xpcom/glue/nsRefPtrHashtable.h@97036ab72558 (annotated)
xpcom/glue/nsRefPtrHashtable.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 | #ifndef nsRefPtrHashtable_h__ |
| michael@0 | 7 | #define nsRefPtrHashtable_h__ |
| michael@0 | 8 | |
| michael@0 | 9 | #include "nsBaseHashtable.h" |
| michael@0 | 10 | #include "nsHashKeys.h" |
| michael@0 | 11 | #include "nsAutoPtr.h" |
| michael@0 | 12 | |
| michael@0 | 13 | /** |
| michael@0 | 14 | * templated hashtable class maps keys to reference pointers. |
| michael@0 | 15 | * See nsBaseHashtable for complete declaration. |
| michael@0 | 16 | * @param KeyClass a wrapper-class for the hashtable key, see nsHashKeys.h |
| michael@0 | 17 | * for a complete specification. |
| michael@0 | 18 | * @param RefPtr the reference-type being wrapped |
| michael@0 | 19 | * @see nsDataHashtable, nsClassHashtable |
| michael@0 | 20 | */ |
| michael@0 | 21 | template<class KeyClass, class RefPtr> |
| michael@0 | 22 | class nsRefPtrHashtable : |
| michael@0 | 23 | public nsBaseHashtable< KeyClass, nsRefPtr<RefPtr> , RefPtr* > |
| michael@0 | 24 | { |
| michael@0 | 25 | public: |
| michael@0 | 26 | typedef typename KeyClass::KeyType KeyType; |
| michael@0 | 27 | typedef RefPtr* UserDataType; |
| michael@0 | 28 | typedef nsBaseHashtable< KeyClass, nsRefPtr<RefPtr> , RefPtr* > base_type; |
| michael@0 | 29 | |
| michael@0 | 30 | nsRefPtrHashtable() |
| michael@0 | 31 | { |
| michael@0 | 32 | } |
| michael@0 | 33 | explicit nsRefPtrHashtable(uint32_t aInitSize) |
| michael@0 | 34 | : nsBaseHashtable<KeyClass,nsRefPtr<RefPtr>,RefPtr*>(aInitSize) |
| michael@0 | 35 | { |
| michael@0 | 36 | } |
| michael@0 | 37 | |
| michael@0 | 38 | /** |
| michael@0 | 39 | * @copydoc nsBaseHashtable::Get |
| michael@0 | 40 | * @param pData This is an XPCOM getter, so pData is already_addrefed. |
| michael@0 | 41 | * If the key doesn't exist, pData will be set to nullptr. |
| michael@0 | 42 | */ |
| michael@0 | 43 | bool Get(KeyType aKey, UserDataType* pData) const; |
| michael@0 | 44 | |
| michael@0 | 45 | /** |
| michael@0 | 46 | * Gets a weak reference to the hashtable entry. |
| michael@0 | 47 | * @param aFound If not nullptr, will be set to true if the entry is found, |
| michael@0 | 48 | * to false otherwise. |
| michael@0 | 49 | * @return The entry, or nullptr if not found. Do not release this pointer! |
| michael@0 | 50 | */ |
| michael@0 | 51 | RefPtr* GetWeak(KeyType aKey, bool* aFound = nullptr) const; |
| michael@0 | 52 | |
| michael@0 | 53 | // Overload Remove, rather than overriding it. |
| michael@0 | 54 | using base_type::Remove; |
| michael@0 | 55 | |
| michael@0 | 56 | /** |
| michael@0 | 57 | * Remove the data for the associated key, swapping the current value into |
| michael@0 | 58 | * pData, thereby avoiding calls to AddRef and Release. |
| michael@0 | 59 | * @param aKey the key to remove from the hashtable |
| michael@0 | 60 | * @param pData This is an XPCOM getter, so pData is already_addrefed. |
| michael@0 | 61 | * If the key doesn't exist, pData will be set to nullptr. Must be non-null. |
| michael@0 | 62 | */ |
| michael@0 | 63 | bool Remove(KeyType aKey, UserDataType* pData); |
| michael@0 | 64 | }; |
| michael@0 | 65 | |
| michael@0 | 66 | template <typename K, typename T> |
| michael@0 | 67 | inline void |
| michael@0 | 68 | ImplCycleCollectionUnlink(nsRefPtrHashtable<K, T>& aField) |
| michael@0 | 69 | { |
| michael@0 | 70 | aField.Clear(); |
| michael@0 | 71 | } |
| michael@0 | 72 | |
| michael@0 | 73 | template <typename K, typename T> |
| michael@0 | 74 | inline void |
| michael@0 | 75 | ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback, |
| michael@0 | 76 | nsRefPtrHashtable<K, T>& aField, |
| michael@0 | 77 | const char* aName, |
| michael@0 | 78 | uint32_t aFlags = 0) |
| michael@0 | 79 | { |
| michael@0 | 80 | nsBaseHashtableCCTraversalData userData(aCallback, aName, aFlags); |
| michael@0 | 81 | |
| michael@0 | 82 | aField.EnumerateRead(ImplCycleCollectionTraverse_EnumFunc<typename K::KeyType,T*>, |
| michael@0 | 83 | &userData); |
| michael@0 | 84 | } |
| michael@0 | 85 | |
| michael@0 | 86 | // |
| michael@0 | 87 | // nsRefPtrHashtable definitions |
| michael@0 | 88 | // |
| michael@0 | 89 | |
| michael@0 | 90 | template<class KeyClass, class RefPtr> |
| michael@0 | 91 | bool |
| michael@0 | 92 | nsRefPtrHashtable<KeyClass,RefPtr>::Get |
| michael@0 | 93 | (KeyType aKey, UserDataType* pRefPtr) const |
| michael@0 | 94 | { |
| michael@0 | 95 | typename base_type::EntryType* ent = this->GetEntry(aKey); |
| michael@0 | 96 | |
| michael@0 | 97 | if (ent) { |
| michael@0 | 98 | if (pRefPtr) { |
| michael@0 | 99 | *pRefPtr = ent->mData; |
| michael@0 | 100 | |
| michael@0 | 101 | NS_IF_ADDREF(*pRefPtr); |
| michael@0 | 102 | } |
| michael@0 | 103 | |
| michael@0 | 104 | return true; |
| michael@0 | 105 | } |
| michael@0 | 106 | |
| michael@0 | 107 | // if the key doesn't exist, set *pRefPtr to null |
| michael@0 | 108 | // so that it is a valid XPCOM getter |
| michael@0 | 109 | if (pRefPtr) { |
| michael@0 | 110 | *pRefPtr = nullptr; |
| michael@0 | 111 | } |
| michael@0 | 112 | |
| michael@0 | 113 | return false; |
| michael@0 | 114 | } |
| michael@0 | 115 | |
| michael@0 | 116 | template<class KeyClass, class RefPtr> |
| michael@0 | 117 | RefPtr* |
| michael@0 | 118 | nsRefPtrHashtable<KeyClass,RefPtr>::GetWeak |
| michael@0 | 119 | (KeyType aKey, bool* aFound) const |
| michael@0 | 120 | { |
| michael@0 | 121 | typename base_type::EntryType* ent = this->GetEntry(aKey); |
| michael@0 | 122 | |
| michael@0 | 123 | if (ent) { |
| michael@0 | 124 | if (aFound) { |
| michael@0 | 125 | *aFound = true; |
| michael@0 | 126 | } |
| michael@0 | 127 | |
| michael@0 | 128 | return ent->mData; |
| michael@0 | 129 | } |
| michael@0 | 130 | |
| michael@0 | 131 | // Key does not exist, return nullptr and set aFound to false |
| michael@0 | 132 | if (aFound) { |
| michael@0 | 133 | *aFound = false; |
| michael@0 | 134 | } |
| michael@0 | 135 | |
| michael@0 | 136 | return nullptr; |
| michael@0 | 137 | } |
| michael@0 | 138 | |
| michael@0 | 139 | template<class KeyClass, class RefPtr> |
| michael@0 | 140 | bool |
| michael@0 | 141 | nsRefPtrHashtable<KeyClass,RefPtr>::Remove(KeyType aKey, |
| michael@0 | 142 | UserDataType* pRefPtr) |
| michael@0 | 143 | { |
| michael@0 | 144 | MOZ_ASSERT(pRefPtr); |
| michael@0 | 145 | typename base_type::EntryType* ent = this->GetEntry(aKey); |
| michael@0 | 146 | |
| michael@0 | 147 | if (ent) { |
| michael@0 | 148 | ent->mData.forget(pRefPtr); |
| michael@0 | 149 | this->Remove(aKey); |
| michael@0 | 150 | return true; |
| michael@0 | 151 | } |
| michael@0 | 152 | |
| michael@0 | 153 | // If the key doesn't exist, set *pRefPtr to null |
| michael@0 | 154 | // so that it is a valid XPCOM getter. |
| michael@0 | 155 | *pRefPtr = nullptr; |
| michael@0 | 156 | return false; |
| michael@0 | 157 | } |
| michael@0 | 158 | |
| michael@0 | 159 | #endif // nsRefPtrHashtable_h__ |
