Commit Graph

612 Commits

Author SHA1 Message Date
Igor Canadi
6bb7e3ef25 Merger test
Summary: I abandoned https://reviews.facebook.net/D18789, but I wrote a good unit test there, so let's check it in. :)

Test Plan: this is test

Reviewers: sdong, yhchiang, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22827
2014-09-08 22:24:40 -07:00
Igor Canadi
88841bd007 Explicitly cast char to signed char in Hash()
Summary:
The compilers we use treat char as signed. However, this is not guarantee of C standard and some compilers (for ARM platform for example), treat char as unsigned. Code that assumes that char is either signed or unsigned is wrong.

This change explicitly casts the char to signed version. This will not break any of our use cases on x86, which, I believe are all of them. In case somebody out there is using RocksDB on ARM AND using bloom filters, they're going to have a bad time. However, it is very unlikely that this is the case.

Test Plan: sanity test with previous commit (with new sanity test)

Reviewers: yhchiang, ljin, sdong

Reviewed By: ljin

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D22767
2014-09-08 18:57:40 -07:00
Lei Jin
52311463e9 MemTableOptions
Summary: removed reference to options in WriteBatch and DBImpl::Get()

Test Plan: make all check

Reviewers: yhchiang, igor, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23049
2014-09-08 18:46:52 -07:00
Lei Jin
659d2d50c3 move compaction_filter to immutable_options
Summary:
all shared_ptrs are in immutable_options now. This will also make
options assignment a little cheaper

Test Plan: make release

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23001
2014-09-08 15:09:25 -07:00
Lei Jin
048560a642 reduce references to cfd->options() in DBImpl
Summary:
I found it is almost impossible to get rid of this function in a single
batch. I will take a step by step approach

Test Plan: make release

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22995
2014-09-08 15:04:34 -07:00
Igor Canadi
a2bb7c3c33 Push- instead of pull-model for managing Write stalls
Summary:
Introducing WriteController, which is a source of truth about per-DB write delays. Let's define an DB epoch as a period where there are no flushes and compactions (i.e. new epoch is started when flush or compaction finishes). Each epoch can either:
* proceed with all writes without delay
* delay all writes by fixed time
* stop all writes

The three modes are recomputed at each epoch change (flush, compaction), rather than on every write (which is currently the case).

When we have a lot of column families, our current pull behavior adds a big overhead, since we need to loop over every column family for every write. With new push model, overhead on Write code-path is minimal.

This is just the start. Next step is to also take care of stalls introduced by slow memtable flushes. The final goal is to eliminate function MakeRoomForWrite(), which currently needs to be called for every column family by every write.

Test Plan: make check for now. I'll add some unit tests later. Also, perf test.

Reviewers: dhruba, yhchiang, MarkCallaghan, sdong, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22791
2014-09-08 11:20:25 -07:00
Feng Zhu
0af157f9bf Implement full filter for block based table.
Summary:
1. Make filter_block.h a base class. Derive block_based_filter_block and full_filter_block. The previous one is the traditional filter block. The full_filter_block is newly added. It would generate a filter block that contain all the keys in SST file.

2. When querying a key, table would first check if full_filter is available. If not, it would go to the exact data block and check using block_based filter.

3. User could choose to use full_filter or tradional(block_based_filter). They would be stored in SST file with different meta index name. "filter.filter_policy" or "full_filter.filter_policy". Then, Table reader is able to know the fllter block type.

4. Some optimizations have been done for full_filter_block, thus it requires a different interface compared to the original one in filter_policy.h.

5. Actual implementation of filter bits coding/decoding is placed in util/bloom_impl.cc

Benchmark: base commit 1d23b5c470
Command:
db_bench --db=/dev/shm/rocksdb --num_levels=6 --key_size=20 --prefix_size=20 --keys_per_prefix=0 --value_size=100 --write_buffer_size=134217728 --max_write_buffer_number=2 --target_file_size_base=33554432 --max_bytes_for_level_base=1073741824 --verify_checksum=false --max_background_compactions=4 --use_plain_table=0 --memtablerep=prefix_hash --open_files=-1 --mmap_read=1 --mmap_write=0 --bloom_bits=10 --bloom_locality=1 --memtable_bloom_bits=500000 --compression_type=lz4 --num=393216000 --use_hash_search=1 --block_size=1024 --block_restart_interval=16 --use_existing_db=1 --threads=1 --benchmarks=readrandom —disable_auto_compactions=1
Read QPS increase for about 30% from 2230002 to 2991411.

Test Plan:
make all check
valgrind db_test
db_stress --use_block_based_filter = 0
./auto_sanity_test.sh

Reviewers: igor, yhchiang, ljin, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D20979
2014-09-08 10:37:05 -07:00
Nik Bougalis
9f8aa09395 Don't leak data returned by opendir 2014-09-05 20:50:29 -07:00
Nik Bougalis
bfee319fb0 sizeof(int*) where sizeof(int) was intended 2014-09-05 20:50:29 -07:00
Feng Zhu
40ddc3d6c4 add cache bench
Summary: 1. A benchmark for cache

Test Plan: ./cache_bench

Reviewers: yhchiang, dhruba, sdong, igor, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22809
2014-09-05 15:55:43 -07:00
liuhuahang
bb6ae0f80c fix more compile warnings
N/A

Change-Id: I5b6f9c70aea7d3f3489328834fed323d41106d9f
Signed-off-by: liuhuahang <liuhuahang@zerus.co>
2014-09-05 14:14:37 +08:00
Stanislau Hlebik
45a5e3ede0 Remove path with arena==nullptr from NewInternalIterator
Summary:
Simply code by removing code path which does not use Arena
from NewInternalIterator

Test Plan:
make all check
make valgrind_check

Reviewers: sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22395
2014-09-04 17:40:41 -07:00
Lei Jin
5665e5e285 introduce ImmutableOptions
Summary:
As a preparation to support updating some options dynamically, I'd like
to first introduce ImmutableOptions, which is a subset of Options that
cannot be changed during the course of a DB lifetime without restart.

ColumnFamily will keep both Options and ImmutableOptions. Any component
below ColumnFamily should only take ImmutableOptions in their
constructor. Other options should be taken from APIs, which will be
allowed to adjust dynamically.

I am yet to make changes to memtable and other related classes to take
ImmutableOptions in their ctor. That can be done in a seprate diff as
this one is already pretty big.

Test Plan: make all check

Reviewers: yhchiang, igor, sdong

Reviewed By: sdong

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D22545
2014-09-04 16:18:36 -07:00
Igor Canadi
51ea889002 Fix travis builds
Summary:
Lots of travis builds are failing because on EnvPosixTest.RandomAccessUniqueID: https://travis-ci.org/facebook/rocksdb/builds/34400833

This is the result of their environment and not because of RocksDB's bug.

Also note that RocksDB works correctly even though UniqueID feature is not present in the system (as it's the case with os x)

Test Plan:
OPT=-DTRAVIS make env_test && ./env_test
Observed that offending tests are not being run

Reviewers: sdong, yhchiang, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22803
2014-09-04 10:23:45 -07:00
liuhuahang
ef5b384729 fix a few compile warnings
1, const qualifiers on return types make no sense and will trigger a compile warning: warning: type qualifiers ignored on function return type [-Wignored-qualifiers]

2, class HistogramImpl has virtual functions and thus should have a virtual destructor

3, with some toolchain, the macro __STDC_FORMAT_MACROS is predefined and thus should be checked before define

Change-Id: I69747a03bfae88671bfbb2637c80d17600159c99
Signed-off-by: liuhuahang <liuhuahang@zerus.co>
2014-09-04 23:06:23 +08:00
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
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
Lei Jin
7e9f28cb23 limit max bytes that can be read/written per pread/write syscall
Summary:
BlockBasedTable sst file size can grow to a large size when universal
compaction is used. When index block exceeds 2G, pread seems to fail and
return truncated data and causes "trucated block" error. I tried to use
```
  #define _FILE_OFFSET_BITS 64
```
But the problem still persists. Splitting a big write/read into smaller
batches seems to solve the problem.

Test Plan:
successfully compacted a case with resulting sst file at ~90G (2.1G
index block size)

Reviewers: yhchiang, igor, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22569
2014-08-29 21:21:49 -07:00
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
Igor Canadi
536e9973e3 Remove assert in vector rep
Summary: This assert makes Insert O(n^2) instead of O(n) in debug mode. Memtable insert is in the critical path. No need to assert uniqunnes of the key here, since we're adding a sequence number to it anyway.

Test Plan: none

Reviewers: sdong, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22443
2014-08-27 11:05:41 -07:00
Radheshyam Balasundaram
4142a3e783 Adding a user comparator for comparing Uint64 slices.
Summary:
- New Uint64 comparator
- Modify Reader and Builder to take custom user comparators instead of bytewise comparator
- Modify logic for choosing unused user key in builder
- Modify iterator logic in reader
- test changes

Test Plan:
cuckoo_table_{builder,reader,db}_test
make check all

Reviewers: ljin, sdong

Reviewed By: ljin

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D22377
2014-08-27 10:39:31 -07:00
Lei Jin
1755581f19 improve OptimizeForPointLookup()
Summary: also fix HISTORY.md

Test Plan: make all check

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22437
2014-08-26 14:15:00 -07:00
Igor Canadi
d9c0785812 Fix assertion in PosixRandomAccessFile
Summary:
See https://github.com/facebook/rocksdb/issues/244#issuecomment-53372297
Also see this: https://github.com/facebook/rocksdb/blob/master/util/env_posix.cc#L1075

Test Plan: compiles

Reviewers: yhchiang, ljin, sdong

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22419
2014-08-26 15:28:36 -04:00
Lei Jin
a98badff16 print table options
Summary: Add a virtual function in table factory that will print table options

Test Plan: make release

Reviewers: igor, yhchiang, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22149
2014-08-25 14:24:09 -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
Jonah Cohen
e173bf9c19 Eliminate VersionSet memory leak
Summary:
ManifestDumpCommand::DoCommand was allocating a VersionSet and never
freeing it.

Test Plan: make

Reviewers: igor

Reviewed By: igor

Differential Revision: https://reviews.facebook.net/D22221
2014-08-20 13:52:03 -07:00
Igor Canadi
6929b08616 Remove BitStream* tests 2014-08-19 09:52:54 -04:00
Igor Canadi
50b790c6d4 Removing BitStream* functions
Summary: I was checking some functions in coding.h and coding.cc when I noticed these unused functions. Let's remove them.

Test Plan: compiles

Reviewers: sdong, ljin, yhchiang, dhruba

Reviewed By: dhruba

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22077
2014-08-19 06:48:21 -07:00
Lei Jin
c7037153c3 attempt to fix auto_roll_logger_test
Summary:
auto_roll_logger_test fails from time to time. I wasn't able to repro
the issue but by looking at the code, it seems like the initial ctime_
value can be set to the boundary of the second so it may still have a
chance to get rolled when interval is set to 1 second.

```
util/auto_roll_logger_test.cc:120: failed: 118 > 708
==19470== Syscall param msync(start) points to unaddressable byte(s)
==19470==    at 0x4E46CE0: __msync_nocancel (in
/usr/local/fbcode/gcc-4.8.1-glibc-2.17/lib/libpthread-2.17.so)
==19470==    by 0x584EFB: access_mem (Ginit.c:137)
==19470==    by 0x5834E3: _ULx86_64_access_reg (libunwind_i.h:162)
==19470==    by 0x585601: apply_reg_state (Gparser.c:742)
==19470==    by 0x5866BE: _ULx86_64_dwarf_find_save_locs (Gparser.c:883)
==19470==    by 0x584550: _ULx86_64_dwarf_step (Gstep.c:34)
==19470==    by 0x583653: _ULx86_64_step (Gstep.c:71)
==19470==    by 0x583FD2: _ULx86_64_tdep_trace (Gtrace.c:217)
==19470==    by 0x5831C3: backtrace (backtrace.c:69)

Test Plan: ./auto_roll_logger_test

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D21951
2014-08-18 10:23:18 -07:00
Lei Jin
625b9ef4e0 Merge pull request #234 from bbiao/master
fix compile error under Mac OS X
2014-08-14 20:34:48 -07:00
Jonah Cohen
59a2763d5c Fix typo huage => huge
Test Plan: Inspection

Reviewers: sdong

Reviewed By: sdong

Differential Revision: https://reviews.facebook.net/D21891
2014-08-14 17:01:20 -07:00
Jonah Cohen
f611935e9a Fix autovector iterator increment/decrement comments
Summary: The prefix and postfix operators were mixed up in the autovector class.

Test Plan: Inspection

Reviewers: sdong, kailiu

Reviewed By: kailiu

Differential Revision: https://reviews.facebook.net/D21873
2014-08-14 14:56:11 -07:00
ZHANG Biao
8dfe2fdd51 fix compile error under Mac OS X 2014-08-14 20:01:01 +08:00
Lei Jin
58c49466d2 Allow env_posix to lower background thread IO priority
Summary: This is a linux-specific system call.

Test Plan: ran db_bench

Reviewers: igor, yhchiang, sdong

Reviewed By: sdong

Subscribers: haobo, leveldb

Differential Revision: https://reviews.facebook.net/D21183
2014-08-13 20:49:58 -07:00
Feng Zhu
6a2be31f14 fix_valgrind_error_caused_in_db_info_dummper
Summary: 1. add default value to FileType type, thus avoid valgrind error

Test Plan: valgrind ./db_test

Reviewers: sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D21807
2014-08-13 17:53:43 -07:00
Lei Jin
e91ebf1399 print compaction_filter name in Options.Dump
Summary:
Was looking at an issue. All options are the same except
compaction_filter was missed from a newer package. Our option dump does
not capture that

Test Plan: make release

Reviewers: sdong, igor, yhchiang

Reviewed By: yhchiang

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D21765
2014-08-13 15:58:31 -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
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
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
Radheshyam Balasundaram
0c9d03ba10 Fixing broken Mac build
Summary: Made some small changes to fix the broken mac build

Test Plan: make check all in both linux and mac. All tests pass.

Reviewers: sdong, igor, ljin, yhchiang

Reviewed By: ljin, yhchiang

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D20895
2014-07-31 20:52:13 -07:00
sdong
473e829784 Fix ldb dump_manifest
Summary:
We now reads table properties in VersionSet::LogAndApply(), which requires options.db_paths to be set. But since ldb_cmd directly creates VersionSet without initialization db_paths, causing a seg fault. This patch fix it by initializing db_paths.

log_and_apply_bench still shows segfault, because table cache is nullptr in VersionSet created.

Test Plan: Run ldb dump_manifest which used to fail.

Reviewers: yhchiang, ljin, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D20751
2014-07-30 10:17:48 -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
Lei Jin
d650612c4c expose RateLimiter definition
Summary:
User gets undefinied error since the definition is not exposed.
Also re-enable the db test with only upper bound check

Test Plan: db_test, rate_limit_test

Reviewers: igor, yhchiang, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D20403
2014-07-25 15:17:06 -07:00
Yueh-Hsuan Chiang
00f56dfa28 Fixed a compile error in util/options_builder.cc
Summary:
Fixed the following compile error by replacing pow by shift, as it computes
power of 2.

util/options_builder.cc:133:14: error: no member named 'pow' in namespace 'std'
        std::pow(2, std::max(0, std::min(3, level0_stop_writes_trigger -
        ~~~~~^
1 error generated.
make: *** [util/options_builder.o] Error 1

Test Plan: make success in mac and linux

Reviewers: ljin, igor, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D20475
2014-07-23 10:31:32 -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
sdong
e6de02103a Add a utility function to guess optimized options based on constraints
Summary:
Add a function GetOptions(), where based on four parameters users give: read/write amplification threshold, memory budget for mem tables and target DB size, it picks up a compaction style and parameters for them. Background threads are not touched yet.

One limit of this algorithm: since compression rate and key/value size are hard to predict, it's hard to predict level 0 file size from write buffer size. Simply make 1:1 ratio here.

Sample results: https://reviews.facebook.net/P477

Test Plan: Will add some a unit test where some sample scenarios are given and see they pick the results that make sense

Reviewers: yhchiang, dhruba, haobo, igor, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D18741
2014-07-22 15:24:21 -07:00
Stanislau Hlebik
9d70cce047 Adding option to save PlainTable index and bloom filter in SST file.
Summary:
Adding option to save PlainTable index and bloom filter in SST file.
If there is no bloom block and/or index block, PlainTableReader builds
new ones. Otherwise PlainTableReader just use these blocks.

Test Plan: make all check

Reviewers: sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D19527
2014-07-18 16:58:13 -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