A few more C API functions.
Merge pull request #90 from alberts/morecapi

A few more C API functions.
expose wal_dir in db_bench

Summary: as title

Test Plan: ran db_bench

Reviewers: dhruba, haobo

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16269
Schedule flush when waiting on flush

Summary:
This will also help with avoiding the deadlock. If a flush failed and we're waiting for a memtable to be flushed, we should schedule a new flush and hope a new one succeedes.

If paranoid_checks = false, Wait() will still hang on ENOSPC, but at least it will automatically continue when the space frees up. Current behavior both hangs and deadlocks.

Also, I renamed some 'compaction' to 'flush'. 'compaction' was leveldb way of saying things.

Test Plan: make check

Reviewers: dhruba, haobo, ljin

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16281
[CF] Log deletion in column families

Summary:
* Added unit test that verifies that obsolete files are deleted.
* Advance log number for empty column family when cutting log file.
* MinLogNumber() bug fix! (caught by the new unit test)

Test Plan: unit test

Reviewers: dhruba, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16311
Merge branch 'master' into columnfamilies
thread local pointer storage

Summary:
This is not a generic thread local implementation in the sense that it
only takes pointer. But it does support multiple instances per thread
and lets user plugin function to perform cleanup when thread exits or an
instance gets destroyed.

Test Plan: unit test for now

Reviewers: haobo, igor, sdong, dhruba

Reviewed By: igor

CC: leveldb, kailiu

Differential Revision: https://reviews.facebook.net/D16131
Merge branch 'master' into columnfamilies
[CF] Handle failure in WriteBatch::Handler

Summary:
* Add ColumnFamilyHandle::GetID() function. Client needs to know column family's ID to be able to construct WriteBatch
* Handle WriteBatch::Handler failure gracefully. Since WriteBatch is not a very smart function (it takes raw CF id), client can add data to WriteBatch for column family that doesn't exist. In that case, we need to gracefully return failure status from DB::Write(). To do that, I added a return Status to WriteBatch functions PutCF, DeleteCF and MergeCF.

Test Plan: Added test to column_family_test

Reviewers: dhruba, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16323
[CF] Fix lint errors in CF code

Summary: Big CF diff uncovered some lint errors. This diff fixes some of them. Not much to see here

Test Plan: make check

Reviewers: dhruba, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16347