gecko-dev/xpcom/components/nsCategoryManager.h

147 lines
3.8 KiB
C++

/* -*- 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 "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:
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:
NS_METHOD GetLeaf(const char* aEntryName,
char** aResult);
NS_METHOD AddLeaf(const char* aEntryName,
const char* aValue,
bool aReplace,
char** aResult,
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** aResult);
// 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 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