rocksdb/util/rate_limiter.h
Andrew Kryczka c217e0b9c7 Call RateLimiter for compaction reads
Summary:
Allow users to rate limit background work based on read bytes, written bytes, or sum of read and written bytes. Support these by changing the RateLimiter API, so no additional options were needed.
Closes https://github.com/facebook/rocksdb/pull/2433

Differential Revision: D5216946

Pulled By: ajkr

fbshipit-source-id: aec57a8357dbb4bfde2003261094d786d94f724e
2017-06-13 14:56:46 -07:00

107 lines
3.2 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
// This source code is also licensed under the GPLv2 license found in the
// COPYING file in the root directory of this source tree.
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#pragma once
#include <algorithm>
#include <atomic>
#include <deque>
#include "port/port.h"
#include "util/mutexlock.h"
#include "util/random.h"
#include "rocksdb/env.h"
#include "rocksdb/rate_limiter.h"
namespace rocksdb {
class GenericRateLimiter : public RateLimiter {
public:
GenericRateLimiter(int64_t refill_bytes, int64_t refill_period_us,
int32_t fairness,
RateLimiter::Mode mode = RateLimiter::Mode::kWritesOnly);
virtual ~GenericRateLimiter();
// This API allows user to dynamically change rate limiter's bytes per second.
virtual void SetBytesPerSecond(int64_t bytes_per_second) override;
// Request for token to write bytes. If this request can not be satisfied,
// the call is blocked. Caller is responsible to make sure
// bytes <= GetSingleBurstBytes()
using RateLimiter::Request;
virtual void Request(const int64_t bytes, const Env::IOPriority pri,
Statistics* stats) override;
virtual int64_t GetSingleBurstBytes() const override {
return refill_bytes_per_period_.load(std::memory_order_relaxed);
}
virtual int64_t GetTotalBytesThrough(
const Env::IOPriority pri = Env::IO_TOTAL) const override {
MutexLock g(&request_mutex_);
if (pri == Env::IO_TOTAL) {
return total_bytes_through_[Env::IO_LOW] +
total_bytes_through_[Env::IO_HIGH];
}
return total_bytes_through_[pri];
}
virtual int64_t GetTotalRequests(
const Env::IOPriority pri = Env::IO_TOTAL) const override {
MutexLock g(&request_mutex_);
if (pri == Env::IO_TOTAL) {
return total_requests_[Env::IO_LOW] + total_requests_[Env::IO_HIGH];
}
return total_requests_[pri];
}
virtual int64_t GetBytesPerSecond() const override {
return rate_bytes_per_sec_;
}
private:
void Refill();
int64_t CalculateRefillBytesPerPeriod(int64_t rate_bytes_per_sec);
uint64_t NowMicrosMonotonic(Env* env) {
return env->NowNanos() / std::milli::den;
}
// This mutex guard all internal states
mutable port::Mutex request_mutex_;
const int64_t kMinRefillBytesPerPeriod = 100;
const int64_t refill_period_us_;
int64_t rate_bytes_per_sec_;
// This variable can be changed dynamically.
std::atomic<int64_t> refill_bytes_per_period_;
Env* const env_;
bool stop_;
port::CondVar exit_cv_;
int32_t requests_to_wait_;
int64_t total_requests_[Env::IO_TOTAL];
int64_t total_bytes_through_[Env::IO_TOTAL];
int64_t available_bytes_;
int64_t next_refill_us_;
int32_t fairness_;
Random rnd_;
struct Req;
Req* leader_;
std::deque<Req*> queue_[Env::IO_TOTAL];
};
} // namespace rocksdb