Commit Graph

1888 Commits

Author SHA1 Message Date
Zitan Chen
6a243b3ade Generalize BackupEngine naming option for share_files_with_checksum SSTs and revert BackupEngine::VerifyBackup to check only file sizes by default (#7032)
Summary:
`bool BackupableDBOptions::new_naming_for_backup_files` is updated to `BackupTableNameOption BackupableDBOptions::share_files_with_checksum_naming`, where `BackupTableNameOption` is an `enum` type with two enumerators `kChecksumAndFileSize` and `kChecksumAndFileSize`. This opens up possibilities of extenting the current naming scheme for backup table files. By default, `BackupTableNameOption BackupableDBOptions::share_files_with_checksum_naming` is set to `kChecksumAndDbSessionId`.

Revert `BackupEngine::VerifyBackup` to only check file sizes by default.

Also fix the construction of the `SstFileDumper` in `GetFileDbIdentities` by setting a proper `Env` of the `Options` passed in the constructor.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7032

Test Plan: make check

Reviewed By: ajkr

Differential Revision: D22237763

Pulled By: gg814

fbshipit-source-id: 466902a4e731babd64e30f0e82ca1aa82962e52e
2020-06-30 18:47:16 -07:00
Burton Li
5be2cb6948 Compaction filter support for BlobDB (#6850)
Summary:
Added compaction filter support for BlobDB non-TTL values. Same as vanilla RocksDB, user compaction filter applies to all k/v pairs of the compaction for non-TTL values. It honors `min_blob_size`, which potentially results value transitions between inlined data and stored-in-blob data when size of value is changed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6850

Reviewed By: siying

Differential Revision: D22263487

Pulled By: ltamasi

fbshipit-source-id: 8fc03f8cde2a5c831e63b436b3dbf1b7f90939e8
2020-06-29 17:32:14 -07:00
Anand Ananthabhotla
9a5886bd8c Extend Get/MultiGet deadline support to table open (#6982)
Summary:
Current implementation of the ```read_options.deadline``` option only checks the deadline for random file reads during point lookups. This PR extends the checks to file opens, prefetches and preloads as part of table open.

The main changes are in the ```BlockBasedTable```, partitioned index and filter readers, and ```TableCache``` to take ReadOptions as an additional parameter. In ```BlockBasedTable::Open```, in order to retain existing behavior w.r.t checksum verification and block cache usage, we filter out most of the options in ```ReadOptions``` except ```deadline```. However, having the ```ReadOptions``` gives us more flexibility to honor other options like verify_checksums, fill_cache etc. in the future.

Additional changes in callsites due to function signature changes in ```NewTableReader()``` and ```FilePrefetchBuffer```.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6982

Test Plan: Add new unit tests in db_basic_test

Reviewed By: riversand963

Differential Revision: D22219515

Pulled By: anand1976

fbshipit-source-id: 8a3b92f4a889808013838603aa3ca35229cd501b
2020-06-29 14:53:17 -07:00
Stanislav Tkach
1b85d57cf5 Expose KeyMayExist in the C API (#7021)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/7021

Reviewed By: ajkr

Differential Revision: D22246297

Pulled By: pdillinger

fbshipit-source-id: 81dfd0a49e4d5ce0c9f00772c17cca425757ea24
2020-06-29 12:21:53 -07:00
Zitan Chen
1569dc48f5 BackupEngine::VerifyBackup verifies checksum by default (#7014)
Summary:
A parameter `verify_with_checksum` is added to `BackupEngine::VerifyBackup`, which is true by default. So now `BackupEngine::VerifyBackup` verifies backup files with checksum AND file size by default. When `verify_with_checksum` is false, `BackupEngine::VerifyBackup` only compares file sizes to verify backup files.

Also add a test for the case when corruption does not change the file size.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7014

Test Plan: Passed backupable_db_test

Reviewed By: zhichao-cao

Differential Revision: D22165590

Pulled By: gg814

fbshipit-source-id: 606a7450714e868bceb38598c89fd356c6004f4f
2020-06-26 11:42:12 -07:00
Stanislav Tkach
70b5d95dc7 Add (more) getters for options to the C API (#6998)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/6998

Reviewed By: ajkr

Differential Revision: D22211700

Pulled By: pdillinger

fbshipit-source-id: 1141c20527dee5e13205059bf8e83927063c4c1e
2020-06-25 13:53:33 -07:00
Zitan Chen
be41c61f22 Add a new option for BackupEngine to store table files under shared_checksum using DB session id in the backup filenames (#6997)
Summary:
`BackupableDBOptions::new_naming_for_backup_files` is added. This option is false by default. When it is true, backup table filenames under directory shared_checksum are of the form `<file_number>_<crc32c>_<db_session_id>.sst`.

Note that when this option is true, it comes into effect only when both `share_files_with_checksum` and `share_table_files` are true.

Three new test cases are added.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6997

Test Plan: Passed make check.

Reviewed By: ajkr

Differential Revision: D22098895

Pulled By: gg814

fbshipit-source-id: a1d9145e7fe562d71cde7ac995e17cb24fd42e76
2020-06-24 19:31:25 -07:00
Yanqin Jin
e66199d848 First step towards handling MANIFEST write error (#6949)
Summary:
This PR provides preliminary support for handling IO error during MANIFEST write.
File write/sync is not guaranteed to be atomic. If we encounter an IOError while writing/syncing to the MANIFEST file, we cannot be sure about the state of the MANIFEST file. The version edits may or may not have reached the file. During cleanup, if we delete the newly-generated SST files referenced by the pending version edit(s), but the version edit(s) actually are persistent in the MANIFEST, then next recovery attempt will process the version edits(s) and then fail since the SST files have already been deleted.
One approach is to truncate the MANIFEST after write/sync error, so that it is safe to delete the SST files. However, file truncation may not be supported on certain file systems. Therefore, we take the following approach.
If an IOError is detected during MANIFEST write/sync, we disable file deletions for the faulty database. Depending on whether the IOError is retryable (set by underlying file system), either RocksDB or application can call `DB::Resume()`, or simply shutdown and restart. During `Resume()`, RocksDB will try to switch to a new MANIFEST and write all existing in-memory version storage in the new file. If this succeeds, then RocksDB may proceed. If all recovery is completed, then file deletions will be re-enabled.
Note that multiple threads can call `LogAndApply()` at the same time, though only one of them will be going through the process MANIFEST write, possibly batching the version edits of other threads. When the leading MANIFEST writer finishes, all of the MANIFEST writing threads in this batch will have the same IOError. They will all call `ErrorHandler::SetBGError()` in which file deletion will be disabled.

Possible future directions:
- Add an `ErrorContext` structure so that it is easier to pass more info to `ErrorHandler`. Currently, as in this example, a new `BackgroundErrorReason` has to be added.

Test plan (dev server):
make check
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6949

Reviewed By: anand1976

Differential Revision: D22026020

Pulled By: riversand963

fbshipit-source-id: f3c68a2ef45d9b505d0d625c7c5e0c88495b91c8
2020-06-24 19:07:08 -07:00
Peter Dillinger
5b2bbacb6f Minimize memory internal fragmentation for Bloom filters (#6427)
Summary:
New experimental option BBTO::optimize_filters_for_memory builds
filters that maximize their use of "usable size" from malloc_usable_size,
which is also used to compute block cache charges.

Rather than always "rounding up," we track state in the
BloomFilterPolicy object to mix essentially "rounding down" and
"rounding up" so that the average FP rate of all generated filters is
the same as without the option. (YMMV as heavily accessed filters might
be unluckily lower accuracy.)

Thus, the option near-minimizes what the block cache considers as
"memory used" for a given target Bloom filter false positive rate and
Bloom filter implementation. There are no forward or backward
compatibility issues with this change, though it only works on the
format_version=5 Bloom filter.

With Jemalloc, we see about 10% reduction in memory footprint (and block
cache charge) for Bloom filters, but 1-2% increase in storage footprint,
due to encoding efficiency losses (FP rate is non-linear with bits/key).

Why not weighted random round up/down rather than state tracking? By
only requiring malloc_usable_size, we don't actually know what the next
larger and next smaller usable sizes for the allocator are. We pick a
requested size, accept and use whatever usable size it has, and use the
difference to inform our next choice. This allows us to narrow in on the
right balance without tracking/predicting usable sizes.

Why not weight history of generated filter false positive rates by
number of keys? This could lead to excess skew in small filters after
generating a large filter.

Results from filter_bench with jemalloc (irrelevant details omitted):

    (normal keys/filter, but high variance)
    $ ./filter_bench -quick -impl=2 -average_keys_per_filter=30000 -vary_key_count_ratio=0.9
    Build avg ns/key: 29.6278
    Number of filters: 5516
    Total size (MB): 200.046
    Reported total allocated memory (MB): 220.597
    Reported internal fragmentation: 10.2732%
    Bits/key stored: 10.0097
    Average FP rate %: 0.965228
    $ ./filter_bench -quick -impl=2 -average_keys_per_filter=30000 -vary_key_count_ratio=0.9 -optimize_filters_for_memory
    Build avg ns/key: 30.5104
    Number of filters: 5464
    Total size (MB): 200.015
    Reported total allocated memory (MB): 200.322
    Reported internal fragmentation: 0.153709%
    Bits/key stored: 10.1011
    Average FP rate %: 0.966313

    (very few keys / filter, optimization not as effective due to ~59 byte
     internal fragmentation in blocked Bloom filter representation)
    $ ./filter_bench -quick -impl=2 -average_keys_per_filter=1000 -vary_key_count_ratio=0.9
    Build avg ns/key: 29.5649
    Number of filters: 162950
    Total size (MB): 200.001
    Reported total allocated memory (MB): 224.624
    Reported internal fragmentation: 12.3117%
    Bits/key stored: 10.2951
    Average FP rate %: 0.821534
    $ ./filter_bench -quick -impl=2 -average_keys_per_filter=1000 -vary_key_count_ratio=0.9 -optimize_filters_for_memory
    Build avg ns/key: 31.8057
    Number of filters: 159849
    Total size (MB): 200
    Reported total allocated memory (MB): 208.846
    Reported internal fragmentation: 4.42297%
    Bits/key stored: 10.4948
    Average FP rate %: 0.811006

    (high keys/filter)
    $ ./filter_bench -quick -impl=2 -average_keys_per_filter=1000000 -vary_key_count_ratio=0.9
    Build avg ns/key: 29.7017
    Number of filters: 164
    Total size (MB): 200.352
    Reported total allocated memory (MB): 221.5
    Reported internal fragmentation: 10.5552%
    Bits/key stored: 10.0003
    Average FP rate %: 0.969358
    $ ./filter_bench -quick -impl=2 -average_keys_per_filter=1000000 -vary_key_count_ratio=0.9 -optimize_filters_for_memory
    Build avg ns/key: 30.7131
    Number of filters: 160
    Total size (MB): 200.928
    Reported total allocated memory (MB): 200.938
    Reported internal fragmentation: 0.00448054%
    Bits/key stored: 10.1852
    Average FP rate %: 0.963387

And from db_bench (block cache) with jemalloc:

    $ ./db_bench -db=/dev/shm/dbbench.no_optimize -benchmarks=fillrandom -format_version=5 -value_size=90 -bloom_bits=10 -num=2000000 -threads=8 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=false
    $ ./db_bench -db=/dev/shm/dbbench -benchmarks=fillrandom -format_version=5 -value_size=90 -bloom_bits=10 -num=2000000 -threads=8 -optimize_filters_for_memory -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=false
    $ (for FILE in /dev/shm/dbbench.no_optimize/*.sst; do ./sst_dump --file=$FILE --show_properties | grep 'filter block' ; done) | awk '{ t += $4; } END { print t; }'
    17063835
    $ (for FILE in /dev/shm/dbbench/*.sst; do ./sst_dump --file=$FILE --show_properties | grep 'filter block' ; done) | awk '{ t += $4; } END { print t; }'
    17430747
    $ #^ 2.1% additional filter storage
    $ ./db_bench -db=/dev/shm/dbbench.no_optimize -use_existing_db -benchmarks=readrandom,stats -statistics -bloom_bits=10 -num=2000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=false -duration=10 -cache_index_and_filter_blocks -cache_size=1000000000
    rocksdb.block.cache.index.add COUNT : 33
    rocksdb.block.cache.index.bytes.insert COUNT : 8440400
    rocksdb.block.cache.filter.add COUNT : 33
    rocksdb.block.cache.filter.bytes.insert COUNT : 21087528
    rocksdb.bloom.filter.useful COUNT : 4963889
    rocksdb.bloom.filter.full.positive COUNT : 1214081
    rocksdb.bloom.filter.full.true.positive COUNT : 1161999
    $ #^ 1.04 % observed FP rate
    $ ./db_bench -db=/dev/shm/dbbench -use_existing_db -benchmarks=readrandom,stats -statistics -bloom_bits=10 -num=2000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=false -optimize_filters_for_memory -duration=10 -cache_index_and_filter_blocks -cache_size=1000000000
    rocksdb.block.cache.index.add COUNT : 33
    rocksdb.block.cache.index.bytes.insert COUNT : 8448592
    rocksdb.block.cache.filter.add COUNT : 33
    rocksdb.block.cache.filter.bytes.insert COUNT : 18220328
    rocksdb.bloom.filter.useful COUNT : 5360933
    rocksdb.bloom.filter.full.positive COUNT : 1321315
    rocksdb.bloom.filter.full.true.positive COUNT : 1262999
    $ #^ 1.08 % observed FP rate, 13.6% less memory usage for filters

(Due to specific key density, this example tends to generate filters that are "worse than average" for internal fragmentation. "Better than average" cases can show little or no improvement.)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6427

Test Plan: unit test added, 'make check' with gcc, clang and valgrind

Reviewed By: siying

Differential Revision: D22124374

Pulled By: pdillinger

fbshipit-source-id: f3e3aa152f9043ddf4fae25799e76341d0d8714e
2020-06-22 13:32:07 -07:00
Matthew Von-Maszewski
1092f19d95 Make EncryptEnv inheritable (#6830)
Summary:
EncryptEnv class is both declared and defined within env_encryption.cc.  This makes it really tough to derive new classes from that base.

This branch moves declaration of the class to rocksdb/env_encryption.h.  The change facilitates making new encryption modules (such as an upcoming openssl AES CTR pull request) possible / easy.

The only coding change was to add the EncryptEnv object to env_basic_test.cc.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6830

Reviewed By: riversand963

Differential Revision: D21706593

Pulled By: ajkr

fbshipit-source-id: 64d2da95a1569ceeb9b1549c3bec5404cf4c89f0
2020-06-22 13:27:16 -07:00
Zitan Chen
94d04529de Store DB identity and DB session ID in SST files (#6983)
Summary:
`db_id` and `db_session_id` are now part of the table properties for all formats and stored in SST files. This adds about 99 bytes to each new SST file.

The `TablePropertiesNames` for these two identifiers are `rocksdb.creating.db.identity` and `rocksdb.creating.session.identity`.

In addition, SST files generated from SstFileWriter and Repairer have DB identity “SST Writer” and “DB Repairer”, respectively. Their DB session IDs are generated in the same way as `DB::GetDbSessionId`.

A table property test is added.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6983

Test Plan: make check and some manual tests.

Reviewed By: zhichao-cao

Differential Revision: D22048826

Pulled By: gg814

fbshipit-source-id: afdf8c11424a6f509b5c0b06dafad584a80103c9
2020-06-17 10:57:40 -07:00
Andrew Kryczka
742b452863 update minor version for 6.11 release (#6994)
Summary:
The 6.11.fb branch is already cut so I will also backport this PR to
that branch.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6994

Reviewed By: riversand963

Differential Revision: D22084532

Pulled By: ajkr

fbshipit-source-id: 0b025f738cc31c65c673cbf89302359e88a34d19
2020-06-16 21:46:05 -07:00
Zitan Chen
88db97b06d Add a DB Session ID (#6959)
Summary:
Added DB::GetDbSessionId by using the same format and machinery as DB::GetDbIdentity.
The DB Session ID is generated (and therefore, updated) each time a DB object is opened. It is written to the LOG file right after the line of “DB SUMMARY”.
A test for the uniqueness, for different openings and during the same opening, is also added.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6959

Test Plan: Passed make check

Reviewed By: zhichao-cao

Differential Revision: D21951721

Pulled By: gg814

fbshipit-source-id: 958a48a612db49a39998ea703cded45987d3fa8b
2020-06-15 10:47:02 -07:00
Zhen Li
9c24a5cb4d Fix persistent cache on windows (#6932)
Summary:
Persistent cache feature caused rocks db crash on windows. I posted a issue for it, https://github.com/facebook/rocksdb/issues/6919. I found this is because no "persistent_cache_key_prefix" is generated for persistent cache. Looking repo history, "GetUniqueIdFromFile" is not implemented on Windows. So my fix is adding "NewId()" function in "persistent_cache" and using it to generate prefix for persistent cache. In this PR, i also re-enable related test cases defined in "db_test2" and "persistent_cache_test" for windows.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6932

Test Plan:
1. run related test cases in "db_test2" and "persistent_cache_test" on windows and see it passed.
2. manually run db_bench.exe with "read_cache_path" and verified.

Reviewed By: riversand963

Differential Revision: D21911608

Pulled By: cheng-chang

fbshipit-source-id: cdfd938d54a385edbb2836b13aaa1d39b0a6f1c2
2020-06-13 13:28:31 -07:00
Cheng Chang
f7613e2a9e Make it able to lower cpu priority to specific level in threadpool (#6969)
Summary:
`Env::LowerThreadPoolCPUPriority` takes a new parameter `CpuPriority` to be able to lower to a specific priority such as `CpuPriority::kIdle`, previously, the priority is always lowered to `CpuPriority::kLow`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6969

Test Plan: unit test `EnvPosixTest::LowerThreadPoolCpuPriority` added to `env_test.cc`.

Reviewed By: siying

Differential Revision: D22011169

Pulled By: cheng-chang

fbshipit-source-id: 568878c24a924912e35cef00c552d4a63431cdf4
2020-06-13 13:25:20 -07:00
Zhichao Cao
b3585a11b4 Ingest SST files with checksum information (#6891)
Summary:
Application can ingest SST files with file checksum information, such that during ingestion, DB is able to check data integrity and identify of the SST file. The PR introduces generate_and_verify_file_checksum to IngestExternalFileOption to control if the ingested checksum information should be verified with the generated checksum.

    1. If generate_and_verify_file_checksum options is *FALSE*: *1)* if DB does not enable SST file checksum, the checksum information ingested will be ignored; *2)* if DB enables the SST file checksum and the checksum function name matches the checksum function name in DB, we trust the ingested checksum, store it in Manifest. If the checksum function name does not match, we treat that as an error and fail the IngestExternalFile() call.
    2. If generate_and_verify_file_checksum options is *TRUE*: *1)* if DB does not enable SST file checksum, the checksum information ingested will be ignored; *2)* if DB enable the SST file checksum, we will use the checksum generator from DB to calculate the checksum for each ingested SST files after they are copied or moved. Then, compare the checksum results with the ingested checksum information: _A)_ if the checksum function name does not match, _verification always report true_ and we store the DB generated checksum information in Manifest. _B)_ if the checksum function name mach, and checksum match, ingestion continues and stores the checksum information in the Manifest. Otherwise, terminate file ingestion and report file corruption.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6891

Test Plan: added unit test, pass make asan_check

Reviewed By: pdillinger

Differential Revision: D21935988

Pulled By: zhichao-cao

fbshipit-source-id: 7b55f486632db467e76d72602218d0658aa7f6ed
2020-06-11 14:27:36 -07:00
Peter Dillinger
edf74d1cb1 Add --version and --help to ldb and sst_dump (#6951)
Summary:
as title
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6951

Test Plan: tests included + manual

Reviewed By: ajkr

Differential Revision: D21918540

Pulled By: pdillinger

fbshipit-source-id: 79d4991f2a831214fc7e477a839ec19dbbace6c5
2020-06-09 10:04:01 -07:00
Yanqin Jin
3020df9df5 Remove unnecessary inclusion of version_edit.h in env (#6952)
Summary:
In db_options.c, we should avoid including header files in the `db` directory to avoid introducing unnecessary dependency. The reason why `version_edit.h` has been included in `db_options.cc` is because we need two constants, `kUnknownChecksum` and `kUnknownChecksumFuncName`. We can put these two constants as `constexpr` in the public header `file_checksum.h`.

Test plan (devserver):
make check
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6952

Reviewed By: zhichao-cao

Differential Revision: D21925341

Pulled By: riversand963

fbshipit-source-id: 2902f3b74c97f0cf16c58ad24c095c787c3a40e2
2020-06-07 21:56:55 -07:00
Akanksha Mahajan
2677bd5967 Add logs and stats in DeleteScheduler (#6927)
Summary:
Add logs and stats for files marked as trash and files deleted immediately in DeleteScheduler
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6927

Test Plan: make check -j64

Reviewed By: riversand963

Differential Revision: D21869068

Pulled By: akankshamahajan15

fbshipit-source-id: e9f673c4fa8049ce648b23c75d742f2f9c6c57a1
2020-06-05 09:43:04 -07:00
Peter Dillinger
c7432cc3c0 Fix more defects reported by Coverity Scan (#6935)
Summary:
Mostly uninitialized values: some probably written before use, but some seem like bugs. Also, destructor needs to be virtual, and possible use-after-free in test
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6935

Test Plan: make check

Reviewed By: siying

Differential Revision: D21885484

Pulled By: pdillinger

fbshipit-source-id: e2e7cb0a0cf196f2b55edd16f0634e81f6cc8e08
2020-06-04 15:35:08 -07:00
Zitan Chen
02df00d97b API change: DB::OpenForReadOnly will not write to the file system unless create_if_missing is true (#6900)
Summary:
DB::OpenForReadOnly will not write anything to the file system (i.e., create directories or files for the DB) unless create_if_missing is true.

This change also fixes some subcommands of ldb, which write to the file system even if the purpose is for readonly.

Two tests for this updated behavior of DB::OpenForReadOnly are also added.

Other minor changes:
1. Updated HISTORY.md to include this API change of DB::OpenForReadOnly;
2. Updated the help information for the put and batchput subcommands of ldb with the option [--create_if_missing];
3. Updated the comment of Env::DeleteDir to emphasize that it returns OK only if the directory to be deleted is empty.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6900

Test Plan: passed make check; also manually tested a few ldb subcommands

Reviewed By: pdillinger

Differential Revision: D21822188

Pulled By: gg814

fbshipit-source-id: 604cc0f0d0326a937ee25a32cdc2b512f9a3be6e
2020-06-03 18:57:49 -07:00
Stanislav Tkach
b7c825d5cf Add (some) getters for options to the C API (#6925)
Summary:
Additionally I have extended the incomplete test added in the https://github.com/facebook/rocksdb/issues/6880.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6925

Reviewed By: ajkr

Differential Revision: D21869788

Pulled By: pdillinger

fbshipit-source-id: e9db80f259c57ca1bdcbc2c66cb938cb1ac26e48
2020-06-03 17:08:50 -07:00
Anatoly Zhmur
22e5c513c2 Add zstd_max_train_bytes to c interop (#6796)
Summary:
Added setting of zstd_max_train_bytes compression option parameter to c interop.

rocksdb_options_set_bottommost_compression_options was using bool parameter and thus not exported, updated it to unsigned char and added to c.h as well.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6796

Reviewed By: cheng-chang

Differential Revision: D21611471

Pulled By: ajkr

fbshipit-source-id: caaaf153de934837ad9af283c7f8c025ff0b0cf5
2020-06-03 12:27:12 -07:00
Stanislav Tkach
38f988d3b4 Expose rocksdb_options_copy function to the C API (#6880)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/6880

Reviewed By: ajkr

Differential Revision: D21842752

Pulled By: pdillinger

fbshipit-source-id: eda326f551ddd9cb397681544b9e9799ea614e52
2020-06-02 13:48:51 -07:00
Peter Dillinger
14eca6bf04 For ApproximateSizes, pro-rate table metadata size over data blocks (#6784)
Summary:
The implementation of GetApproximateSizes was inconsistent in
its treatment of the size of non-data blocks of SST files, sometimes
including and sometimes now. This was at its worst with large portion
of table file used by filters and querying a small range that crossed
a table boundary: the size estimate would include large filter size.

It's conceivable that someone might want only to know the size in terms
of data blocks, but I believe that's unlikely enough to ignore for now.
Similarly, there's no evidence the internal function AppoximateOffsetOf
is used for anything other than a one-sided ApproximateSize, so I intend
to refactor to remove redundancy in a follow-up commit.

So to fix this, GetApproximateSizes (and implementation details
ApproximateSize and ApproximateOffsetOf) now consistently include in
their returned sizes a portion of table file metadata (incl filters
and indexes) based on the size portion of the data blocks in range. In
other words, if a key range covers data blocks that are X% by size of all
the table's data blocks, returned approximate size is X% of the total
file size. It would technically be more accurate to attribute metadata
based on number of keys, but that's not computationally efficient with
data available and rarely a meaningful difference.

Also includes miscellaneous comment improvements / clarifications.

Also included is a new approximatesizerandom benchmark for db_bench.
No significant performance difference seen with this change, whether ~700 ops/sec with cache_index_and_filter_blocks and small cache or ~150k ops/sec without cache_index_and_filter_blocks.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6784

Test Plan:
Test added to DBTest.ApproximateSizesFilesWithErrorMargin.
Old code running new test...

    [ RUN      ] DBTest.ApproximateSizesFilesWithErrorMargin
    db/db_test.cc:1562: Failure
    Expected: (size) <= (11 * 100), actual: 9478 vs 1100

Other tests updated to reflect consistent accounting of metadata.

Reviewed By: siying

Differential Revision: D21334706

Pulled By: pdillinger

fbshipit-source-id: 6f86870e45213334fedbe9c73b4ebb1d8d611185
2020-06-02 12:30:23 -07:00
Akanksha Mahajan
bcefc59e9f Allow MultiGet users to limit cumulative value size (#6826)
Summary:
1. Add a value_size in read options which limits the cumulative value size of keys read in batches. Once the size exceeds read_options.value_size, all the remaining keys are returned with status Abort without further fetching any key.
2. Add a unit test case MultiGetBatchedValueSizeSimple the reads keys from memory and sst files.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6826

Test Plan:
1. make check -j64
	   2. Add a new unit test case

Reviewed By: anand1976

Differential Revision: D21471483

Pulled By: akankshamahajan15

fbshipit-source-id: dea51b8e76d5d1df38ece8cdb29933b1d798b900
2020-05-27 13:07:14 -07:00
Peter Dillinger
803a517b48 Misc things for ASSERT_STATUS_CHECKED, also gcc 4.8.5 (#6871)
Summary:
* Print stack trace on status checked failure
* Make folly_synchronization_distributed_mutex_test a parallel test
* Disable ldb_test.py and rocksdb_dump_test.sh with
  ASSERT_STATUS_CHECKED (broken)
* Fix shadow warning in random_access_file_reader.h reported by gcc
  4.8.5 (ROCKSDB_NO_FBCODE), also https://github.com/facebook/rocksdb/issues/6866
* Work around compiler bug on max_align_t for gcc < 4.9
* Remove an apparently wrong comment in status.h
* Use check_some in Travis config (for proper diagnostic output)
* Fix ignored Status in loop in options_helper.cc
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6871

Test Plan: manual, CI

Reviewed By: ajkr

Differential Revision: D21706619

Pulled By: pdillinger

fbshipit-source-id: daf6364173d6689904eb394461a69a11f5bee2cb
2020-05-23 06:53:37 -07:00
Peter Dillinger
c7aedf1b48 Clean up some code related to file checksums (#6861)
Summary:
* Add missing unit test for schema stability of FileChecksumGenCrc32c
  (previously was only comparing to itself)
* A lot of clarifying comments
* Add some assertions for preconditions
* Rename WritableFileWriter::CalculateFileChecksum -> UpdateFileChecksum
* Simplify FileChecksumGenCrc32c with shared functions
* Implement EndianSwapValue to replace unused EndianTransform

And incidentally since I had trouble with 'make check-format' GitHub action disagreeing with local run,
* Output full diagnostic information when 'make check-format' fails in CI
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6861

Test Plan: new unit test passes before & after other changes

Reviewed By: zhichao-cao

Differential Revision: D21667115

Pulled By: pdillinger

fbshipit-source-id: 6a99970f87605aa024fa540c78cd519ff322c3e6
2020-05-21 08:12:51 -07:00
Zhichao Cao
545e14b53b Generate file checksum in SstFileWriter (#6859)
Summary:
If Option.file_checksum_gen_factory is set, rocksdb generates the file checksum during flush and compaction based on the checksum generator created by the factory and store the checksum and function name in vstorage and Manifest.

This PR enable file checksum generation in SstFileWrite and store the checksum and checksum function name in the  ExternalSstFileInfo, such that application can use them for other purpose, for example, ingest the file checksum with files in IngestExternalFile().
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6859

Test Plan: add unit test and pass make asan_check.

Reviewed By: ajkr

Differential Revision: D21656247

Pulled By: zhichao-cao

fbshipit-source-id: 78a3570c76031d8832e3d2de3d6c79cdf2b675d0
2020-05-20 11:55:31 -07:00
Cheng Chang
b9d65f5aa6 Trigger compaction in CompactOnDeletionCollector based on deletion ratio (#6806)
Summary:
In level compaction, if the total size (even if compensated after taking account of the deletions) of a level hasn't exceeded the limit, but there are lots of deletion entries in some SST files of the level, these files should also be good candidates for compaction. Otherwise, queries for the deleted keys might be slow because they need to go over all the tombstones.

This PR adds an option `deletion_ratio` to the factory of `CompactOnDeletionCollector` to configure it to trigger compaction when the ratio of tombstones >= `deletion_ratio`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6806

Test Plan:
Added new unit test in `compact_on_deletion_collector_test.cc`.
make compact_on_deletion_collector_test && ./compact_on_deletion_collector_test

Reviewed By: ajkr

Differential Revision: D21511981

Pulled By: cheng-chang

fbshipit-source-id: 65a9d0150e8c9c00337787686475252e4535a3e1
2020-05-18 08:42:05 -07:00
Stanislav Tkach
70aaa9ceeb Expose CancellAllBackgroundWork to C api (#6832)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/6832

Reviewed By: cheng-chang

Differential Revision: D21498186

Pulled By: riversand963

fbshipit-source-id: 66bb0d7c06af2bf0df3c6a09b61bca2fb81f2dd3
2020-05-12 14:50:52 -07:00
sdong
a50ea71c00 Improve ldb consistency checks (#6802)
Summary:
When using ldb, users cannot turn on force consistency check in most commands, while they cannot use checksonsistnecy with --try_load_options. The change fixes both by:
1. checkconsistency now calls OpenDB() so that it gets all the options loading and sanitized options logic
2. use options.check_consistency_checks = true by default, and add a --disable_consistency_checks to turn it off.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6802

Test Plan: Add a new unit test. Some manual tests with corrupted DBs.

Reviewed By: pdillinger

Differential Revision: D21388051

fbshipit-source-id: 8d122732d391b426e3982a1c3232a8e3763ffad0
2020-05-08 14:17:47 -07:00
Andrew Kryczka
1c84660457 prototype status check enforcement (#6798)
Summary:
Tried making Status object enforce that it is checked in some way. In cases it is not checked, `PermitUncheckedError()` must be called explicitly.

Added a way to run tests (`ASSERT_STATUS_CHECKED=1 make -j48 check`) on a
whitelist. The effort appears significant to get each test to pass with
this assertion, so I only fixed up enough to get one test (`options_test`)
working and added it to the whitelist.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6798

Reviewed By: pdillinger

Differential Revision: D21377404

Pulled By: ajkr

fbshipit-source-id: 73236f9c8df38f01cf24ecac4a6d1661b72d077e
2020-05-08 12:40:43 -07:00
anand76
f286fb344b Include options.h in table.h (#6823)
Summary:
https://github.com/facebook/rocksdb/issues/6389 replaced the #include of options.h in table.h with forward declarations, which is causing some build failures in RocksDB users in 6.10. Remove the forward declarations and #include options.h as recommended by the style guide - https://google.github.io/styleguide/cppguide.html#Forward_Declarations
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6823

Reviewed By: riversand963

Differential Revision: D21464078

Pulled By: anand1976

fbshipit-source-id: 6033ee2544d279690f57bb0db91bc83816cee11d
2020-05-07 15:55:29 -07:00
Andrew Kryczka
e9ba4ba348 validate range tombstone covers positive range (#6788)
Summary:
We found some files containing nothing but negative range tombstones,
and unsurprisingly their metadata specified a negative range, which made
things crash. Time to add a bit of user input validation.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6788

Reviewed By: zhichao-cao

Differential Revision: D21343719

Pulled By: ajkr

fbshipit-source-id: f1c16e4c3e9fa150958c8c866176632a3206fb74
2020-05-07 11:55:30 -07:00
anand76
c1e1185b7a Update release version to 6.10 (#6797)
Summary:
Update HISTORY.md and version.h to 6.10.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6797

Reviewed By: zhichao-cao

Differential Revision: D21371390

Pulled By: anand1976

fbshipit-source-id: 6017bca24fc5d12076d1ddaec7783c9b85712d42
2020-05-06 16:42:37 -07:00
Cheng Chang
ef0c3eda27 Make users explicitly be aware of prepare before commit (#6775)
Summary:
In current commit protocol of pessimistic transaction, if the transaction is not prepared before commit, the commit protocol implicitly assumes that the user wants to commit without prepare.

This PR adds TransactionOptions::skip_prepare, the default value is `true` because if set to `false`, all existing users who commit without prepare need to update their code to set skip_prepare to true. Although this does not force the user to explicitly express their intention of skip_prepare, it at least lets the user be aware of the assumption of being able to commit without prepare.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6775

Test Plan: added a new unit test TransactionTest::CommitWithoutPrepare

Reviewed By: lth

Differential Revision: D21313270

Pulled By: cheng-chang

fbshipit-source-id: 3d95b7c9b2d6cdddc09bdd66c561bc4fae8c3251
2020-04-30 16:24:20 -07:00
sdong
6277e28039 Flag CompressionOptions::parallel_threads to be experimental (#6781)
Summary:
The feature of CompressionOptions::parallel_threads is still not yet mature. Mention it to be experimental in the comments for now.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6781

Reviewed By: pdillinger

Differential Revision: D21330678

fbshipit-source-id: d7dd7d099fb002a5c6a5d8da689ce5ee08a9eb13
2020-04-30 15:22:06 -07:00
anand76
ab13d43e1d Pass a timeout to FileSystem for random reads (#6751)
Summary:
Calculate ```IOOptions::timeout``` using ```ReadOptions::deadline``` and pass it to ```FileSystem::Read/FileSystem::MultiRead```. This allows us to impose a tighter bound on the time taken by Get/MultiGet on FileSystem/Envs that support IO timeouts. Even on those that don't support, check in ```RandomAccessFileReader::Read``` and ```MultiRead``` and return ```Status::TimedOut()``` if the deadline is exceeded.

For now, TableReader creation, which might do file opens and reads, are not covered. It will be implemented in another PR.

Tests:
Update existing unit tests to verify the correct timeout value is being passed
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6751

Reviewed By: riversand963

Differential Revision: D21285631

Pulled By: anand1976

fbshipit-source-id: d89af843e5a91ece866e87aa29438b52a65a8567
2020-04-30 14:50:39 -07:00
mrambacher
618bf638aa Add Functions to OptionTypeInfo (#6422)
Summary:
Added functions for parsing, serializing, and comparing elements to OptionTypeInfo.  These functions allow all of the special cases that could not be handled directly in the map of OptionTypeInfo to be moved into the map.  Using these functions, every type can be handled via the map rather than special cased.

By adding these functions, the code for handling options can become more standardized (fewer special cases) and (eventually) handled completely by common classes.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6422

Test Plan: pass make check

Reviewed By: siying

Differential Revision: D21269005

Pulled By: zhichao-cao

fbshipit-source-id: 9ba71c721a38ebf9ee88259d60bd81b3282b9077
2020-04-28 18:04:26 -07:00
Peter Dillinger
b810e62b39 Clarifying comments in db.h (#6768)
Summary:
And fix a confusingly worded log message
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6768

Reviewed By: anand1976

Differential Revision: D21284527

Pulled By: pdillinger

fbshipit-source-id: f03c1422c229a901c3a65e524740452349626164
2020-04-28 15:26:03 -07:00
Albert Hse-Lin Chen
cc8d16efd6 Fixed minor typo in comment for MergeOperator::FullMergeV2() (#6759)
Summary:
Fixed minor typo in comment for FullMergeV2().
Last operand up to snapshot should be +4 instead of +3.

Signed-off-by: Albert Hse-Lin Chen <hselin@kalista.io>
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6759

Reviewed By: cheng-chang

Differential Revision: D21260295

Pulled By: zhichao-cao

fbshipit-source-id: cc942306f246c8606538feb30bfdf6df9fb6c54e
2020-04-27 14:44:47 -07:00
Peter Dillinger
249eff0f30 Stats for redundant insertions into block cache (#6681)
Summary:
Since read threads do not coordinate on loading data into block
cache, two threads between Lookup and Insert can end up loading and
inserting the same data. This is particularly concerning with
cache_index_and_filter_blocks since those are hot and more likely to
be race targets if ejected from (or not pre-populated in) the cache.

Particularly with moves toward disaggregated / network storage, the cost
of redundant retrieval might be high, and we should at least have some
hard statistics from which we can estimate impact.

Example with full filter thrashing "cliff":

    $ ./db_bench --benchmarks=fillrandom --num=15000000 --cache_index_and_filter_blocks -bloom_bits=10
    ...
    $ ./db_bench --db=/tmp/rocksdbtest-172704/dbbench --use_existing_db --benchmarks=readrandom,stats --num=200000 --cache_index_and_filter_blocks --cache_size=$((130 * 1024 * 1024)) --bloom_bits=10 --threads=16 -statistics 2>&1 | egrep '^rocksdb.block.cache.(.*add|.*redundant)' | grep -v compress | sort
    rocksdb.block.cache.add COUNT : 14181
    rocksdb.block.cache.add.failures COUNT : 0
    rocksdb.block.cache.add.redundant COUNT : 476
    rocksdb.block.cache.data.add COUNT : 12749
    rocksdb.block.cache.data.add.redundant COUNT : 18
    rocksdb.block.cache.filter.add COUNT : 1003
    rocksdb.block.cache.filter.add.redundant COUNT : 217
    rocksdb.block.cache.index.add COUNT : 429
    rocksdb.block.cache.index.add.redundant COUNT : 241
    $ ./db_bench --db=/tmp/rocksdbtest-172704/dbbench --use_existing_db --benchmarks=readrandom,stats --num=200000 --cache_index_and_filter_blocks --cache_size=$((120 * 1024 * 1024)) --bloom_bits=10 --threads=16 -statistics 2>&1 | egrep '^rocksdb.block.cache.(.*add|.*redundant)' | grep -v compress | sort
    rocksdb.block.cache.add COUNT : 1182223
    rocksdb.block.cache.add.failures COUNT : 0
    rocksdb.block.cache.add.redundant COUNT : 302728
    rocksdb.block.cache.data.add COUNT : 31425
    rocksdb.block.cache.data.add.redundant COUNT : 12
    rocksdb.block.cache.filter.add COUNT : 795455
    rocksdb.block.cache.filter.add.redundant COUNT : 130238
    rocksdb.block.cache.index.add COUNT : 355343
    rocksdb.block.cache.index.add.redundant COUNT : 172478
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6681

Test Plan: Some manual testing (above) and unit test covering key metrics is included

Reviewed By: ltamasi

Differential Revision: D21134113

Pulled By: pdillinger

fbshipit-source-id: c11497b5f00f4ffdfe919823904e52d0a1a91d87
2020-04-27 13:20:27 -07:00
mrambacher
4cbc19d2a1 Add a ConfigOptions for use in comparing objects and converting to/from strings (#6389)
Summary:
The methods in convenience.h are used to compare/convert objects to/from strings.  There is a mishmash of parameters in use here with more needed in the future.  This PR replaces those parameters with a single structure.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6389

Reviewed By: siying

Differential Revision: D21163707

Pulled By: zhichao-cao

fbshipit-source-id: f807b4cc7e2b0af3871536b69546b2604dfa81bd
2020-04-21 17:38:17 -07:00
anand76
c1ccd6b6af Implement deadline support for MultiGet (#6710)
Summary:
Initial implementation of ReadOptions.deadline for MultiGet. If the request takes longer than the deadline, the keys not yet found will be returned with Status::TimedOut(). This
implementation enforces the deadline in DBImpl, which is fairly high
level. Its best effort and may not check the deadline after every key
lookup, but may do so after a batch of keys.

In subsequent stages, we will extend this to passing a timeout down to the FileSystem.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6710

Test Plan: Add new unit tests

Reviewed By: riversand963

Differential Revision: D21149158

Pulled By: anand1976

fbshipit-source-id: 9f44eecffeb40873f5034ed59a66d21f9f88879e
2020-04-21 14:51:51 -07:00
Peter Dillinger
31da5e34c1 C++20 compatibility (#6697)
Summary:
Based on https://github.com/facebook/rocksdb/issues/6648 (CLA Signed), but heavily modified / extended:

* Implicit capture of this via [=] deprecated in C++20, and [=,this] not standard before C++20 -> now using explicit capture lists
* Implicit copy operator deprecated in gcc 9 -> add explicit '= default' definition
* std::random_shuffle deprecated in C++17 and removed in C++20 -> migrated to a replacement in RocksDB random.h API
* Add the ability to build with different std version though -DCMAKE_CXX_STANDARD=11/14/17/20 on the cmake command line
* Minimal rebuild flag of MSVC is deprecated and is forbidden with /std:c++latest (C++20)
* Added MSVC 2019 C++11 & MSVC 2019 C++20 in AppVeyor
* Added GCC 9 C++11 & GCC9 C++20 in Travis
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6697

Test Plan: make check and CI

Reviewed By: cheng-chang

Differential Revision: D21020318

Pulled By: pdillinger

fbshipit-source-id: 12311be5dbd8675a0e2c817f7ec50fa11c18ab91
2020-04-20 13:24:25 -07:00
Yanqin Jin
243852ec15 Add IsDirectory() to Env and FS (#6711)
Summary:
IsDirectory() is a common API to check whether a path is a regular file or
directory.
POSIX: call stat() and use S_ISDIR(st_mode)
Windows: PathIsDirectoryA() and PathIsDirectoryW()
HDFS: FileSystem.IsDirectory()
Java: File.IsDirectory()
...
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6711

Test Plan: make check

Reviewed By: anand1976

Differential Revision: D21053520

Pulled By: riversand963

fbshipit-source-id: 680aadfd8ce982b63689190cf31b3145d5a89e27
2020-04-17 14:39:18 -07:00
Mike Kolupaev
e45673dece Properly report IO errors when IndexType::kBinarySearchWithFirstKey is used (#6621)
Summary:
Context: Index type `kBinarySearchWithFirstKey` added the ability for sst file iterator to sometimes report a key from index without reading the corresponding data block. This is useful when sst blocks are cut at some meaningful boundaries (e.g. one block per key prefix), and many seeks land between blocks (e.g. for each prefix, the ranges of keys in different sst files are nearly disjoint, so a typical seek needs to read a data block from only one file even if all files have the prefix). But this added a new error condition, which rocksdb code was really not equipped to deal with: `InternalIterator::value()` may fail with an IO error or Status::Incomplete, but it's just a method returning a Slice, with no way to report error instead. Before this PR, this type of error wasn't handled at all (an empty slice was returned), and kBinarySearchWithFirstKey implementation was considered a prototype.

Now that we (LogDevice) have experimented with kBinarySearchWithFirstKey for a while and confirmed that it's really useful, this PR is adding the missing error handling.

It's a pretty inconvenient situation implementation-wise. The error needs to be reported from InternalIterator when trying to access value. But there are ~700 call sites of `InternalIterator::value()`, most of which either can't hit the error condition (because the iterator is reading from memtable or from index or something) or wouldn't benefit from the deferred loading of the value (e.g. compaction iterator that reads all values anyway). Adding error handling to all these call sites would needlessly bloat the code. So instead I made the deferred value loading optional: only the call sites that may use deferred loading have to call the new method `PrepareValue()` before calling `value()`. The feature is enabled with a new bool argument `allow_unprepared_value` to a bunch of methods that create iterators (it wouldn't make sense to put it in ReadOptions because it's completely internal to iterators, with virtually no user-visible effect). Lmk if you have better ideas.

Note that the deferred value loading only happens for *internal* iterators. The user-visible iterator (DBIter) always prepares the value before returning from Seek/Next/etc. We could go further and add an API to defer that value loading too, but that's most likely not useful for LogDevice, so it doesn't seem worth the complexity for now.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6621

Test Plan: make -j5 check . Will also deploy to some logdevice test clusters and look at stats.

Reviewed By: siying

Differential Revision: D20786930

Pulled By: al13n321

fbshipit-source-id: 6da77d918bad3780522e918f17f4d5513d3e99ee
2020-04-15 17:40:44 -07:00
anand76
3d6d7bcf17 Log CompactOnDeletionCollectorFactory parameters on DB open (#6686)
Summary:
Log it in the info log to help in troubleshooting. It is logged as follows -
```
2020/04/10-10:51:39.886662 7ffff7fef340                   Options.table_properties_collectors: CompactOnDeletionCollector (Sliding window size = 100 Deletion trigger = 90);
```

Tests:
make check
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6686

Reviewed By: ltamasi

Differential Revision: D21002442

Pulled By: anand1976

fbshipit-source-id: 7adf0dbae7f1febcb00ce61fea5097118ede5c6a
2020-04-13 19:58:04 -07:00
Zhichao Cao
38dfa406ff Add NewFileChecksumGenCrc32cFactory to file checksum (#6688)
Summary:
Add NewFileChecksumGenCrc32cFactory to file checksum public interface such that applications can use the build in crc32 checksum factory.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6688

Test Plan: pass make asan_check

Reviewed By: riversand963

Differential Revision: D21006859

Pulled By: zhichao-cao

fbshipit-source-id: ea8a45196a8b77c310728ab05f6cc0f49f3baef0
2020-04-13 19:13:41 -07:00