Summary: This will allow us to disable them completely for iOS or for better performance

Test Plan: will run make all check

Reviewers: igor, haobo, dhruba

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17511

Summary:
Fixed the following column family related compile error.

./java/rocksjni/write_batch.cc:211:66: error: cannot initialize a parameter of type 'rocksdb::ColumnFamilyMemTables *' with an lvalue of type 'rocksdb::MemTable *'
  rocksdb::Status s = rocksdb::WriteBatchInternal::InsertInto(b, mem, &options);
                                                                   ^~~

Test Plan:
make jni
make jtest

Reviewers: igor, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17577

Summary:
Move PlainTableIterator's copied key from std::string local buffer to avoid paying the extra costs in std::string related to sharing. Reuse the same buffer class in DbIter. Move the class to dbformat.h.

This patch improves iterator performance significantly. Running this benchmark:

./table_reader_bench --num_keys2=17 --iterator --plain_table --time_unit=nanosecond

The average latency is improved to about 750 nanoseconds from 1100 nanoseconds.

Test Plan:
Add a unit test.
make all check

Reviewers: haobo, ljin

Reviewed By: haobo

CC: igor, yhchiang, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D17547

Summary: I think this issue was caused by bad merge. We have to initialize bloom_locality, otherwise valgrind complains: "Use of uninitialised value of size 8"

Test Plan: Run valgrind ./prefix_test

Reviewers: ljin

Reviewed By: ljin

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17553

This will enable user to use only 1 background thread.

Conflicts:
	db/db_impl.cc
	db/db_impl.h
	db/memtable_list.cc
	db/version_set.cc

Summary: If a client specifies wal_dir with trailing '/', we will fail in deleting obsolete log files. See task #4083746

Test Plan: make check

Reviewers: haobo, sdong

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17535

Summary: Update HISTORY.md to make existing items to 2.8 release and add something I think is missing.

Test Plan: N/A

Reviewers: haobo, igor, ljin, dhruba, yhchiang, xjin

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17517

Summary: Our measurement shows that sometimes new log::Write's constructor can take hundreds of milliseconds. It's unclear why but just simply move it out of DB mutex.

Test Plan: make all check

Reviewers: haobo, ljin, igor

Reviewed By: haobo

CC: nkg-, yhchiang, leveldb

Differential Revision: https://reviews.facebook.net/D17487

Summary: per sdong's request, this will help processor prefetch on n->key case.

Test Plan: make all check

Reviewers: sdong, haobo, igor

Reviewed By: sdong

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17415

Summary: Otherwise, if we compile on machine with SSE4.2 support and run it on machine without the support, we will fail.

Test Plan: compiles, verified that isSse42() gets called.

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17505

Summary:
I had to make number of changes to the code and Makefile:
* Add `make lib`, that will create static library without debug info. We need this to avoid growing binary too much. Currently it's 14MB.
* Remove cpuinfo() function and use __SSE4_2__ macro. We actually used the macro as part of Fast_CRC32() function.
As a result, I also accidentally fixed this issue: https://www.facebook.com/groups/rocksdb.dev/permalink/549700778461774/?stream_ref=2
* Remove __thread locals in OS_MACOSX

Test Plan: `make lib PLATFORM=IOS`

Reviewers: ljin, haobo, dhruba, sdong

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17475

Summary: Flushing log buffer earlier to avoid confusion of time holding the locks.

Test Plan: Should be safe as long as several related db test passes

Reviewers: haobo, igor, ljin

Reviewed By: igor

CC: nkg-, leveldb

Differential Revision: https://reviews.facebook.net/D17493

Summary: Fix some signed and unsigned comparisons to make some other build script happy.

Test Plan: Build and run those changed tests

Reviewers: ljin, igor, haobo

Reviewed By: igor

CC: yhchiang, dhruba, kailiu, leveldb

Differential Revision: https://reviews.facebook.net/D17463

Summary: as title, make it easy to turn on/off profiling at per thread level.

Test Plan: make check

Reviewers: sdong, ljin

Reviewed By: ljin

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17469

Summary: Include java related output files in .gitignore

Test Plan:
make jni
git status

Reviewers: ljin, igor, sdong

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17457

Summary: Move several some common logging still in DB mutex to log buffer.

Test Plan: make all check

Reviewers: haobo, igor, ljin, nkg-

Reviewed By: nkg-

CC: nkg-, yhchiang, leveldb

Differential Revision: https://reviews.facebook.net/D17439

Summary:
Add script auto_sanity_test.sh to perform auto sanity test

usage: auto_sanity_test.sh [new_commit] [old_commit]

Running without commit parameter will do the sanity test with the latest
and the latest 10 commit.

Test Plan: ./auto_sanity_test.sh

Reviewers: haobo, igor

Reviewed By: igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17397

C-API enhancements

[C-API] added "rocksdb_options_set_plain_table_factory" to make it possible to use plain table factory

Summary: Avoid a JNI call to GetByteArrayElements, which may introduce a byte-array-copy.

Test Plan: make jtest

Reviewers: haobo, sdong, dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17451

Summary:
Improve the internal interface between java and c++ for basic db operations
by including the RocksDB native handle (i.e., c++ pointer of rocksdb::DB)
as a input parameter of the internal interface.

This improvement reduces one JNI call per db operation from c++.

Test Plan: make test

Reviewers: haobo, sdong, dhruba

Reviewed By: sdong

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17445

Summary: This patch fixed a race condition where a log file is moved to archived dir in the middle of GetSortedWalFiles. Without the fix, the log file would be missed in the result, which leads to transaction log iterator gap. A test utility SyncPoint is added to help reproducing the race condition.

Test Plan: TransactionLogIteratorRace; make check

Reviewers: dhruba, ljin

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17121

Summary: As we know, logging can be slow, or even hang for some file systems. Move one more logging out of DB mutex.

Test Plan: make all check

Reviewers: haobo, igor, ljin

Reviewed By: igor

CC: yhchiang, nkg-, leveldb

Differential Revision: https://reviews.facebook.net/D17427

crc32: build a whole special Extend function for SSE 4.2.