Commit graph

568 commits

Author SHA1 Message Date
Raghav Pisolkar e0b99d4f5d created a new ReadOptions parameter 'iterate_upper_bound' 2014-09-04 11:00:16 -07:00
Lei Jin 9b58c73c7c call SanitizeDBOptionsByCFOptions() in the right place
Summary: It only covers Open() with default column family right now

Test Plan: make release

Reviewers: igor, yhchiang, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22467
2014-09-02 14:42:23 -07:00
Igor Canadi a84234a61b Ignore missing column families
Summary:
Before this diff, whenever we Write to non-existing column family, Write() would fail.

This diff adds an option to not fail a Write() when WriteBatch points to non-existing column family. MongoDB said this would be useful for them, since they might have a transaction updating an index that was dropped by another thread. This way, they don't have to worry about checking if all indexes are alive on every write. They don't care if they lose writes to dropped index.

Test Plan: added a small unit test

Reviewers: sdong, yhchiang, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22143
2014-09-02 13:29:05 -07:00
Igor Canadi 7f19bb93c6 Merge pull request #242 from tdfischer/perf-timer-destructors
Refactor PerfStepTimer to automatically stop on destruct
2014-09-02 13:06:40 -07:00
Feng Zhu 8438a19360 fix dropping column family bug
Summary: 1. db/db_impl.cc:2324 (DBImpl::BackgroundCompaction) should not raise bg_error_ when column family is dropped during compaction.

Test Plan: 1. db_stress

Reviewers: ljin, yhchiang, dhruba, igor, sdong

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22653
2014-09-02 12:25:58 -07:00
Torrie Fischer 6614a48418 Refactor PerfStepTimer to stop on destruct
This eliminates the need to remember to call PERF_TIMER_STOP when a section has
been timed. This allows more useful design with the perf timers and enables
possible return value optimizations. Simplistic example:

class Foo {
  public:
    Foo(int v) : m_v(v);
  private:
    int m_v;
}

Foo makeFrobbedFoo(int *errno)
{
  *errno = 0;
  return Foo();
}

Foo bar(int *errno)
{
  PERF_TIMER_GUARD(some_timer);

  return makeFrobbedFoo(errno);
}

int main(int argc, char[] argv)
{
  Foo f;
  int errno;

  f = bar(&errno);

  if (errno)
    return -1;
  return 0;
}

After bar() is called, perf_context.some_timer would be incremented as if
Stop(&perf_context.some_timer) was called at the end, and the compiler is still
able to produce optimizations on the return value from makeFrobbedFoo() through
to main().
2014-09-02 12:04:22 -07:00
Igor Canadi 7dcadb1d37 Don't let flush preempt compaction in certain cases
Summary:
I have an application configured with 16 background threads. Write rates are high. L0->L1 compactions is very slow and it limits the concurrency of the system. While it's happening, other 15 threads are idle. However, when there is a need of a flush, that one thread busy with L0->L1 is doing flush, instead of any other 15 threads that are just sitting there.

This diff prevents that. If there are threads that are idle, we don't let flush preempt compaction.

Test Plan: Will run stress test

Reviewers: ljin, sdong, yhchiang

Reviewed By: sdong, yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D22299
2014-09-02 08:34:54 -07:00
Nik Bougalis f09329cb01 Fix candidate file comparison when using path ids 2014-08-31 00:54:15 -07:00
Lei Jin 722d80c374 reduce recordTick overhead in compaction loop
Summary: It is too expensive to bump ticker to every key/vaue pair

Test Plan: make release

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22527
2014-08-29 09:51:09 -07:00
Igor Canadi d977e55596 Don't let other compactions run when manual compaction runs
Summary:
Based on discussions from t4982833. This is just a short-term fix, I plan to revamp manual compaction process as part of t4982812.

Also, I think we should schedule automatic compactions at the very end of manual compactions, not when we're done with one level. I made that change as part of this diff. Let me know if you disagree.

Test Plan: make check for now

Reviewers: sdong, tnovak, yhchiang, ljin

Reviewed By: yhchiang

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22401
2014-08-28 13:06:28 -04:00
Igor Canadi d5bd6c772b Fix ios compile
Summary: No __thread for ios.

Test Plan: compile works for ios now

Reviewers: ljin, dhruba

Reviewed By: dhruba

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22491
2014-08-28 12:46:05 -04:00
Stanislau Hlebik 9dcb75b6d9 Add is-file-deletions-enabled property
Summary:
Add property 'rocksdb.is-file-deletions-enable'
	 which equals disable_delete_obsole_file_

Test Plan: make all check

Reviewers: sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22119
2014-08-26 16:26:29 -07:00
Lei Jin 23861857c4 ReadOptions.total_order_seek to allow total order seek for block-based table when hash index is enabled
Summary: as title

Test Plan: table_test

Reviewers: igor, yhchiang, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22239
2014-08-25 16:14:30 -07:00
Lei Jin 384400128f move block based table related options BlockBasedTableOptions
Summary:
I will move compression related options in a separate diff since this
diff is already pretty lengthy.
I guess I will also need to change JNI accordingly :(

Test Plan: make all check

Reviewers: yhchiang, igor, sdong

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D21915
2014-08-25 14:22:05 -07:00
Yueh-Hsuan Chiang 63a2215c63 Improve Options sanitization and add MmapReadRequired() to TableFactory
Summary:
Currently, PlainTable must use mmap_reads.  When PlainTable is used but
allow_mmap_reads is not set, rocksdb will fail in flush.

This diff improve Options sanitization and add MmapReadRequired() to
TableFactory.

Test Plan:
export ROCKSDB_TESTS=PlainTableOptionsSanitizeTest
make db_test -j32
./db_test

Reviewers: sdong, ljin

Reviewed By: ljin

Subscribers: you, leveldb

Differential Revision: https://reviews.facebook.net/D21939
2014-08-20 15:53:39 -07:00
sdong 10720a5587 Revert the unintended change that DestroyDB() doesn't clean up info logs.
Summary: A previous change triggered a change by mistake: DestroyDB() will keep info logs under DB directory. Revert the unintended change.

Test Plan: Add a unit test case to verify it.

Reviewers: ljin, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22209
2014-08-20 12:07:32 -07:00
Igor Canadi c8ecfaedd0 Merge pull request #230 from cockroachdb/spencerkimball/send-user-keys-to-v2-filter
Pass parsed user key to prefix extractor in V2 compaction
2014-08-18 11:09:30 -04:00
sdong 58b0f9d890 Support purging logs from separate log directory
Summary:
1. Support purging info logs from a separate paths from DB path. Refactor the codes of generating info log prefixes so that it can be called when generating new files and scanning log directory.
2. Fix the bug of not scanning multiple DB paths (should only impact multiple DB paths)

Test Plan:
Add unit test for generating and parsing info log files
Add end-to-end test in db_test

Reviewers: yhchiang, ljin

Reviewed By: ljin

Subscribers: leveldb, igor, dhruba

Differential Revision: https://reviews.facebook.net/D21801
2014-08-14 13:22:50 -07:00
Feng Zhu 5e642403a9 log db path info before open
Summary: 1. write db MANIFEST, CURRENT, IDENTITY, sst files, log files to log before open

Test Plan: run db and check LOG file

Reviewers: ljin, yhchiang, igor, dhruba, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D21459
2014-08-13 13:45:13 -07:00
sdong 48081777f3 Revert "Include candidate files under options.db_log_dir in FindObsoleteFiles()"
This reverts commit 54153ab07a.
2014-08-12 18:14:27 -07:00
Lei Jin 218857b3f5 remove tailing_iter.h/cc
Summary: as title

Test Plan:
make all check
ran db_bench and saw seek stats at the end

Reviewers: yhchiang, igor, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D21651
2014-08-12 17:13:15 -07:00
Lei Jin 5d0074c471 set bytes_per_sync to 1MB if rate limiter is enabled
Summary: as title

Test Plan: make all check

Reviewers: igor, yhchiang, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D21201
2014-08-12 16:42:18 -07:00
Spencer Kimball 3fcf7b26b9 Pass parsed user key to prefix extractor in V2 compaction
Previously, the prefix extractor was being supplied with the RocksDB
key instead of a parsed user key. This makes correct interpretation
by calling application fragile or impossible.
2014-08-12 18:48:28 -04:00
Stanislau Hlebik 2fa643466d Add scope guard
Summary: Small change: replace mutex_.Lock/mutex_.Unlock() with scope guard

Test Plan: make all check

Reviewers: igor, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D21609
2014-08-12 12:13:13 -07:00
Stanislau Hlebik 06a52bda64 Flush only one column family
Summary:
Currently DBImpl::Flush() triggers flushes in all column families.
Instead we need to trigger just the column family specified.

Test Plan: make all check

Reviewers: igor, ljin, yhchiang, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D20841
2014-08-11 22:10:32 -07:00
miguelportilla 93e6b5e9d9 Changes to support unity build:
* Script for building the unity.cc file via Makefile
* Unity executable Makefile target for testing builds
* Source code changes to fix compilation of unity build
2014-08-11 13:22:47 -04:00
sdong 54153ab07a Include candidate files under options.db_log_dir in FindObsoleteFiles()
Summary: In FindObsoleteFiles(), we don't scan db_log_dir. Add it.

Test Plan: make all check

Reviewers: ljin, igor, yhchiang

Reviewed By: yhchiang

Subscribers: leveldb, yhchiang

Differential Revision: https://reviews.facebook.net/D21429
2014-08-08 17:37:03 -07:00
sdong 4632239d13 Need to schedule compactions when manual compaction finishes
Summary: If there is an outstanding compaction scheduled but at the time a manual compaction is triggered, the manual compaction will preempt. In the end of the manual compaction, we should try to schedule compactions to make sure those preempted ones are not skipped.

Test Plan: make all check

Reviewers: yhchiang, ljin

Reviewed By: ljin

Subscribers: leveldb, dhruba, igor

Differential Revision: https://reviews.facebook.net/D21321
2014-08-08 12:28:36 -07:00
Igor Canadi 5e0868147d Fix SIGSEGV in travis
Summary:
Travis build was failing a lot. For example see https://travis-ci.org/facebook/rocksdb/builds/31425845

This fixes it.

Also, please don't put any code after SignalAll :)

Test Plan: no more SIGSEGV

Reviewers: yhchiang, sdong, ljin

Reviewed By: ljin

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D21417
2014-08-08 10:24:00 -07:00
Igor Canadi f8d6a2981f Merge pull request #224 from cockroachdb/spencerkimball/compaction-filter-v2-c-bindings
Add support for C bindings to the compaction V2 filter mechanism.
2014-08-07 14:10:54 -04:00
sdong 7abe9655d3 Fix valgrind failure caused by recent checked-in.
Summary: Initialize un-initialized parameters

Test Plan: run the failed test (c_test)

Reviewers: yhchiang, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D21249
2014-08-06 17:45:47 -07:00
Spencer Kimball 38e8b727a8 Fix typo, add missing inclusion of state void* in invocation of
create_compaction_filter_v2_.
2014-08-06 18:42:15 -04:00
Spencer Kimball c1f588af71 Add support for C bindings to the compaction V2 filter mechanism.
Test Plan: make c_test && ./c_test

Some fixes after merge.
2014-08-06 15:55:48 -04:00
sdong 1242bfcad7 Add DB property "rocksdb.estimate-table-readers-mem"
Summary:
Add a DB Property "rocksdb.estimate-table-readers-mem" to return estimated memory usage by all loaded table readers, other than allocated from block cache.

Refactor the property codes to allow getting property from a version, with DB mutex not acquired.

Test Plan: Add several checks of this new property in existing codes for various cases.

Reviewers: yhchiang, ljin

Reviewed By: ljin

Subscribers: xjin, igor, leveldb

Differential Revision: https://reviews.facebook.net/D20733
2014-08-06 11:39:46 -07:00
Feng Zhu 1129921e9b logging_when_create_and_delete_manifest
Summary:
  1. logging when create and delete manifest file
  2. fix formating in table/format.cc

Test Plan:
  make all check
  run db_bench, track the LOG file.

Reviewers: ljin, yhchiang, igor, yufei.zhu, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D21009
2014-08-04 11:25:42 -07:00
Igor Canadi e4c3673923 Never CompactRange to level 0 in level compaction
Summary: I was bit by this when developing SpatialDB. In case all files are at level 0, CompactRange() will output the compacted files to level 0. This is not ideal, since read amp. is much better at level 1 and higher.

Test Plan: Compacted data in SpatialDB, read manifest using ldb, verified that files are now at level 1 instead of 0.

Reviewers: sdong, ljin, yhchiang, dhruba

Reviewed By: dhruba

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D20901
2014-08-01 06:41:48 -07:00
Yueh-Hsuan Chiang 49ee5a4ac4 Fixed the crash when merge_operator is not properly set after reopen.
Summary:
Fixed the crash when merge_operator is not properly set after reopen
and added two test cases for this.

Test Plan:
make merge_test
./merge_test

Reviewers: igor, ljin, sdong

Reviewed By: sdong

Subscribers: benj, mvikjord, leveldb

Differential Revision: https://reviews.facebook.net/D20793
2014-07-30 17:24:36 -07:00
sdong f04356e660 Add DB::GetIntProperty() to return integer properties to be returned as integers
Summary: We have quite some properties that are integers and we are adding more. Add a function to directly return them as an integer, instead of a string

Test Plan: Add several unit test checks

Reviewers: yhchiang, igor, dhruba, haobo, ljin

Reviewed By: ljin

Subscribers: yoshinorim, leveldb

Differential Revision: https://reviews.facebook.net/D20637
2014-07-28 16:55:57 -07:00
Lei Jin 7e8bb71dd0 InternalStats to take cfd on constructor
Summary:
It has one-to-one relationship with CFD. Take a pointer to CFD on
constructor to avoid passing cfd through member functions.

Test Plan: make

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D20565
2014-07-28 12:27:08 -07:00
Lei Jin 1bd3431f7c Change StopWatch interface
Summary: So that we can avoid calling NowSecs() in MakeRoomForWrite twice

Test Plan: make all check

Reviewers: yhchiang, igor, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D20529
2014-07-28 12:22:37 -07:00
Lei Jin f6ca226c17 make statistics forward-able
Summary:
Make StatisticsImpl being able to forward stats to provided statistics
implementation. The main purpose is to allow us to collect internal
stats in the future even when user supplies custom statistics
implementation. It avoids intrumenting 2 sets of stats collection code.
One immediate use case is tuning advisor, which needs to collect some
internal stats, users may not be interested.

Test Plan:
ran db_bench and see stats show up at the end of run
Will run make all check since some tests rely on statistics

Reviewers: yhchiang, sdong, igor

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D20145
2014-07-28 12:10:49 -07:00
Lei Jin 40fa8a4cd5 make statistics forward-able
Summary:
Make StatisticsImpl being able to forward stats to provided statistics
implementation. The main purpose is to allow us to collect internal
stats in the future even when user supplies custom statistics
implementation. It avoids intrumenting 2 sets of stats collection code.
One immediate use case is tuning advisor, which needs to collect some
internal stats, users may not be interested.

Test Plan:
ran db_bench and see stats show up at the end of run
Will run make all check since some tests rely on statistics

Reviewers: yhchiang, sdong, igor

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D20145
2014-07-28 12:05:36 -07:00
sdong f6b7e1ed1a Allow user to specify DB path of output file of manual compaction
Summary: Add a parameter path_id to DB::CompactRange(), to indicate where the output file should be placed to.

Test Plan: add a unit test

Reviewers: yhchiang, ljin

Reviewed By: ljin

Subscribers: xjin, igor, dhruba, MarkCallaghan, leveldb

Differential Revision: https://reviews.facebook.net/D20085
2014-07-21 19:06:00 -07:00
Lei Jin f6f1533c6f make internal stats independent of statistics
Summary:
also make it aware of column family
output from db_bench

```
** Compaction Stats [default] **
Level Files Size(MB) Score Read(GB)  Rn(GB) Rnp1(GB) Write(GB) Wnew(GB) RW-Amp W-Amp Rd(MB/s) Wr(MB/s)  Rn(cnt) Rnp1(cnt) Wnp1(cnt) Wnew(cnt)  Comp(sec) Comp(cnt) Avg(sec) Stall(sec) Stall(cnt) Avg(ms)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  L0    14      956   0.9      0.0     0.0      0.0       2.7      2.7    0.0   0.0      0.0    111.6        0         0         0         0         24        40    0.612      75.20     492387    0.15
  L1    21     2001   2.0      5.7     2.0      3.7       5.3      1.6    5.4   2.6     71.2     65.7       31        43        55        12         82         2   41.242      43.72      41183    1.06
  L2   217    18974   1.9     16.5     2.0     14.4      15.1      0.7   15.6   7.4     70.1     64.3       17       182       185         3        241        16   15.052       0.00          0    0.00
  L3  1641   188245   1.8      9.1     1.1      8.0       8.5      0.5   15.4   7.4     61.3     57.2        9        75        76         1        152         9   16.887       0.00          0    0.00
  L4  4447   449025   0.4     13.4     4.8      8.6       9.1      0.5    4.7   1.9     77.8     52.7       38        79       100        21        176        38    4.639       0.00          0    0.00
 Sum  6340   659201   0.0     44.7    10.0     34.7      40.6      6.0   32.0  15.2     67.7     61.6       95       379       416        37        676       105    6.439     118.91     533570    0.22
 Int     0        0   0.0      1.2     0.4      0.8       1.3      0.5    5.2   2.7     59.1     65.6        3         7         9         2         20        10    2.003       0.00          0    0.00
Stalls(secs): 75.197 level0_slowdown, 0.000 level0_numfiles, 0.000 memtable_compaction, 43.717 leveln_slowdown
Stalls(count): 492387 level0_slowdown, 0 level0_numfiles, 0 memtable_compaction, 41183 leveln_slowdown

** DB Stats **
Uptime(secs): 202.1 total, 13.5 interval
Cumulative writes: 6291456 writes, 6291456 batches, 1.0 writes per batch, 4.90 ingest GB
Cumulative WAL: 6291456 writes, 6291456 syncs, 1.00 writes per sync, 4.90 GB written
Interval writes: 1048576 writes, 1048576 batches, 1.0 writes per batch, 836.0 ingest MB
Interval WAL: 1048576 writes, 1048576 syncs, 1.00 writes per sync, 0.82 MB written

Test Plan: ran it

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D19917
2014-07-21 12:57:29 -07:00
Yueh-Hsuan Chiang 3178510153 Allow class Compaction to handle input files from multiple levels.
Summary:
Allow class Compaction to handle input files from multiple levels.
This diff is a subset of https://reviews.facebook.net/D19263 where
only db/compaction.cc and db/compaction.h are changed.

Test Plan:
make db_test
export ROCKSDB_TESTS=Compaction
./db_test

Reviewers: igor, sdong, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D19923
2014-07-17 14:36:41 -07:00
Feng Zhu 87895c62db fix bug in LOG for flush memtable
Summary:
  One line change to fix a bug in the LOG when flush memtable

Test Plan:
  NONE

Reviewers: sdong

Reviewed By: sdong

Differential Revision: https://reviews.facebook.net/D20049
2014-07-16 16:56:49 -07:00
sdong 0abaed2e08 Support multiple DB directories in universal compaction style
Summary:
This patch adds a target size parameter in options.db_paths and universal compaction will base it to determine which DB path to place a new file.
Level-style stays the same.

Test Plan: Add new unit tests

Reviewers: ljin, yhchiang

Reviewed By: yhchiang

Subscribers: MarkCallaghan, dhruba, igor, leveldb

Differential Revision: https://reviews.facebook.net/D19869
2014-07-15 12:06:28 -07:00
Igor Canadi 20c056306b Remove stats logger
Summary: Browsing through the code, looks like StatsLogger is not used at all!

Test Plan: compiles

Reviewers: ljin, sdong, yhchiang, dhruba

Reviewed By: dhruba

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D19827
2014-07-15 09:16:32 -04:00
Lei Jin 46f0f6ddd5 improve InternalStats output
Summary: as title

Test Plan:
sampe output:
Level Files Size(MB) Score Read(GB)  Rn(GB) Rnp1(GB) Write(BG) Wnew(GB) RW-Amp W-Amp Rd(MB/s) Wr(MB/s)  Rn(cnt) Rnp1(cnt) Wnp1(cnt) Wnew(cnt)  Comp(sec) Comp(cnt) Avg(sec) Stall(sec) Stall(cnt) Avg(ms)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  L0    15     1024   1.0      0.0     0.0      0.0       8.2      8.2    0.0   0.0      0.0    111.4        0         0         1         1         75       123    0.612     295.94    1939238    0.15
  L1    23     2118   2.1     20.9     8.3     12.7      20.0      7.3    5.0   2.4     73.2     69.9      124       141       208        67        293         8   36.582      17.05      16100    1.06
  L2   162    15333   1.5     47.0     7.1     40.0      42.6      2.6   12.7   6.0     67.9     61.5       62       457       482        25        709        55   12.898       0.00          0    0.00
  L3   985   108065   1.1     37.8     4.0     33.9      36.9      3.0   18.8   9.3     60.1     58.5       41       338       363        25        645        31   20.812       0.00          0    0.00
  L4  2788   356033   0.3      0.0     0.0      0.0       0.0      0.0    0.0   0.0      0.0      0.0        0         0         0         0          0         0    0.000       0.00          0    0.00
 Sum  3973   482572   0.0    105.8    19.3     86.5     107.7     21.2   11.1   5.6     62.9     64.0      227       936      1054       118       1723       217    7.938     312.99    1955338    0.16

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D19707
2014-07-11 15:03:30 -07:00
Feng Zhu 178fd6f9db use FileLevel in LevelFileNumIterator
Summary:
  Use FileLevel in LevelFileNumIterator, thus use new version of findFile.
  Old version of findFile function is deleted.
  Write a function in version_set.cc to generate FileLevel from files_.
  Add GenerateFileLevelTest in version_set_test.cc

Test Plan:
  make all check

Reviewers: ljin, haobo, yhchiang, sdong

Reviewed By: sdong

Subscribers: igor, dhruba

Differential Revision: https://reviews.facebook.net/D19659
2014-07-11 12:52:41 -07:00