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/* 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
#include "mozilla/ChromeProfilerCounter.h"
#include "mozilla/ProfilerCounts.h"
namespace mozilla {
ChromeProfilerCounter::ChromeProfilerCounter(const nsACString& aName,
const nsACString& aCategory,
const nsACString& aDescription)
: BaseProfilerCount(nullptr, nullptr, nullptr),
mNameStorage(aName),
mCategoryStorage(aCategory),
mDescriptionStorage(aDescription),
mCount(0) {
mLabel = mNameStorage.get();
mCategory = mCategoryStorage.get();
mDescription = mDescriptionStorage.get();
}
ChromeProfilerCounter::~ChromeProfilerCounter() = default;
void ChromeProfilerCounter::Register() {
profiler_add_sampled_chrome_counter(this);
}
void ChromeProfilerCounter::Unregister() {
profiler_remove_sampled_chrome_counter(this);
}
size_t ChromeProfilerCounter::SizeOfIncludingThis(
MallocSizeOf aMallocSizeOf) const {
return aMallocSizeOf(this) +
mNameStorage.SizeOfExcludingThisIfUnshared(aMallocSizeOf) +
mCategoryStorage.SizeOfExcludingThisIfUnshared(aMallocSizeOf) +
mDescriptionStorage.SizeOfExcludingThisIfUnshared(aMallocSizeOf);
}
BaseProfilerCount::CountSample ChromeProfilerCounter::Sample() {
CountSample sample = {
.count = mCount,
// The counter's number field is deliberately left set to zero and is not
// exposed through the JavaScript API. The number field is a secondary,
// monotonically increasing series that tracks how many operations
// occurred rather than the value being measured, and it exists to drive
// an activity indication alongside the main count curve. Only a few
// built-in counters populate it for a specific purpose: the memory
// counter reports the number of allocations and deallocations, and the
// bandwidth counter reports the number of read and write operations. The
// Firefox Profiler front end reads this series in exactly one place,
// namely the counter tooltip, and it only displays it when the counter's
// category is one of those recognized presets. Because a
// JavaScript-created counter uses an arbitrary category, it falls through
// to the generic display, which never renders the number series, so any
// value it sent would be invisible end to end. Exposing the field would
// also add real complexity, since it must never decrease and a naive API
// could easily violate that invariant. For these reasons the feature
// stays provisional and scoped to the single count series, and number can
// be revisited later if a concrete consumer and a matching front-end
// display are added together.
.number = 0,
.isSampleNew = true,
};
return sample;
}
} // namespace mozilla