1 files changed, 145 insertions, 0 deletions
diff --git a/xpcom/components/nsCategoryManager.h b/xpcom/components/nsCategoryManager.h
new file mode 100644
index 0000000000..765882fe47
--- /dev/null
+++ b/xpcom/components/nsCategoryManager.h
@@ -0,0 +1,145 @@
+/* -*- 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 NSCATEGORYMANAGER_H
+#define NSCATEGORYMANAGER_H
+
+#include "prio.h"
+#include "nsClassHashtable.h"
+#include "nsICategoryManager.h"
+#include "nsIMemoryReporter.h"
+#include "mozilla/ArenaAllocator.h"
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/Attributes.h"
+
+class nsIMemoryReporter;
+
+typedef mozilla::ArenaAllocator<1024 * 8, 8> CategoryAllocator;
+
+/* 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:
+  explicit 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:
+  nsresult GetLeaf(const nsACString& aEntryName, nsACString& aResult);
+
+  nsresult AddLeaf(const nsACString& aEntryName, const nsACString& aValue,
+                   bool aReplace, nsACString& aResult,
+                   CategoryAllocator* aArena);
+
+  void DeleteLeaf(const nsACString& aEntryName);
+
+  void Clear() {
+    mozilla::MutexAutoLock lock(mLock);
+    mTable.Clear();
+  }
+
+  uint32_t Count() {
+    mozilla::MutexAutoLock lock(mLock);
+    uint32_t tCount = mTable.Count();
+    return tCount;
+  }
+
+  nsresult Enumerate(nsISimpleEnumerator** aResult);
+
+  // CategoryNode is arena-allocated, with the strings
+  static CategoryNode* Create(CategoryAllocator* aArena);
+  ~CategoryNode();
+  void operator delete(void*) {}
+
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf);
+
+ private:
+  CategoryNode() : mLock("CategoryLeaf") {}
+
+  void* operator new(size_t aSize, CategoryAllocator* aArena);
+
+  nsTHashtable<CategoryLeaf> mTable MOZ_GUARDED_BY(mLock);
+  mozilla::Mutex mLock;
+};
+
+/**
+ * The main implementation of nsICategoryManager.
+ *
+ * This implementation is thread-safe.
+ */
+class nsCategoryManager 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.
+   */
+  nsresult SuppressNotifications(bool aSuppress);
+
+  void AddCategoryEntry(const nsACString& aCategory, const nsACString& aKey,
+                        const nsACString& aValue, bool aReplace,
+                        nsACString& aOldValue);
+
+  void AddCategoryEntry(const nsACString& aCategory, const nsACString& aKey,
+                        const nsACString& aValue, bool aReplace = true) {
+    nsCString oldValue;
+    return AddCategoryEntry(aCategory, aKey, aValue, aReplace, oldValue);
+  }
+
+  static nsresult Create(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 nsACString& aName) MOZ_REQUIRES(mLock);
+  void NotifyObservers(
+      const char* aTopic,
+      const nsACString& aCategoryName,  // must be a static string
+      const nsACString& aEntryName);
+
+  CategoryAllocator mArena;  // Mainthread only
+  nsClassHashtable<nsDepCharHashKey, CategoryNode> mTable MOZ_GUARDED_BY(mLock);
+  mozilla::Mutex mLock;
+  bool mSuppressNotifications;  // Mainthread only
+};
+
+#endif