Summary:
Pre-fetching is a common operation performed by data stores for
disk/flash based systems as part of database startup.

This is part of task 5197184.

Test Plan: Run the newly added unit test

Reviewers: rven, igor, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D33933

Summary:
fix typo

Task ID: #

Blame Rev:

Test Plan:
Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D34251

Summary: As title

Test Plan: compiles

Reviewers: sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D34191

Summary: I was pretty sure I compiled this before landing, sorry :/

Test Plan: compiles

Reviewers: sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D34173

Summary:
This diff fixes a bug introduced by D28521. Read-only backup engine can delete a backup that is later than the latest -- we never check the condition.

I also added a bunch of logging that will help with debugging cases like this in the future.

See more discussion at t6218248.

Test Plan: Added a unit test that was failing before the change. Also, see new LOG file contents: https://phabricator.fb.com/P19738984

Reviewers: benj, sanketh, sumeet, yhchiang, rven, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D33897

Summary: adding stdlib to fbson to fix FreeBSD compilation

Test Plan: https://github.com/facebook/mysql-5.6/commit/4cfccf14f4abc5a142b25c54ce1d0f4dafe95f9c

Reviewers: igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D34143

Summary: as title, we have unused variables. this is a short-term solution

Test Plan: compiles

Reviewers: IslamAbdelRahman, sdong, rven

Reviewed By: rven

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D34125

Summary:
    Summary:
    Added a new option to ColumnFamllyOptions  - optimize_filters_for_hits. This option can be used in the case where most
    accesses to the store are key hits and we dont need to optimize performance for key misses.
    This is useful when you have a very large database and most of your lookups succeed.  The option allows the store to
     not store and use filters in the last level (the largest level which contains data). These filters can take a large amount of
     space for large databases (in memory and on-disk). For the last level, these filters are only useful for key misses and not
     for key hits. If we are not optimizing for key misses, we can choose to not store these filters for that level.

    This option is only provided for BlockBasedTable. We skip the filters when we are compacting

Test Plan:
1. Modified db_test toalso run tests with an additonal option (skip_filters_on_last_level)
 2. Added another unit test to db_test which specifically tests that filters are being skipped

Reviewers: rven, igor, sdong

Reviewed By: sdong

Subscribers: lgalanis, yoshinorim, MarkCallaghan, rven, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D33717

Summary:
This patch will update the Makefile and source code so that we can build RocksDB successfully on FreeBSD 10 and 11 (64-bit and 32-bit)
I have also encountered some problems when running tests on FreeBSD, I will try to fix them individually in different diffs

Notes:

  - FreeBSD uses clang as it's default compiler (http://lists.freebsd.org/pipermail/freebsd-current/2012-September/036480.html)
  - GNU C++ compiler have C++ 11 problems on FreeBSD (https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=193528)
  - make is not gmake on FreeBSD (http://www.khmere.com/freebsd_book/html/ch01.html)

Test Plan:
Using VMWare Fusion Create 4 VM machines (FreeBSD 11 64-bit, FreeBSD 11 32-bit, FreeBSD 10 64-bit, FreeBSD 10 32-bit)

  - pkg install git gmake gflags archivers/snappy
  - git clone https://github.com/facebook/rocksdb.git
  - apply this patch
  - setenv CXX c++
  - setenv CPATH /usr/local/include/
  - setenv LIBRARY_PATH  /usr/local/lib/
  - gmake db_bench
  - make sure compilation is successful and db_bench is running
  - gmake all
  - make sure compilation is successful

Reviewers: sdong, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D33891

Summary: Current clang path in fbcode points to clang 3.5. This diff updates clang path to clang 3.7.

Test Plan:
Make sure clang 3.7 is in use and all tests are passing.
```lang=bash
% USE_CLANG make check
```

Reviewers: meyering, sdong, rven, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D34119

Summary:
The LoadDependency function does not take a lock when it runs
and it could be modifying data structures while other threads are
accessing it.

Test Plan: Run TSAN.

Reviewers: igor, sdong

Reviewed By: igor, sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D34095

Summary:
When using latest clang (3.6 or 3.7/trunck) rocksdb is failing with many errors. Some errors are uninitialized use errors.

```
...
  CC       db/log_test.o
util/ldb_cmd.cc:394:16: error: base class 'rocksdb::LDBCommand' is uninitialized when used here to access 'rocksdb::LDBCommand::BuildCmdLineOptions' [-Werror,-Wuninitialized]
               BuildCmdLineOptions({ARG_FROM, ARG_TO, ARG_HEX, ARG_KEY_HEX,
               ^
...
```

```lang=c++
CompactorCommand::CompactorCommand(const vector<string>& params,
      const map<string, string>& options, const vector<string>& flags) :
    LDBCommand(options, flags, false,
               BuildCmdLineOptions({ARG_FROM, ARG_TO, ARG_HEX, ARG_KEY_HEX,
                                    ARG_VALUE_HEX, ARG_TTL})),
    null_from_(true), null_to_(true) {
. . .
}
```
For the fourth parameter of the base constructor (`LDBCommand`) we call `BuildCmdLineOptions`, which is a private non-static method of `LDBCommand` base class.

This diff adds missing `static` keyword for `LDBCommand::BuildCmdLineOptions` method.

Test Plan:
Build with trunk clang and make sure all tests are passing.
```lang=bash
% # Have trunk clang present in path.
% ROCKSDB_NO_FBCODE=1 CC=clang CXX=clang++ make check
``

Reviewers: meyering, sdong, rven, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D34083

[RocksJava] RocksJava Testcases

- NativeLibraryLoader Test
- EnvironmentTest Bugfix

Summary: mac compile is fixed in fbson, so it can be returned back from 7ce1b2c1

Test Plan:
make all check
make valgrind_check

Reviewers: golovachalexander, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D33855

Summary:
When using latest clang (3.6 or 3.7/trunck) rocksdb is failing with many errors. Almost all of them are missing override errors. This diff adds missing override keyword. No manual changes.

Prerequisites: bear and clang 3.5 build with extra tools

```lang=bash
% USE_CLANG=1 bear make all # generate a compilation database http://clang.llvm.org/docs/JSONCompilationDatabase.html
% clang-modernize -p . -include . -add-override
% make format
```

Test Plan:
Make sure all tests are passing.
```lang=bash
% #Use default fb code clang.
% make check
```
Verify less error and no missing override errors.
```lang=bash
% # Have trunk clang present in path.
% ROCKSDB_NO_FBCODE=1 CC=clang CXX=clang++ make
```

Reviewers: igor, kradhakrishnan, rven, meyering, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D34077

Summary:
This changes the RocksDB build to share headers provided by MongoDB. It is invoked as:
  ROCKSDB_FOR_MONGO=/path/to/mongodb/root make static_lib

Task ID: #

Blame Rev:

Test Plan:
Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D34071

[RocksJava] Final usage correction

Summary:
BlockBasedTable pre-fetches the filter and index blocks on Open call.
This is an optimistic optimization targeted for runtime scenario. The
optimization is unnecessary for sst_dump_tool

- Added a provision to disable pre-fetching of index and filter blocks
  in BlockBasedTable
- Disabled pre-fetching for the sst_dump tool

Stack for reference :

#01  0x00000000005ed944 in snappy::InternalUncompress<snappy::SnappyArrayWriter> () from /home/engshare/third-party2/snappy/1.0.3/src/snappy-1.0.3/snappy.cc:148
#02  0x00000000005edeee in snappy::RawUncompress () from /home/engshare/third-party2/snappy/1.0.3/src/snappy-1.0.3/snappy.cc:947
#03  0x00000000004e0b4d in rocksdb::UncompressBlockContents () from /data/users/paultuckfield/rocksdb/./util/compression.h:69
#04  0x00000000004e145c in rocksdb::ReadBlockContents () from /data/users/paultuckfield/rocksdb/table/format.cc:334
#05  0x00000000004ca424 in rocksdb::(anonymous namespace)::ReadBlockFromFile () from /data/users/paultuckfield/rocksdb/table/block_based_table_reader.cc:70
#06  0x00000000004cccad in rocksdb::BlockBasedTable::CreateIndexReader () from /data/users/paultuckfield/rocksdb/table/block_based_table_reader.cc:173
#07  0x00000000004d17e5 in rocksdb::BlockBasedTable::Open () from /data/users/paultuckfield/rocksdb/table/block_based_table_reader.cc:553
#08  0x00000000004c8184 in rocksdb::BlockBasedTableFactory::NewTableReader () from /data/users/paultuckfield/rocksdb/table/block_based_table_factory.cc:51
#09  0x0000000000598463 in rocksdb::SstFileReader::NewTableReader () from /data/users/paultuckfield/rocksdb/util/sst_dump_tool.cc:69
#10  0x00000000005986c2 in rocksdb::SstFileReader::SstFileReader () from /data/users/paultuckfield/rocksdb/util/sst_dump_tool.cc:26
#11  0x0000000000599047 in rocksdb::SSTDumpTool::Run () from /data/users/paultuckfield/rocksdb/util/sst_dump_tool.cc:332
#12  0x0000000000409b06 in main () from /data/users/paultuckfield/rocksdb/tools/sst_dump.cc:12

Test Plan:
- Added a unit test to trigger the code.
- Also did some manual verification.
- Passed all unit tests

task #6296048

Reviewers: igor, rven, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D34041

Summary:
An old commit (482401) changed DoWrite to use the value of --writes rather
than --num to determine the range for keys. This restores the old and correct
behavior which is to limit it using --num.

Task ID: #6353043

Blame Rev:

Test Plan:
run db_bench

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D34065

[RocksJava] Updated TickerTypes and Histogram to 3.10

Updated tickers and histogram types to 3.10.

Summary:
Introduced final keyword to parameters with immutable values and classes
which should not be derived.

Test Plan:
make rocksdbjava
make jtest

Reviewers: yhchiang, adamretter, ankgup87

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D33417

Summary:
In a release build, a member was not being accessed. This
member was only being accessed in a debug build. We now add an accessor
function for this member and the buid succeeds.

Test Plan: build release/unity/debug on linux/mac

Reviewers: sdong, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D34035

This reverts commit bd339a97.

Conflicts:
	db/managed_iterator.cc

[RocksJava] Raw use of parametrized class

[RocksJava] Redundant access-modifier in interfaces

Summary: See https://www.facebook.com/groups/rocksdb.dev/permalink/718536351578215/. We should enable people to run without warning-as-error, since we break this so often for different compilers.

Test Plan: introduce an warning, compile sucessfully

Reviewers: yhchiang, meyering, igor.sugak, rven, sdong

Reviewed By: sdong

Subscribers: adamretter, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D33963

Summary: This causes warnings on OS X

Test Plan: compiles

Reviewers: rven, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D33969

Summary: Replaced LevelDb include guards with #pragma once

Test Plan: make all check

Reviewers: igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D33939

Summary:
* Updated Makefile to exit `make analyze` with status 1 if scan-build detected any bugs.
* scan-build automatically detects which c++ compiler to use, and some times is uses wrong ones (from $CPP). Added implicit parameters to use $CC and $CXX.
* Added `scan_build_report` directory to .gitignore file.
* Added `scan_build_report` directory to clean target.

Test Plan:
Run `make analyze` and verify that exit status is 1, if there are scan-build bugs detected.
Run `make clean` and verify that files in `scan_build_report` directory are deleted.
After running `make analyze; git status` and verify that no untracked files in `scan_build_report` directory.

Reviewers: meyering, sdong, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D33831

Test Plan: Run "make clean && make all check"

Reviewers: rven, igor, yhchiang, kradhakrishnan, MarkCallaghan, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D33627

Summary:
This diff contains trivial fixes for 6 scan-build warnings:

**db/c_test.c**
`db` variable is never read. Removed assignment.
scan-build report:
http://home.fburl.com/~sugak/latest20/report-9b77d2.html#EndPath

**db/db_iter.cc**
`skipping` local variable is assigned to false. Then in the next switch block the only "non return" case assign `skipping` to true, the rest cases don't use it and all do return.
scan-build report:
http://home.fburl.com/~sugak/latest20/report-13fca7.html#EndPath

**db/log_reader.cc**
In `bool Reader::SkipToInitialBlock()` `offset_in_block` local variable is assigned to 0 `if (offset_in_block > kBlockSize - 6)` and then never used. Removed the assignment and renamed it to `initial_offset_in_block` to avoid confusion.
scan-build report:
http://home.fburl.com/~sugak/latest20/report-a618dd.html#EndPath

In `bool Reader::ReadRecord(Slice* record, std::string* scratch)` local variable `in_fragmented_record` in switch case `kFullType` block is assigned to false and then does `return` without use. In the other switch case `kFirstType` block the same `in_fragmented_record` is assigned to false, but later assigned to true without prior use. Removed assignment for both cases.
scan-build reprots:
http://home.fburl.com/~sugak/latest20/report-bb86b0.html#EndPath
http://home.fburl.com/~sugak/latest20/report-a975be.html#EndPath

**table/plain_table_key_coding.cc**
Local variable `user_key_size` is assigned when declared. But then in both places where it is used assigned to `static_cast<uint32_t>(key.size() - 8)`. Changed to initialize the variable to the proper value in declaration.
scan-build report:
http://home.fburl.com/~sugak/latest20/report-9e6b86.html#EndPath

**tools/db_stress.cc**
Missing `break` in switch case block. This seems to be a bug. Added missing `break`.

Test Plan:
Make sure all tests are passing and scan-build does not report 'Dead assignment' and 'Dead initialization' bugs.
```lang=bash
% make check
% make analyze
```

Reviewers: meyering, igor, kradhakrishnan, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D33795

Summary:
The unit test was supposed to check that the old file and the new file contains
the header message.

Test Plan: Run the unit test.

Reviewers: sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D33705

Summary:
* Makefile (WARNING_FLAGS): Add -W and -Wextra, and at least for now,
-Wno-unused-parameter.  Without that latter one, there would be
many errors/warnings about unused parameters.

Test Plan:
run these and ensure there is no warning:
  make clean && make
  make clean && USE_CLANG=1 make

Reviewers: ljin, sdong, igor.sugak, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D33819