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/UserAgentStyleSheetID.h"
  19 #include "mozilla/css/Loader.h"
  20
  21 class nsIFile;
  22 class nsIURI;
  23
  24 namespace mozilla {
  25 class CSSStyleSheet;
  26 }  // namespace mozilla
  27
  28 namespace mozilla {
  29 namespace css {
  30
  31 // Enum defining how error should be handled.
  32 enum FailureAction { eCrash = 0, eLogToConsole };
  33
  34 }  // namespace css
  35
  36 class GlobalStyleSheetCache final : public nsIObserver,
  37                                     public nsIMemoryReporter {
  38  public:
  39   NS_DECL_ISUPPORTS
  40   NS_DECL_NSIOBSERVER
  41   NS_DECL_NSIMEMORYREPORTER
  42
  43   static GlobalStyleSheetCache* Singleton();
  44
  45 #define STYLE_SHEET(identifier_, url_, shared_) \
  46   NotNull<StyleSheet*> identifier_##Sheet();
  47 #include "mozilla/UserAgentStyleSheetList.h"
  48 #undef STYLE_SHEET
  49
  50   StyleSheet* GetUserContentSheet();
  51   StyleSheet* GetUserChromeSheet();
  52
  53   static void Shutdown();
  54
  55   static void SetUserContentCSSURL(nsIURI* aURI);
  56
  57   size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const;
  58
  59   // Set the shared memory segment to load the shared UA sheets from.
  60   // Called early on in a content process' life from
  61   // ContentChild::InitSharedUASheets, before the GlobalStyleSheetCache
  62   // singleton has been created.
  63   static void SetSharedMemory(base::SharedMemoryHandle aHandle,
  64                               uintptr_t aAddress);
  65
  66   // Obtain a shared memory handle for the shared UA sheets to pass into a
  67   // content process.  Called by ContentParent::InitInternal shortly after
  68   // a content process has been created.
  69   base::SharedMemoryHandle CloneHandle();
  70
  71   // Returns the address of the shared memory segment that holds the shared UA
  72   // sheets.
  73   uintptr_t GetSharedMemoryAddress() {
  74     return sSharedMemory ? uintptr_t(sSharedMemory->memory()) : 0;
  75   }
  76
  77   // Size of the shared memory buffer we'll create to store the shared UA
  78   // sheets.  We choose a value that is big enough on both 64 bit and 32 bit.
  79   //
  80   // If this isn't big enough for the current contents of the shared UA
  81   // sheets, we'll crash under InitSharedSheetsInParent.
  82   static constexpr size_t kSharedMemorySize = 1024 * 450;
  83
  84  private:
  85   // Shared memory header.
  86   struct Header {
  87     static constexpr uint32_t kMagic = 0x55415353;
  88     uint32_t mMagic;  // Must be set to kMagic.
  89     const StyleLockedCssRules* mSheets[size_t(UserAgentStyleSheetID::Count)];
  90     uint8_t mBuffer[1];
  91   };
  92
  93   GlobalStyleSheetCache();
  94   ~GlobalStyleSheetCache();
  95
  96   void InitFromProfile();
  97   void InitSharedSheetsInParent();
  98   void InitMemoryReporter();
  99   RefPtr<StyleSheet> LoadSheetURL(const char* aURL,
 100                                   css::SheetParsingMode aParsingMode,
 101                                   css::FailureAction aFailureAction);
 102   RefPtr<StyleSheet> LoadSheetFile(nsIFile* aFile,
 103                                    css::SheetParsingMode aParsingMode);
 104   RefPtr<StyleSheet> LoadSheet(nsIURI* aURI, css::SheetParsingMode aParsingMode,
 105                                css::FailureAction aFailureAction);
 106   void LoadSheetFromSharedMemory(const char* aURL, RefPtr<StyleSheet>* aSheet,
 107                                  css::SheetParsingMode, Header*,
 108                                  UserAgentStyleSheetID);
 109
 110   static StaticRefPtr<GlobalStyleSheetCache> gStyleCache;
 111   static StaticRefPtr<css::Loader> gCSSLoader;
 112   static StaticRefPtr<nsIURI> gUserContentSheetURL;
 113
 114 #define STYLE_SHEET(identifier_, url_, shared_) \
 115   RefPtr<StyleSheet> m##identifier_##Sheet;
 116 #include "mozilla/UserAgentStyleSheetList.h"
 117 #undef STYLE_SHEET
 118
 119   RefPtr<StyleSheet> mUserChromeSheet;
 120   RefPtr<StyleSheet> mUserContentSheet;
 121
 122   // Shared memory segment storing shared style sheets.
 123   static StaticAutoPtr<base::SharedMemory> sSharedMemory;
 124
 125   // How much of the shared memory buffer we ended up using.  Used for memory
 126   // reporting in the parent process.
 127   static size_t sUsedSharedMemory;
 128 };
 129
 130 }  // namespace mozilla
 131
 132 #endif