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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#ifndef mozilla_glean_GleanTimingDistribution_h
#define mozilla_glean_GleanTimingDistribution_h
#include "mozilla/dom/BindingDeclarations.h"
#include "mozilla/glean/bindings/DistributionData.h"
#include "mozilla/glean/bindings/GleanMetric.h"
#include "mozilla/Maybe.h"
#include "mozilla/Result.h"
#include "mozilla/TimeStamp.h"
#include "nsTArray.h"
namespace mozilla::dom {
struct GleanDistributionData;
} // namespace mozilla::dom
namespace mozilla::glean {
// Forward declaration to make the friend class below work.
class GleanTimingDistribution;
namespace impl {
class TimingDistributionMetric {
public:
constexpr explicit TimingDistributionMetric(uint32_t aId) : mId(aId) {}
/*
* Starts tracking time for the provided metric.
*
* @returns A unique TimerId for the new timer
*/
TimerId Start() const;
/*
* Stops tracking time for the provided metric and associated timer id.
*
* Adds a count to the corresponding bucket in the timing distribution.
* This will record an error if no `Start` was called on this TimerId or
* if this TimerId was used to call `Cancel`.
*
* @param aId The TimerId to associate with this timing. This allows for
* concurrent timing of events associated with different ids.
*/
void StopAndAccumulate(const TimerId&& aId) const;
/*
* Adds a duration sample to a timing distribution metric.
*
* Adds a count to the corresponding bucket in the timing distribution.
* Prefer Start() and StopAndAccumulate() where possible.
* Users of this API are responsible for ensuring the timing source used
* to calculate the TimeDuration is monotonic and consistent accross
* platforms.
*
* NOTE: Negative durations are not handled and will saturate to INT64_MAX
* nanoseconds.
*
* @param aDuration The duration of the sample to add to the distribution.
*/
void AccumulateRawDuration(const TimeDuration& aDuration) const;
/*
* Aborts a previous `Start` call. No error is recorded if no `Start` was
* called.
*
* @param aId The TimerId whose `Start` you wish to abort.
*/
void Cancel(const TimerId&& aId) const;
/**
* **Test-only API**
*
* Gets the currently stored value as a DistributionData.
*
* This function will attempt to await the last parent-process task (if any)
* writing to the the metric's storage engine before returning a value.
* This function will not wait for data from child processes.
*
* This doesn't clear the stored value.
* Parent process only. Panics in child processes.
*
* @param aPingName The (optional) name of the ping to retrieve the metric
* for. Defaults to the first value in `send_in_pings`.
*
* @return value of the stored metric, or Nothing() if there is no value.
*/
Result<Maybe<DistributionData>, nsCString> TestGetValue(
const nsACString& aPingName = nsCString()) const;
private:
const uint32_t mId;
friend class mozilla::glean::GleanTimingDistribution;
};
} // namespace impl
class GleanTimingDistribution final : public GleanMetric {
public:
explicit GleanTimingDistribution(uint64_t aId, nsISupports* aParent)
: GleanMetric(aParent), mTimingDist(aId) {}
virtual JSObject* WrapObject(
JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override final;
uint64_t Start();
void StopAndAccumulate(uint64_t aId);
void Cancel(uint64_t aId);
void AccumulateSamples(const nsTArray<int64_t>& aSamples);
void AccumulateSingleSample(int64_t aSample);
void TestGetValue(const nsACString& aPingName,
dom::Nullable<dom::GleanDistributionData>& aRetval,
ErrorResult& aRv);
void TestAccumulateRawMillis(uint64_t aSample);
private:
virtual ~GleanTimingDistribution() = default;
const impl::TimingDistributionMetric mTimingDist;
};
} // namespace mozilla::glean
#endif /* mozilla_glean_GleanTimingDistribution_h */