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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
* file, You can obtain one at */
#ifndef mozilla_GlobalStyleSheetCache_h__
#define mozilla_GlobalStyleSheetCache_h__
#include "nsIMemoryReporter.h"
#include "nsIObserver.h"
#include "base/shared_memory.h"
#include "mozilla/Attributes.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/PreferenceSheet.h"
#include "mozilla/NotNull.h"
#include "mozilla/StaticPtr.h"
#include "mozilla/UserAgentStyleSheetID.h"
#include "mozilla/css/Loader.h"
class nsIFile;
class nsIURI;
namespace mozilla {
class CSSStyleSheet;
} // namespace mozilla
namespace mozilla {
namespace css {
// Enum defining how error should be handled.
enum FailureAction { eCrash = 0, eLogToConsole };
} // namespace css
class GlobalStyleSheetCache final : public nsIObserver,
public nsIMemoryReporter {
static GlobalStyleSheetCache* Singleton();
#define STYLE_SHEET(identifier_, url_, shared_) \
NotNull<StyleSheet*> identifier_##Sheet();
#include "mozilla/UserAgentStyleSheetList.h"
StyleSheet* GetUserContentSheet();
StyleSheet* GetUserChromeSheet();
static void Shutdown();
static void SetUserContentCSSURL(nsIURI* aURI);
size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const;
// Set the shared memory segment to load the shared UA sheets from.
// Called early on in a content process' life from
// ContentChild::InitSharedUASheets, before the GlobalStyleSheetCache
// singleton has been created.
static void SetSharedMemory(base::SharedMemoryHandle aHandle,
uintptr_t aAddress);
// Obtain a shared memory handle for the shared UA sheets to pass into a
// content process. Called by ContentParent::InitInternal shortly after
// a content process has been created.
base::SharedMemoryHandle CloneHandle();
// Returns the address of the shared memory segment that holds the shared UA
// sheets.
uintptr_t GetSharedMemoryAddress() {
return sSharedMemory ? uintptr_t(sSharedMemory->memory()) : 0;
// Size of the shared memory buffer we'll create to store the shared UA
// sheets. We choose a value that is big enough on both 64 bit and 32 bit.
// If this isn't big enough for the current contents of the shared UA
// sheets, we'll crash under InitSharedSheetsInParent.
static constexpr size_t kSharedMemorySize = 1024 * 450;
// Shared memory header.
struct Header {
static constexpr uint32_t kMagic = 0x55415353;
uint32_t mMagic; // Must be set to kMagic.
const StyleLockedCssRules* mSheets[size_t(UserAgentStyleSheetID::Count)];
uint8_t mBuffer[1];
void InitFromProfile();
void InitSharedSheetsInParent();
void InitMemoryReporter();
RefPtr<StyleSheet> LoadSheetURL(const char* aURL,
css::SheetParsingMode aParsingMode,
css::FailureAction aFailureAction);
RefPtr<StyleSheet> LoadSheetFile(nsIFile* aFile,
css::SheetParsingMode aParsingMode);
RefPtr<StyleSheet> LoadSheet(nsIURI* aURI, css::SheetParsingMode aParsingMode,
css::FailureAction aFailureAction);
void LoadSheetFromSharedMemory(const char* aURL, RefPtr<StyleSheet>* aSheet,
css::SheetParsingMode, Header*,
static StaticRefPtr<GlobalStyleSheetCache> gStyleCache;
static StaticRefPtr<css::Loader> gCSSLoader;
static StaticRefPtr<nsIURI> gUserContentSheetURL;
#define STYLE_SHEET(identifier_, url_, shared_) \
RefPtr<StyleSheet> m##identifier_##Sheet;
#include "mozilla/UserAgentStyleSheetList.h"
RefPtr<StyleSheet> mUserChromeSheet;
RefPtr<StyleSheet> mUserContentSheet;
// Shared memory segment storing shared style sheets.
static StaticAutoPtr<base::SharedMemory> sSharedMemory;
// How much of the shared memory buffer we ended up using. Used for memory
// reporting in the parent process.
static size_t sUsedSharedMemory;
} // namespace mozilla