rocksdb/util/stop_watch.h
Abhishek Kona 63f216ee0a memory manage statistics
Summary:
Earlier Statistics object was a raw pointer. This meant the user had to clear up
the Statistics object after creating the database. In most use cases the database is created in a function and the statistics pointer is out of scope. Hence the statistics object would never be deleted.
Now Using a shared_ptr to manage this.

Want this in before the next release.

Test Plan: make all check.

Reviewers: dhruba, emayanke

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9735
2013-03-27 11:27:39 -07:00

69 lines
1.9 KiB
C++

#ifndef STORAGE_LEVELDB_UTIL_STOP_WATCH_H_
#define STORAGE_LEVELDB_UTIL_STOP_WATCH_H_
#include "leveldb/env.h"
#include "leveldb/statistics.h"
#include <iostream>
namespace leveldb {
class StopWatch {
public:
virtual uint64_t ElapsedMicros() = 0;
virtual ~StopWatch() {}
};
class DoNothingStopWatch : public StopWatch {
public:
virtual uint64_t ElapsedMicros() {
return 0;
}
};
// Auto-scoped.
// Records the statistic into the corresponding histogram.
class ScopedRecordingStopWatch : public StopWatch {
public:
ScopedRecordingStopWatch(Env * const env,
std::shared_ptr<Statistics> statistics,
const Histograms histogram_name) :
env_(env),
start_time_(env->NowMicros()),
statistics_(statistics),
histogram_name_(histogram_name) {}
virtual uint64_t ElapsedMicros() {
return env_->NowMicros() - start_time_;
}
virtual ~ScopedRecordingStopWatch() {
uint64_t elapsed_time = env_->NowMicros() - start_time_;
statistics_->measureTime(histogram_name_, elapsed_time);
}
private:
Env* const env_;
const uint64_t start_time_;
std::shared_ptr<Statistics> statistics_;
const Histograms histogram_name_;
};
namespace stats {
// Helper method
std::unique_ptr<StopWatch> StartStopWatch(Env * const env,
std::shared_ptr<Statistics> stats,
Histograms histogram_name) {
assert(env);
if (stats) {
return std::unique_ptr<StopWatch>(new ScopedRecordingStopWatch(
env,
stats,
histogram_name));
} else {
return std::unique_ptr<StopWatch>(new DoNothingStopWatch());
}
};
} // namespace stats
} // namespace leveldb
#endif // STORAGE_LEVELDB_UTIL_STOP_WATCH_H_