Commit Graph

31 Commits

Author SHA1 Message Date
Victor Gao
1d7048c598 comment out unused parameters
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
2017-07-21 14:57:44 -07:00
Islam AbdelRahman
68a8e6b8fa Introduce FullMergeV2 (eliminate memcpy from merge operators)
Summary:
This diff update the code to pin the merge operator operands while the merge operation is done, so that we can eliminate the memcpy cost, to do that we need a new public API for FullMerge that replace the std::deque<std::string> with std::vector<Slice>

This diff is stacked on top of D56493 and D56511

In this diff we
- Update FullMergeV2 arguments to be encapsulated in MergeOperationInput and MergeOperationOutput which will make it easier to add new arguments in the future
- Replace std::deque<std::string> with std::vector<Slice> to pass operands
- Replace MergeContext std::deque with std::vector (based on a simple benchmark I ran https://gist.github.com/IslamAbdelRahman/78fc86c9ab9f52b1df791e58943fb187)
- Allow FullMergeV2 output to be an existing operand

```
[Everything in Memtable | 10K operands | 10 KB each | 1 operand per key]

DEBUG_LEVEL=0 make db_bench -j64 && ./db_bench --benchmarks="mergerandom,readseq,readseq,readseq,readseq,readseq" --merge_operator="max" --merge_keys=10000 --num=10000 --disable_auto_compactions --value_size=10240 --write_buffer_size=1000000000

[FullMergeV2]
readseq      :       0.607 micros/op 1648235 ops/sec; 16121.2 MB/s
readseq      :       0.478 micros/op 2091546 ops/sec; 20457.2 MB/s
readseq      :       0.252 micros/op 3972081 ops/sec; 38850.5 MB/s
readseq      :       0.237 micros/op 4218328 ops/sec; 41259.0 MB/s
readseq      :       0.247 micros/op 4043927 ops/sec; 39553.2 MB/s

[master]
readseq      :       3.935 micros/op 254140 ops/sec; 2485.7 MB/s
readseq      :       3.722 micros/op 268657 ops/sec; 2627.7 MB/s
readseq      :       3.149 micros/op 317605 ops/sec; 3106.5 MB/s
readseq      :       3.125 micros/op 320024 ops/sec; 3130.1 MB/s
readseq      :       4.075 micros/op 245374 ops/sec; 2400.0 MB/s
```

```
[Everything in Memtable | 10K operands | 10 KB each | 10 operand per key]

DEBUG_LEVEL=0 make db_bench -j64 && ./db_bench --benchmarks="mergerandom,readseq,readseq,readseq,readseq,readseq" --merge_operator="max" --merge_keys=1000 --num=10000 --disable_auto_compactions --value_size=10240 --write_buffer_size=1000000000

[FullMergeV2]
readseq      :       3.472 micros/op 288018 ops/sec; 2817.1 MB/s
readseq      :       2.304 micros/op 434027 ops/sec; 4245.2 MB/s
readseq      :       1.163 micros/op 859845 ops/sec; 8410.0 MB/s
readseq      :       1.192 micros/op 838926 ops/sec; 8205.4 MB/s
readseq      :       1.250 micros/op 800000 ops/sec; 7824.7 MB/s

[master]
readseq      :      24.025 micros/op 41623 ops/sec;  407.1 MB/s
readseq      :      18.489 micros/op 54086 ops/sec;  529.0 MB/s
readseq      :      18.693 micros/op 53495 ops/sec;  523.2 MB/s
readseq      :      23.621 micros/op 42335 ops/sec;  414.1 MB/s
readseq      :      18.775 micros/op 53262 ops/sec;  521.0 MB/s

```

```
[Everything in Block cache | 10K operands | 10 KB each | 1 operand per key]

[FullMergeV2]
$ DEBUG_LEVEL=0 make db_bench -j64 && ./db_bench --benchmarks="readseq,readseq,readseq,readseq,readseq" --merge_operator="max" --num=100000 --db="/dev/shm/merge-random-10K-10KB" --cache_size=1000000000 --use_existing_db --disable_auto_compactions
readseq      :      14.741 micros/op 67837 ops/sec;  663.5 MB/s
readseq      :       1.029 micros/op 971446 ops/sec; 9501.6 MB/s
readseq      :       0.974 micros/op 1026229 ops/sec; 10037.4 MB/s
readseq      :       0.965 micros/op 1036080 ops/sec; 10133.8 MB/s
readseq      :       0.943 micros/op 1060657 ops/sec; 10374.2 MB/s

[master]
readseq      :      16.735 micros/op 59755 ops/sec;  584.5 MB/s
readseq      :       3.029 micros/op 330151 ops/sec; 3229.2 MB/s
readseq      :       3.136 micros/op 318883 ops/sec; 3119.0 MB/s
readseq      :       3.065 micros/op 326245 ops/sec; 3191.0 MB/s
readseq      :       3.014 micros/op 331813 ops/sec; 3245.4 MB/s
```

```
[Everything in Block cache | 10K operands | 10 KB each | 10 operand per key]

DEBUG_LEVEL=0 make db_bench -j64 && ./db_bench --benchmarks="readseq,readseq,readseq,readseq,readseq" --merge_operator="max" --num=100000 --db="/dev/shm/merge-random-10-operands-10K-10KB" --cache_size=1000000000 --use_existing_db --disable_auto_compactions

[FullMergeV2]
readseq      :      24.325 micros/op 41109 ops/sec;  402.1 MB/s
readseq      :       1.470 micros/op 680272 ops/sec; 6653.7 MB/s
readseq      :       1.231 micros/op 812347 ops/sec; 7945.5 MB/s
readseq      :       1.091 micros/op 916590 ops/sec; 8965.1 MB/s
readseq      :       1.109 micros/op 901713 ops/sec; 8819.6 MB/s

[master]
readseq      :      27.257 micros/op 36687 ops/sec;  358.8 MB/s
readseq      :       4.443 micros/op 225073 ops/sec; 2201.4 MB/s
readseq      :       5.830 micros/op 171526 ops/sec; 1677.7 MB/s
readseq      :       4.173 micros/op 239635 ops/sec; 2343.8 MB/s
readseq      :       4.150 micros/op 240963 ops/sec; 2356.8 MB/s
```

Test Plan: COMPILE_WITH_ASAN=1 make check -j64

Reviewers: yhchiang, andrewkr, sdong

Reviewed By: sdong

Subscribers: lovro, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D57075
2016-07-20 09:49:03 -07:00
Islam AbdelRahman
a163cc2d5a Lint everything
Summary:
```
arc2 lint --everything
```

run the linter on the whole code repo to fix exisitng lint issues

Test Plan: make check -j64

Reviewers: sdong, rven, anthony, kradhakrishnan, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D50769
2015-11-16 12:56:21 -08:00
sdong
85ac65536b Tests to avoid to use TMPDIR directly
Summary: Directly using TMPDIR can cause problems when running tests using parallel option. Fix them.

Test Plan: Run all tests in parallel

Reviewers: kradhakrishnan, yhchiang, IslamAbdelRahman, anthony

Reviewed By: anthony

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D42807
2015-07-21 19:07:34 -07:00
Dmitri Smirnov
9dbde7277c Merge remote-tracking branch 'origin' into ms_win_port 2015-07-02 11:34:22 -07:00
Dmitri Smirnov
18285c1e2f Windows Port from Microsoft
Summary: Make RocksDb build and run on Windows to be functionally
 complete and performant. All existing test cases run with no
 regressions. Performance numbers are in the pull-request.

 Test plan: make all of the existing unit tests pass, obtain perf numbers.

 Co-authored-by: Praveen Rao praveensinghrao@outlook.com
 Co-authored-by: Sherlock Huang baihan.huang@gmail.com
 Co-authored-by: Alex Zinoviev alexander.zinoviev@me.com
 Co-authored-by: Dmitri Smirnov dmitrism@microsoft.com
2015-07-01 16:13:56 -07:00
Yueh-Hsuan Chiang
62a8fd154a Make stringappend_test runnable in ROCKSDB_LITE
Summary: Make stringappend_test runnable in ROCKSDB_LITE

Test Plan: stringappend_test

Reviewers: sdong, rven, anthony, kradhakrishnan, IslamAbdelRahman, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D40593
2015-06-24 15:01:43 -07:00
Islam AbdelRahman
12e030a992 Use CompactRangeOptions for CompactRange
Summary:
This diff update DB::CompactRange to use RangeCompactionOptions instead of using multiple parameters
Old CompactRange is still available but deprecated

Test Plan:
make all check
make rocksdbjava
USE_CLANG=1 make all
OPT=-DROCKSDB_LITE make release

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D40209
2015-06-17 14:36:14 -07:00
Igor Sugak
b4b69e4f77 rocksdb: switch to gtest
Summary:
Our existing test notation is very similar to what is used in gtest. It makes it easy to adopt what is different.
In this diff I modify existing [[ https://code.google.com/p/googletest/wiki/Primer#Test_Fixtures:_Using_the_Same_Data_Configuration_for_Multiple_Te | test fixture ]] classes to inherit from `testing::Test`. Also for unit tests that use fixture class, `TEST` is replaced with `TEST_F` as required in gtest.

There are several custom `main` functions in our existing tests. To make this transition easier, I modify all `main` functions to fallow gtest notation. But eventually we can remove them and use implementation of `main` that gtest provides.

```lang=bash
% cat ~/transform
#!/bin/sh
files=$(git ls-files '*test\.cc')
for file in $files
do
  if grep -q "rocksdb::test::RunAllTests()" $file
  then
    if grep -Eq '^class \w+Test {' $file
    then
      perl -pi -e 's/^(class \w+Test) {/${1}: public testing::Test {/g' $file
      perl -pi -e 's/^(TEST)/${1}_F/g' $file
    fi
    perl -pi -e 's/(int main.*\{)/${1}::testing::InitGoogleTest(&argc, argv);/g' $file
    perl -pi -e 's/rocksdb::test::RunAllTests/RUN_ALL_TESTS/g' $file
  fi
done
% sh ~/transform
% make format
```

Second iteration of this diff contains only scripted changes.

Third iteration contains manual changes to fix last errors and make it compilable.

Test Plan:
Build and notice no errors.
```lang=bash
% USE_CLANG=1 make check -j55
```
Tests are still testing.

Reviewers: meyering, sdong, rven, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D35157
2015-03-17 14:08:00 -07:00
Igor Sugak
9fd6edf81c rocksdb: Replace ASSERT* with EXPECT* in functions that does not return void value
Summary:
gtest does not use exceptions to fail a unit test by design, and `ASSERT*`s are implemented using `return`. As a consequence we cannot use `ASSERT*` in a function that does not return `void` value ([[ https://code.google.com/p/googletest/wiki/AdvancedGuide#Assertion_Placement | 1]]), and have to fix our existing code. This diff does this in a generic way, with no manual changes.

In order to detect all existing `ASSERT*` that are used in functions that doesn't return void value, I change the code to generate compile errors for such cases.

In `util/testharness.h` I defined `EXPECT*` assertions, the same way as `ASSERT*`, and redefined `ASSERT*` to return `void`. Then executed:

```lang=bash
% USE_CLANG=1 make all -j55 -k 2> build.log
% perl -naF: -e 'print "-- -number=".$F[1]." ".$F[0]."\n" if  /: error:/' \
build.log | xargs -L 1 perl -spi -e 's/ASSERT/EXPECT/g if $. == $number'
% make format
```
After that I reverted back change to `ASSERT*` in `util/testharness.h`. But preserved introduced `EXPECT*`, which is the same as `ASSERT*`. This will be deleted once switched to gtest.

This diff is independent and contains manual changes only in `util/testharness.h`.

Test Plan:
Make sure all tests are passing.
```lang=bash
% USE_CLANG=1 make check
```

Reviewers: igor, lgalanis, sdong, yufei.zhu, rven, meyering

Reviewed By: meyering

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D33333
2015-03-16 20:52:32 -07:00
Igor Sugak
95344346af rocksdb: Small refactoring before migrating to gtest
Summary: These changes are necessary to make tests look more generic, and avoid feature conflicts with gtest.

Test Plan:
Make sure no build errors, and all test are passing.
```
% make check
```

Reviewers: igor, meyering

Reviewed By: meyering

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D35145
2015-03-16 18:08:59 -07:00
Igor Canadi
0ff183a0d9 Move include/utilities/*.h to include/rocksdb/utilities/*.h
Summary:
All public headers need to be under `include/rocksdb` directory. Otherwise, clients include our header files like this:

    #include <rocksdb/db.h>
    #include <utilities/backupable_db.h> // still our public header!

Also, internally, we include:

    #include "utilities/backupable/backupable_db.h" // internal header
    #include "utilities/backupable_db.h" // public header

which is confusing.

This way, when we install rocksdb as a system library, we can just copy `include/rocksdb` directory to system's header files. We can't really copy `utilities` directory to system's header files.

Test Plan: compiles

Reviewers: dhruba, ljin, yhchiang, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D20409
2014-07-23 10:21:38 -04:00
Igor Canadi
91ef2eae23 Use new DBWithTTL API in tests 2014-04-28 23:46:24 -04:00
Igor Canadi
4daea66343 Turn on -Wmissing-prototypes
Summary: Compiling for iOS has by default turned on -Wmissing-prototypes, which causes rocksdb to fail compiling. This diff turns on -Wmissing-prototypes in our compile options and cleans up all functions with missing prototypes.

Test Plan: compiles

Reviewers: dhruba, haobo, ljin, sdong

Reviewed By: ljin

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17649
2014-04-09 21:17:14 -07:00
Yueh-Hsuan Chiang
cda4006e87 Enhance partial merge to support multiple arguments
Summary:
* PartialMerge api now takes a list of operands instead of two operands.
* Add min_pertial_merge_operands to Options, indicating the minimum
  number of operands to trigger partial merge.
* This diff is based on Schalk's previous diff (D14601), but it also
  includes necessary changes such as updating the pure C api for
  partial merge.

Test Plan:
* make check all
* develop tests for cases where partial merge takes more than two
  operands.

TODOs (from Schalk):
* Add test with min_partial_merge_operands > 2.
* Perform benchmarks to measure the performance improvements (can probably
  use results of task #2837810.)
* Add description of problem to doc/index.html.
* Change wiki pages to reflect the interface changes.

Reviewers: haobo, igor, vamsi

Reviewed By: haobo

CC: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D16815
2014-03-24 17:57:13 -07:00
Igor Canadi
0a5ec49895 Make DBWithTTL more like StackableDB
Summary: Now DBWithTTL takes DB* and can behave more like StackableDB. This saves us a lot of duplicate work by defining interfaces

Test Plan: ttl_test with ASAN - OK

Reviewers: emayanke

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14481
2013-12-06 16:10:43 -08:00
Pascal Borreli
443e04e62d Fixed typos 2013-11-16 11:21:34 +00:00
Dhruba Borthakur
4463b11cad Migrate names of properties from 'leveldb' prefix to 'rocksdb' prefix.
Summary: Migrate names of properties from 'leveldb' prefix to 'rocksdb' prefix.

Test Plan: make check

Reviewers: emayanke, haobo

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13311
2013-10-06 00:14:26 -07:00
Dhruba Borthakur
a143ef9b38 Change namespace from leveldb to rocksdb
Summary:
Change namespace from leveldb to rocksdb. This allows a single
application to link in open-source leveldb code as well as
rocksdb code into the same process.

Test Plan: compile rocksdb

Reviewers: emayanke

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13287
2013-10-04 11:59:26 -07:00
Dhruba Borthakur
1186192ed1 Replace include/leveldb with include/rocksdb.
Summary: Replace include/leveldb with include/rocksdb.

Test Plan:
make clean; make check
make clean; make release

Differential Revision: https://reviews.facebook.net/D12489
2013-08-23 10:51:00 -07:00
Deon Nicholas
6f4e3ee3e8 Added include guards to stringappend and redis-list
Summary: added "#pragma once" in the .h files

Test Plan: make and run: stringappend_test, redis_test

Reviewers: emayanke, haobo

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12495
2013-08-23 10:28:16 -07:00
Deon Nicholas
b87dcae1a3 Made merge_oprator a shared_ptr; and added TTL unit tests
Test Plan:
- make all check;
- make release;
- make stringappend_test; ./stringappend_test

Reviewers: haobo, emayanke

Reviewed By: haobo

CC: leveldb, kailiu

Differential Revision: https://reviews.facebook.net/D12381
2013-08-20 13:35:28 -07:00
Deon Nicholas
e1346968d8 Merge operator fixes part 1.
Summary:
-Added null checks and revisions to DBIter::MergeValuesNewToOld()
-Added DBIter test to stringappend_test
-Major fix with Merge and TTL
More plans for fixes later.

Test Plan:
-make clean; make stringappend_test -j 32; ./stringappend_test
-make all check;

Reviewers: haobo, emayanke, vamsi, dhruba

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12315
2013-08-19 11:42:47 -07:00
Deon Nicholas
ad48c3c262 Benchmarking for Merge Operator
Summary:
Updated db_bench and utilities/merge_operators.h to allow for dynamic benchmarking
of merge operators in db_bench. Added a new test (--benchmarks=mergerandom), which performs
a bunch of random Merge() operations over random keys. Also added a "--merge_operator=" flag
so that the tester can easily benchmark different merge operators. Currently supports
the PutOperator and UInt64Add operator. Support for stringappend or list append may come later.

Test Plan:
	1. make db_bench
	2. Test the PutOperator (simulating Put) as follows:
./db_bench --benchmarks=fillrandom,readrandom,updaterandom,readrandom,mergerandom,readrandom --merge_operator=put
--threads=2

3. Test the UInt64AddOperator (simulating numeric addition) similarly:
./db_bench --value_size=8 --benchmarks=fillrandom,readrandom,updaterandom,readrandom,mergerandom,readrandom
--merge_operator=uint64add --threads=2

Reviewers: haobo, dhruba, zshao, MarkCallaghan

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11535
2013-08-15 17:13:07 -07:00
Deon Nicholas
c2d7826ced [RocksDB] [MergeOperator] The new Merge Interface! Uses merge sequences.
Summary:
Here are the major changes to the Merge Interface. It has been expanded
to handle cases where the MergeOperator is not associative. It does so by stacking
up merge operations while scanning through the key history (i.e.: during Get() or
Compaction), until a valid Put/Delete/end-of-history is encountered; it then
applies all of the merge operations in the correct sequence starting with the
base/sentinel value.

I have also introduced an "AssociativeMerge" function which allows the user to
take advantage of associative merge operations (such as in the case of counters).
The implementation will always attempt to merge the operations/operands themselves
together when they are encountered, and will resort to the "stacking" method if
and only if the "associative-merge" fails.

This implementation is conjectured to allow MergeOperator to handle the general
case, while still providing the user with the ability to take advantage of certain
efficiencies in their own merge-operator / data-structure.

NOTE: This is a preliminary diff. This must still go through a lot of review,
revision, and testing. Feedback welcome!

Test Plan:
  -This is a preliminary diff. I have only just begun testing/debugging it.
  -I will be testing this with the existing MergeOperator use-cases and unit-tests
(counters, string-append, and redis-lists)
  -I will be "desk-checking" and walking through the code with the help gdb.
  -I will find a way of stress-testing the new interface / implementation using
db_bench, db_test, merge_test, and/or db_stress.
  -I will ensure that my tests cover all cases: Get-Memtable,
Get-Immutable-Memtable, Get-from-Disk, Iterator-Range-Scan, Flush-Memtable-to-L0,
Compaction-L0-L1, Compaction-Ln-L(n+1), Put/Delete found, Put/Delete not-found,
end-of-history, end-of-file, etc.
  -A lot of feedback from the reviewers.

Reviewers: haobo, dhruba, zshao, emayanke

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11499
2013-08-05 20:14:32 -07:00
Deon Nicholas
34ef873290 Added stringappend_test back into the unit tests.
Summary:
With the Makefile now updated to correctly update all .o files, this
should fix the issues recompiling stringappend_test. This should also fix the
"segmentation-fault" that we were getting earlier. Now, stringappend_test should
be clean, and I have added it back to the unit-tests. Also made some minor updates
to the tests themselves.

Test Plan:
1. make clean; make stringappend_test -j 32	(will test it by itself)
2. make clean; make all check -j 32		(to run all unit tests)
3. make clean; make release			(test in release mode)
4. valgrind ./stringappend_test 		(valgrind tests)

Reviewers: haobo, jpaton, dhruba

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11505
2013-06-26 11:41:13 -07:00
Deon Nicholas
8926b72751 Minor tweaks to StringAppend MergeOperator.
Summary:
I'm concerned about a random seg-fault that sometimes occurs when
running stringappend_test. I will investigate further. First, I am removing
stringappend_test from the regular release tests, and making some clean-ups
to the code.

Test Plan:
1. make stringappend_test
2. ./stringappend_test

Reviewers: haobo, dhruba

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11313
2013-06-14 16:44:39 -07:00
Deon Nicholas
5679107b07 Completed the implementation and test cases for Redis API.
Summary:
Completed the implementation for the Redis API for Lists.
The Redis API uses rocksdb as a backend to persistently
store maps from key->list. It supports basic operations
for appending, inserting, pushing, popping, and accessing
a list, given its key.

Test Plan:
  - Compile with: make redis_test
  - Test with: ./redis_test
  - Run all unit tests (for all rocksdb) with: make all check
  - To use an interactive REDIS client use: ./redis_test -m
  - To clean the database before use:       ./redis_test -m -d

Reviewers: haobo, dhruba, zshao

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10833
2013-06-11 11:19:49 -07:00
Deon Nicholas
db1f0cddf3 Fixed valgrind errors 2013-06-05 17:25:16 -07:00
Haobo Xu
8a59ed9bc7 [RockdDB] fix build
Summary: assert => ASSERT_TRUE

Test Plan: make release; make check

Reviewers: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10839
2013-05-17 16:15:44 -07:00
Deon Nicholas
accd3debbb Implemented StringAppendOperator and unit tests.
Summary:
Implemented the StringAppendOperator class (subclass of MergeOperator).
Found in utilities/merge_operators/string_append/stringappend.{h,cc}

It is a rocksdb Merge Operator that supports string/list concatenation
 with a configurable delimiter.

The tests are found in .../stringappend_test.cc. It implements a
 map : key -> (list of strings), with core operations Append(list_key,val)
 and Get(list_key).

Test Plan:
1. Navigate to your rocksdb repository
2. Execute: make stringappend_test  (to compile)
3. Execute: ./stringappend_test (to run the tests)
4. Execute: make all check (to test the ENTIRE rocksdb codebase / regression)

Reviewers: haobo, dhruba, zshao

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10737
2013-05-13 15:09:42 -07:00