Commit Graph

35 Commits

Author SHA1 Message Date
mrambacher
30b08878d8 Make FilterPolicy Customizable (#9590)
Summary:
Make FilterPolicy into a Customizable class.  Allow new FilterPolicy to be discovered through the ObjectRegistry

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9590

Reviewed By: pdillinger

Differential Revision: D34327367

Pulled By: mrambacher

fbshipit-source-id: 37e7edac90ec9457422b72f359ab8ef48829c190
2022-02-18 13:22:31 -08:00
Peter Dillinger
e24734f843 Use -Wno-invalid-offsetof instead of dangerous offset_of hack (#9563)
Summary:
After https://github.com/facebook/rocksdb/issues/9515 added a unique_ptr to Status, we see some
warnings-as-error in some internal builds like this:

```
stderr: rocksdb/src/db/compaction/compaction_job.cc:2839:7: error:
offset of on non-standard-layout type 'struct CompactionServiceResult'
[-Werror,-Winvalid-offsetof]
     {offsetof(struct CompactionServiceResult, status),
      ^                                        ~~~~~~
```

I see three potential solutions to resolving this:

* Expand our use of an idiom that works around the warning (see offset_of
functions removed in this change, inspired by
https://gist.github.com/graphitemaster/494f21190bb2c63c5516)  However,
this construction is invoking undefined behavior that assumes consistent
layout with no compiler-introduced indirection. A compiler incompatible
with our assumptions will likely compile the code and exhibit undefined
behavior.
* Migrate to something in place of offset, like a function mapping
CompactionServiceResult* to Status* (for the `status` field). This might
be required in the long term.
* **Selected:** Use our new C++17 dependency to use offsetof in a well-defined way
when the compiler allows it. From a comment on
https://gist.github.com/graphitemaster/494f21190bb2c63c5516:

> A final note: in C++17, offsetof is conditionally supported, which
> means that you can use it on any type (not just standard layout
> types) and the compiler will error if it can't compile it correctly.
> That appears to be the best option if you can live with C++17 and
> don't need constexpr support.

The C++17 semantics are confirmed on
https://en.cppreference.com/w/cpp/types/offsetof, so we can suppress the
warning as long as we accept that we might run into a compiler that
rejects the code, and at that point we will find a solution, such as
the more intrusive "migrate" solution above.

Although this is currently only showing in our buck build, it will
surely show up also with make and cmake, so I have updated those
configurations as well.

Also in the buck build, -Wno-expansion-to-defined does not appear to be
needed anymore (both current compiler configurations) so I
removed it.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9563

Test Plan: Tried out buck builds with both current compiler configurations

Reviewed By: riversand963

Differential Revision: D34220931

Pulled By: pdillinger

fbshipit-source-id: d39436008259bd1eaaa87c77be69fb2a5b559e1f
2022-02-15 09:19:19 -08:00
mrambacher
fe9d495112 Return different Status based on ObjectRegistry::NewObject calls (#9333)
Summary:
This fix addresses https://github.com/facebook/rocksdb/issues/9299.

If attempting to create a new object via the ObjectRegistry and a factory is not found, the ObjectRegistry will return a "NotSupported" status.  This is the same behavior as previously.

If the factory is found but could not successfully create the object, an "InvalidArgument" status is returned.  If the factory returned a reason why (in the errmsg), this message will be in the returned status.

In practice, there are two options in the ConfigOptions that control how these errors are propagated:
- If "ignore_unknown_options=true", then both InvalidArgument and NotSupported status codes will be swallowed internally.  Both cases will return success
- If "ignore_unsupported_options=true", then having no factory will return success but a failing factory will return an error
- If both options are false, both cases (no and failing factory) will return errors.

In practice this likely only changes Customizable that may be partially available.  For example, the JEMallocMemoryAllocator is a built-in allocator that is registered with the system but may not be compiled in.  In this case, the status code for this allocator changed from NotSupported("JEMalloc not available") to InvalidArgumen("JEMalloc not available").  Other Customizable builtins/plugins would have the same semantics.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9333

Reviewed By: pdillinger

Differential Revision: D33517681

Pulled By: mrambacher

fbshipit-source-id: 8033052d4a4a7b88c2d9f90147b1b4467e51f6fd
2022-02-11 05:11:24 -08:00
mrambacher
1973fcba11 Restore Regex support for ObjectLibrary::Register, rename new APIs to allow old one to be deprecated in the future (#9362)
Summary:
In order to support old-style regex function registration, restored the original "Register<T>(string, Factory)" method using regular expressions.  The PatternEntry methods were left in place but renamed to AddFactory.  The goal is to allow for the deprecation of the original regex Registry method in an upcoming release.

Added modes to the PatternEntry kMatchZeroOrMore and kMatchAtLeastOne to match * or +, respectively (kMatchAtLeastOne was the original behavior).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9362

Reviewed By: pdillinger

Differential Revision: D33432562

Pulled By: mrambacher

fbshipit-source-id: ed88ab3f9a2ad0d525c7bd1692873f9bb3209d02
2022-01-11 06:33:48 -08:00
Yanqin Jin
55a2105258 Make RocksDB codebase compatible with newer compilers like clang-12 (#9370)
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9370

GCC and newer clang, e.g. clang-12 treat `std::unique_ptr` slightly differently.
For the following code
```
#include <iostream>
#include <memory>
#include <type_traits>

struct A {
    std::unique_ptr<int> m1;
};

int main()
{
    std::cout << std::boolalpha;
    std::cout << std::is_standard_layout<A>::value << '\n';
    return 0;
}
```
GCC11(C++20) (tested on https://en.cppreference.com/w/cpp/types/is_standard_layout) will print "true", while newer clang, e.g. clang-12 will print "false". This breaks the usage of `offsetof()` on structs with non-static members of type `std::unique_ptr`.
Fixing this by replacing the builtin `offsetof` with a trick documented at https://gist.github.com/graphitemaster/494f21190bb2c63c5516.

Reviewed By: jay-zhuang

Differential Revision: D33420840

fbshipit-source-id: 02bde281dfa28809bec787ad0f7019e85dd9c607
2022-01-10 11:09:05 -08:00
mrambacher
1c39b7952b Remove/Reduce use of Regex in ObjectRegistry/Library (#9264)
Summary:
Added new ObjectLibrary::Entry classes to replace/reduce the use of Regex.  For simple factories that only do name matching, there are "StringEntry" and "AltStringEntry" classes.  For classes that use some semblance of regular expressions, there is a PatternEntry class that can match a name and prefixes.  There is also a class for Customizable::IndividualId format matches.

Added tests for the new derivative classes and got all unit tests to pass.

Resolves https://github.com/facebook/rocksdb/issues/9225.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9264

Reviewed By: pdillinger

Differential Revision: D33062001

Pulled By: mrambacher

fbshipit-source-id: c2d2143bd2d38bdf522705c8280c35381b135c03
2021-12-29 07:56:23 -08:00
mrambacher
423538a816 Make MemoryAllocator into a Customizable class (#8980)
Summary:
- Make MemoryAllocator and its implementations into a Customizable class.
- Added a "DefaultMemoryAllocator" which uses new and delete
- Added a "CountedMemoryAllocator" that counts the number of allocs and free
- Updated the existing tests to use these new allocators
- Changed the memkind allocator test into a generic test that can test the various allocators.
- Added tests for creating all of the allocators
- Added tests to verify/create the JemallocNodumpAllocator using its options.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8980

Reviewed By: zhichao-cao

Differential Revision: D32990403

Pulled By: mrambacher

fbshipit-source-id: 6fdfe8218c10dd8dfef34344a08201be1fa95c76
2021-12-17 04:20:47 -08:00
mrambacher
7cd5835a28 Make RateLimiter Customizable (#9141)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/9141

Reviewed By: zhichao-cao

Differential Revision: D32432190

Pulled By: mrambacher

fbshipit-source-id: 7930ed88a02412128cd407b5063522484e45c6ce
2021-12-01 06:57:02 -08:00
mrambacher
7aa31ba4a9 Fix GetOptionsPtr for Wrapped Customizable; Allow null options map (#9213)
Summary:
1.  Fix GetOptionsPtr for Wrapped (Inner() != nullptr) Customizable objects.  This allows the inner options to be returned via this method.

2.  Allow the option type map to be nullptr.  This allows objects to be registered as options (for GetOptionsPtr) but not be used by the configuration methods.

Added tests as appropriate.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9213

Reviewed By: zhichao-cao

Differential Revision: D32718882

Pulled By: mrambacher

fbshipit-source-id: 563203d1f006a2629060feb31c5dff9a233e1e83
2021-11-30 13:23:25 -08:00
mrambacher
f72c834eab Make FileSystem a Customizable Class (#8649)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8649

Reviewed By: zhichao-cao

Differential Revision: D32036059

Pulled By: mrambacher

fbshipit-source-id: 4f1e7557ecac52eb849b83ae02b8d7d232112295
2021-11-02 09:07:11 -07:00
mrambacher
8fb3fe8d39 Allow unregistered options to be ignored in DBOptions from files (#9045)
Summary:
Adds changes to DBOptions (comparable to ColumnFamilyOptions) to allow some option values to be ignored on rehydration from the Options file.  This is necessary for some customizable classes that were not registered with the ObjectRegistry but are saved/restored from the Options file.

All tests pass.  Will run check_format_compatible.sh shortly.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9045

Reviewed By: zhichao-cao

Differential Revision: D31761664

Pulled By: mrambacher

fbshipit-source-id: 300c2251639cce2b223481c3bb2a63877b1f3766
2021-10-19 10:43:04 -07:00
mrambacher
7fd68b7c39 Make WalFilter, SstPartitionerFactory, FileChecksumGenFactory, and TableProperties Customizable (#8638)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8638

Reviewed By: zhichao-cao

Differential Revision: D31024729

Pulled By: mrambacher

fbshipit-source-id: 954c04ccab0b8dee64050a27aadf78ed119106c0
2021-09-28 05:32:02 -07:00
mrambacher
e0f697d2bd Make SliceTransform into a Customizable class (#8641)
Summary:
Made SliceTransform into a Customizable class.

Would be nice to write a test that stored and used a custom transform  in an SST table.

There are a set of tests (DBBlockFliterTest.PrefixExtractor*, SamePrefixTest.InDomainTest, PrefixTest.PrefixAndWholeKeyTest that run the same with or without a SliceTransform/PrefixFilter.  Is this expected?

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8641

Reviewed By: zhichao-cao

Differential Revision: D31142793

Pulled By: mrambacher

fbshipit-source-id: bb08672fccbfdc263dcae21f25a62307e1facda1
2021-09-27 07:43:47 -07:00
mrambacher
6924869867 Make SystemClock into a Customizable Class (#8636)
Summary:
Made SystemClock into a Customizable class, complete with CreateFromString.

Cleaned up some of the existing SystemClock implementations that were redundant (NoSleep was the same as the internal one for MockEnv).

Changed MockEnv construction to allow Clock to be passed to the Memory/MockFileSystem.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8636

Reviewed By: zhichao-cao

Differential Revision: D30483360

Pulled By: mrambacher

fbshipit-source-id: cd0e3a876c39f8c98fe13374c06e8edbd5b9f2a1
2021-09-21 09:23:48 -07:00
mrambacher
dc0dc90cf5 Make Statistics a Customizable Class (#8637)
Summary:
Make the Statistics object into a Customizable object.  Statistics can now be stored and created to/from the Options file.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8637

Reviewed By: zhichao-cao

Differential Revision: D30530550

Pulled By: mrambacher

fbshipit-source-id: 5fc7d01d8431f37b2c205bbbd8342c9f697023bd
2021-09-10 09:47:39 -07:00
mrambacher
0fb938c448 Add support to the ObjectRegistry for ManagedObjects (#8658)
Summary:
ManagedObjects are  shared pointer objects where RocksDB wants to share a single object between multiple configurations.  For example, the Cache may be shared between multiple column families/tables or the Statistics may be shared between multiple databases.

ManagedObjects are stored in the ObjectRegistry by Type (e.g. Cache) and ID.  For a given type/ID name, a single object is stored.

APIs were added to get/set/create these objects.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8658

Reviewed By: pdillinger

Differential Revision: D30806273

Pulled By: mrambacher

fbshipit-source-id: 832ac4423b210c4c4b4a456b35897334775d3160
2021-09-10 05:21:04 -07:00
mrambacher
beed86473a Make MemTableRepFactory into a Customizable class (#8419)
Summary:
This PR does the following:
-> Makes the MemTableRepFactory into a Customizable class and creatable/configurable via CreateFromString
-> Makes the existing implementations compatible with configurations
-> Moves the "SpecialRepFactory" test class into testutil, accessible via the ObjectRegistry or a NewSpecial API

New tests were added to validate the functionality and all existing tests pass.  db_bench and memtablerep_bench were hand-tested to verify the functionality in those tools.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8419

Reviewed By: zhichao-cao

Differential Revision: D29558961

Pulled By: mrambacher

fbshipit-source-id: 81b7229636e4e649a0c914e73ac7b0f8454c931c
2021-09-08 07:46:44 -07:00
mrambacher
6e63e77af1 Make Configurable/Customizable options copyable (#8704)
Summary:
The atomic variable "is_prepared_" was keeping Configurable objects from being copy-constructed.  Removed the atomic to allow copies.

Since the variable is only changed from false to true (and never back), there is no reason it had to be atomic.

Added tests that simple Configurable and Customizable objects can be put on the stack and copied.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8704

Reviewed By: anand1976

Differential Revision: D30530526

Pulled By: ltamasi

fbshipit-source-id: 4dd4439b3e5ad7fa396573d0b25d9fb709160576
2021-08-25 17:48:08 -07:00
mrambacher
2e062b2227 Fix LITE build (#8689)
Summary:
Conditional compilation of static functions not used in LITE mode.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8689

Reviewed By: ltamasi

Differential Revision: D30476218

Pulled By: mrambacher

fbshipit-source-id: 5f3af90982d34818f47d2cb1d36dd5816d0333a5
2021-08-23 05:10:13 -07:00
mrambacher
9eb002fcf0 Fix some minor issues in the Customizable infrastructure (#8566)
Summary:
- Fix issue with OptionType::Vector when the nested item is a Customizable with no names
- Fix issue with OptionType::Vector to appropriately wrap the elements in a Vector;
- Fix an issue with nested Customizable object with a null immutable object still appearing in the mutable options;
- Fix/Add tests for null/empty customizable objects
- Move the RegisterTestObjects from customizable_test into testutil.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8566

Reviewed By: zhichao-cao

Differential Revision: D30303724

Pulled By: mrambacher

fbshipit-source-id: 33fa8ea2a3b663210cb356da05e64aab7585b1b5
2021-08-19 10:10:47 -07:00
mrambacher
d057e8326d Make MergeOperator+CompactionFilter/Factory into Customizable Classes (#8481)
Summary:
- Changed MergeOperator, CompactionFilter, and CompactionFilterFactory into Customizable classes.
 - Added Options/Configurable/Object Registration for TTL and Cassandra variants
 - Changed the StringAppend MergeOperators to accept a string delimiter rather than a simple char.  Made the delimiter into a configurable option
 - Added tests for new functionality

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8481

Reviewed By: zhichao-cao

Differential Revision: D30136050

Pulled By: mrambacher

fbshipit-source-id: 271d1772835935b6773abaf018ee71e42f9491af
2021-08-06 08:27:25 -07:00
mrambacher
3aee4fbd41 Make EventListener into a Customizable Class (#8473)
Summary:
- Added Type/CreateFromString
- Added ability to load EventListeners to DBOptions
- Since EventListeners did not previously have a Name(), defaulted to "".  If there is no name, the listener cannot be loaded from the ObjectRegistry.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8473

Reviewed By: zhichao-cao

Differential Revision: D29901488

Pulled By: mrambacher

fbshipit-source-id: 2d3a4aa6db1562ac03e7ad41b360e3521d486254
2021-07-27 07:47:02 -07:00
mrambacher
ac37bfded0 Allow CreateFromString to work on complex URIs (#8547)
Summary:
Some URIs for creating instances (ala SecondaryCache) use complex URIs like (cache://name;prop=value).  These URIs were treated as name-value properties.  With this change, if the URI does not contain an "id=XX" setting, it will be treated as a single string value (and not an ID and map of name-value properties).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8547

Reviewed By: anand1976

Differential Revision: D29741386

Pulled By: mrambacher

fbshipit-source-id: 0621f62bec3a6699a7b66c7c0b5634b2856653aa
2021-07-16 15:05:45 -07:00
Mark Rambacher
42ba60b3ba Make EncryptionProvider and BlockCipher into Customizable objects (#8354)
Summary:
Made the EncryptionProvider and BlockCipher classes inherit from Customizable.  Added/fixed the CreateFromString method to these classes to create instances from builtin or registered classes.  Added tests to verify that instances can be registered and retrieved as appropriate.

Added the ability to configure the builtin (CTR, ROT13) classes from configurable properties.  Added the appropriate tests.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8354

Reviewed By: zhichao-cao

Differential Revision: D29558949

Pulled By: mrambacher

fbshipit-source-id: c20286b32d179777e060f51a58943e9b0cf81d04
2021-07-16 07:58:51 -07:00
mrambacher
c8665611bc Make FlushBlockPolicyFactory into a Customizable class (#8432)
Summary:
Add ability to treat FlushBlockPolicyFactory as a Customizable.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8432

Reviewed By: zhichao-cao

Differential Revision: D29558941

Pulled By: mrambacher

fbshipit-source-id: 4a791af941ea4a65fc2f1fdfb1d7a95f42ca6774
2021-07-12 09:04:59 -07:00
mrambacher
570248aeff Make SecondaryCache Customizable (#8480)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8480

Reviewed By: zhichao-cao

Differential Revision: D29528740

Pulled By: mrambacher

fbshipit-source-id: fd0f70d15f66611c8498257a9973f7e98ca13839
2021-07-06 09:18:08 -07:00
mrambacher
41c4b665f4 Fix PrepareOptions for Customizable Classes (#8468)
Summary:
Added the Customizable::ConfigureNewObject method.  The method will configure the object if options are found and invoke PrepareOptions if the flag is set properly.

Added tests to test that PrepareOptions is properly called and to test if PrepareOptions fails.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8468

Reviewed By: zhichao-cao

Differential Revision: D29494703

Pulled By: mrambacher

fbshipit-source-id: d5767dee5d7a98620ac66190262101cd0aa9d2b7
2021-06-30 14:09:36 -07:00
mrambacher
89f66d4484 Add customizable_util.h to the public API (#8301)
Summary:
Useful for allowing new classes to create and manage Customizable objects without using internal APIs.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8301

Reviewed By: zhichao-cao

Differential Revision: D29428303

Pulled By: mrambacher

fbshipit-source-id: 3d33d5197cc8379fe35b54d3d169f91f0dfe7a47
2021-06-29 09:08:57 -07:00
mrambacher
373e3a154d Fix Immutable Customizable Serialization (#8457)
Summary:
If a Customizable option was not mutable, it would still appear in the list of mutable options when serialized. This meant that when the immutable options were used to configure another immutable object, an "option not changeable" status would be returned.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8457

Reviewed By: zhichao-cao

Differential Revision: D29428298

Pulled By: mrambacher

fbshipit-source-id: 3945b0b822f8e5955a7c5590fe64dfd5bc1fe6a0
2021-06-28 12:28:28 -07:00
mrambacher
d81c2d1e3d Add Inner method and support for wrapped Customizable (#8373)
Summary:
Inner method added for classes to override to return has-a relationship.  CheckedCast expanded to use Inner to return has-a relationship.

Future Customizable classes (Env, FileSystem, Statistics, etc) will use this feature

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8373

Reviewed By: pdillinger

Differential Revision: D29176369

Pulled By: mrambacher

fbshipit-source-id: cfb6d7702fa365ca4e40c4a50a19e3a534e5ac43
2021-06-17 08:39:36 -07:00
mrambacher
6ad0810393 Make Comparator into a Customizable Object (#8336)
Summary:
Makes the Comparator class into a Customizable object.  Added/Updated the CreateFromString method to create Comparators.  Added test for using the ObjectRegistry to create one.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8336

Reviewed By: jay-zhuang

Differential Revision: D28999612

Pulled By: mrambacher

fbshipit-source-id: bff2cb2814eeb9fef6a00fddc61d6e34b6fbcf2e
2021-06-11 06:22:59 -07:00
mrambacher
9f2d255aed Add ObjectRegistry to ConfigOptions (#8166)
Summary:
This change enables a couple of things:
- Different ConfigOptions can have different registry/factory associated with it, thereby allowing things like a "Test" ConfigOptions versus a "Production"
- The ObjectRegistry is created fewer times and can be re-used

The ConfigOptions can also be initialized/constructed from a DBOptions, in which case it will grab some of its settings (Env, Logger) from the DBOptions.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8166

Reviewed By: zhichao-cao

Differential Revision: D27657952

Pulled By: mrambacher

fbshipit-source-id: ae1d6200bb7ab127405cdeefaba43c7fe694dfdd
2021-05-11 06:47:22 -07:00
mrambacher
6bab3a34e9 Move RegisterOptions into the Configurable API (#8223)
Summary:
As previously coded, a Configurable extension would need access to code not in the public API.  This change moves RegisterOptions into the Configurable class and therefore available to public extensions.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8223

Reviewed By: anand1976

Differential Revision: D27960188

Pulled By: mrambacher

fbshipit-source-id: ac88b19397183df633902def5b5701b9b65fbf40
2021-04-26 03:13:24 -07:00
mrambacher
4bc9df9459 Fix handling of Mutable options; Allow DB::SetOptions to update mutable TableFactory Options (#7936)
Summary:
Added a "only_mutable_options" flag to the ConfigOptions.  When set, the Configurable methods will only look at/update options that are marked as kMutable.

Fixed DB::SetOptions to allow for the update of any mutable TableFactory options.  Fixes https://github.com/facebook/rocksdb/issues/7385.

Added tests for the new flag.  Updated HISTORY.md

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7936

Reviewed By: akankshamahajan15

Differential Revision: D26389646

Pulled By: mrambacher

fbshipit-source-id: 6dc247f6e999fa2814059ebbd0af8face109fea0
2021-02-19 10:29:02 -08:00
mrambacher
c442f6809f Create a Customizable class to load classes and configurations (#6590)
Summary:
The Customizable class is an extension of the Configurable class and allows instances to be created by a name/ID.  Classes that extend customizable can define their Type (e.g. "TableFactory", "Cache") and  a method to instantiate them (TableFactory::CreateFromString).  Customizable objects can be registered with the ObjectRegistry and created dynamically.

Future PRs will make more types of objects extend Customizable.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/6590

Reviewed By: cheng-chang

Differential Revision: D24841553

Pulled By: zhichao-cao

fbshipit-source-id: d0c2132bd932e971cbfe2c908ca2e5db30c5e155
2020-11-11 15:10:41 -08:00