1 files changed, 140 insertions, 0 deletions
diff --git a/layout/style/GlobalStyleSheetCache.h b/layout/style/GlobalStyleSheetCache.h
new file mode 100644
index 0000000000..a0aa738108
--- /dev/null
+++ b/layout/style/GlobalStyleSheetCache.h
@@ -0,0 +1,140 @@
+/* -*- 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 "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/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 {
+ 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();
+  StyleSheet* ChromePreferenceSheet();
+  StyleSheet* ContentPreferenceSheet();
+
+  static void InvalidatePreferenceSheets();
+
+  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(const 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.
+  bool ShareToProcess(base::ProcessId aProcessId,
+                      base::SharedMemoryHandle* aHandle);
+
+  // 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;
+
+ private:
+  // Shared memory header.
+  struct Header {
+    static constexpr uint32_t kMagic = 0x55415353;
+    uint32_t mMagic;  // Must be set to kMagic.
+    const ServoCssRules* 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);
+  void BuildPreferenceSheet(RefPtr<StyleSheet>* aSheet,
+                            const PreferenceSheet::Prefs&);
+
+  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> mChromePreferenceSheet;
+  RefPtr<StyleSheet> mContentPreferenceSheet;
+  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
+
+#endif