Commit Graph

7893 Commits

Author SHA1 Message Date
Andrew Kryczka
616a1464ea Fix DeleteRange including sentinels in output files
Summary:
when writing RangeDelAggregator::AddToBuilder, I forgot that there are sentinel tombstones in the middle of the interval map since gaps between real tombstones are represented with sentinels.

blame: #1614
Closes https://github.com/facebook/rocksdb/pull/1804

Differential Revision: D4460426

Pulled By: ajkr

fbshipit-source-id: 69444b5
2017-01-25 11:09:12 -08:00
Zongzhi Chen
c918c4b76a Update USERS.md add user Pika
Summary:
add rocksdb users pika
Closes https://github.com/facebook/rocksdb/pull/1805

Differential Revision: D4462809

Pulled By: siying

fbshipit-source-id: 7289886
2017-01-25 10:39:17 -08:00
Islam AbdelRahman
03ca2ac8a9 Remove function from DBImpl that are not used anywhere
Summary:
GetAndRefSuperVersionUnlocked
ReturnAndCleanupSuperVersionUnlocked
GetColumnFamilyHandleUnlocked

Are dead code that are not used any where
Closes https://github.com/facebook/rocksdb/pull/1802

Differential Revision: D4459948

Pulled By: IslamAbdelRahman

fbshipit-source-id: 30fa89d
2017-01-24 19:24:13 -08:00
Andrew Kryczka
b0029bc7fa Test merge op covered by range deletion in memtable
Summary:
It's a test case for #1797. Also got rid of kTypeDeletion in the conditional since we treat it the same as kTypeRangeDeletion.
Closes https://github.com/facebook/rocksdb/pull/1800

Differential Revision: D4451300

Pulled By: ajkr

fbshipit-source-id: b39dda1
2017-01-24 13:39:11 -08:00
Andrew Kryczka
d438e1ec17 Test range deletion block outlives table reader
Summary:
This test ensures RangeDelAggregator can still access blocks even if it outlives the table readers that created them (detailed description in comments).

I plan to optimize away the extra cache lookup we currently do in BlockBasedTable::NewRangeTombstoneIterator(), as it is ~5% CPU in my random read benchmark in a database with 1k tombstones. This test will help make sure nothing breaks in the process.
Closes https://github.com/facebook/rocksdb/pull/1739

Differential Revision: D4375954

Pulled By: ajkr

fbshipit-source-id: aef9357
2017-01-24 13:24:14 -08:00
Arun Sharma
fba726e555 Version librocksdb.so
Summary:
After make install, I see a directory hierarchy that looks like

```
./usr
./usr/include
./usr/include/rocksdb
./usr/include/rocksdb/filter_policy.h
[..]
./usr/include/rocksdb/iterator.h
./usr/include/rocksdb/utilities
./usr/include/rocksdb/utilities/ldb_cmd_execute_result.h
./usr/include/rocksdb/utilities/lua
./usr/include/rocksdb/utilities/lua/rocks_lua_custom_library.h
./usr/include/rocksdb/utilities/lua/rocks_lua_util.h
./usr/include/rocksdb/utilities/lua/rocks_lua_compaction_filter.h
./usr/include/rocksdb/utilities/backupable_db.h
[..]
./usr/include/rocksdb/utilities/env_registry.h
[..]
./usr/include/rocksdb/env.h
./usr/lib64
./usr/lib64/librocksdb.so.5
./usr/lib64/librocksdb.so.5.0.0
./usr/lib64/librocksdb.so
./usr/lib64/librocksdb.a
```
Closes https://github.com/facebook/rocksdb/pull/1798

Differential Revision: D4456536

Pulled By: yiwu-arbug

fbshipit-source-id: 5494e91
2017-01-24 11:09:10 -08:00
Andrew Kryczka
9da4d542fe Range deletions unsupported in tailing iterator
Summary:
change the iterator status to NotSupported as soon as a range tombstone
is encountered by a ForwardIterator.
Closes https://github.com/facebook/rocksdb/pull/1593

Differential Revision: D4246294

Pulled By: ajkr

fbshipit-source-id: aef9f49
2017-01-23 13:39:12 -08:00
Hyeonseok Oh
f2b4939da4 fixed typo
Summary:
I fixed exisit -> exist
Closes https://github.com/facebook/rocksdb/pull/1799

Differential Revision: D4451466

Pulled By: yiwu-arbug

fbshipit-source-id: b447c3a
2017-01-23 12:54:13 -08:00
yinqiwen
973f1b78fd memtable: delete merge value for range deleteion
Summary: Closes https://github.com/facebook/rocksdb/pull/1797

Differential Revision: D4448004

Pulled By: ajkr

fbshipit-source-id: 3ffc27c
2017-01-23 12:24:14 -08:00
jsteemann
aebfd1703b fix non-portable behavior in encoder
Summary:
using ~0UL for mask uses a uint32_t at least in MSVC, but a uint64_t is required for it to work properly
Closes https://github.com/facebook/rocksdb/pull/1777

Differential Revision: D4444004

Pulled By: yiwu-arbug

fbshipit-source-id: 057cc42
2017-01-20 16:39:22 -08:00
Vitaliy Liptchinsky
753ff84a3d Fix get approx size
Summary:
Fixing GetApproximateSize bug for the case of computing stats for mem tables only.
Closes https://github.com/facebook/rocksdb/pull/1795

Differential Revision: D4445507

Pulled By: IslamAbdelRahman

fbshipit-source-id: 3905846
2017-01-20 15:54:12 -08:00
Arun Sharma
d7ea44f2f9 Fixup a couple of builds errors on Linux.
Summary:
The libraries produced on linux are now named
librocksdb.a
librocksdb.so

Other fixes:

* Also link with -lrt to avoid linker errors.
* Generalize comments at the top to include Linux
* Move -lgtest before -lpthread to avoid linker errors
* move add_subdirectory(tools) to the end so it picks up
  the right libraries
Closes https://github.com/facebook/rocksdb/pull/1364

Differential Revision: D4444138

Pulled By: yiwu-arbug

fbshipit-source-id: f0e2c19
2017-01-20 13:24:13 -08:00
Jay Lee
537da370da c: allow set savepoint to writebatch
Summary:
Allow set SavePoint to WriteBatch in C ABI.
Closes https://github.com/facebook/rocksdb/pull/1698

Differential Revision: D4378556

Pulled By: yiwu-arbug

fbshipit-source-id: afca746
2017-01-20 13:24:13 -08:00
Min Wei
af6ec4d78e fix batchresult handle leak
Summary:
This is related to PR https://github.com/facebook/rocksdb/pull/1642

Sorry about this extra PR, as my workflow was messed up when I checked in another work item by accident.
Closes https://github.com/facebook/rocksdb/pull/1681

Differential Revision: D4379513

Pulled By: yiwu-arbug

fbshipit-source-id: a668d4c
2017-01-20 13:24:12 -08:00
Adam Retter
e29bb934f7 Zlib 1.2.8 is no longer available, switched to 1.2.10
Summary: Closes https://github.com/facebook/rocksdb/pull/1741

Differential Revision: D4380116

Pulled By: yiwu-arbug

fbshipit-source-id: 7cf09df
2017-01-20 13:24:12 -08:00
Changli Gao
5ac97314e7 Fix std::out_of_range when DBOptions::keep_log_file_num is zero
Summary:
We should validate this option, otherwise we may see
std::out_of_range thrown at: db/db_impl.cc:1124

1123     for (unsigned int i = 0; i <= end; i++) {
1124       std::string& to_delete = old_info_log_files.at(i);
1125       std::string full_path_to_delete =
1126           (immutable_db_options_.db_log_dir.empty()
Closes https://github.com/facebook/rocksdb/pull/1722

Differential Revision: D4379495

Pulled By: yiwu-arbug

fbshipit-source-id: e136552
2017-01-20 13:24:12 -08:00
Kefu Chai
4e35ffdfab cmake: check -momit-leaf-frame-pointer before using it
Summary:
because not all archs support this option. see
https://gcc.gnu.org/onlinedocs/gcc/Option-Summary.html.

also do not pass "-fno-omit-frame-pointer" and
"-momit-leaf-frame-pointer" to compiler if ${CMAKE_BUILD_TYPE} is
"Debug". this matches the behaviour of DEBUG_LEVEL=2 in Makefile.

Signed-off-by: Kefu Chai <tchaikov@gmail.com>
Closes https://github.com/facebook/rocksdb/pull/1762

Differential Revision: D4444036

Pulled By: yiwu-arbug

fbshipit-source-id: 8596fbe
2017-01-20 13:09:11 -08:00
Shu Zhang
3c0852d1da Make ingest external file backward compatible
Summary: Closes https://github.com/facebook/rocksdb/pull/1783

Differential Revision: D4443463

Pulled By: IslamAbdelRahman

fbshipit-source-id: 39d21d6
2017-01-20 12:09:19 -08:00
Siying Dong
0e8dfd6062 Fix OptimizeForPointLookup()
Summary:
If users directly call OptimizeForPointLookup(), it is broken as the option isn't compatible with parallel memtable insert. Fix it by using memtable bloomo filter instead.
Closes https://github.com/facebook/rocksdb/pull/1791

Differential Revision: D4442836

Pulled By: siying

fbshipit-source-id: bf6c9cd
2017-01-20 10:54:12 -08:00
Vitaliy Liptchinsky
e840213d6e Change DB::GetApproximateSizes for more flexibility needed for MyRocks
Summary:
Added an option to GetApproximateSizes to exclude file stats, as MyRocks has those counted exactly and we need only stats from memtables.
Closes https://github.com/facebook/rocksdb/pull/1787

Differential Revision: D4441111

Pulled By: IslamAbdelRahman

fbshipit-source-id: c11f4c3
2017-01-20 09:39:11 -08:00
Yi Wu
9239103cd4 Flush job should release reference current version if sync log failed
Summary:
Fix the bug when sync log fail, FlushJob::Run() will not be execute and
reference to cfd->current() will not be release.
Closes https://github.com/facebook/rocksdb/pull/1792

Differential Revision: D4441316

Pulled By: yiwu-arbug

fbshipit-source-id: 5523e28
2017-01-19 23:09:15 -08:00
Islam AbdelRahman
da54d36a96 Disable IngestExternalFile in ReadOnly mode
Summary:
Disable IngestExternalFile() in read only mode
Closes https://github.com/facebook/rocksdb/pull/1781

Differential Revision: D4439179

Pulled By: IslamAbdelRahman

fbshipit-source-id: b7e46e7
2017-01-19 15:54:19 -08:00
Reid Horuff
5cf176ca15 Fix for 2PC causing WAL to grow too large
Summary:
Consider the following single column family scenario:
prepare in log A
commit in log B
*WAL is too large, flush all CFs to releast log A*
*CFA is on log B so we do not see CFA is depending on log A so no flush is requested*

To fix this we must also consider the log containing the prepare section when determining what log a CF is dependent on.
Closes https://github.com/facebook/rocksdb/pull/1768

Differential Revision: D4403265

Pulled By: reidHoruff

fbshipit-source-id: ce800ff
2017-01-19 15:39:12 -08:00
Islam AbdelRahman
4a73bb0b43 Split travis jobs
Summary:
Some travis jobs are running out of space, splitting to more jobs should reduce the chance of that happening
Closes https://github.com/facebook/rocksdb/pull/1789

Differential Revision: D4438039

Pulled By: IslamAbdelRahman

fbshipit-source-id: 05787ff
2017-01-19 13:39:12 -08:00
Dmitri Smirnov
c70d3c7ade Enable DBTest.GroupCommit as it runs in a reasonlable time now.
Summary:
Remove ReRuns as they only waste time.
  Add env_basic_test to get more foundation coverage.
Closes https://github.com/facebook/rocksdb/pull/1788

Differential Revision: D4431433

Pulled By: IslamAbdelRahman

fbshipit-source-id: 50d07f8
2017-01-18 14:24:11 -08:00
Yi Wu
602c13a964 Remove fadvise with direct IO read
Summary:
Remove the logic since we don't use buffer cache with direct IO. Resolve
read regression we currently have.
Closes https://github.com/facebook/rocksdb/pull/1782

Differential Revision: D4430408

Pulled By: yiwu-arbug

fbshipit-source-id: 5557bba
2017-01-18 12:09:10 -08:00
Andrew Kryczka
f9d18e22d2 Fix DeleteRange file boundary correctness issue with max_compaction_bytes
Summary:
Cockroachdb exposed this bug in #1778. The bug happens when a compaction's output files are ended due to exceeding max_compaction_bytes. In that case we weren't taking into account the next file's start key when deciding how far to extend the current file's max_key. This caused the non-overlapping key-range invariant to be violated.

Note this was correctly handled for the usual case of cutting compaction output, which is file size exceeding max_output_file_size. I am not sure why these are two separate code paths, but we can consider refactoring it to prevent such errors in the future.
Closes https://github.com/facebook/rocksdb/pull/1784

Differential Revision: D4430235

Pulled By: ajkr

fbshipit-source-id: 80af748
2017-01-18 11:54:22 -08:00
Islam AbdelRahman
3ce091fd73 Add KEEP_DB env var option
Summary:
When debugging tests, it's useful to preserve the DB to investigate it and check the logs
This will allow us to set KEEP_DB=1 to preserve the DB
Closes https://github.com/facebook/rocksdb/pull/1759

Differential Revision: D4393826

Pulled By: IslamAbdelRahman

fbshipit-source-id: 1bff689
2017-01-17 13:54:20 -08:00
Siying Dong
77b4806625 Fix 2PC with concurrent memtable insert
Summary:
If concurrent memtable insert is enabled, and one prepare command and a normal command are grouped into a commit group, the sequence ID will be calculated incorrectly.
Closes https://github.com/facebook/rocksdb/pull/1730

Differential Revision: D4371081

Pulled By: siying

fbshipit-source-id: cd40c6d
2017-01-17 11:24:28 -08:00
Kefu Chai
e8a096000b util/thread_local.h: silence a clang-build warning
Summary:
otherwise clang complains with

/home/jenkins/workspace/ceph-master/src/rocksdb/util/thread_local.h:205:5:
error: macro expansion producing 'defined' has undefined behavior
[-Werror,-Wexpansion-to-defined]
^
/home/jenkins/workspace/ceph-master/src/rocksdb/util/thread_local.h:22:4:
note: expanded from macro 'ROCKSDB_SUPPORT_THREAD_LOCAL'
!defined(OS_WIN) && !defined(OS_MACOSX) && !defined(IOS_CROSS_COMPILE)
^`

Signed-off-by: Kefu Chai <tchaikov@gmail.com>
Closes https://github.com/facebook/rocksdb/pull/1757

Differential Revision: D4394140

Pulled By: siying

fbshipit-source-id: f0beda0
2017-01-15 13:24:16 -08:00
Dmitri Smirnov
324a0f988e Follow up for DirectIO refactor
Summary: Windows follow up for  dc2584eea0

Differential Revision: D4420337

Pulled By: IslamAbdelRahman

fbshipit-source-id: fedc5b5
2017-01-15 13:24:16 -08:00
Daniel Black
bc5d7b7029 travis: For linux, do all tests under gcc
Summary:
apologies yiwu-arbug, I thought I'd included this part of the commit.

Seems as though "JOB_NAME=unittests ROCKSDBTESTS_END=db_block_cache_test" has space issues and it did occasional previously too. May need to look up splitting tests more.
Closes https://github.com/facebook/rocksdb/pull/1766

Differential Revision: D4417493

Pulled By: siying

fbshipit-source-id: 3007ba5
2017-01-13 15:39:13 -08:00
Aaron Gao
3e6899d116 change UseDirectIO() to use_direct_io()
Summary:
also change variable name `direct_io_` to `use_direct_io_` in WritableFile to make it consistent with read path.
Closes https://github.com/facebook/rocksdb/pull/1770

Differential Revision: D4416435

Pulled By: lightmark

fbshipit-source-id: 4143c53
2017-01-13 12:09:15 -08:00
Aaron Gao
d4e07a8459 fix warning of unused direct io helper functions
Summary:
add build guard
Closes https://github.com/facebook/rocksdb/pull/1771

Differential Revision: D4410779

Pulled By: siying

fbshipit-source-id: 3796c30
2017-01-12 12:39:14 -08:00
Aaron Gao
dc2584eea0 direct reads refactor
Summary:
direct IO reads refactoring
remove unnecessary classes and unified interfaces
tested with db_bench

need more change for options and ON/OFF for different files.
Since disabled is default, it should be fine now
Closes https://github.com/facebook/rocksdb/pull/1636

Differential Revision: D4307189

Pulled By: lightmark

fbshipit-source-id: 6991e22
2017-01-11 16:54:12 -08:00
Mike Kolupaev
d18dd2c41f Abort compactions more reliably when closing DB
Summary:
DB shutdown aborts running compactions by setting an atomic shutting_down=true that CompactionJob periodically checks. Without this PR it checks it before processing every _output_ value. If compaction filter filters everything out, the compaction is uninterruptible. This PR adds checks for shutting_down on every _input_ value (in CompactionIterator and MergeHelper).

There's also some minor code cleanup along the way.
Closes https://github.com/facebook/rocksdb/pull/1639

Differential Revision: D4306571

Pulled By: yiwu-arbug

fbshipit-source-id: f050890
2017-01-11 15:09:21 -08:00
Anirban Rahut
62384ebe9c Guarding extra fallocate call with TRAVIS because its not working pro…
Summary:
…perly on travis

 There is some old code in PosixWritableFile::Close(), which
truncates the file to the measured size and then does an extra fallocate
with KEEP_SIZE. This is commented as a failsafe because in some
cases ftruncate doesn't do the right job (I don't know of an instance of
this btw). However doing an fallocate with KEEP_SIZE should not increase
the file size. However on Travis Worker which is Docker (likely AUFS )
its not working. There are comments on web that show that the AUFS
author had initially not implemented fallocate, and then did it later.
So not sure what is the quality of the implementation.
Closes https://github.com/facebook/rocksdb/pull/1765

Differential Revision: D4401340

Pulled By: anirbanr-fb

fbshipit-source-id: e2d8100
2017-01-11 14:24:13 -08:00
Changli Gao
9f246298e2 Performance: Iterate vector by reference
Summary: Closes https://github.com/facebook/rocksdb/pull/1763

Differential Revision: D4398796

Pulled By: yiwu-arbug

fbshipit-source-id: b82636d
2017-01-11 10:54:37 -08:00
Andrew Kryczka
fe395fb63d Allow incrementing refcount on cache handles
Summary:
Previously the only way to increment a handle's refcount was to invoke Lookup(), which (1) did hash table lookup to get cache handle, (2) incremented that handle's refcount. For a future DeleteRange optimization, I added a function, Ref(), for when the caller already has a cache handle and only needs to do (2).
Closes https://github.com/facebook/rocksdb/pull/1761

Differential Revision: D4397114

Pulled By: ajkr

fbshipit-source-id: 9addbe5
2017-01-10 16:54:20 -08:00
Sunpoet Po-Chuan Hsieh
2172b660eb Fix build on FreeBSD
Summary:
```
  CC       utilities/column_aware_encoding_exp.o
utilities/column_aware_encoding_exp.cc:149:5: error: use of undeclared identifier 'exit'
    exit(1);
    ^
utilities/column_aware_encoding_exp.cc:154:5: error: use of undeclared identifier 'exit'
    exit(1);
    ^
utilities/column_aware_encoding_exp.cc:158:5: error: use of undeclared identifier 'exit'
    exit(1);
    ^
3 errors generated.
```
Closes https://github.com/facebook/rocksdb/pull/1754

Differential Revision: D4399044

Pulled By: IslamAbdelRahman

fbshipit-source-id: fbab5a2
2017-01-10 11:39:12 -08:00
Dmitri Smirnov
3c233ca4ea Fix Windows environment issues
Summary:
Enable directIO on WritableFileImpl::Append
     with offset being current length of the file.
     Enable UniqueID tests on Windows, disable others but
     leeting them to compile. Unique tests are valuable to
     detect failures on different filesystems and upcoming
     ReFS.
     Clear output in WinEnv Getchildren.This is different from
     previous strategy, do not touch output on failure.
     Make sure DBTest.OpenWhenOpen works with windows error message
Closes https://github.com/facebook/rocksdb/pull/1746

Differential Revision: D4385681

Pulled By: IslamAbdelRahman

fbshipit-source-id: c07b702
2017-01-09 15:54:12 -08:00
Maysam Yabandeh
7631734563 Fix the error in ColumnFamiliesTest
Summary:
In the test the last change to AAAZZZ in handles[1] is deleting it. The
result of the get must be NotFound then. Previosuly the test did not
check for the return value of Get and assumed that the status is ok. It
then move ahead asserting the returned value. The passed-by-reference
string value however was not changed (since the key was not found) and
the asserted value is what it contained before doing the Get.
Closes https://github.com/facebook/rocksdb/pull/1753

Differential Revision: D4390982

Pulled By: maysamyabandeh

fbshipit-source-id: dd55a34
2017-01-09 14:09:13 -08:00
Daniel Black
7a02ad070f Update travis to ubuntu trusty
Summary:
Distro gflags is now acceptable in build.

Add gcc for two linux builds, JOB_NAME=unittests and lite_build.
unittests will be built with g++-6.

Use apt and ccache during build.

Seems more up to date than precise :-)

llvm repos for trusty aren't whitelisted yet (ref: https://github.com/travis-ci/apt-source-whitelist/pull/309, https://github.com/travis-ci/apt-source-whitelist/issues/332, https://github.com/travis-ci/apt-source-whitelist/issues/332)
Closes https://github.com/facebook/rocksdb/pull/1685

Differential Revision: D4340378

Pulled By: yiwu-arbug

fbshipit-source-id: a143b9d
2017-01-09 13:54:19 -08:00
Siying Dong
60c509ff18 Fix valgrind failure in test CurrentFileModifiedWhileCheckpointing2PC
Summary:
Fix some memory leaks in the test. Also rename the test class name from DBTest to CheckpointTest to avoid confusion.
Closes https://github.com/facebook/rocksdb/pull/1752

Differential Revision: D4390355

Pulled By: siying

fbshipit-source-id: 0fa388a
2017-01-09 11:54:13 -08:00
Maysam Yabandeh
d0ba8ec8f9 Revert "PinnableSlice"
Summary:
This reverts commit 54d94e9c2c.

The pull request was landed by mistake.
Closes https://github.com/facebook/rocksdb/pull/1755

Differential Revision: D4391678

Pulled By: maysamyabandeh

fbshipit-source-id: 36d5149
2017-01-08 14:24:12 -08:00
Maysam Yabandeh
54d94e9c2c PinnableSlice
Summary:
Currently the point lookup values are copied to a string provided by the user.
This incures an extra memcpy cost. This patch allows doing point lookup
via a PinnableSlice which pins the source memory location (instead of
copying their content) and releases them after the content is consumed
by the user. The old API of Get(string) is translated to the new API
underneath.

 Here is the summary for improvements:
 1. value 100 byte: 1.8%  regular, 1.2% merge values
 2. value 1k   byte: 11.5% regular, 7.5% merge values
 3. value 10k byte: 26% regular,    29.9% merge values

 The improvement for merge could be more if we extend this approach to
 pin the merge output and delay the full merge operation until the user
 actually needs it. We have put that for future work.

PS:
Sometimes we observe a small decrease in performance when switching from
t5452014 to this patch but with the old Get(string) API. The difference
is a little and could be noise. More importantly it is safely
cancelled
Closes https://github.com/facebook/rocksdb/pull/1732

Differential Revision: D4374613

Pulled By: maysamyabandeh

fbshipit-source-id: a077f1a
2017-01-08 13:54:13 -08:00
Dmitri Smirnov
e04480faed Fix MS warnings. Use ROCKSDB_Prsz for size_t.
Summary: Closes https://github.com/facebook/rocksdb/pull/1737

Differential Revision: D4378852

Pulled By: yiwu-arbug

fbshipit-source-id: ba8b02d
2017-01-06 16:24:14 -08:00
Yi Wu
c081f7215b 5.0.1 release blog post
Summary:
5.0.1 release blog post
Closes https://github.com/facebook/rocksdb/pull/1751

Differential Revision: D4388962

Pulled By: yiwu-arbug

fbshipit-source-id: 59559e1
2017-01-06 15:24:15 -08:00
Islam AbdelRahman
ac73d7558b Add GetSupportedCompressions() convenience function
Summary:
This function will return a list of supported compression types in RocksDB
This is needed for MyRocks https://github.com/facebook/mysql-5.6/pull/446
Closes https://github.com/facebook/rocksdb/pull/1747

Differential Revision: D4385921

Pulled By: IslamAbdelRahman

fbshipit-source-id: 2f5b59f
2017-01-06 11:24:14 -08:00
Andrew Kryczka
b104b87814 Maintain position in range deletions map
Summary:
When deletion-collapsing mode is enabled (i.e., for DBIter/CompactionIterator), we maintain position in the tombstone maps across calls to ShouldDelete(). Since iterators often access keys sequentially (or reverse-sequentially), scanning forward/backward from the last position can be faster than binary-searching the map for every key.

- When Next() is invoked on an iterator, we use kForwardTraversal to scan forwards, if needed, until arriving at the range deletion containing the next key.
- Similarly for Prev(), we use kBackwardTraversal to scan backwards in the range deletion map.
- When the iterator seeks, we use kBinarySearch for repositioning
- After tombstones are added or before the first ShouldDelete() invocation, the current position is set to invalid, which forces kBinarySearch to be used.
- Non-iterator users (i.e., Get()) use kFullScan, which has the same behavior as before---scan the whole map for every key passed to ShouldDelete().
Closes https://github.com/facebook/rocksdb/pull/1701

Differential Revision: D4350318

Pulled By: ajkr

fbshipit-source-id: 5129b76
2017-01-05 10:39:12 -08:00