Summary:
Add GetThreadList API, which allows developer to track the
status of each process.  Currently, calling GetThreadList will
only get the list of background threads in RocksDB with their
thread-id and thread-type (priority) set.  Will add more support
on this in the later diffs.

ThreadStatus currently has the following properties:

  // An unique ID for the thread.
  const uint64_t thread_id;

  // The type of the thread, it could be ROCKSDB_HIGH_PRIORITY,
  // ROCKSDB_LOW_PRIORITY, and USER_THREAD
  const ThreadType thread_type;

  // The name of the DB instance where the thread is currently
  // involved with.  It would be set to empty string if the thread
  // does not involve in any DB operation.
  const std::string db_name;

  // The name of the column family where the thread is currently
  // It would be set to empty string if the thread does not involve
  // in any column family.
  const std::string cf_name;

  // The event that the current thread is involved.
  // It would be set to empty string if the information about event
  // is not currently available.

Test Plan:
./thread_list_test
export ROCKSDB_TESTS=GetThreadList
./db_test

Reviewers: rven, igor, sdong, ljin

Reviewed By: ljin

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D25047

[RocksJava] Build improvements

Currently maven publishing uses the library with debug symbols. What
leads to unnecessary big library sizes. Included strip to remove
unnecessary stuff. 40M -> 2.7M

Previous to this commit too much targets got dependencies
on javadocs target.

Introduced one additional target "javalib" which resolves
that situation. JavaDoc will now be generated once while
executing a task with prefix "rocksdbjava".

- Remove JNI includes on clean
- Remove target folder generated by Maven
- Remove shared object
- Remove jar

Summary:
as title

[RocksJava] Convenience methods for Options

Missing header in build on CentOS 6.5, GCC4.7

While building RocksJava the build fails on
CentOS because of the missing stdexcept header.

Addressed review comments.

RocksDB introduced in 3.7.0 convenience methods
for getting ColumnFamilyOptions and DBOptions
instances from predefined configuration structures.

There is now also a method in RocksJava to load DBOptions
as well as ColumnFamilyOptions from a predefined Properties
based configuration.

Summary:
The very last reference happens in DBImpl::GetOptions()
I built with both DBImpl::GetOptions() and ColumnFamilyData::options() commented out

Test Plan: make all check

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D29073

Summary: We should not reference cfd->options() directly!

Test Plan: make release

Reviewers: sdong, rven, igor, yhchiang

Reviewed By: igor, yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D29061

Summary:
Add unit support in options helper so we can specify, e.g., 10m for
10 megabytes.

Test Plan: Updated options_test

Reviewers: sdong, igor, ljin

Reviewed By: ljin

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D28977

[RocksJava] GetIntProperty in RocksDB

Improved comments in RocksDB getLongProperty methods,
to describe the behavior more detailed.

Expose GetIntProperty methods to RocksJava. As the integer(64-Bit)
value is no integer in Java the method is aligned with the return
type which is long.

[RocksJava] JavaDoc corrections - Java8

This commit solves build problems in Java8 due
to wrong JavaDoc.

Summary: Fixed a bug which could hide non-ok status in CompactionJob::Run()

Test Plan: make

Reviewers: sdong, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D28995

Use correct classloader in Java NativeLibraryLoader

Summary:
Improve the comment in InfoLogLevelTest.java

Test Plan:
make rocksdbjava

[RocksJava] LogLevel support in Options

Native Library

[RocksJava] Bump version to 3.8.0 in rocksjni.pom

Summary: This way we can gurantee that old MemTables get destructed before DBImpl gets destructed, which might be useful if we want to make them depend on state from DBImpl.

Test Plan: make check with asserts in JobContext's destructor

Reviewers: ljin, sdong, yhchiang, rven, jonahcohen

Reviewed By: jonahcohen

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D28959

It's now possible to set a LogLevel in Options and
DBOptions to control LOG verbosity.

Cuckoo table options missing in the C interface

[RocksJava] Test framework support