Summary:
cuckoo table iterator creation is quite expensive since it needs to load
all data and sort them. After compaction, RocksDB creates a new iterator
of the new file to make sure it is in good state. That makes the DB
creation quite slow. Delay the iterator db sort to the seek time to
speed it up.

Test Plan: db_bench

Reviewers: igor, yhchiang, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23775

Summary:
builder currently buffers all key value pairs as a vector of
pair<string, string>. That is too much due to std::string
overhead. It wasn't able to fit 1B key/values (12bytes total) in 100GB
of ram. Switch to use a plain string to store the key/value sequence and
use only 12GB of ram as a result.

Test Plan: db_bench

Reviewers: igor, sdong, yhchiang

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23763

Summary:
When creating a new iterator, instead of storing mapping from key to
bucket id for sorting, store only bucket id and read key from mmap file
based on the id. This reduces from 20 bytes per entry to only 4 bytes.

Test Plan: db_bench

Reviewers: igor, yhchiang, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23757

Summary:
Using module to calculate hash makes lookup ~8% slower. But it has its
benefit: file size is more predictable, more space enffient

Test Plan: db_bench

Reviewers: igor, yhchiang, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23691

Summary:
Add the MultiGet API to allow prefetching.
With file size of 1.5G, I configured it to have 0.9 hash ratio that can
fill With 115M keys and result in 2 hash functions, the lookup QPS is
~4.9M/s  vs. 3M/s for Get().
It is tricky to set the parameters right. Since files size is determined
by power-of-two factor, that means # of keys is fixed in each file. With
big file size (thus smaller # of files), we will have more chance to
waste lot of space in the last file - lower space utilization as a
result. Using smaller file size can improve the situation, but that
harms lookup speed.

Test Plan: db_bench

Reviewers: yhchiang, sdong, igor

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23673

Summary:
Add a CompactedDBImpl that will enabled when calling OpenForReadOnly()
and the DB only has one level (>0) of files. As a performan comparison,
CuckooTable performs 2.1M/s with CompactedDBImpl vs. 1.78M/s with
ReadOnlyDBImpl.

Test Plan: db_bench

Reviewers: yhchiang, igor, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23553

Summary: While debugging clients compaction issues, I noticed bunch of delete bugs: P16329995. MakeTableName returns sst file with "/" prefix. We also need "/" prefix when we get the files though GetChildren(), so that we can properly dedup the files.

Test Plan: none

Reviewers: sdong, yhchiang, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23457

Summary: See https://reviews.facebook.net/D19365

Test Plan: compiles

Reviewers: sdong, yhchiang, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23907

[Java] Add remaining options to BlockBasedTableConfig and add getProperty() API

Summary:
Now the file summary is too small for printing. Enlarge it.
To enable it, allow to pass a size to log buffer.

Test Plan:
Add a unit test.
make all check

Reviewers: ljin, yhchiang

Reviewed By: yhchiang

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D21723

RocksDB Staticbuild

Summary:
It was commented out in D22545 by accident. Keep the option in
ImmutableOptions for now. I can make it dynamic in
https://reviews.facebook.net/D23349

Test Plan: make release

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23865

Summary:
Previously, one single column family is given to WriteBatchWithIndex to index keys for all column families. An extra map from column family ID to comparator is maintained which can override the default comparator given in the constructor. A WriteBatchWithIndex::SetComparatorForCF() is added for user to add comparators per column family.

Also move more codes into anonymous namespace.

Test Plan: Add a unit test

Reviewers: ljin, igor

Reviewed By: igor

Subscribers: dhruba, leveldb, yhchiang

Differential Revision: https://reviews.facebook.net/D23355

Summary: It contrains the file size to be 4G max with int

Test Plan:
tried to grep instance and made sure other related variables are also
uint64

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23697

Summary:
Compaction creates backup_input iterator even though it only needed
when compaction filter v2 is enabled

Test Plan: make all check

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23769

Update logging.cc

fix cast style to cpp static_cast

fixed #303: replace %ld with % PRId64

remove unused variable

[Java] Add rate limiter

Summary:
compression_size_percent is an int but was printed as
an unsigned int. So the default of -1 is displayed as a big number.

Test Plan: make check

Reviewers: sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23679

Summary: To avoid false positive test failures when the file system doesn't support fallocate. In EnvTest.AllocateTest, we first make a simple fallocate call and check the error codes to rule out the possibility that it is not supported. Skip the test if the error code indicates it is not supported.

Test Plan: Run the test and make sure it passes on file systems supporting and not supporting fallocate

Reviewers: yhchiang, ljin, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23667

Summary: I want to use open source build rather than fbcode one. This enables me to run `ROCKSDB_NO_FBCODE=1 make` and run it with my system g++.

Test Plan:
ROCKSDB_NO_FBCODE=1 make
make

Reviewers: sdong, ljin, yhchiang

Reviewed By: yhchiang

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23613

Summary: Use PRIu64 to format uint64 in a portable manner

Test Plan: Run "make all check"

Reviewers: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23595