Revision df5eeb85caf76a2f038d4029f95de36b91ee0054 authored by Yi Wu on 13 November 2016, 21:00:52 UTC, committed by Facebook Github Bot on 13 November 2016, 21:09:16 UTC
Summary: Implement a insert hint into skip-list to hint insert position. This is to optimize for the write workload where there are multiple stream of sequential writes. For example, there is a stream of keys of a1, a2, a3... but also b1, b2, b2... Each stream are not neccessary strictly sequential, but can get reorder a little bit. User can specify a prefix extractor and the `SkipListRep` can thus maintan a hint for each of the stream for fast insert into memtable. This is the internal implementation part. See #1419 for the interface part. See inline comments for details. Closes https://github.com/facebook/rocksdb/pull/1449 Differential Revision: D4106781 Pulled By: yiwu-arbug fbshipit-source-id: f4d48c4
1 parent 5ed6508
perf_step_timer.h
// 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.
//
#pragma once
#include "rocksdb/env.h"
#include "util/perf_level_imp.h"
#include "util/stop_watch.h"
namespace rocksdb {
class PerfStepTimer {
public:
explicit PerfStepTimer(uint64_t* metric, bool for_mutex = false)
: enabled_(perf_level >= PerfLevel::kEnableTime ||
(!for_mutex && perf_level >= kEnableTimeExceptForMutex)),
env_(enabled_ ? Env::Default() : nullptr),
start_(0),
metric_(metric) {}
~PerfStepTimer() {
Stop();
}
void Start() {
if (enabled_) {
start_ = env_->NowNanos();
}
}
void Measure() {
if (start_) {
uint64_t now = env_->NowNanos();
*metric_ += now - start_;
start_ = now;
}
}
void Stop() {
if (start_) {
*metric_ += env_->NowNanos() - start_;
start_ = 0;
}
}
private:
const bool enabled_;
Env* const env_;
uint64_t start_;
uint64_t* metric_;
};
} // namespace rocksdb
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