/* -*- 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;

  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(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 nsACString& aName);

  void NotifyObservers(const char* aTopic,

                       const nsACString& aCategoryName, // must be a static string

                       const nsACString& aEntryName);

  CategoryAllocator mArena;

  nsClassHashtable<nsDepCharHashKey, CategoryNode> mTable;

  mozilla::Mutex mLock;

  bool mSuppressNotifications;

};

#endif