rocksdb/monitoring/file_read_sample.h
Peter Dillinger 4e60663b31 Remove unnecessary, confusing 'extern' (#12300)
Summary:
In C++, `extern` is redundant in a number of cases:
* "Global" function declarations and definitions
* "Global" variable definitions when already declared `extern`

For consistency and simplicity, I've removed these in code that *we own*. In a couple of cases, I removed obsolete declarations, and for MagicNumber constants, I have consolidated the declarations into a header file (format.h)
as standard best practice would prescribe.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12300

Test Plan: no functional changes, CI

Reviewed By: ajkr

Differential Revision: D53148629

Pulled By: pdillinger

fbshipit-source-id: fb8d927959892e03af09b0c0d542b0a3b38fd886
2024-01-29 10:38:08 -08:00

24 lines
829 B
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
//
#pragma once
#include "db/version_edit.h"
#include "util/random.h"
namespace ROCKSDB_NAMESPACE {
static const uint32_t kFileReadSampleRate = 1024;
bool should_sample_file_read();
void sample_file_read_inc(FileMetaData*);
inline bool should_sample_file_read() {
return (Random::GetTLSInstance()->Next() % kFileReadSampleRate == 307);
}
inline void sample_file_read_inc(FileMetaData* meta) {
meta->stats.num_reads_sampled.fetch_add(kFileReadSampleRate,
std::memory_order_relaxed);
}
} // namespace ROCKSDB_NAMESPACE