gecko-dev/docshell/base/TimelineMarker.h

100 строки
3.0 KiB
C++

/* -*- 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
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef TimelineMarker_h__
#define TimelineMarker_h__
#include "nsString.h"
#include "GeckoProfiler.h"
#include "mozilla/dom/ProfileTimelineMarkerBinding.h"
#include "nsContentUtils.h"
#include "jsapi.h"
class nsDocShell;
// Objects of this type can be added to the timeline. The class can
// also be subclassed to let a given marker creator provide custom
// details.
class TimelineMarker
{
public:
enum TimelineStackRequest { STACK, NO_STACK };
TimelineMarker(nsDocShell* aDocShell, const char* aName,
TracingMetadata aMetaData);
TimelineMarker(nsDocShell* aDocShell, const char* aName,
TracingMetadata aMetaData,
const nsAString& aCause,
TimelineStackRequest aStackRequest = STACK);
virtual ~TimelineMarker();
// Check whether two markers should be considered the same,
// for the purpose of pairing start and end markers. Normally
// this definition suffices.
virtual bool Equals(const TimelineMarker& aOther)
{
return strcmp(mName, aOther.mName) == 0;
}
// Add details specific to this marker type to aMarker. The
// standard elements have already been set. This method is
// called on both the starting and ending markers of a pair.
// Ordinarily the ending marker doesn't need to do anything
// here.
virtual void AddDetails(JSContext* aCx,
mozilla::dom::ProfileTimelineMarker& aMarker)
{}
virtual void AddLayerRectangles(
mozilla::dom::Sequence<mozilla::dom::ProfileTimelineLayerRect>&)
{
MOZ_ASSERT_UNREACHABLE("can only be called on layer markers");
}
const char* GetName() const { return mName; }
TracingMetadata GetMetaData() const { return mMetaData; }
DOMHighResTimeStamp GetTime() const { return mTime; }
const nsString& GetCause() const { return mCause; }
JSObject* GetStack()
{
if (mStackTrace.initialized()) {
return mStackTrace;
}
return nullptr;
}
protected:
void CaptureStack()
{
JSContext* ctx = nsContentUtils::GetCurrentJSContext();
if (ctx) {
JS::RootedObject stack(ctx);
if (JS::CaptureCurrentStack(ctx, &stack)) {
mStackTrace.init(ctx, stack.get());
} else {
JS_ClearPendingException(ctx);
}
}
}
private:
const char* mName;
TracingMetadata mMetaData;
DOMHighResTimeStamp mTime;
nsString mCause;
// While normally it is not a good idea to make a persistent root,
// in this case changing nsDocShell to participate in cycle
// collection was deemed too invasive, and the markers are only held
// here temporarily to boot.
JS::PersistentRooted<JSObject*> mStackTrace;
};
#endif /* TimelineMarker_h__ */