GlobalStyleSheetCache.h

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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 http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_GlobalStyleSheetCache_h__

#define mozilla_GlobalStyleSheetCache_h__

#include "nsIMemoryReporter.h"

#include "nsIObserver.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"

#include "mozilla/ipc/SharedMemory.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 {

 public:

  NS_DECL_ISUPPORTS

  NS_DECL_NSIOBSERVER

  NS_DECL_NSIMEMORYREPORTER

  static GlobalStyleSheetCache* Singleton();

#define STYLE_SHEET(identifier_, url_, shared_) \

  NotNull<StyleSheet*> identifier_##Sheet();

#include "mozilla/UserAgentStyleSheetList.h"

#undef STYLE_SHEET

  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(mozilla::ipc::SharedMemory::Handle 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.

  mozilla::ipc::SharedMemoryHandle CloneHandle();

  // Returns the address of the shared memory segment that holds the shared UA

  // sheets.

  uintptr_t GetSharedMemoryAddress() {

    return sSharedMemory.IsEmpty() ? 0 : uintptr_t(sSharedMemory.data());

  // 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;

 private:

  // 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];

};

  GlobalStyleSheetCache();

  ~GlobalStyleSheetCache();

  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*,

                                 UserAgentStyleSheetID);

  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"

#undef STYLE_SHEET

  RefPtr<StyleSheet> mUserChromeSheet;

  RefPtr<StyleSheet> mUserContentSheet;

  // Shared memory segment storing shared style sheets.

  static Span<uint8_t> 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

#endif