Summary:
For testing backups, we needed an Env that is fully isolated from other
Envs on the same machine. Our in-memory Envs (MockEnv and InMemoryEnv) were
insufficient because they don't implement most directory operations.

This diff introduces a new Env, "ChrootEnv", that translates paths such that the
chroot directory appears to be the root directory. This way, multiple Envs can
be isolated in the filesystem by using different chroot directories. Since we
use the filesystem, all directory operations are trivially supported.

Test Plan:
I parameterized the existing EnvPosixTest so it runs tests on ChrootEnv
except the ioctl-related cases.

Reviewers: sdong, lightmark, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D57543

Summary: Revert D54093 and D57453

Test Plan: running make check

Reviewers: horuff, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D57819

Summary:
This is needed so that rocksdb users can add more
commands to the included ldb tool by adding more custom
commands.

Test Plan: make -j ldb

Reviewers: sdong, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D57243

Closes https://github.com/facebook/rocksdb/issues/1071

Summary: Have sandcastle run unit test in lite mode for every diff.

Test Plan: seems sandcastle picked up changes here and running lite_test for this diff.

Reviewers: kradhakrishnan

Reviewed By: kradhakrishnan

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D57741

Summary:
For backwards compatibility with older option strings, the parser needs
to treat this argument as optional.

Test Plan:
Updated unit test to cover case where compression_opts is present but
max_dict_bytes is omitted.

Reviewers: MarkCallaghan, sdong, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D57759

Summary: This is to provide a way for users to skip prefix bloom in point look-up.

Test Plan: Add a new unit test scenario.

Reviewers: IslamAbdelRahman

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D57747

Summary: We changed default options of max_open_files and max_file_opening_threads but didn't revert it in OptimizeForSmallDb().

Test Plan: Add a unit test

Reviewers: igor, yhchiang, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D57675

Summary: This test is failing under valgrind because we dont delete the Env that we allocated

Test Plan: run the test under valgrind

Reviewers: andrewkr, yhchiang, yiwu, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D57693

Summary:
Add optimize_filters_for_hits option to db_bench

Task ID: #

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: sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D57621

Summary: Fixing lite build broke in unit test. `FilesPerLevel()` depends on `DB::GetProperty()`, which lite build doesn't support.

Test Plan: OPT=-DROCKSDB_LITE make check -j64

Reviewers: sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D57651

Summary:
Add an option `iterator_readahead_size` to `ReadOptions` to enable
configurable readahead for iterators similar to the corresponding
option for compaction.

Test Plan:
```
make commit_prereq
```

Reviewers: kumar.rangarajan, ott, igor, sdong

Reviewed By: sdong

Subscribers: yiwu, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D55419

Summary: We should not use IterKey::SetKey with copy = false except if we are pinning the iterator thru it's life time, otherwise we may release the temporarily pinned blocks and in this case the IterKey will be pointing to freed memory

Test Plan: added a new test

Reviewers: sdong, andrewkr

Reviewed By: andrewkr

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D57561

Summary:
This diff is stacked on top of this diff https://reviews.facebook.net/D56493
The current Iterator::Prev() implementation need to copy every value since the underlying Iterator may move after reading the value.
This can be optimized by making sure that the block containing the value is pinned until the Iterator move. which will improve the throughput by up to 1.5X

master
```
==> 1000000_Keys_100Byte.txt <==
readreverse  :       0.449 micros/op 2225887 ops/sec;  246.2 MB/s
readreverse  :       0.433 micros/op 2311508 ops/sec;  255.7 MB/s
readreverse  :       0.436 micros/op 2294335 ops/sec;  253.8 MB/s
readreverse  :       0.471 micros/op 2121295 ops/sec;  234.7 MB/s
readreverse  :       0.465 micros/op 2152227 ops/sec;  238.1 MB/s
readreverse  :       0.454 micros/op 2203011 ops/sec;  243.7 MB/s
readreverse  :       0.451 micros/op 2216095 ops/sec;  245.2 MB/s
readreverse  :       0.462 micros/op 2162447 ops/sec;  239.2 MB/s
readreverse  :       0.476 micros/op 2099151 ops/sec;  232.2 MB/s
readreverse  :       0.472 micros/op 2120710 ops/sec;  234.6 MB/s

avg : 242.34 MB/s

==> 1000000_Keys_1KB.txt <==
readreverse  :       1.013 micros/op 986793 ops/sec;  978.7 MB/s
readreverse  :       0.942 micros/op 1061136 ops/sec; 1052.5 MB/s
readreverse  :       0.951 micros/op 1051901 ops/sec; 1043.3 MB/s
readreverse  :       0.932 micros/op 1072894 ops/sec; 1064.1 MB/s
readreverse  :       1.024 micros/op 976720 ops/sec;  968.7 MB/s
readreverse  :       0.935 micros/op 1069169 ops/sec; 1060.4 MB/s
readreverse  :       1.012 micros/op 988132 ops/sec;  980.1 MB/s
readreverse  :       0.962 micros/op 1039579 ops/sec; 1031.1 MB/s
readreverse  :       0.991 micros/op 1008924 ops/sec; 1000.7 MB/s
readreverse  :       1.004 micros/op 996144 ops/sec;  988.0 MB/s

avg : 1016.76 MB/s

==> 1000000_Keys_10KB.txt <==
readreverse  :       4.167 micros/op 239952 ops/sec; 2346.9 MB/s
readreverse  :       4.070 micros/op 245713 ops/sec; 2403.3 MB/s
readreverse  :       4.572 micros/op 218733 ops/sec; 2139.4 MB/s
readreverse  :       4.497 micros/op 222388 ops/sec; 2175.2 MB/s
readreverse  :       4.203 micros/op 237920 ops/sec; 2327.1 MB/s
readreverse  :       4.206 micros/op 237756 ops/sec; 2325.5 MB/s
readreverse  :       4.181 micros/op 239149 ops/sec; 2339.1 MB/s
readreverse  :       4.157 micros/op 240552 ops/sec; 2352.8 MB/s
readreverse  :       4.187 micros/op 238848 ops/sec; 2336.1 MB/s
readreverse  :       4.106 micros/op 243575 ops/sec; 2382.4 MB/s

avg : 2312.78 MB/s

==> 100000_Keys_100KB.txt <==
readreverse  :      41.281 micros/op 24224 ops/sec; 2366.0 MB/s
readreverse  :      39.722 micros/op 25175 ops/sec; 2458.9 MB/s
readreverse  :      40.319 micros/op 24802 ops/sec; 2422.5 MB/s
readreverse  :      39.762 micros/op 25149 ops/sec; 2456.4 MB/s
readreverse  :      40.916 micros/op 24440 ops/sec; 2387.1 MB/s
readreverse  :      41.188 micros/op 24278 ops/sec; 2371.4 MB/s
readreverse  :      40.061 micros/op 24962 ops/sec; 2438.1 MB/s
readreverse  :      40.221 micros/op 24862 ops/sec; 2428.4 MB/s
readreverse  :      40.084 micros/op 24947 ops/sec; 2436.7 MB/s
readreverse  :      40.655 micros/op 24597 ops/sec; 2402.4 MB/s

avg : 2416.79 MB/s

==> 10000_Keys_1MB.txt <==
readreverse  :     298.038 micros/op 3355 ops/sec; 3355.3 MB/s
readreverse  :     335.001 micros/op 2985 ops/sec; 2985.1 MB/s
readreverse  :     286.956 micros/op 3484 ops/sec; 3484.9 MB/s
readreverse  :     329.954 micros/op 3030 ops/sec; 3030.8 MB/s
readreverse  :     306.428 micros/op 3263 ops/sec; 3263.5 MB/s
readreverse  :     330.749 micros/op 3023 ops/sec; 3023.5 MB/s
readreverse  :     328.903 micros/op 3040 ops/sec; 3040.5 MB/s
readreverse  :     324.853 micros/op 3078 ops/sec; 3078.4 MB/s
readreverse  :     320.488 micros/op 3120 ops/sec; 3120.3 MB/s
readreverse  :     320.536 micros/op 3119 ops/sec; 3119.8 MB/s

avg : 3150.21 MB/s
```

After memcpy elimination
```

==> 1000000_Keys_100Byte.txt <==
readreverse  :       0.395 micros/op 2529890 ops/sec;  279.9 MB/s
readreverse  :       0.368 micros/op 2715922 ops/sec;  300.5 MB/s
readreverse  :       0.384 micros/op 2603929 ops/sec;  288.1 MB/s
readreverse  :       0.375 micros/op 2663286 ops/sec;  294.6 MB/s
readreverse  :       0.357 micros/op 2802180 ops/sec;  310.0 MB/s
readreverse  :       0.363 micros/op 2757684 ops/sec;  305.1 MB/s
readreverse  :       0.372 micros/op 2689603 ops/sec;  297.5 MB/s
readreverse  :       0.379 micros/op 2638599 ops/sec;  291.9 MB/s
readreverse  :       0.375 micros/op 2663803 ops/sec;  294.7 MB/s
readreverse  :       0.375 micros/op 2665579 ops/sec;  294.9 MB/s

avg: 295.72 MB/s (1.22 X)

==> 1000000_Keys_1KB.txt <==
readreverse  :       0.879 micros/op 1138112 ops/sec; 1128.8 MB/s
readreverse  :       0.842 micros/op 1187998 ops/sec; 1178.3 MB/s
readreverse  :       0.837 micros/op 1194915 ops/sec; 1185.1 MB/s
readreverse  :       0.845 micros/op 1182983 ops/sec; 1173.3 MB/s
readreverse  :       0.877 micros/op 1140308 ops/sec; 1131.0 MB/s
readreverse  :       0.849 micros/op 1177581 ops/sec; 1168.0 MB/s
readreverse  :       0.915 micros/op 1093284 ops/sec; 1084.3 MB/s
readreverse  :       0.863 micros/op 1159418 ops/sec; 1149.9 MB/s
readreverse  :       0.895 micros/op 1117670 ops/sec; 1108.5 MB/s
readreverse  :       0.852 micros/op 1174116 ops/sec; 1164.5 MB/s

avg: 1147.17 MB/s (1.12 X)

==> 1000000_Keys_10KB.txt <==
readreverse  :       3.870 micros/op 258386 ops/sec; 2527.2 MB/s
readreverse  :       3.568 micros/op 280296 ops/sec; 2741.5 MB/s
readreverse  :       4.005 micros/op 249694 ops/sec; 2442.2 MB/s
readreverse  :       3.550 micros/op 281719 ops/sec; 2755.5 MB/s
readreverse  :       3.562 micros/op 280758 ops/sec; 2746.1 MB/s
readreverse  :       3.507 micros/op 285125 ops/sec; 2788.8 MB/s
readreverse  :       3.463 micros/op 288739 ops/sec; 2824.1 MB/s
readreverse  :       3.428 micros/op 291734 ops/sec; 2853.4 MB/s
readreverse  :       3.553 micros/op 281491 ops/sec; 2753.2 MB/s
readreverse  :       3.535 micros/op 282885 ops/sec; 2766.9 MB/s

avg : 2719.89 MB/s (1.17 X)

==> 100000_Keys_100KB.txt <==
readreverse  :      22.815 micros/op 43830 ops/sec; 4281.0 MB/s
readreverse  :      29.957 micros/op 33381 ops/sec; 3260.4 MB/s
readreverse  :      25.334 micros/op 39473 ops/sec; 3855.4 MB/s
readreverse  :      23.037 micros/op 43409 ops/sec; 4239.8 MB/s
readreverse  :      27.810 micros/op 35958 ops/sec; 3512.1 MB/s
readreverse  :      30.327 micros/op 32973 ops/sec; 3220.6 MB/s
readreverse  :      29.704 micros/op 33665 ops/sec; 3288.2 MB/s
readreverse  :      29.423 micros/op 33987 ops/sec; 3319.6 MB/s
readreverse  :      23.334 micros/op 42856 ops/sec; 4185.9 MB/s
readreverse  :      29.969 micros/op 33368 ops/sec; 3259.1 MB/s

avg : 3642.21 MB/s (1.5 X)

==> 10000_Keys_1MB.txt <==
readreverse  :     244.748 micros/op 4085 ops/sec; 4085.9 MB/s
readreverse  :     230.208 micros/op 4343 ops/sec; 4344.0 MB/s
readreverse  :     235.655 micros/op 4243 ops/sec; 4243.6 MB/s
readreverse  :     235.730 micros/op 4242 ops/sec; 4242.2 MB/s
readreverse  :     237.346 micros/op 4213 ops/sec; 4213.3 MB/s
readreverse  :     227.306 micros/op 4399 ops/sec; 4399.4 MB/s
readreverse  :     194.957 micros/op 5129 ops/sec; 5129.4 MB/s
readreverse  :     238.359 micros/op 4195 ops/sec; 4195.4 MB/s
readreverse  :     221.588 micros/op 4512 ops/sec; 4513.0 MB/s
readreverse  :     235.911 micros/op 4238 ops/sec; 4239.0 MB/s

avg : 4360.52 MB/s (1.38 X)
```

Test Plan: COMPILE_WITH_ASAN=1 make check -j64

Reviewers: andrewkr, yhchiang, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D56511

Summary: Release RocksDB 4.8.0

Test Plan: N/A

Reviewers: sdong, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D57525

Using explicit 64-bit type in conditional in platforms above 32-bits
This appears to be necessary on Mac OSX as std::conditional does not appear to short circuit and evaluates the third template arg
Making the third template arg be 64 bits explicitly works around this problem and will work on both 32 bit and 64+ bit platforms.

Summary: GetCurrentMutableCFOptions() can only be called when DB mutex is held so we cannot call it in CompactionJob::ProcessKeyValueCompaction() since it's not holding the db mutex

Test Plan: make check -j64

Reviewers: sdong, andrewkr

Reviewed By: andrewkr

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D57471

make preallocation inline with other writable files
  make sure that we map no more than pre-allocated size.

Summary: fix clang build

Test Plan: USE_CLANG make all -j64

Reviewers: horuff, sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D57453

Summary: Adds three new WriteBatch data types: Prepare(xid), Commit(xid), Rollback(xid). Prepare(xid) should precede the (single) operation to which is applies. There can obviously be multiple Prepare(xid) markers. There should only be one Rollback(xid) or Commit(xid) marker yet not both. None of this logic is currently enforced and will most likely be implemented further up such as in the memtableinserter. All three markers are similar to PutLogData in that they are writebatch meta-data, ie stored but not counted. All three markers differ from PutLogData in that they will actually be written to disk. As for WriteBatchWithIndex, Prepare, Commit, Rollback are all implemented just as PutLogData and none are tested just as PutLogData.

Test Plan: single unit test in write_batch_test.

Reviewers: hermanlee4, sdong, anthony

Subscribers: andrewkr, vasilep, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D54093

Summary: Added EventListener::OnTableFileCreationStarted. EventListener::OnTableFileCreated will be called on failure case. User can check creation status via TableFileCreationInfo::status.

Test Plan: unit test.

Reviewers: dhruba, yhchiang, ott, sdong

Reviewed By: sdong

Subscribers: sdong, kradhakrishnan, IslamAbdelRahman, andrewkr, yhchiang, leveldb, ott, dhruba

Differential Revision: https://reviews.facebook.net/D56337

This reverts commit b54c3474.

Revert async file handle change as it causes failures with appveyor

Summary:
Changing several option defaults:
 options.max_open_files changes from 5000 to -1
 options.base_background_compactions changes from max_background_compactions to 1
 options.wal_recovery_mode changes from kTolerateCorruptedTailRecords to kTolerateCorruptedTailRecords
 options.compaction_pri changes from kByCompensatedSize to kByCompensatedSize

Test Plan: Write unit tests to see OldDefaults() works as expected.

Reviewers: IslamAbdelRahman, yhchiang, igor

Reviewed By: igor

Subscribers: MarkCallaghan, yiwu, kradhakrishnan, leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D56427

This avoids excessive iteration in tombstone fields.

Summary: Warning is printed out with USE_CLANG=1 when including jemalloc.h. Disable it in that case.

Test Plan: Run db_bench with USE_CLANG=1 and not. Make sure they can all build and jemalloc status is printed out in the case where USE_CLANG is not set.

Reviewers: andrewkr, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D57399

Summary:
crash_test grep for 'fail' string in the output and if found it consider that we failed.
Update the output to use something else

Test Plan: make crash_test (still running)

Reviewers: yhchiang, sdong, andrewkr

Reviewed By: andrewkr

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D57381

Summary:
This test relies on "rocksdb.num-files-at-levelN" property that isn't
implemented in rocksdb lite. So we will compile it only for non-lite builds.

Test Plan:
  $ make -j40 check 'OPT=-g -DROCKSDB_LITE'

Reviewers: sdong, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D57387

Summary:
There was one narrowing conversion in D52287 that only showed up with
clang on osx.

Test Plan:
  $ make clean && USE_CLANG=1 DISABLE_JEMALLOC=1 TEST_TMPDIR=/dev/shm/rocksdb OPT=-g make -j32 check

Reviewers: sdong, lightmark, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D57357

fix typos and remove duplicated words

Summary: Fix typo in build_tools/fbcode_config.sh

Test Plan: none

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D57363

Summary: There were a few narrowing conversions that clang didn't like.

Test Plan:
  $ make clean && USE_CLANG=1 DISABLE_JEMALLOC=1 TEST_TMPDIR=/dev/shm/rocksdb OPT=-g make -j32 check

Reviewers: IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D57351

Summary: It looks like we mistakenly enable JEMALLOC even if it's not available on the machine, that's why travis is failing

Test Plan:
check on my devserver
check on my mac

Reviewers: sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D57345

Summary:
Made compression type and dictionary size configurable via environment
variables.

Depends on D52287.

Test Plan:
check these options are passed to the db.

  $ COMPRESSION_MAX_DICT_BYTES=65536 COMPRESSION_TYPE=LZ4 NUM_KEYS=10000000 DB_DIR=./tmp/ WAL_DIR=./tmp/ ./tools/benchmark.sh filluniquerandom
  ...
  $ grep Options.compression tmp/LOG
  2016/04/22-19:11:30.397829 7f5f263a2980          Options.compression: LZ4
  ...
  2016/04/22-19:11:30.397837 7f5f263a2980         Options.compression_opts.max_dict_bytes: 65536

Reviewers: IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D57141

Summary:
This adds a new metablock containing a shared dictionary that is used
to compress all data blocks in the SST file. The size of the shared dictionary
is configurable in CompressionOptions and defaults to 0. It's currently only
used for zlib/lz4/lz4hc, but the block will be stored in the SST regardless of
the compression type if the user chooses a nonzero dictionary size.

During compaction, computes the dictionary by randomly sampling the first
output file in each subcompaction. It pre-computes the intervals to sample
by assuming the output file will have the maximum allowable length. In case
the file is smaller, some of the pre-computed sampling intervals can be beyond
end-of-file, in which case we skip over those samples and the dictionary will
be a bit smaller. After the dictionary is generated using the first file in a
subcompaction, it is loaded into the compression library before writing each
block in each subsequent file of that subcompaction.

On the read path, gets the dictionary from the metablock, if it exists. Then,
loads that dictionary into the compression library before reading each block.

Test Plan: new unit test

Reviewers: yhchiang, IslamAbdelRahman, cyan, sdong

Reviewed By: sdong

Subscribers: andrewkr, yoshinorim, kradhakrishnan, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D52287

Summary:
As db_stress with CompactFiles possibly catches a previous bug currently,
temporarily disable CompactFiles in db_stress in its default setting
to allows new bug to be detected while investigating the bug in CompactFiles.

Test Plan: crash test

Reviewers: sdong, kradhakrishnan, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D57333

Summary:
Introduced option to dump malloc statistics using new option flag.
    Added new command line option to db_bench tool to enable this
    funtionality.
    Also extended build to support environments with/without jemalloc.

Test Plan:
1) Build rocksdb using `make` command. Launch the following command
    `./db_bench --benchmarks=fillrandom --dump_malloc_stats=true
    --num=10000000` end verified that jemalloc dump is present in LOG file.
    2) Build rocksdb using `DISABLE_JEMALLOC=1  make db_bench -j32` and ran
    the same db_bench tool and found the following message in LOG file:
    "Please compile with jemalloc to enable malloc dump".
    3) Also built rocksdb using `make` command on MacOS to verify behavior
    in non-FB environment.
    Also to debug build configuration change temporary changed
    AM_DEFAULT_VERBOSITY = 1 in Makefile to see compiler and build
    tools output. For case 1) -DROCKSDB_JEMALLOC was present in compiler
    command line. For both 2) and 3) this flag was not present.

Reviewers: sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D57321