Improve the robustnesss of PartialCompactionFailure test.

Summary:
Improve the robustness of PartialCompactionFailure test.

Test Plan:
./db_test
Improve the robustness of PartialCompactionFailure test again.

Summary:
Improve the robustness of PartialCompactionFailure test again.

Test Plan:
./db_test
TableMock + framework for mock classes

Summary:
This diff replaces BlockBasedTable in flush_job_test with TableMock, making it depend on less things and making it closer to an unit test than integration test.

It also introduces a framework to compile mock classes -- Any file named *mock.cc will not be compiled into the build. It will only get compiled into the tests. What way we can mock out most other classes, Version, VersionSet, DBImpl, etc.

Test Plan: flush_job_test

Reviewers: ljin, rven, yhchiang, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D27681
Include all the mocks
Include atomic in mock_table.h
Remove an unnecessary include file in version_edit.cc

Summary:
Remove an unnecessary include file in version_edit.cc
Move the check to the beginning of the loop in VersionEdit::EncodeTo()
DBTest: options clean up - part 1

Summary:
DBTest has several functions (Reopen(), TryReopen(), ChangeOptins(), etc
that takes a pointer to options), depending on if it is nullptr, it uses
different options underneath. This makes it really hard to track what
options is used in different test case. We should just kill the default
value and make it being passed into explicitly. It is going to be very
hairy. I will start with simple ones.

Test Plan:
make db_test
stacked diffs, will run test with full stack

Reviewers: sdong, yhchiang, rven, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D27687
DBTest: options clean up - part 2

Summary: as title

Test Plan: same as part 1

Reviewers: sdong, yhchiang, rven, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D27693
DBTest: options clean up - part 3

Summary: as title

Test Plan: same as part 1

Reviewers: sdong, yhchiang, rven, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D27705
DBTest: options clean up - part 4

Summary: as title

Test Plan: as part 1

Reviewers: sdong, yhchiang, rven, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D27789
add an env var ROCKSDB_TESTS_FROM to control where to start from a list of tests

Summary:
Sometimes, I got a test failure. After fixing that, I want to resume
db_test from that test. ROCKSDB_TESTS_FROM is for this purpose.

Test Plan: as title

Reviewers: yhchiang, rven, igor, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D27807
use fallocate(FALLOC_FL_PUNCH_HOLE) to release unused blocks at the end of file

Summary:
ftruncate does not always free preallocated unused space at the end of file.
In some cases, we pin too much disk space than it should

Test Plan: env_test

Reviewers: sdong, rven, yhchiang, igor

Reviewed By: igor

Subscribers: nkg-, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D25641
minor - remove default value for ChangeFilterOptions() and ChangeCompactionOptions()

Summary:
So now all open() in db_test should get options from callsite. And
destroy() always uses the last used options saved on open()
I will start to integrate env_mem in the next diff

Test Plan: make all check -j32

Reviewers: sdong, yhchiang, rven, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D27819
tmp

Summary:

Test Plan:

Reviewers:

CC:

Task ID: #

Blame Rev:
remove dead code

Summary:
as title

Test Plan:
make db_test
Apply InfoLogLevel to the logs in db/db_filesnapshot.cc

Summary: Apply InfoLogLevel to the logs in db/db_filesnapshot.cc

Test Plan: make

Reviewers: ljin, sdong, rven, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D27813
Apply InfoLogLevel to the logs in db/compaction_picker.cc

Summary: Apply InfoLogLevel to the logs in db/compaction_picker.cc

Test Plan: make

Reviewers: ljin, sdong, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D27837
Apply InfoLogLevel to the logs in db/column_family.cc

Summary: Apply InfoLogLevel to the logs in db/column_family.cc

Test Plan: make

Reviewers: ljin, sdong, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D27843
Apply InfoLogLevel to the logs in db/flush_job.cc

Summary: Apply InfoLogLevel to the logs in db/flush_job.cc

Test Plan: make

Reviewers: ljin, sdong, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D27849