diff -r 000000000000 -r 6474c204b198 xpcom/components/nsCategoryManager.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/components/nsCategoryManager.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,147 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 NSCATEGORYMANAGER_H
+#define NSCATEGORYMANAGER_H
+
+#include "prio.h"
+#include "plarena.h"
+#include "nsClassHashtable.h"
+#include "nsICategoryManager.h"
+#include "nsIMemoryReporter.h"
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/Attributes.h"
+
+class nsIMemoryReporter;
+
+/* 16d222a6-1dd2-11b2-b693-f38b02c021b2 */
+#define NS_CATEGORYMANAGER_CID \
+{ 0x16d222a6, 0x1dd2, 0x11b2, \
+  {0xb6, 0x93, 0xf3, 0x8b, 0x02, 0xc0, 0x21, 0xb2} }
+
+/**
+ * a "leaf-node", managed by the nsCategoryNode hashtable.
+ *
+ * we need to keep a "persistent value" (which will be written to the registry)
+ * and a non-persistent value (for the current runtime): these are usually
+ * the same, except when aPersist==false. The strings are permanently arena-
+ * allocated, and will never go away.
+ */
+class CategoryLeaf : public nsDepCharHashKey
+{
+public:
+  CategoryLeaf(const char* aKey)
+    : nsDepCharHashKey(aKey),
+      value(nullptr) { }
+  const char* value;
+};
+
+
+/**
+ * CategoryNode keeps a hashtable of its entries.
+ * the CategoryNode itself is permanently allocated in
+ * the arena.
+ */
+class CategoryNode
+{
+public:
+  NS_METHOD GetLeaf(const char* aEntryName,
+                    char** _retval);
+
+  NS_METHOD AddLeaf(const char* aEntryName,
+                    const char* aValue,
+                    bool aReplace,
+                    char** _retval,
+                    PLArenaPool* aArena);
+
+  void DeleteLeaf(const char* aEntryName);
+
+  void Clear() {
+    mozilla::MutexAutoLock lock(mLock);
+    mTable.Clear();
+  }
+
+  uint32_t Count() {
+    mozilla::MutexAutoLock lock(mLock);
+    uint32_t tCount = mTable.Count();
+    return tCount;
+  }
+
+  NS_METHOD Enumerate(nsISimpleEnumerator** _retval);
+
+  // CategoryNode is arena-allocated, with the strings
+  static CategoryNode* Create(PLArenaPool* aArena);
+  ~CategoryNode();
+  void operator delete(void*) { }
+
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf);
+
+private:
+  CategoryNode()
+    : mLock("CategoryLeaf")
+  { }
+
+  void* operator new(size_t aSize, PLArenaPool* aArena);
+
+  nsTHashtable<CategoryLeaf> mTable;
+  mozilla::Mutex mLock;
+};
+
+
+/**
+ * The main implementation of nsICategoryManager.
+ *
+ * This implementation is thread-safe.
+ */
+class nsCategoryManager MOZ_FINAL
+  : public nsICategoryManager
+  , public nsIMemoryReporter
+{
+public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSICATEGORYMANAGER
+  NS_DECL_NSIMEMORYREPORTER
+
+  /**
+   * Suppress or unsuppress notifications of category changes to the
+   * observer service. This is to be used by nsComponentManagerImpl
+   * on startup while reading the stored category list.
+   */
+  NS_METHOD SuppressNotifications(bool aSuppress);
+
+  void AddCategoryEntry(const char* aCategory,
+                        const char* aKey,
+                        const char* aValue,
+                        bool aReplace = true,
+                        char** aOldValue = nullptr);
+
+  static nsresult Create(nsISupports* aOuter, REFNSIID aIID, void** aResult);
+  void InitMemoryReporter();
+
+  static nsCategoryManager* GetSingleton();
+  static void Destroy();
+
+private:
+  static nsCategoryManager* gCategoryManager;
+
+  nsCategoryManager();
+  ~nsCategoryManager();
+
+  size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf);
+
+  CategoryNode* get_category(const char* aName);
+  void NotifyObservers(const char* aTopic,
+                       const char* aCategoryName, // must be a static string
+                       const char* aEntryName);
+
+  PLArenaPool mArena;
+  nsClassHashtable<nsDepCharHashKey, CategoryNode> mTable;
+  mozilla::Mutex mLock;
+  bool mSuppressNotifications;
+};
+
+#endif