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xpcom/components/nsCategoryManager.h@97036ab72558 (annotated)

xpcom/components/nsCategoryManager.h

Tue, 06 Jan 2015 21:39:09 +0100

author

Michael Schloh von Bennewitz <michael@schloh.com>

date

Tue, 06 Jan 2015 21:39:09 +0100

branch

TOR_BUG_9701

changeset 8

97036ab72558

permissions

-rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

michael@0	1	/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0	2	/* This Source Code Form is subject to the terms of the Mozilla Public
michael@0	3	* License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0	4	* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0	5
michael@0	6
michael@0	7	#ifndef NSCATEGORYMANAGER_H
michael@0	8	#define NSCATEGORYMANAGER_H
michael@0	9
michael@0	10	#include "prio.h"
michael@0	11	#include "plarena.h"
michael@0	12	#include "nsClassHashtable.h"
michael@0	13	#include "nsICategoryManager.h"
michael@0	14	#include "nsIMemoryReporter.h"
michael@0	15	#include "mozilla/MemoryReporting.h"
michael@0	16	#include "mozilla/Mutex.h"
michael@0	17	#include "mozilla/Attributes.h"
michael@0	18
michael@0	19	class nsIMemoryReporter;
michael@0	20
michael@0	21	/* 16d222a6-1dd2-11b2-b693-f38b02c021b2 */
michael@0	22	#define NS_CATEGORYMANAGER_CID \
michael@0	23	{ 0x16d222a6, 0x1dd2, 0x11b2, \
michael@0	24	{0xb6, 0x93, 0xf3, 0x8b, 0x02, 0xc0, 0x21, 0xb2} }
michael@0	25
michael@0	26	/**
michael@0	27	* a "leaf-node", managed by the nsCategoryNode hashtable.
michael@0	28	*
michael@0	29	* we need to keep a "persistent value" (which will be written to the registry)
michael@0	30	* and a non-persistent value (for the current runtime): these are usually
michael@0	31	* the same, except when aPersist==false. The strings are permanently arena-
michael@0	32	* allocated, and will never go away.
michael@0	33	*/
michael@0	34	class CategoryLeaf : public nsDepCharHashKey
michael@0	35	{
michael@0	36	public:
michael@0	37	CategoryLeaf(const char* aKey)
michael@0	38	: nsDepCharHashKey(aKey),
michael@0	39	value(nullptr) { }
michael@0	40	const char* value;
michael@0	41	};
michael@0	42
michael@0	43
michael@0	44	/**
michael@0	45	* CategoryNode keeps a hashtable of its entries.
michael@0	46	* the CategoryNode itself is permanently allocated in
michael@0	47	* the arena.
michael@0	48	*/
michael@0	49	class CategoryNode
michael@0	50	{
michael@0	51	public:
michael@0	52	NS_METHOD GetLeaf(const char* aEntryName,
michael@0	53	char** _retval);
michael@0	54
michael@0	55	NS_METHOD AddLeaf(const char* aEntryName,
michael@0	56	const char* aValue,
michael@0	57	bool aReplace,
michael@0	58	char** _retval,
michael@0	59	PLArenaPool* aArena);
michael@0	60
michael@0	61	void DeleteLeaf(const char* aEntryName);
michael@0	62
michael@0	63	void Clear() {
michael@0	64	mozilla::MutexAutoLock lock(mLock);
michael@0	65	mTable.Clear();
michael@0	66	}
michael@0	67
michael@0	68	uint32_t Count() {
michael@0	69	mozilla::MutexAutoLock lock(mLock);
michael@0	70	uint32_t tCount = mTable.Count();
michael@0	71	return tCount;
michael@0	72	}
michael@0	73
michael@0	74	NS_METHOD Enumerate(nsISimpleEnumerator** _retval);
michael@0	75
michael@0	76	// CategoryNode is arena-allocated, with the strings
michael@0	77	static CategoryNode* Create(PLArenaPool* aArena);
michael@0	78	~CategoryNode();
michael@0	79	void operator delete(void*) { }
michael@0	80
michael@0	81	size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf);
michael@0	82
michael@0	83	private:
michael@0	84	CategoryNode()
michael@0	85	: mLock("CategoryLeaf")
michael@0	86	{ }
michael@0	87
michael@0	88	void* operator new(size_t aSize, PLArenaPool* aArena);
michael@0	89
michael@0	90	nsTHashtable<CategoryLeaf> mTable;
michael@0	91	mozilla::Mutex mLock;
michael@0	92	};
michael@0	93
michael@0	94
michael@0	95	/**
michael@0	96	* The main implementation of nsICategoryManager.
michael@0	97	*
michael@0	98	* This implementation is thread-safe.
michael@0	99	*/
michael@0	100	class nsCategoryManager MOZ_FINAL
michael@0	101	: public nsICategoryManager
michael@0	102	, public nsIMemoryReporter
michael@0	103	{
michael@0	104	public:
michael@0	105	NS_DECL_ISUPPORTS
michael@0	106	NS_DECL_NSICATEGORYMANAGER
michael@0	107	NS_DECL_NSIMEMORYREPORTER
michael@0	108
michael@0	109	/**
michael@0	110	* Suppress or unsuppress notifications of category changes to the
michael@0	111	* observer service. This is to be used by nsComponentManagerImpl
michael@0	112	* on startup while reading the stored category list.
michael@0	113	*/
michael@0	114	NS_METHOD SuppressNotifications(bool aSuppress);
michael@0	115
michael@0	116	void AddCategoryEntry(const char* aCategory,
michael@0	117	const char* aKey,
michael@0	118	const char* aValue,
michael@0	119	bool aReplace = true,
michael@0	120	char** aOldValue = nullptr);
michael@0	121
michael@0	122	static nsresult Create(nsISupports* aOuter, REFNSIID aIID, void** aResult);
michael@0	123	void InitMemoryReporter();
michael@0	124
michael@0	125	static nsCategoryManager* GetSingleton();
michael@0	126	static void Destroy();
michael@0	127
michael@0	128	private:
michael@0	129	static nsCategoryManager* gCategoryManager;
michael@0	130
michael@0	131	nsCategoryManager();
michael@0	132	~nsCategoryManager();
michael@0	133
michael@0	134	size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf);
michael@0	135
michael@0	136	CategoryNode* get_category(const char* aName);
michael@0	137	void NotifyObservers(const char* aTopic,
michael@0	138	const char* aCategoryName, // must be a static string
michael@0	139	const char* aEntryName);
michael@0	140
michael@0	141	PLArenaPool mArena;
michael@0	142	nsClassHashtable<nsDepCharHashKey, CategoryNode> mTable;
michael@0	143	mozilla::Mutex mLock;
michael@0	144	bool mSuppressNotifications;
michael@0	145	};
michael@0	146
michael@0	147	#endif