Summary:
List of changes:

1) Fix the snprintf() usage in cases where wrong variable was used to determine the output buffer size.

2) Remove unnecessary checks before calling delete operator.

3) Increase code correctness by using size_t type when getting vector's size.

4) Unify the coding style by removing namespace::std usage at the top of the file to confirm to the majority usage.

5) Fix various lint errors pointed out by 'arc lint'.

Test Plan:
Code review and build:

git diff
make clean
make -j 32 commit-prereq
arc lint

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

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D51849

Use port size_t formatting

Fix typo

Summary: Reuse db_test_util in listener_test

Test Plan:
make listener_test -j64 && ./listener_test
USE_CLANG=1 make listener_test -j64 && ./listener_test

Reviewers: yhchiang, rven, kradhakrishnan, anthony

Reviewed By: anthony

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D51939

Running manual compactions in parallel with other automatic or manual compactions in restricted cases

Summary:
This diff provides a framework for doing manual
compactions in parallel with other compactions. We now have a deque of manual compactions. We also pass manual compactions as an argument from RunManualCompactions down to
BackgroundCompactions, so that RunManualCompactions can be reentrant.
Parallelism is controlled by the two routines
ConflictingManualCompaction to allow/disallow new parallel/manual
compactions based on already existing ManualCompactions. In this diff, by default manual compactions still have to run exclusive of other compactions. However, by setting the compaction option, exclusive_manual_compaction to false, it is possible to run other compactions in parallel with a manual compaction. However, we are still restricted to one manual compaction per column family at a time. All of these restrictions will be relaxed in future diffs.
I will be adding more tests later.

Test Plan: Rocksdb regression + new tests + valgrind

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

Reviewed By: sdong

Subscribers: yoshinorim, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D47973

Fix appVeyor Build problem

Summary: Add support to change write options after creating a transaction.  This is needed for MongoRocks.

Test Plan: added test

Reviewers: sdong, rven, kradhakrishnan, IslamAbdelRahman, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D51867

Summary:
Currently, transactions can fail even if there is no actual write conflict.  This is due to relying on only the memtables to check for write-conflicts.  Users have to tune memtable settings to try to avoid this, but it's hard to figure out exactly how to tune these settings.

With this diff, TransactionDB will use both memtables and SST files to determine if there are any write conflicts.  This relies on the fact that BlockBasedTable stores sequence numbers for all writes that happen after any open snapshot.  Also, D50295 is needed to prevent SingleDelete from disappearing writes (the TODOs in this test code will be fixed once the other diff is approved and merged).

Note that Optimistic transactions will still rely on tuning memtable settings as we do not want to read from SST while on the write thread.  Also, memtable settings can still be used to reduce how often TransactionDB needs to read SST files.

Test Plan: unit tests, db bench

Reviewers: rven, yhchiang, kradhakrishnan, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb, yoshinorim

Differential Revision: https://reviews.facebook.net/D50475

Summary: Improving the parser string to make better error report. Currently the
error report fails to capture the assert details. This fix addresses the issue.

Test Plan: None

Reviewers:

CC: leveldb@

Task ID: #6968635

Blame Rev:

Summary:
By default, RocksDB initializes the singletons of ThreadLocalPtr first, then initializes PosixEnv
via static initializer.  Destructor terminates objects in reverse order, so terminating PosixEnv
(calling pthread_mutex_lock), then ThreadLocal (calling pthread_mutex_destroy).

However, in certain case, application might initialize PosixEnv first, then ThreadLocalPtr.
This will cause core dump at the end of the program (eg. https://github.com/facebook/mysql-5.6/issues/122)

This patch fix this issue by ensuring the destruction order by moving the global static singletons
to function static singletons.  Since function static singletons are initialized when the function is first
called, this property allows us invoke to enforce the construction of the static PosixEnv and the
singletons of ThreadLocalPtr by calling the function where the ThreadLocalPtr singletons belongs
right before we initialize the static PosixEnv.

Test Plan: Verified in the MyRocks.

Reviewers: yoshinorim, IslamAbdelRahman, rven, kradhakrishnan, anthony, sdong, MarkCallaghan

Reviewed By: anthony

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D51789

implement EnvMirror

This is an Env implementation that mirrors all storage-related methods on
two different backend Env's and verifies that they return the same
results (return status and read results).  This is useful for implementing
a new Env and verifying its correctness.
Signed-off-by: NSage Weil <sage@redhat.com>

Summary: Correct a comment in include/rocksdb/cache.h

Test Plan: No code change.

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

Reviewed By: anthony

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D51831

Summary: Fixed the valgrind error in ColumnFamilyTest::CreateAndDropRace

Test Plan: valgrind --error-exitcode=2 --leak-check=full ./column_family_test

Reviewers: kradhakrishnan, rven, anthony, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D51795

Summary: For Transactions, we want to start using the SST files to do write conflict checking.  To do this, we need to make sure that compaction never removes all writes if an earlier snapshot exists.  So I had to change the way we process SingleDeletes to sometimes leave a SingleDelete behind when we encounter a Put followed by a SingleDelete.  See the comments in this diff for a more detailed explanation.

Test Plan: added more unit tests

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

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D50295

fix typos in comments

Summary: Deprecate options.soft_rate_limit, which is hard to tune, with options.soft_pending_compaction_bytes_limit, which would trigger the slowdown if estimated pending compaction bytes exceeds the threshold. The hope is to make it more striaght-forward to tune.

Test Plan: Modify DBTest.SoftLimit to cover options.soft_pending_compaction_bytes_limit instead; run all unit tests.

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

Reviewed By: anthony

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D51117

Summary: Introduce a compaction picking priority that picks files who contains the oldest rows to compact. This is a mode that slightly improves write amplification for random update cases.

Test Plan: Add a unit test and run it in valgrind too.

Reviewers: yhchiang, anthony, IslamAbdelRahman, rven, kradhakrishnan, MarkCallaghan, igor

Reviewed By: igor

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D51459

Prefer integer arithmetics

Fix EstimateNumKeys Counter Inaccurate Issue

  The code had conversion to double then casting to size_t
  and then casting uint32_t which caused compiler warning (VS15).

Add compaction_iterator and delete_scheduler tests to Windows build

Summary: Now in benchmark "uncompress" in db_bench, we get size from compressed stream for all other compression types except Snappy, where we allocate memory based on parameter. Change it to match to behavior of other compression types.

Test Plan: Run ./db_bench --benchmarks=uncompress with snappy and other compression types.

Reviewers: yhchiang, kradhakrishnan, anthony, IslamAbdelRahman, igor

Reviewed By: igor

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D51681

Move posix threads into a library

Enable C4267 warning

Split histogram per OperationType in db_bench

Replace malloc with new for LRU Cache Handle

Summary: Added 4.3.0 version

Test Plan:

Reviewers:

CC: leveldb@

Task ID: #9298965

Blame Rev:

Summary: fb build for gcc 4.8.1 is broken for the ZSTD dependency is not fixed after ea119235. Fixing it.

Test Plan: ROCKSDB_FBCODE_BUILD_WITH_481=1 make -j40 OPT=-g

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D51741

Summary:
This patch fix a race condition in persisting options which will cause a crash when:

* Thread A obtain cf options and start to persist options based on that cf options.
* Thread B kicks in and finish DropColumnFamily and delete cf_handle.
* Thread A wakes up and tries to finish the persisting options and crashes.

Test Plan: Add a test in column_family_test that can reproduce the crash

Reviewers: anthony, IslamAbdelRahman, rven, kradhakrishnan, sdong

Reviewed By: sdong

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D51717

Summary: Ldb and sst_dump are not included in shared library now. Add it.

Test Plan:
Build
make release
make shared_lib

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

Reviewed By: IslamAbdelRahman, anthony

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D51735

Summary:
D51183 was reverted due to breaking the LITE build.

This diff is the same as D51183 but with a fix for the LITE BUILD(D51693)

Test Plan: run all unit tests

Reviewers: sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D51711

Summary: Change to call the new compression function.

Test Plan: build and run db_bench with the compression to make sure it compresses.

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

Reviewed By: yhchiang

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D51603

Summary:
Update examples/rocksdb_option_file_example.ini to use the options file
generated by the db_bench readwhilewriting benchmark.

Test Plan: no code change.

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

Reviewed By: anthony

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D51567

Summary:
Fixing a valgrind failure in DBTestUniversalCompaction
in the IncreaseUniversalCompactionNumLevels test. Using
SpecialSkipList with 10 rows per file.

Test Plan: Run valgrind and functional tests.

Reviewers: anthony, yhchiang, kradhakrishnan, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D51705