Commit Graph

320 Commits

Author SHA1 Message Date
Peter Dillinger 50e9b3f9c7 Default print stack traces with GDB on Linux (#11272)
Summary:
On Linux systems using full ASLR, including CircleCI, the old backtrace()+addr2line stack traces are pretty useless, as seen in some failures under ASSERT_STATUS_CHECKED=1 LIB_MODE=static. Use gdb by default for stack traces under Linux. More detail in code comments.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11272

Test Plan: manual testing locally and on CircleCI with ssh

Reviewed By: anand1976

Differential Revision: D43786211

Pulled By: pdillinger

fbshipit-source-id: f8c7c77f774b504fbdf7c786ff2430cbc8f5b939
2023-03-05 08:21:57 -08:00
Andrew Kryczka fcd816d534 Add missing override keyword in env_win.h functions (#11232)
Summary:
I couldn't figure out why this causes failures in our 8.0 release to fbcode while this issue appears to not be new in 8.0. Anyways, we can add the missing `override` keywords to these functions as the compiler insists.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11232

Reviewed By: pdillinger

Differential Revision: D43420656

Pulled By: ajkr

fbshipit-source-id: da748eeef6ba38dd113dbe4b5143d7558daf38dd
2023-02-18 17:30:15 -08:00
Wentian Guo 42d6652ba2 remove dependency on options.h for port_posix.h andport_win.h (#11214)
Summary:
The files in `port/`, such as `port_posix.h`, are layering over the system libraries, so shouldn't include the DB-specific files like `options.h`. This PR remove this dependency.

# How
The reason that `port_posix.h` (or `port_win.h`) include `options.h` is to use `CpuPriority`, as there is a method `SetCpuPriority()` in `port_posix.h` that uses `CpuPriority.`
- I think `SetCpuPriority()` make sense to exist in `port_posix.h` as it provides has platform-dependent implementation
- `CpuPriority` enum is defined in `env.h`, but used in `rocksdb/include` and `port/`.

Hence, let us define `CpuPriority` enum in a common file, say `port_defs.h`, such that both directories `rocksdb/include` and `port/` can include.

When we remove this dependency, some other files have compile errors because they can't find definitions, so add header files to resolve

# Test
make all check -j

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11214

Reviewed By: pdillinger

Differential Revision: D43196910

Pulled By: guowentian

fbshipit-source-id: 70deccb72844cfb08fcc994f76c6ef6df5d55ab9
2023-02-13 02:21:38 -08:00
Peter Dillinger 27cf09172c Fix compile gettid on older Linux (#11184)
Summary:
Seen only in post-PR CI job benchmark-linux. Some context: https://stackoverflow.com/questions/30680550/c-gettid-was-not-declared-in-this-scope

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11184

Test Plan: watch CI

Reviewed By: cbi42

Differential Revision: D43013891

Pulled By: pdillinger

fbshipit-source-id: 48b3b7231080a0f803fdc36d13946d5524770302
2023-02-03 16:49:54 -08:00
Peter Dillinger e17f31057b Support stack traces with gdb (and debugger invocation) (#11150)
Summary:
LIB_MODE=shared is much more efficient for building all the unit tests but comes with the downside of ugly stack traces, generally missing name demangling and source line info. Searching the internet suggests the reliable way to get stack traces with dynamic loading is with gdb.

This change automatically tries to use gdb to get a stack trace if built with LIB_MODE=shared, and only on Linux because that's where we have the capability to attach to the proper thread. (We could revise the exact conditions in the future.) If there's a failure invoking gdb, it falls back on the old method. Obscure details of making the output reasonable / pretty are in the source code comments.

Based on this, it was easy to make it so that running a test command with ROCKSDB_DEBUG=1 would invoke gdb whenever the stack trace handler was invoked, so I included that.

Intended follow-up: make LIB_MODE=shared the new default `make` build config

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11150

Test Plan:
manual, mostly by injecting an "assert(false)" into a unit test and trying different build modes etc.

Although gdb is slower to start showing stack trace output, it seems overall faster in many if not most cases, presumably because it doesn't reload the symbol table for each stack entry. At least with parallel test runs, having many tests dumping stacks with the old method can take so long it appears to hang the test run.

Reviewed By: cbi42

Differential Revision: D42894064

Pulled By: pdillinger

fbshipit-source-id: 608143309d8c69c40049c9a4abcde4f22e87b4d8
2023-02-03 13:21:03 -08:00
sdong 4720ba4391 Remove RocksDB LITE (#11147)
Summary:
We haven't been actively mantaining RocksDB LITE recently and the size must have been gone up significantly. We are removing the support.

Most of changes were done through following comments:

unifdef -m -UROCKSDB_LITE `git grep -l ROCKSDB_LITE | egrep '[.](cc|h)'`

by Peter Dillinger. Others changes were manually applied to build scripts, CircleCI manifests, ROCKSDB_LITE is used in an expression and file db_stress_test_base.cc.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11147

Test Plan: See CI

Reviewed By: pdillinger

Differential Revision: D42796341

fbshipit-source-id: 4920e15fc2060c2cd2221330a6d0e5e65d4b7fe2
2023-01-27 13:14:19 -08:00
Wenlong Zhang 1cfe3528a2 support loongarch64 for rocksdb (#10036)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/10036

Reviewed By: hx235

Differential Revision: D42424074

Pulled By: ajkr

fbshipit-source-id: 004adb75005a26bd01c5d568d1ec6ac442cd59dd
2023-01-13 08:42:44 -08:00
Peter Dillinger 5d3953114f Fix include of windows.h in mmap.h (#10885)
Summary:
If windows.h is not included in a particular way, it can conflict with other code including it. I don't know all the details, but having just one standard place where we include windows.h in header files seems best and seems to fix the internal issue we hit.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10885

Test Plan: CI and internal validation

Reviewed By: anand1976

Differential Revision: D40738945

Pulled By: pdillinger

fbshipit-source-id: 88f635e895b1c7b810baad159e6dbb8351344cac
2022-10-26 18:07:57 -07:00
sdong 7cf27eae0a clang format files under port/ (#10849)
Summary:
Run "clang-format" against files under port to make it happy.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10849

Test Plan: Watch existing CI to pass.

Reviewed By: anand1976

Differential Revision: D40645839

fbshipit-source-id: 582b4215503223795cf6234af90cc4e8e4eba773
2022-10-24 16:56:01 -07:00
Peter Dillinger 7555243bcf Refactor ShardedCache for more sharing, static polymorphism (#10801)
Summary:
The motivations for this change include
* Free up space in ClockHandle so that we can add data for secondary cache handling while still keeping within single cache line (64 byte) size.
  * This change frees up space by eliminating the need for the `hash` field by making the fixed-size key itself a hash, using a 128-bit bijective (lossless) hash.
* Generally more customizability of ShardedCache (such as hashing) without worrying about virtual call overheads
  * ShardedCache now uses static polymorphism (template) instead of dynamic polymorphism (virtual overrides) for the CacheShard. No obvious performance benefit is seen from the change (as mostly expected; most calls to virtual functions in CacheShard could already be optimized to static calls), but offers more flexibility without incurring the runtime cost of adhering to a common interface (without type parameters or static callbacks).
  * You'll also notice less `reinterpret_cast`ing and other boilerplate in the Cache implementations, as this can go in ShardedCache.

More detail:
* Don't have LRUCacheShard maintain `std::shared_ptr<SecondaryCache>` copies (extra refcount) when LRUCache can be in charge of keeping a `shared_ptr`.
* Renamed `capacity_mutex_` to `config_mutex_` to better represent the scope of what it guards.
* Some preparation for 64-bit hash and indexing in LRUCache, but didn't include the full change because of slight performance regression.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10801

Test Plan:
Unit test updates were non-trivial because of major changes to the ClockCacheShard interface in handling of key vs. hash.

Performance:
Create with `TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=fillrandom -num=30000000 -disable_wal=1 -bloom_bits=16`

Test with
```
TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=readrandom[-X1000] -readonly -num=30000000 -bloom_bits=16 -cache_index_and_filter_blocks=1 -cache_size=610000000 -duration 20 -threads=16
```

Before: `readrandom [AVG 150 runs] : 321147 (± 253) ops/sec`
After: `readrandom [AVG 150 runs] : 321530 (± 326) ops/sec`

So possibly ~0.1% improvement.

And with `-cache_type=hyper_clock_cache`:
Before: `readrandom [AVG 30 runs] : 614126 (± 7978) ops/sec`
After: `readrandom [AVG 30 runs] : 645349 (± 8087) ops/sec`

So roughly 5% improvement!

Reviewed By: anand1976

Differential Revision: D40252236

Pulled By: pdillinger

fbshipit-source-id: ff8fc70ef569585edc95bcbaaa0386f61355ae5b
2022-10-18 22:06:57 -07:00
Peter Dillinger e466173d5c Print stack traces on frozen tests in CI (#10828)
Summary:
Instead of existing calls to ps from gnu_parallel, call a new wrapper that does ps, looks for unit test like processes, and uses pstack or gdb to print thread stack traces. Also, using `ps -wwf` instead of `ps -wf` ensures output is not cut off.

For security, CircleCI runs with security restrictions on ptrace (/proc/sys/kernel/yama/ptrace_scope = 1), and this change adds a work-around to `InstallStackTraceHandler()` (only used by testing tools) to allow any process from the same user to debug it. (I've also touched >100 files to ensure all the unit tests call this function.)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10828

Test Plan: local manual + temporary infinite loop in a unit test to observe in CircleCI

Reviewed By: hx235

Differential Revision: D40447634

Pulled By: pdillinger

fbshipit-source-id: 718a4c4a5b54fa0f9af2d01a446162b45e5e84e1
2022-10-18 00:35:35 -07:00
Peter Dillinger 8367f0d2d7 Improve / refactor anonymous mmap capabilities (#10810)
Summary:
The motivation for this change is a planned feature (related to HyperClockCache) that will depend on a large array that can essentially grow automatically, up to some bound, without the pointer address changing and with guaranteed zero-initialization of the data. Anonymous mmaps provide such functionality, and this change provides an internal API for that.

The other existing use of anonymous mmap in RocksDB is for allocating in huge pages. That code and other related Arena code used some awkward non-RAII and pre-C++11 idioms, so I cleaned up much of that as well, with RAII, move semantics, constexpr, etc.

More specifcs:
* Minimize conditional compilation
* Add Windows support for anonymous mmaps
* Use std::deque instead of std::vector for more efficient bag

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10810

Test Plan: unit test added for new functionality

Reviewed By: riversand963

Differential Revision: D40347204

Pulled By: pdillinger

fbshipit-source-id: ca83fcc47e50fabf7595069380edd2954f4f879c
2022-10-17 17:10:16 -07:00
Andrew Hutchings ce529a4ce1 Fix FreeBSD building (#10575)
Summary:
FreeBSD doesn't have `JEMALLOC_USABLE_SIZE_CONST` so we need to define
it.

This fixes MariaDB MDEV-20248.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10575

Reviewed By: jay-zhuang

Differential Revision: D39057665

Pulled By: ajkr

fbshipit-source-id: 3874779d12a1dd5036324947f6372e6ad57a7b08
2022-08-28 00:05:51 -07:00
sdong cc2099803a Use EnvLogger instead of PosixLogger (#10436)
Summary:
EnvLogger was built to replace PosixLogger that supports multiple Envs. Make FileSystem use EnvLogger by default, remove Posix FS specific implementation and remove PosixLogger code,
Some hacky changes are made to make sure iostats are not polluted by logging, in order to pass existing unit tests.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10436

Test Plan: Run db_bench and watch info log files.

Reviewed By: anand1976

Differential Revision: D38259855

fbshipit-source-id: 67d65874bfba7a33535b6d0dd0ed92cbbc9888b8
2022-08-01 14:37:18 -07:00
zczhu 96206531bc Support reservation in thread pool (#10278)
Summary:
Add `ReserveThreads` and `ReleaseThreads` functions in thread pool to support reservation in for a specific thread pool.  With this feature, a thread will be blocked if the number of waiting threads (noted by `num_waiting_threads_`) equals the number of reserved threads (noted by `reserved_threads_`), normally `reserved_threads_` is upper bounded by `num_waiting_threads_`; in rare cases (e.g. `SetBackgroundThreadsInternal` is called when some threads are already reserved), `num_waiting_threads_` can be less than `reserved_threads`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10278

Test Plan: Add `ReserveThreads` unit test in `env_test`. Update the unit test `SimpleColumnFamilyInfoTest` in `thread_list_test` with adding `ReserveThreads` related assertions.

Reviewed By: hx235

Differential Revision: D37640946

Pulled By: littlepig2013

fbshipit-source-id: 4d691f6b9a433569f96ab52d52c3defe5b065367
2022-07-08 19:48:09 -07:00
Johnny Shaw c2dc4c0c52 Fix GetWindowsErrSz nullptr bug (#10282)
Summary:
`GetWindowsErrSz` may assign a `nullptr` to `std::string` in the event it cannot format the error code to a string. This will result in a crash when `std::string` attempts to calculate the length from `nullptr`.

The change here checks the output from `FormatMessageA` and only assigns to the otuput `std::string` if it is not null. Additionally, the call to free the buffer is only made if a non-null value is returned from `FormatMessageA`. In the event `FormatMessageA` does not output a string, an empty string is returned instead.

Fixes https://github.com/facebook/rocksdb/issues/10274

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10282

Reviewed By: riversand963

Differential Revision: D37542143

Pulled By: ajkr

fbshipit-source-id: c21f5119ddb451f76960acec94639d0f538052f2
2022-06-29 20:41:54 -07:00
Bo Wang c073ed7601 Fix typo in comments and code (#10233)
Summary:
Fix typo in comments and code.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10233

Test Plan: Existing unit tests should pass.

Reviewed By: jay-zhuang, anand1976

Differential Revision: D37356702

Pulled By: gitbw95

fbshipit-source-id: 32c019adcc6dcc95a9882b38147a310091368e51
2022-06-22 15:45:21 -07:00
Peter Dillinger 1aac814578 Use optimized folly DistributedMutex in LRUCache when available (#10179)
Summary:
folly DistributedMutex is faster than standard mutexes though
imposes some static obligations on usage. See
https://github.com/facebook/folly/blob/main/folly/synchronization/DistributedMutex.h
for details. Here we use this alternative for our Cache implementations
(especially LRUCache) for better locking performance, when RocksDB is
compiled with folly.

Also added information about which distributed mutex implementation is
being used to cache_bench output and to DB LOG.

Intended follow-up:
* Use DMutex in more places, perhaps improving API to support non-scoped
locking
* Fix linking with fbcode compiler (needs ROCKSDB_NO_FBCODE=1 currently)

Credit: Thanks Siying for reminding me about this line of work that was previously
left unfinished.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10179

Test Plan:
for correctness, existing tests. CircleCI config updated.
Also Meta-internal buck build updated.

For performance, ran simultaneous before & after cache_bench. Out of three
comparison runs, the middle improvement to ops/sec was +21%:

Baseline: USE_CLANG=1 DEBUG_LEVEL=0 make -j24 cache_bench (fbcode
compiler)

```
Complete in 20.201 s; Rough parallel ops/sec = 1584062
Thread ops/sec = 107176

Operation latency (ns):
Count: 32000000 Average: 9257.9421  StdDev: 122412.04
Min: 134  Median: 3623.0493  Max: 56918500
Percentiles: P50: 3623.05 P75: 10288.02 P99: 30219.35 P99.9: 683522.04 P99.99: 7302791.63
```

New: (add USE_FOLLY=1)

```
Complete in 16.674 s; Rough parallel ops/sec = 1919135  (+21%)
Thread ops/sec = 135487

Operation latency (ns):
Count: 32000000 Average: 7304.9294  StdDev: 108530.28
Min: 132  Median: 3777.6012  Max: 91030902
Percentiles: P50: 3777.60 P75: 10169.89 P99: 24504.51 P99.9: 59721.59 P99.99: 1861151.83
```

Reviewed By: anand1976

Differential Revision: D37182983

Pulled By: pdillinger

fbshipit-source-id: a17eb05f25b832b6a2c1356f5c657e831a5af8d1
2022-06-17 13:08:45 -07:00
Ali Saidi 2e5a323dbd Change the instruction used for a pause on arm64 (#10118)
Summary:
While the yield instruction conseptually sounds correct on most platforms it is
a simple nop that doesn't delay the execution anywhere close to what an x86
pause instruction does. In other projects with spin-wait loops an isb has been
observed to be much closer to the x86 behavior.

On a Graviton3 system the following test improves on average by 2x with this
change averaged over 20 runs:

```
./db_bench  -benchmarks=fillrandom -threads=64 -batch_size=1
-memtablerep=skip_list -value_size=100 --num=100000
level0_slowdown_writes_trigger=9999 -level0_stop_writes_trigger=9999
-disable_auto_compactions --max_write_buffer_number=8 -max_background_flushes=8
--disable_wal --write_buffer_size=160000000 --block_size=16384
--allow_concurrent_memtable_write -compression_type none
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10118

Reviewed By: jay-zhuang

Differential Revision: D37120578

fbshipit-source-id: c20bde4298222edfab7ff7cb6d42497e7012400d
2022-06-15 13:08:11 -07:00
Ali Saidi b550fc0b09 Modify the instructions emited for PREFETCH on arm64 (#10117)
Summary:
__builtin_prefetch(...., 1) prefetches into the L2 cache on x86 while the same
emits a pldl3keep instruction on arm64 which doesn't seem to be close enough.

Testing on a Graviton3, and M1 system with memtablerep_bench fillrandom and
skiplist througpuh increased as follows adjusting the 1 to 2 or 3:
```
           1 -> 2     1 -> 3
----------------------------
Graviton3   +10%        +15%
M1          +10%        +10%
```

Given that prefetching into the L1 cache seems to help, I chose that conversion

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10117

Reviewed By: pdillinger

Differential Revision: D37120475

fbshipit-source-id: db1ef43f941445019c68316500a2250acc643d5e
2022-06-14 17:58:44 -07:00
Zichen Zhu 65893ad959 Explicitly closing all directory file descriptors (#10049)
Summary:
Currently, the DB directory file descriptor is left open until the deconstruction process (`DB::Close()` does not close the file descriptor). To verify this, comment out the lines between `db_ = nullptr` and `db_->Close()` (line 512, 513, 514, 515 in ldb_cmd.cc) to leak the ``db_'' object, build `ldb` tool and run
```
strace --trace=open,openat,close ./ldb --db=$TEST_TMPDIR --ignore_unknown_options put K1 V1 --create_if_missing
```
There is one directory file descriptor that is not closed in the strace log.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10049

Test Plan: Add a new unit test DBBasicTest.DBCloseAllDirectoryFDs: Open a database with different WAL directory and three different data directories, and all directory file descriptors should be closed after calling Close(). Explicitly call Close() after a directory file descriptor is not used so that the counter of directory open and close should be equivalent.

Reviewed By: ajkr, hx235

Differential Revision: D36722135

Pulled By: littlepig2013

fbshipit-source-id: 07bdc2abc417c6b30997b9bbef1f79aa757b21ff
2022-06-01 18:03:34 -07:00
tagliavini 6c50082654 Remove code that only compiles for Visual Studio versions older than 2015 (#10065)
Summary:
There are currently some preprocessor checks that assume support for Visual Studio versions older than 2015 (i.e., 0 < _MSC_VER < 1900), although we don't support them any more.

We removed all code that only compiles on those older versions, except third-party/ files.

The ROCKSDB_NOEXCEPT symbol is now obsolete, since it now always gets replaced by noexcept. We removed it.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10065

Reviewed By: pdillinger

Differential Revision: D36721901

Pulled By: guidotag

fbshipit-source-id: a2892d365ef53cce44a0a7d90dd6b72ee9b5e5f2
2022-05-26 16:55:08 -07:00
Levi Tamasi af7ae912e2 Fix potential ambiguities in/around port/sys_time.h (#10045)
Summary:
There are some time-related POSIX APIs that are not available on Windows
(e.g. `localtime_r`), which we have worked around by providing our own
implementations in `port/sys_time.h`. This workaround actually relies on
some ambiguity: on Windows, a call to `localtime_r` calls
`ROCKSDB_NAMESPACE::port::localtime_r` (which is pulled into
`ROCKSDB_NAMESPACE` by a using-declaration), while on other platforms
it calls the global `localtime_r`. This works fine as long as there is only one
candidate function; however, it breaks down when there is more than one
`localtime_r` visible in a scope.

The patch fixes this by introducing `ROCKSDB_NAMESPACE::port::{TimeVal, GetTimeOfDay, LocalTimeR}`
to eliminate any ambiguity.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10045

Test Plan: `make check`

Reviewed By: riversand963

Differential Revision: D36639372

Pulled By: ltamasi

fbshipit-source-id: fc13dbfa421b7c8918111a6d9e24ce77e91a7c50
2022-05-24 18:20:17 -07:00
Yaroslav Stepanchuk 0a43061f8d Remove ROCKSDB_SUPPORT_THREAD_LOCAL define because it's a part of C++11 (#10015)
Summary:
ROCKSDB_SUPPORT_THREAD_LOCAL definition has been removed.
`__thread`(#define) has been replaced with `thread_local`(C++ keyword) across the code base.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10015

Reviewed By: siying

Differential Revision: D36485491

Pulled By: pdillinger

fbshipit-source-id: 6522d212514ee190b90b4e2750c80c7e34013c78
2022-05-18 15:25:19 -07:00
mrambacher b11ff347b4 Use STATIC_AVOID_DESTRUCTION for static objects with non-trivial destructors (#9958)
Summary:
Changed the static objects that had non-trivial destructors to use the STATIC_AVOID_DESTRUCTION construct.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9958

Reviewed By: pdillinger

Differential Revision: D36442982

Pulled By: mrambacher

fbshipit-source-id: 029d47b1374d30d198bfede369a4c0ae7a4eb519
2022-05-17 09:39:22 -07:00
mrambacher 204a42ca97 Added GetFactoryCount/Names/Types to ObjectRegistry (#9358)
Summary:
These methods allow for more thorough testing of the ObjectRegistry and Customizable infrastructure in a simpler manner.  With this change, the Customizable tests can now check what factories are registered and attempt to create each of them in a systematic fashion.

With this change, I think all of the factories registered with the ObjectRegistry/CreateFromString are now tested via the customizable_test classes.

Note that there were a few other minor changes.  There was a "posix://*" register with the ObjectRegistry which was missed during the PatternEntry conversion -- these changes found that.  The nickname and default names for the FileSystem classes was also inverted.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9358

Reviewed By: pdillinger

Differential Revision: D33433542

Pulled By: mrambacher

fbshipit-source-id: 9a32da74e6620745b4eeffb2712be70eeeadfa7e
2022-05-16 09:44:43 -07:00
sdong 49628c9a83 Use std::numeric_limits<> (#9954)
Summary:
Right now we still don't fully use std::numeric_limits but use a macro, mainly for supporting VS 2013. Right now we only support VS 2017 and up so it is not a problem. The code comment claims that MinGW still needs it. We don't have a CI running MinGW so it's hard to validate. since we now require C++17, it's hard to imagine MinGW would still build RocksDB but doesn't support std::numeric_limits<>.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9954

Test Plan: See CI Runs.

Reviewed By: riversand963

Differential Revision: D36173954

fbshipit-source-id: a35a73af17cdcae20e258cdef57fcf29a50b49e0
2022-05-05 13:08:21 -07:00
Peter Dillinger efd035164b Meta-internal folly integration with F14FastMap (#9546)
Summary:
Especially after updating to C++17, I don't see a compelling case for
*requiring* any folly components in RocksDB. I was able to purge the existing
hard dependencies, and it can be quite difficult to strip out non-trivial components
from folly for use in RocksDB. (The prospect of doing that on F14 has changed
my mind on the best approach here.)

But this change creates an optional integration where we can plug in
components from folly at compile time, starting here with F14FastMap to replace
std::unordered_map when possible (probably no public APIs for example). I have
replaced the biggest CPU users of std::unordered_map with compile-time
pluggable UnorderedMap which will use F14FastMap when USE_FOLLY is set.
USE_FOLLY is always set in the Meta-internal buck build, and a simulation of
that is in the Makefile for public CI testing. A full folly build is not needed, but
checking out the full folly repo is much simpler for getting the dependency,
and anything else we might want to optionally integrate in the future.

Some picky details:
* I don't think the distributed mutex stuff is actually used, so it was easy to remove.
* I implemented an alternative to `folly::constexpr_log2` (which is much easier
in C++17 than C++11) so that I could pull out the hard dependencies on
`ConstexprMath.h`
* I had to add noexcept move constructors/operators to some types to make
F14's complainUnlessNothrowMoveAndDestroy check happy, and I added a
macro to make that easier in some common cases.
* Updated Meta-internal buck build to use folly F14Map (always)

No updates to HISTORY.md nor INSTALL.md as this is not (yet?) considered a
production integration for open source users.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9546

Test Plan:
CircleCI tests updated so that a couple of them use folly.

Most internal unit & stress/crash tests updated to use Meta-internal latest folly.
(Note: they should probably use buck but they currently use Makefile.)

Example performance improvement: when filter partitions are pinned in cache,
they are tracked by PartitionedFilterBlockReader::filter_map_ and we can build
a test that exercises that heavily. Build DB with

```
TEST_TMPDIR=/dev/shm/rocksdb ./db_bench -benchmarks=fillrandom -num=10000000 -disable_wal=1 -write_buffer_size=30000000 -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -partition_index_and_filters
```

and test with (simultaneous runs with & without folly, ~20 times each to see
convergence)

```
TEST_TMPDIR=/dev/shm/rocksdb ./db_bench_folly -readonly -use_existing_db -benchmarks=readrandom -num=10000000 -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -partition_index_and_filters -duration=40 -pin_l0_filter_and_index_blocks_in_cache
```

Average ops/s no folly: 26229.2
Average ops/s with folly: 26853.3 (+2.4%)

Reviewed By: ajkr

Differential Revision: D34181736

Pulled By: pdillinger

fbshipit-source-id: ffa6ad5104c2880321d8a1aa7187e00ab0d02e94
2022-04-13 07:34:01 -07:00
Yuriy Chernyshov a6a179859e #include <winioctl.h> as MSDN prescribes (#9612)
Summary:
The recommendation can be found e. g. [here](https://docs.microsoft.com/en-us/windows/win32/api/winioctl/ns-winioctl-storage_property_query).

While `<windows.h>` transitively includes `<winioctl.h>` by default, this can be switched off by `/DWIN32_LEAN_AND_MEAN` which forces the user to include-what-you-use.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9612

Reviewed By: riversand963

Differential Revision: D34845629

Pulled By: ajkr

fbshipit-source-id: 1ef9273074e3d84864c6833a7de6eb9df81e29d9
2022-03-13 17:01:21 -07:00
Peter Dillinger fd3e0f43b3 Require C++17 (#9481)
Summary:
Drop support for some old compilers by requiring C++17 standard
(or higher). See https://github.com/facebook/rocksdb/issues/9388

First modification based on this is to remove some conditional compilation in slice.h (also
better for ODR)

Also in this PR:
* Fix some Makefile formatting that seems to affect ASSERT_STATUS_CHECKED config in
some cases
* Add c_test to NON_PARALLEL_TEST in Makefile
* Fix a clang-analyze reported "potential leak" in lru_cache_test
* Better "compatibility" definition of DEFINE_uint32 for old versions of gflags
* Fix a linking problem with shared libraries in Makefile (`./random_test: error while loading shared libraries: librocksdb.so.6.29: cannot open shared object file: No such file or directory`)
* Always set ROCKSDB_SUPPORT_THREAD_LOCAL and use thread_local (from C++11)
  * TODO in later PR: clean up that obsolete flag
* Fix a cosmetic typo in c.h (https://github.com/facebook/rocksdb/issues/9488)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9481

Test Plan:
CircleCI config substantially updated.

* Upgrade to latest Ubuntu images for each release
* Generally prefer Ubuntu 20, but keep a couple Ubuntu 16 builds with oldest supported
compilers, to ensure compatibility
* Remove .circleci/cat_ignore_eagain except for Ubuntu 16 builds, because this is to work
around a kernel bug that should not affect anything but Ubuntu 16.
* Remove designated gcc-9 build, because the default linux build now uses GCC 9 from
Ubuntu 20.
* Add some `apt-key add` to fix some apt "couldn't be verified" errors
* Generally drop SKIP_LINK=1; work-around no longer needed
* Generally `add-apt-repository` before `apt-get update` as manual testing indicated the
reverse might not work.

Travis:
* Use gcc-7 by default (remove specific gcc-7 and gcc-4.8 builds)
* TODO in later PR: fix s390x "Assembler messages: Error: invalid switch -march=z14" failure

AppVeyor:
* Completely dropped because we are dropping VS2015 support and CircleCI covers
VS >= 2017

Also local testing with old gflags (out of necessity when using ROCKSDB_NO_FBCODE=1).

Reviewed By: mrambacher

Differential Revision: D33946377

Pulled By: pdillinger

fbshipit-source-id: ae077c823905b45370a26c0103ada119459da6c1
2022-02-04 17:13:10 -08:00
Peter Dillinger e7ac7363b4 Add to HISTORY and minor loose ends from #9294, #9254 (#9386)
Summary:
Loose ends relate to mmap on 32-bit systems. (Testing is more
complicated when the feature was completely disabled on 32-bit.)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9386

Test Plan: CI

Reviewed By: ajkr

Differential Revision: D33590715

Pulled By: pdillinger

fbshipit-source-id: f2637036a538a552200adee65b6765fce8cae27b
2022-01-21 13:04:19 -08:00
Yanqin Jin 0376869f05 Remove using namespace (#9369)
Summary:
As title.
This is part of an fb-internal task.
First, remove all `using namespace` statements if applicable.
Next, utilize multiple build platforms and see if anything is broken.
Should anything become broken, fix the compilation errors with as little extra change as possible.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9369

Test Plan:
internal build and make check
make clean && make static_lib && cd examples && make all

Reviewed By: pdillinger

Differential Revision: D33517260

Pulled By: riversand963

fbshipit-source-id: 3fc4ce6402a073421dfd9a9b2d1c79441dca7a40
2022-01-12 09:31:12 -08:00
mrambacher fe31dc53ca Make the Env class Customizable (#9293)
Summary:
Allows the Env to have options (Configurable) and loads like other Customizable classes.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9293

Reviewed By: pdillinger, zhichao-cao

Differential Revision: D33181591

Pulled By: mrambacher

fbshipit-source-id: 55e823886c654d214eda9eedd45ccdc54dac14d7
2022-01-04 16:45:49 -08:00
Adam Retter 65996dd757 Fixes for building RocksJava builds on s390x (#9321)
Summary:
* Added Docker build environment for RocksJava on s390x
* Cache alignment size for s390x was incorrectly calculated on gcc 6.4.0
* Tighter control over which installed version of Java is used is required - build now correctly adheres to `JAVA_HOME` if it is set
* Alpine build scripts should be used on Alpine (previously CentOS script worked by falling through to minimal gcc version)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9321

Reviewed By: mrambacher

Differential Revision: D33259624

Pulled By: jay-zhuang

fbshipit-source-id: d791a5150581344925c3c3f9cbb9a3622d63b3b6
2021-12-22 12:57:50 -08:00
Peter Dillinger fc3a6eb74a Fix/improve 'must free heap allocations' code (#9209)
Summary:
Added missing include, and cleaned up to make same mistake less
likely in future (minimize conditional compilation)

Fixes https://github.com/facebook/rocksdb/issues/9183

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9209

Test Plan: added to existing test

Reviewed By: mrambacher

Differential Revision: D32631390

Pulled By: pdillinger

fbshipit-source-id: 63a0501855cf5fac9e22ca1e5c4f53725dbf3f93
2021-11-29 10:53:52 -08:00
Ikko Ashimine afcd32533c Fix typo in env_win.h (#9138)
Summary:
overide -> override

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9138

Reviewed By: jay-zhuang

Differential Revision: D32245235

Pulled By: mrambacher

fbshipit-source-id: bed62b843925bed806c06ca3485d33bb45a56dc7
2021-11-10 12:22:21 -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
Calin Culianu 82846f41d3 Fix incorrect order of comments in win_thread.cc (#9033)
Summary:
The comments in the `#endif` section at the end of the file were in the
wrong order.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9033

Reviewed By: mrambacher

Differential Revision: D31935856

Pulled By: ajkr

fbshipit-source-id: 24aca039993d6e27022cfe8d6434e90f2934c87c
2021-10-27 13:25:01 -07:00
Jonathan Albrecht e970248602 Add support for building on s390x platform (#8962)
Summary:
This PR adds support for building on s390x including updating travis CI. It uses the previous work in https://github.com/facebook/rocksdb/pull/6168 and adds some more changes to get all current tests (make check and jni tests) to pass. The tests were run with snappy, lz4, bzip2 and zstd all compiled in.

There are a few pieces still needed to get the travis build working that I don't think I can do. adamretter is this something you could help with?

1. A prebuilt https://rocksdb-deps.s3-us-west-2.amazonaws.com/cmake/cmake-3.14.5-Linux-s390x.deb package
2. A https://hub.docker.com/r/evolvedbinary/rocksjava s390x image

Not sure if there is more required for travis. Happy to help in any way I can.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8962

Reviewed By: mrambacher

Differential Revision: D31802198

Pulled By: pdillinger

fbshipit-source-id: 683511466fa6b505f85ba5a9964a268c6151f0c2
2021-10-22 10:13:15 -07:00
Andrew Kryczka 791bff5b4e Prevent deadlock in db_stress with DbStressCompactionFilter (#8956)
Summary:
The cyclic dependency was:

- `StressTest::OperateDb()` locks the mutex for key 'k'
- `StressTest::OperateDb()` calls a function like `PauseBackgroundWork()`, which waits for pending compaction to complete.
- The pending compaction reaches key `k` and `DbStressCompactionFilter::FilterV2()` calls `Lock()` on that key's mutex, which hangs forever.

The cycle can be broken by using a new function, `port::Mutex::TryLock()`, which returns immediately upon failure to acquire a lock. In that case `DbStressCompactionFilter::FilterV2()` can just decide to keep the key.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8956

Reviewed By: riversand963

Differential Revision: D31183718

Pulled By: ajkr

fbshipit-source-id: 329e4a31ce43085af174cf367ef560b5a04399c5
2021-09-24 16:54:02 -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
Peter Dillinger 4750421ece Replace most typedef with using= (#8751)
Summary:
Old typedef syntax is confusing

Most but not all changes with

    perl -pi -e 's/typedef (.*) ([a-zA-Z0-9_]+);/using $2 = $1;/g' list_of_files
    make format

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8751

Test Plan: existing

Reviewed By: zhichao-cao

Differential Revision: D30745277

Pulled By: pdillinger

fbshipit-source-id: 6f65f0631c3563382d43347896020413cc2366d9
2021-09-07 11:31:59 -07:00
Peter Dillinger 13ded69484 Built-in support for generating unique IDs, bug fix (#8708)
Summary:
Env::GenerateUniqueId() works fine on Windows and on POSIX
where /proc/sys/kernel/random/uuid exists. Our other implementation is
flawed and easily produces collision in a new multi-threaded test.
As we rely more heavily on DB session ID uniqueness, this becomes a
serious issue.

This change combines several individually suitable entropy sources
for reliable generation of random unique IDs, with goal of uniqueness
and portability, not cryptographic strength nor maximum speed.

Specifically:
* Moves code for getting UUIDs from the OS to port::GenerateRfcUuid
rather than in Env implementation details. Callers are now told whether
the operation fails or succeeds.
* Adds an internal API GenerateRawUniqueId for generating high-quality
128-bit unique identifiers, by combining entropy from three "tracks":
  * Lots of info from default Env like time, process id, and hostname.
  * std::random_device
  * port::GenerateRfcUuid (when working)
* Built-in implementations of Env::GenerateUniqueId() will now always
produce an RFC 4122 UUID string, either from platform-specific API or
by converting the output of GenerateRawUniqueId.

DB session IDs now use GenerateRawUniqueId while DB IDs (not as
critical) try to use port::GenerateRfcUuid but fall back on
GenerateRawUniqueId with conversion to an RFC 4122 UUID.

GenerateRawUniqueId is declared and defined under env/ rather than util/
or even port/ because of the Env dependency.

Likely follow-up: enhance GenerateRawUniqueId to be faster after the
first call and to guarantee uniqueness within the lifetime of a single
process (imparting the same property onto DB session IDs).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8708

Test Plan:
A new mini-stress test in env_test checks the various public
and internal APIs for uniqueness, including each track of
GenerateRawUniqueId individually. We can't hope to verify anywhere close
to 128 bits of entropy, but it can at least detect flaws as bad as the
old code. Serial execution of the new tests takes about 350 ms on
my machine.

Reviewed By: zhichao-cao, mrambacher

Differential Revision: D30563780

Pulled By: pdillinger

fbshipit-source-id: de4c9ff4b2f581cf784fcedb5f39f16e5185c364
2021-08-30 15:20:41 -07:00
Peter Dillinger 318fe6941a Add port::GetProcessID() (#8693)
Summary:
Useful in some places for object uniqueness across processes.
Currently used for generating a host-wide identifier of Cache objects
but expected to be used soon in some unique id generation code.

`int64_t` is chosen for return type because POSIX uses signed integer type,
usually `int`, for `pid_t` and Windows uses `DWORD`, which is `uint32_t`.

Future work: avoid copy-pasted declarations in port_*.h, perhaps with
port_common.h always included from port.h

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8693

Test Plan: manual for now

Reviewed By: ajkr, anand1976

Differential Revision: D30492876

Pulled By: pdillinger

fbshipit-source-id: 39fc2788623cc9f4787866bdb67a4d183dde7eef
2021-08-24 17:46:14 -07:00
Burton Li 9b0a32f802 Support dynamic sector size in alignment validation for Windows. (#8613)
Summary:
- Use dynamic section size when calling IsSectorAligned()
- Support relative path for GetSectorSize().
- Move buffer and sector alignment check to assert for better retail performance.
- Typo fixes.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8613

Reviewed By: ajkr

Differential Revision: D30136082

Pulled By: mrambacher

fbshipit-source-id: e8cb849befdcae4fea99de5ed5dd6565e612425f
2021-08-16 07:31:57 -07:00
Peter Dillinger aeb913dd01 Standardize on GCC for TSAN conditional compilation (#8543)
Summary:
In https://github.com/facebook/rocksdb/issues/8539 I accidentally only checked for GCC TSAN, which is
what I tested locally, while CircleCI and FB CI use clang TSAN. Related:
other existing code like in stack_trace.cc only check for clang TSAN.

I've now standardized these to the GCC convention in port/lang.h, so now

    #ifdef __SANITIZE_THREAD__

can check for any TSAN (assuming lang.h include)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8543

Test Plan:
Put an assert(false) in slice_test and look for the NOTE
about "signal-unsafe call", both GCC and clang. Eventually, CircleCI
TSAN in https://github.com/facebook/rocksdb/issues/8538

Reviewed By: zhichao-cao

Differential Revision: D29728483

Pulled By: pdillinger

fbshipit-source-id: 8a3b8015c2ed48078214c3ee17146a2c3f11c9f7
2021-07-15 23:50:00 -07:00
Peter Dillinger a53d6d25e0 Improve support for valgrind error on reachable (#8503)
Summary:
MyRocks apparently uses valgrind to check for unreachable
unfreed data, which is stricter than our valgrind checks. Internal ref:
D29257815

This patch adds valgrind support to STATIC_AVOID_DESTRUCTION so that it's
not reported with those stricter checks.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8503

Test Plan:
make valgrind_test
Also, with modified VALGRIND_OPTS (see Makefile), more kinds of
failures seen before than after this commit.

Reviewed By: ajkr, yizhang82

Differential Revision: D29597784

Pulled By: pdillinger

fbshipit-source-id: 360de157a176aec4d1be99ca20d160ecd47c0873
2021-07-12 17:00:27 -07:00
Andrew Kryczka bac399449d jemalloc_helper: Limit the mm_malloc.h hack to glibc on linux (#8425)
Summary:
Original author: kraj (https://github.com/facebook/rocksdb/issues/8413)

We have a hack to ensure clang's `posix_memalign()` hack works to be
compatible with glibc's `posix_memalign()` declaration. Our side of the
hack is irrelevant and should be omitted when not using glibc.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8425

Reviewed By: mrambacher

Differential Revision: D29239029

Pulled By: ajkr

fbshipit-source-id: 12b900f50a4823b880a6558f25d8590dbfc0aa26
2021-06-29 08:40:02 -07:00
Lucian Petrut 390c5246d2 Allow using WindowsThread with Mingw (#8108)
Summary:
Allow using WindowsThread with Mingw

Most Mingw builds require Posix threads in order to use std::thread.
As per https://github.com/facebook/rocksdb/issues/7764, this is not always the case.

That being considered, we're going to improve the Mingw thread model
checks.

Closes: https://github.com/facebook/rocksdb/issues/7764
Signed-off-by: Lucian Petrut <lpetrut@cloudbasesolutions.com>

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8108

Reviewed By: jay-zhuang

Differential Revision: D27365778

Pulled By: mrambacher

fbshipit-source-id: 2c15b1f04ae90e1e3a25a33e86ceb779224a9529
2021-06-29 06:52:08 -07:00
Peter Dillinger 311a544c2a Use deleters to label cache entries and collect stats (#8297)
Summary:
This change gathers and publishes statistics about the
kinds of items in block cache. This is especially important for
profiling relative usage of cache by index vs. filter vs. data blocks.
It works by iterating over the cache during periodic stats dump
(InternalStats, stats_dump_period_sec) or on demand when
DB::Get(Map)Property(kBlockCacheEntryStats), except that for
efficiency and sharing among column families, saved data from
the last scan is used when the data is not considered too old.

The new information can be seen in info LOG, for example:

    Block cache LRUCache@0x7fca62229330 capacity: 95.37 MB collections: 8 last_copies: 0 last_secs: 0.00178 secs_since: 0
    Block cache entry stats(count,size,portion): DataBlock(7092,28.24 MB,29.6136%) FilterBlock(215,867.90 KB,0.888728%) FilterMetaBlock(2,5.31 KB,0.00544%) IndexBlock(217,180.11 KB,0.184432%) WriteBuffer(1,256.00 KB,0.262144%) Misc(1,0.00 KB,0%)

And also through DB::GetProperty and GetMapProperty (here using
ldb just for demonstration):

    $ ./ldb --db=/dev/shm/dbbench/ get_property rocksdb.block-cache-entry-stats
    rocksdb.block-cache-entry-stats.bytes.data-block: 0
    rocksdb.block-cache-entry-stats.bytes.deprecated-filter-block: 0
    rocksdb.block-cache-entry-stats.bytes.filter-block: 0
    rocksdb.block-cache-entry-stats.bytes.filter-meta-block: 0
    rocksdb.block-cache-entry-stats.bytes.index-block: 178992
    rocksdb.block-cache-entry-stats.bytes.misc: 0
    rocksdb.block-cache-entry-stats.bytes.other-block: 0
    rocksdb.block-cache-entry-stats.bytes.write-buffer: 0
    rocksdb.block-cache-entry-stats.capacity: 8388608
    rocksdb.block-cache-entry-stats.count.data-block: 0
    rocksdb.block-cache-entry-stats.count.deprecated-filter-block: 0
    rocksdb.block-cache-entry-stats.count.filter-block: 0
    rocksdb.block-cache-entry-stats.count.filter-meta-block: 0
    rocksdb.block-cache-entry-stats.count.index-block: 215
    rocksdb.block-cache-entry-stats.count.misc: 1
    rocksdb.block-cache-entry-stats.count.other-block: 0
    rocksdb.block-cache-entry-stats.count.write-buffer: 0
    rocksdb.block-cache-entry-stats.id: LRUCache@0x7f3636661290
    rocksdb.block-cache-entry-stats.percent.data-block: 0.000000
    rocksdb.block-cache-entry-stats.percent.deprecated-filter-block: 0.000000
    rocksdb.block-cache-entry-stats.percent.filter-block: 0.000000
    rocksdb.block-cache-entry-stats.percent.filter-meta-block: 0.000000
    rocksdb.block-cache-entry-stats.percent.index-block: 2.133751
    rocksdb.block-cache-entry-stats.percent.misc: 0.000000
    rocksdb.block-cache-entry-stats.percent.other-block: 0.000000
    rocksdb.block-cache-entry-stats.percent.write-buffer: 0.000000
    rocksdb.block-cache-entry-stats.secs_for_last_collection: 0.000052
    rocksdb.block-cache-entry-stats.secs_since_last_collection: 0

Solution detail - We need some way to flag what kind of blocks each
entry belongs to, preferably without changing the Cache API.
One of the complications is that Cache is a general interface that could
have other users that don't adhere to whichever convention we decide
on for keys and values. Or we would pay for an extra field in the Handle
that would only be used for this purpose.

This change uses a back-door approach, the deleter, to indicate the
"role" of a Cache entry (in addition to the value type, implicitly).
This has the added benefit of ensuring proper code origin whenever we
recognize a particular role for a cache entry; if the entry came from
some other part of the code, it will use an unrecognized deleter, which
we simply attribute to the "Misc" role.

An internal API makes for simple instantiation and automatic
registration of Cache deleters for a given value type and "role".

Another internal API, CacheEntryStatsCollector, solves the problem of
caching the results of a scan and sharing them, to ensure scans are
neither excessive nor redundant so as not to harm Cache performance.

Because code is added to BlocklikeTraits, it is pulled out of
block_based_table_reader.cc into its own file.

This is a reformulation of https://github.com/facebook/rocksdb/issues/8276, without the type checking option
(could still be added), and with actual stat gathering.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8297

Test Plan: manual testing with db_bench, and a couple of basic unit tests

Reviewed By: ltamasi

Differential Revision: D28488721

Pulled By: pdillinger

fbshipit-source-id: 472f524a9691b5afb107934be2d41d84f2b129fb
2021-05-19 16:51:13 -07:00