layout/style/GlobalStyleSheetCache.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_GlobalStyleSheetCache_h__
   8 #define mozilla_GlobalStyleSheetCache_h__
   9
  10 #include "nsIMemoryReporter.h"
  11 #include "nsIObserver.h"
  12 #include "base/shared_memory.h"
  13 #include "mozilla/Attributes.h"
  14 #include "mozilla/MemoryReporting.h"
  15 #include "mozilla/PreferenceSheet.h"
  16 #include "mozilla/NotNull.h"
  17 #include "mozilla/StaticPtr.h"
  18 #include "mozilla/css/Loader.h"
  19
  20 class nsIFile;
  21 class nsIURI;
  22
  23 namespace mozilla {
  24 class CSSStyleSheet;
  25 }  // namespace mozilla
  26
  27 namespace mozilla {
  28 namespace css {
  29
  30 // Enum defining how error should be handled.
  31 enum FailureAction { eCrash = 0, eLogToConsole };
  32
  33 }  // namespace css
  34
  35 class GlobalStyleSheetCache final : public nsIObserver,
  36                                     public nsIMemoryReporter {
  37  public:
  38   NS_DECL_ISUPPORTS
  39   NS_DECL_NSIOBSERVER
  40   NS_DECL_NSIMEMORYREPORTER
  41
  42   static GlobalStyleSheetCache* Singleton();
  43
  44 #define STYLE_SHEET(identifier_, url_, shared_) \
  45   NotNull<StyleSheet*> identifier_##Sheet();
  46 #include "mozilla/UserAgentStyleSheetList.h"
  47 #undef STYLE_SHEET
  48
  49   StyleSheet* GetUserContentSheet();
  50   StyleSheet* GetUserChromeSheet();
  51   StyleSheet* ChromePreferenceSheet();
  52   StyleSheet* ContentPreferenceSheet();
  53
  54   static void InvalidatePreferenceSheets();
  55
  56   static void Shutdown();
  57
  58   static void SetUserContentCSSURL(nsIURI* aURI);
  59
  60   size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const;
  61
  62   // Set the shared memory segment to load the shared UA sheets from.
  63   // Called early on in a content process' life from
  64   // ContentChild::InitSharedUASheets, before the GlobalStyleSheetCache
  65   // singleton has been created.
  66   static void SetSharedMemory(const base::SharedMemoryHandle& aHandle,
  67                               uintptr_t aAddress);
  68
  69   // Obtain a shared memory handle for the shared UA sheets to pass into a
  70   // content process.  Called by ContentParent::InitInternal shortly after
  71   // a content process has been created.
  72   bool ShareToProcess(base::ProcessId aProcessId,
  73                       base::SharedMemoryHandle* aHandle);
  74
  75   // Returns the address of the shared memory segment that holds the shared UA
  76   // sheets.
  77   uintptr_t GetSharedMemoryAddress() {
  78     return sSharedMemory ? uintptr_t(sSharedMemory->memory()) : 0;
  79   }
  80
  81   // Size of the shared memory buffer we'll create to store the shared UA
  82   // sheets.  We choose a value that is big enough on both 64 bit and 32 bit.
  83   //
  84   // If this isn't big enough for the current contents of the shared UA
  85   // sheets, we'll crash under InitSharedSheetsInParent.
  86   static constexpr size_t kSharedMemorySize = 1024 * 450;
  87
  88  private:
  89   // Shared memory header.
  90   struct Header {
  91     static constexpr uint32_t kMagic = 0x55415353;
  92     uint32_t mMagic;  // Must be set to kMagic.
  93     const ServoCssRules* mSheets[size_t(UserAgentStyleSheetID::Count)];
  94     uint8_t mBuffer[1];
  95   };
  96
  97   GlobalStyleSheetCache();
  98   ~GlobalStyleSheetCache();
  99
 100   void InitFromProfile();
 101   void InitSharedSheetsInParent();
 102   void InitMemoryReporter();
 103   RefPtr<StyleSheet> LoadSheetURL(const char* aURL,
 104                                   css::SheetParsingMode aParsingMode,
 105                                   css::FailureAction aFailureAction);
 106   RefPtr<StyleSheet> LoadSheetFile(nsIFile* aFile,
 107                                    css::SheetParsingMode aParsingMode);
 108   RefPtr<StyleSheet> LoadSheet(nsIURI* aURI, css::SheetParsingMode aParsingMode,
 109                                css::FailureAction aFailureAction);
 110   void LoadSheetFromSharedMemory(const char* aURL, RefPtr<StyleSheet>* aSheet,
 111                                  css::SheetParsingMode, Header*,
 112                                  UserAgentStyleSheetID);
 113   void BuildPreferenceSheet(RefPtr<StyleSheet>* aSheet,
 114                             const PreferenceSheet::Prefs&);
 115
 116   static StaticRefPtr<GlobalStyleSheetCache> gStyleCache;
 117   static StaticRefPtr<css::Loader> gCSSLoader;
 118   static StaticRefPtr<nsIURI> gUserContentSheetURL;
 119
 120 #define STYLE_SHEET(identifier_, url_, shared_) \
 121   RefPtr<StyleSheet> m##identifier_##Sheet;
 122 #include "mozilla/UserAgentStyleSheetList.h"
 123 #undef STYLE_SHEET
 124
 125   RefPtr<StyleSheet> mChromePreferenceSheet;
 126   RefPtr<StyleSheet> mContentPreferenceSheet;
 127   RefPtr<StyleSheet> mUserChromeSheet;
 128   RefPtr<StyleSheet> mUserContentSheet;
 129
 130   // Shared memory segment storing shared style sheets.
 131   static StaticAutoPtr<base::SharedMemory> sSharedMemory;
 132
 133   // How much of the shared memory buffer we ended up using.  Used for memory
 134   // reporting in the parent process.
 135   static size_t sUsedSharedMemory;
 136 };
 137
 138 }  // namespace mozilla
 139
 140 #endif