Commit Graph

3315 Commits

Author SHA1 Message Date
Yueh-Hsuan Chiang
6284eef4c0 Merge pull request #545 from fyrz/RocksJava-Level-Compression
[RocksJava] Add compression per level to API
2015-03-24 12:14:09 -07:00
Yueh-Hsuan Chiang
248c063ba1 Report elapsed time in micros in ThreadStatus instead of start time.
Summary:
Report elapsed time of a thread operation in micros in ThreadStatus
instead of start time of a thread operation in seconds since the
Epoch, 1970-01-01 00:00:00 (UTC).

Test Plan:
./db_bench --benchmarks=fillrandom --num=100000 --threads=40 \
--max_background_compactions=10 --max_background_flushes=3 \
--thread_status_per_interval=1000 --key_size=16 --value_size=1000 \
--num_column_families=10

Sample Output:
            ThreadID ThreadType                    cfName    Operation  ElapsedTime                                         Stage        State
     140667724562496   High Pri column_family_name_000002        Flush   772.419 ms                    FlushJob::WriteLevel0Table
     140667728756800   High Pri                   default        Flush   617.845 ms                    FlushJob::WriteLevel0Table
     140667732951104   High Pri column_family_name_000005        Flush   772.078 ms                    FlushJob::WriteLevel0Table
     140667875557440    Low Pri column_family_name_000008   Compaction  1409.216 ms                        CompactionJob::Install
     140667737145408    Low Pri
     140667749728320    Low Pri
     140667816837184    Low Pri column_family_name_000007   Compaction  1071.815 ms      CompactionJob::ProcessKeyValueCompaction
     140667787477056    Low Pri column_family_name_000009   Compaction   772.516 ms      CompactionJob::ProcessKeyValueCompaction
     140667741339712    Low Pri
     140667758116928    Low Pri column_family_name_000004   Compaction   620.739 ms      CompactionJob::ProcessKeyValueCompaction
     140667753922624    Low Pri
     140667842003008    Low Pri column_family_name_000006   Compaction  1260.079 ms      CompactionJob::ProcessKeyValueCompaction
     140667745534016    Low Pri

Reviewers: sdong, igor, rven

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D35769
2015-03-24 11:32:25 -07:00
Igor Canadi
315abac945 Undeprecate GetLiveFiles()
Summary: There is no alternative to GetLiveFiles() function

Test Plan: none

Reviewers: sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D35805
2015-03-24 09:42:38 -07:00
Yueh-Hsuan Chiang
a057bb2a8e Improve ThreadStatusSingleCompaction
Summary:
Improve ThreadStatusSingleCompaction in two ways:
1. Use SYNC_POINT to ensure compaction won't happen
   before the test finishes its "Put Phase" instead of
   using sleep.
2. In Put Phase, it continues until we have sufficient
   number of L0 files.  Note that during the put phase,
   there won't be any compaction that consumes L0 files
   because of item 1.

Test Plan: ./db_test  --gtest_filter="*ThreadStatusSingleCompaction*"

Reviewers: sdong, igor, rven

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D35727
2015-03-23 15:30:45 -07:00
krad
868968c8e5 Merge branch 'master' of github.com:facebook/rocksdb 2015-03-23 15:04:48 -07:00
krad
689391406a Make SSTDumpTest.GetProperties less noisy
Summary:
Limiting verbose printing to "command=scan"

Test Plan:
Run make check and manual testing of sst_dump_test

Reviewers: sdong

CC: leveldb

Task ID: #6575982

Blame Rev:
2015-03-23 14:30:11 -07:00
Yueh-Hsuan Chiang
8d8656243e Merge pull request #551 from fyrz/RocksJava-JavaDoc-Fix
[RocksJava] Add missing JavaDoc annotations
2015-03-23 13:25:37 -07:00
Yueh-Hsuan Chiang
f8c505b23a Merge pull request #550 from fyrz/RocksJava-Sample-Fix
[RocksJava] Java sample bugfix
2015-03-23 13:24:37 -07:00
fyrz
46443bfa94 [RocksJava] Add missing JavaDoc annotations 2015-03-23 21:17:20 +01:00
fyrz
864b7e88f4 [RocksJava] Java sample bugfix
One of the latest commits broke the sample code. This
resolves the introduced bug.
2015-03-23 21:03:28 +01:00
fyrz
004b89fba4 [RocksJava] Add compression per level to API
Summary:
RocksDB offers the possibility to set different compression types
on a per level basis. This shall be also available using RocksJava.

Test Plan:
make rocksdbjava
make jtest

Reviewers: adamretter, yhchiang, ankgup87

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D35577
2015-03-23 18:58:56 +01:00
Adam Retter
51da3aab4a Merge pull request #536 from fyrz/RocksJava-32-Bit-adjustment
[RocksJava] 32-Bit adjustments
2015-03-22 23:33:35 +00:00
Adam Retter
b7e88cfb5f Merge pull request #543 from fyrz/RocksJava-Logger-Comment
[RocksJava] Enhanced Logger comment
2015-03-22 23:16:02 +00:00
sdong
38d286f146 Clean-up WAL directory before running db_test
Summary: DBTest doesn't clean up wal directory. It might cause failure after a failure test run. Fix it.

Test Plan:
Run unit tests
Try open DB with non-empty db_path/wal.

Reviewers: rven, yhchiang, kradhakrishnan, igor

Reviewed By: igor

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D35559
2015-03-20 12:34:24 -07:00
Igor Sugak
28bc6de989 rocksdb: print status error message when (ASSERT|EXPECT)_OK fails
Summary: Modified rocksdb status assertions ASSERT_OK and EXPECT_OK to print error message from Status::ToString() when failed.

Test Plan: Modify a test to fail status assertions ASSERT_OK and EXPECT_OK and notice an error message that came from Status::ToString()

Reviewers: meyering, sdong, yhchiang, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D35469
2015-03-19 17:32:43 -07:00
Igor Sugak
9405b5ef8f rocksdb: Remove #include "util/string_util.h" from util/testharness.h
Summary:
1. Manually deleted #include "util/string_util.h" from util/testharness.h
2.
```
% USE_CLANG=1 make all -j55 -k 2> build.log
% perl -naF: -E 'say $F[0] if /: error:/' build.log | sort -u | xargs sed -i '/#include "util\/testharness.h"/i #include "util\/string_util.h"'
```

Test Plan:
Make sure make all completes with no errors.
```
% make all -j55
```

Reviewers: meyering, igor, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D35493
2015-03-19 17:29:37 -07:00
Igor Sugak
220d0dff7c rocksdb: Remove #include "util/random.h" from util/testharness.h
Summary: Cleaning util/testharness.h

Test Plan:
Make completes with no errors.
```
% make all
```

Reviewers: meyering, igor, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D35487
2015-03-19 17:06:02 -07:00
Igor Canadi
b088c83e6e Don't delete files when column family is dropped
Summary:
To understand the bug read t5943287 and check out the new test in column_family_test (ReadDroppedColumnFamily), iter 0.

RocksDB contract allowes you to read a drop column family as long as there is a live reference. However, since our iteration ignores dropped column families, AddLiveFiles() didn't mark files of a dropped column families as live. So we deleted them.

In this patch I no longer ignore dropped column families in the iteration. I think this behavior was confusing and it also led to this bug. Now if an iterator client wants to ignore dropped column families, he needs to do it explicitly.

Test Plan: Added a new unit test that is failing on master. Unit test succeeds now.

Reviewers: sdong, rven, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D32535
2015-03-19 17:04:29 -07:00
Igor Sugak
17ae3fcbca rocksdb: initial util/testharness clean up
Summary: Deleted some redundant code. More comming.

Test Plan:
```lang=bash
% USE_CLANG=1 make check
```

Reviewers: meyering, sdong, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D35463
2015-03-19 16:52:59 -07:00
fyrz
39f4271be0 [RocksJava] Enhanced Logger comment
Added information about performance penalties using a custom
logger implementation.
2015-03-19 22:01:00 +01:00
fyrz
5615e23d8c [RocksJava] 32-Bit adjustments
Summary:
Before this change overflowing size_t values led to a checked Exception.

After that change:

size_t overflows on 32-Bit architecture throw now an IllegalArgumentException,
which removes the necessity for a developer to catch these Exceptions explicitly.

This is especially an advantage for developers targeting 64-Bit systems because
it is not necessary anymore to catch exceptions which are never thrown on a 64-Bit
system.

Test Plan:
make clean jclean rocksdbjava jtest
mvn -f rocksjni.pom package

Reviewers: adamretter, yhchiang, ankgup87

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D34923
2015-03-19 20:45:55 +01:00
Adam Retter
836bcc2f00 Merge pull request #532 from fyrz/RocksJava-LevelCompactionDynamicLevelBytes
[RocksJava] Added LevelCompactionDynamicLevelBytes to Options
2015-03-19 12:51:40 +00:00
Igor Sugak
67d995808a rocksdb: fix make unity
Summary:
changed make unity target to use $LIB_SOURCES as a source of library source code. In the old way (using find) table/mock_table.h was added to a list of library objects and this was a course of `make unity` break.

`build_tools/unity` contains some redundant code, I deleted it and moved the functionality in the Makefile.

Test Plan:
Make sure unity completes with no errors.
```lang=bash
% make unity
```

Reviewers: sdong, rven, igor, meyering

Reviewed By: igor, meyering

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D35385
2015-03-18 19:12:23 -07:00
Igor Canadi
52e0f3353f Clean up compactions_in_progress_
Summary: Suprisingly, the only way we use this vector is to keep track of level0 compactions. Thus, I simplified it.

Test Plan: make check

Reviewers: rven, yhchiang, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D35313
2015-03-18 18:25:15 -07:00
Igor Sugak
6b626ff24c rocksdb: change db_test::MultiThreadedDBTest as value parameterized test.
Summary: This is a simple change to make db_test::MultiThreadedDBTest as value parameterized test. There is a value of creating a separate set of such tests later.

Test Plan:
```lang=bash
% make db_test
% ./make db_test
```

Also with the following command I can execute all db_test in 2:37.87 on my box
```
% ./db_test --gtest_list_tests | sed 's/\# GetParam.*//' | tr -d ' ' | env time parallel --gnu --eta --joblog=LOG -- 'TEST_TMPDIR=/dev/shm/rocksdb-{} ./db_test --gtest_filter="*{}"'
```

Reviewers: igor, rven, meyering, sdong

Reviewed By: meyering

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D35361
2015-03-18 18:18:12 -07:00
sdong
9720ea4dee A build option to run through all check-in requirements.
Summary: Make it easier for people to run all the tests.

Test Plan: Run it.

Reviewers: rven, yhchiang, igor, MarkCallaghan, IslamAbdelRahman, igor.sugak, anthony, kradhakrishnan, meyering

Reviewed By: meyering

Subscribers: meyering, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D35319
2015-03-18 17:57:42 -07:00
sdong
0831a35994 Add a DB Property For Number of Deletions in Memtables
Summary: Add a DB property for number of deletions in memtables. It can sometimes help people debug slowness because of too many deletes.

Test Plan: Add test cases.

Reviewers: rven, yhchiang, kradhakrishnan, igor

Reviewed By: igor

Subscribers: leveldb, dhruba, yoshinorim

Differential Revision: https://reviews.facebook.net/D35247
2015-03-18 17:03:59 -07:00
Yueh-Hsuan Chiang
f7ed654641 Fix RocksJava test failure due to deprecation of table_cache_remove_scan_count_limit
Summary:
table_cache_remove_scan_count_limit is marked as deprecated in RocksDB C++.
(see rocksdb/options.h).  This patch made necessary changes on RocksJava
side.

Test Plan:
make rocksdbjava -j32
make jtest

Reviewers: rven, igor, fyrz, adamretter, ankgup87, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D35355
2015-03-18 15:40:27 -07:00
Igor Canadi
51301b869f Enable dynamic changing of rate limiter's bytes_per_second
Summary: This feature is going to be useful for mongodb+rocksdb. I'll expose it through mongo's API.

Test Plan: added new unit test. also will run TSAN on the new unit test

Reviewers: meyering, sdong

Reviewed By: meyering, sdong

Subscribers: meyering, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D35307
2015-03-18 15:35:55 -07:00
Yueh-Hsuan Chiang
652db51a31 Fix compilation error in rocksjni/write_batch_test.cc
Summary: Fix compilation error in rocksjni/write_batch_test.cc

Test Plan: make rocksdbjava -j32

Reviewers: sdong, igor, rven

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D35343
2015-03-18 15:10:57 -07:00
Mark Callaghan
dfccc7b4e2 Add readwhilemerging benchmark
Summary:
This is like readwhilewriting but uses Merge rather than Put in the writer thread.
I am using it for in-progress benchmarks. I don't think the other benchmarks for Merge
cover this behavior. The purpose for this test is to measure read performance when
readers might have to merge results. This will also benefit from work-in-progress
to add skewed key generation.

Task ID: #

Blame Rev:

Test Plan:
Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D35115
2015-03-18 13:50:52 -07:00
fyrz
c345d1ee88 [RocksJava] Integrated changes for D34857 2015-03-18 21:38:17 +01:00
fyrz
12350115da [RocksJava] Added LevelCompactionDynamicLevelBytes to Options
Summary: Added LevelCompactionDynamicLevelBytes to Options.

Test Plan:
make clean jclean rocksdbjava jtest
mvn -f rocksjni.pom package

Reviewers: adamretter, ankgup87, yhchiang

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D34857
2015-03-18 21:38:17 +01:00
Venkatesh Radhakrishnan
230e68727a Fix TSAN failue in env_test
Summary: Check for state of task before deleting it.

Test Plan: Run env_test with TSAN

Reviewers: igor, sdong

Reviewed By: sdong

Subscribers: meyering, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D35283
2015-03-18 11:40:46 -07:00
Islam AbdelRahman
155d468c56 Using chrono as a fallback
Summary:
Right now if they system we are compiling on is not Linux and not Mac we will get a compilation error
this diff use chrono as a fallback when we are compiling on something other than Linux/FreeBSD/Mac

Test Plan:
compile on CentOS/FreeBSD
./db_test (still running)

Reviewers: igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D35277
2015-03-18 11:26:10 -07:00
agiardullo
81345b90f9 Create an abstract interface for write batches
Summary: WriteBatch and WriteBatchWithIndex now both inherit from a common abstract base class.  This makes it easier to write code that is agnostic toward the implementation of the particular write batch.  In particular, I plan on utilizing this abstraction to allow transactions to support using either implementation of a write batch.

Test Plan: modified existing WriteBatchWithIndex tests to test new functions.  Running all tests.

Reviewers: igor, rven, yhchiang, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D34017
2015-03-17 19:23:08 -07:00
Igor Canadi
46214df4a1 Only run db_test in Travis 2015-03-17 15:24:16 -07:00
Igor Canadi
c88ff4ca76 Deprecate removeScanCountLimit in NewLRUCache
Summary: It is no longer used by the implementation, so we should also remove it from the public API.

Test Plan: make check

Reviewers: sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D34971
2015-03-17 15:04:37 -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 Canadi
413e35273e Merge pull request #540 from dalgaaf/wip-da-fix-elif
Fix '#elif with no expression'
2015-03-17 10:33:21 -07:00
Danny Al-Gaaf
969aa806b7 util/xfunc.h: fix #elif check for NDEBUG
Fix '#elif with no expression', add defined() to check.

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>
2015-03-17 12:04:05 +01:00
Danny Al-Gaaf
87c7d49d67 util/env_posix.cc: fix #elif check for __MACH__
Fix '#elif with no expression' add defined() to check.

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>
2015-03-17 12:03:11 +01:00
Danny Al-Gaaf
c86e5d7b93 stack_trace.cc: fix #elif check for OS_MACOSX
Fix '#elif with no expression' add defined() to check.

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>
2015-03-17 12:00:55 +01:00
Venkatesh Radhakrishnan
98c37fda5d Remove unused parameter in CancelAllBackgroundWork
Summary: Some suggestions for cleanup from Igor.

Test Plan: Regression tests.

Reviewers: igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D35169
2015-03-16 21:07:54 -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
Venkatesh Radhakrishnan
d4d42c02ea Fixed clang build in env.h
Summary: Mark function as override.

Test Plan: USE_CLANG=1 make -j32 check

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D35163
2015-03-16 19:51:25 -07:00
Venkatesh Radhakrishnan
b2b3086524 Speed up rocksDB close call.
Summary:
On RocksDB, when there are multiple instances doing
flushes/compactions in the background, the close call takes a long time
because the flushes/compactions need to complete before the database can
shut down. If another instance is using the background threads and the compaction for this instance is in the queue since it has been scheduled, we still cannot shutdown. We now remove the scheduled background tasks which have not yet started running, so that shutdown is speeded up.

Test Plan: DB Test added.

Reviewers: yhchiang, igor, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D33741
2015-03-16 18:49:14 -07:00
Igor Sugak
a7aba2ef6b rocksdb: Add gtest
Summary:
Adds gtest fused source code into `third-party` directory. No manual changes.

gtest latest released 1.7 has clang dev compilation errors. Trunk version requires only one disabled warning (-Wno-missing-field-initializers)

Fused code is made as described here https://fburl.com/90806322
Details about why we need gtest source code instead of precompiled library https://fburl.com/90805763
Source used from http://googletest.googlecode.com/svn/trunk

Test Plan:
Build and notice no errors. Also check in logs that gtest-all.o being compiled gtest-all.o.
```lang=bash
% USE_CLANG=1 make all
```

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

Reviewed By: meyering

Subscribers: meyering, yhchiang, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D33345
2015-03-16 18:27:30 -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 Sugak
bd4963e64d rocksdb: update reference to the latest version of clang dev in fbcode
Summary: Updated reference to the latest clang dev in fbcode. Since RocksDB already uses recent version of clang dev no code changes need.

Test Plan:
Make sure can be build with clang.
```lang=bash
% USE_CLANG=1 make all
```

Reviewers: meyering, sdong, rven, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D35121
2015-03-16 17:08:05 -07:00