89 lines
2.3 KiB
C
89 lines
2.3 KiB
C
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// Copyright (c) 2014, Facebook, Inc. All rights reserved.
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// This source code is licensed under the BSD-style license found in the
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// LICENSE file in the root directory of this source tree. An additional grant
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// of patent rights can be found in the PATENTS file in the same directory.
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//
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// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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#pragma once
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#include <thread>
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#include <deque>
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#include "port/port_posix.h"
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#include "util/mutexlock.h"
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#include "util/random.h"
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#include "rocksdb/env.h"
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namespace rocksdb {
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class RateLimiter {
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public:
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RateLimiter(int64_t refill_bytes, int64_t refill_period_us, int32_t fairness);
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~RateLimiter();
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// Request for token to write bytes. If this request can not be satisfied,
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// the call is blocked. Caller is responsible to make sure
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// bytes < GetSingleBurstBytes()
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void Request(const int64_t bytes, const Env::IOPriority pri);
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int64_t GetTotalBytesThrough(
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const Env::IOPriority pri = Env::IO_TOTAL) const {
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MutexLock g(&request_mutex_);
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if (pri == Env::IO_TOTAL) {
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return total_bytes_through_[Env::IO_LOW] +
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total_bytes_through_[Env::IO_HIGH];
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}
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return total_bytes_through_[pri];
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}
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int64_t GetTotalRequests(const Env::IOPriority pri = Env::IO_TOTAL) const {
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MutexLock g(&request_mutex_);
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if (pri == Env::IO_TOTAL) {
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return total_requests_[Env::IO_LOW] + total_requests_[Env::IO_HIGH];
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}
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return total_requests_[pri];
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}
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int64_t GetSingleBurstBytes() const {
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// const var
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return refill_bytes_per_period_;
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}
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int64_t GetAvailableBytes() const {
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MutexLock g(&request_mutex_);
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return available_bytes_;
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}
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private:
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void Refill();
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// This mutex guard all internal states
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mutable port::Mutex request_mutex_;
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const int64_t refill_period_us_;
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const int64_t refill_bytes_per_period_;
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Env* const env_;
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bool stop_;
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port::CondVar exit_cv_;
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int32_t requests_to_wait_;
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int64_t total_requests_[Env::IO_TOTAL];
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int64_t total_bytes_through_[Env::IO_TOTAL];
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int64_t available_bytes_;
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int64_t next_refill_us_;
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int32_t fairness_;
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Random rnd_;
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struct Req;
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Req* leader_;
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std::deque<Req*> queue_[Env::IO_TOTAL];
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};
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} // namespace rocksdb
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