers: sdong, igor, anthony, yhchiang, rven
Reviewed By: rven
Subscribers: dhruba, lovro, adsharma
Differential Revision: https://reviews.facebook.net/D48999
Summary:
Reverting https://reviews.facebook.net/D34269 for now
after I landed it a flaky test started continuously failing, I am almost sure this patch is not related to the test but I will revert it until I figure out why it's failing
Test Plan: make check
Reviewers: kradhakrishnan
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D50385
Summary:
This diff introduce new table properties that will be written for block based tables
These properties are
- comparator name
- merge operator name
- property collectors names
Test Plan:
- Added a new unit test to verify that these tests are written/read correctly
- Running all other tests right now (wont land until all tests finish)
Reviewers: rven, kradhakrishnan, igor, sdong, anthony, yhchiang
Reviewed By: yhchiang
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D34269
Summary: It would be nice to have and access to table properties in compaction callbacks. In MyRocks project, it will make possible to update optimizer statistics online.
Test Plan: ran the unit test. Ran myrocks with the new way of collecting stats.
Reviewers: igor, rven, yhchiang
Reviewed By: yhchiang
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D48267
Summary: Pass column family ID through TablePropertiesCollectorFactory::CreateTablePropertiesCollector() so that users can identify which column family this file is for and handle it differently.
Test Plan: Add unit test scenarios in tests related to table properties collectors to verify the information passed in is correct.
Reviewers: rven, yhchiang, anthony, kradhakrishnan, igor, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: yoshinorim, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D48411
Summary: Add ZSTD compression type. The same way as adding LZ4.
Test Plan: run all tests. Generate files in db_bench. Make sure reads succeed. But the SST files cannot be opened in older versions. Also some other adhoc tests.
Reviewers: rven, anthony, IslamAbdelRahman, kradhakrishnan, igor
Reviewed By: igor
Subscribers: MarkCallaghan, maykov, yoshinorim, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D45747
Summary: We want to keep Env a think layer for better portability. Less platform dependent codes should be moved out of Env. In this patch, I create a wrapper of file readers and writers, and put rate limiting, write buffering, as well as most perf context instrumentation and random kill out of Env. It will make it easier to maintain multiple Env in the future.
Test Plan: Run all existing unit tests.
Reviewers: anthony, kradhakrishnan, IslamAbdelRahman, yhchiang, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D42321
Summary: This helps Windows port to format their changes, as discussed. Might have formatted some other codes too becasue last 10 commits include more.
Test Plan: Build it.
Reviewers: anthony, IslamAbdelRahman, kradhakrishnan, yhchiang, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D41961
Andrew Kryczka