Summary: Client doesn't need to know anything about ColumnFamily ID. By making WriteBatch take ColumnFamilyHandle as a parameter, we can eliminate method GetID() from ColumnFamilyHandle

Test Plan: column_family_test

Reviewers: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16887

Summary:
I'm cleaning up some code preparing for the big diff review tomorrow. This is the first part of the cleanup.

Changes are mostly cosmetic. The goal is to decrease amount of code difference between columnfamilies and master branch.

This diff also fixes race condition when dropping column family.

Test Plan: Ran db_stress with variety of parameters

Reviewers: dhruba, haobo

Differential Revision: https://reviews.facebook.net/D16833

Summary:
I had this diff for a while to test column families implementation. Last night, I ran it sucessfully for 10 hours with the command:

   time ./db_stress --threads=30 --ops_per_thread=200000000 --max_key=5000 --column_families=20 --clear_column_family_one_in=3000000 --verify_before_write=1  --reopen=50 --max_background_compactions=10 --max_background_flushes=10 --db=/tmp/db_stress

It is ready to be committed :)

Test Plan: Ran it for 10 hours

Reviewers: dhruba, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16797

Summary: Adding the last missing function -- NewIterators(). Pretty simple implementation

Test Plan: added a unit test

Reviewers: dhruba, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16689

Summary:
Column family IDs should be unique, even if column family is dropped. To achieve this, we save max column family in manifest.

Note that the diff is still not ready. I'm only using differential to move the patch to my Mac machine.

Test Plan: added a test to column_family_test

Reviewers: dhruba, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16581

Summary:
This fixes few bugs with CreateColumnFamily
* We first have to LogAndApply and then call VersionSet::CreateColumnFamily. Otherwise, WriteSnapshot might be invoked, writing out column family add inside of LogAndApply, even though it's not really committed
* Fix LogAndApplyHelper() to not apply log number to column_family_data, which is in case of column family add, just a dummy (default) column family
* Create SuperVerion when creating column family

Test Plan: column_family_test

Reviewers: dhruba, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16443

Summary: If we sleep for 300ms the test fails in valgrind because it takes more than 300ms to flush. This way we WaitForFlush() when we're expecting flush, but still sleep and check if the flush happens even though it's not supposed to.

Test Plan: notest

Reviewers: dhruba, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16401

Summary:
Two new column family tests:
* DifferentMergeOperators -- three column families, one without merge operator, one with add operator and one with append operator. verify that operations work as expected.
* DifferentCompactionStyles -- three column families, two with level compactions and one with universal compaction. trigger the compactions and verify they work as expected.

Test Plan: nope

Reviewers: dhruba, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16377

Summary: Retry GetSortedWalFiles() and also wait 20ms before counting number of log files. WaitForFlush() doesn't necessarily wait for logs to be deleted, since logs are deleted outside of the mutex.

Test Plan: column_family_test

Reviewers: dhruba, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16371

Summary: New unit tests for column families

Test Plan: this is a test

Reviewers: dhruba, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16359

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

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

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

Summary:
This is a huge diff and it was hectic, but the idea is actually quite simple. Every operation (Put, Get, etc.) done on default column family in DBTest is now forwarded to non-default ("pikachu"). The good news is that we had zero test failures! Column families look stable so far.

One interesting test that I adapted for column families is MultiThreadedTest. I replaced every Put() with a WriteBatch writing to all column families concurrently. Every Put in the write batch contains unique_id. Instead of Get() I do a multiget across all column families with the same key. If atomicity holds, I expect to see the same unique_id in all column families.

Test Plan: This is a test!

Reviewers: dhruba, haobo, kailiu, sdong

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16149

Summary:
The change to the public behavior:
* When opening a DB or creating new column family client gets a ColumnFamilyHandle.
* As long as column family handle is alive, client can do whatever he wants with it, even drop it
* Dropped column family can still be read from (using the column family handle)
* Added a new call CloseColumnFamily(). Client has to close all column families that he has opened before deleting the DB
* As soon as column family is closed, any calls to DB using that column family handle will fail (also any outstanding calls)

Internally:
* Ref-counting ColumnFamilyData
* New thread-safety for ColumnFamilySet
* Dropped column families are now completely dropped and their memory cleaned-up

Test Plan: added some tests to column_family_test

Reviewers: dhruba, haobo, kailiu, sdong

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16101

Summary: By discussion with @dhruba, overloading Open makes more sense

Test Plan: compiles!

Reviewers: dhruba

CC: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D16017

Summary: This diff enables non-default column families to get compacted both automatically and also by calling CompactRange()

Test Plan: make check

Reviewers: dhruba, haobo, kailiu, sdong

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15813

Summary: Removed default_cfd_ from all flush code paths. This means we can now flush memtables from arbitrary column families!

Test Plan: Added a new unit test

Reviewers: dhruba, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15789

Summary: This one is big. It adds ability to write to and read from different column families (see the unit test). It also supports recovery of different column families from log, which was the hardest part to reason about. We need to make sure to never delete the log file which has unflushed data from any column family. To support that, I added another concept, which is versions_->MinLogNumber()

Test Plan: Added a unit test in column_family_test

Reviewers: dhruba, haobo, sdong, kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15537

Summary:
I created a separate class ColumnFamilySet to keep track of column families. Before we did this in VersionSet and I believe this approach is cleaner.

Let me know if you have any comments. I will commit tomorrow.

Test Plan: make check

Reviewers: dhruba, haobo, kailiu, sdong

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15357

Summary:
In addition to implementing OpenWithColumnFamilies, this diff also includes some minor changes:
* Changed all column family names from Slice() to std::string. The performance of column family name handling is not critical, and it's more convenient and cleaner to have names as std::strings
* Implemented ColumnFamilyOptions(const Options&) and DBOptions(const Options&)
* Added ColumnFamilyOptions to VersionSet::ColumnFamilyData. ColumnFamilyOptions are specified on OpenWithColumnFamilies() and CreateColumnFamily()

I will keep the diff in the Phabricator for a day or two and will push to the branch then. Feel free to comment even after the diff has been pushed.

Test Plan: Added a simple unit test

Reviewers: dhruba, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15033

Summary:
This diff provides basic implementations of CreateColumnFamily(), DropColumnFamily() and ListColumnFamilies(). It builds on top of https://reviews.facebook.net/D14733

It also includes a bug fix for DBImplReadOnly, where Get implementation would be redirected to DBImpl instead of DBImplReadOnly.

Test Plan: Added unit test

Reviewers: dhruba, haobo, kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15021