1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/xpcom/glue/nsRefPtrHashtable.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,159 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef nsRefPtrHashtable_h__
1.10 +#define nsRefPtrHashtable_h__
1.11 +
1.12 +#include "nsBaseHashtable.h"
1.13 +#include "nsHashKeys.h"
1.14 +#include "nsAutoPtr.h"
1.15 +
1.16 +/**
1.17 + * templated hashtable class maps keys to reference pointers.
1.18 + * See nsBaseHashtable for complete declaration.
1.19 + * @param KeyClass a wrapper-class for the hashtable key, see nsHashKeys.h
1.20 + * for a complete specification.
1.21 + * @param RefPtr the reference-type being wrapped
1.22 + * @see nsDataHashtable, nsClassHashtable
1.23 + */
1.24 +template<class KeyClass, class RefPtr>
1.25 +class nsRefPtrHashtable :
1.26 + public nsBaseHashtable< KeyClass, nsRefPtr<RefPtr> , RefPtr* >
1.27 +{
1.28 +public:
1.29 + typedef typename KeyClass::KeyType KeyType;
1.30 + typedef RefPtr* UserDataType;
1.31 + typedef nsBaseHashtable< KeyClass, nsRefPtr<RefPtr> , RefPtr* > base_type;
1.32 +
1.33 + nsRefPtrHashtable()
1.34 + {
1.35 + }
1.36 + explicit nsRefPtrHashtable(uint32_t aInitSize)
1.37 + : nsBaseHashtable<KeyClass,nsRefPtr<RefPtr>,RefPtr*>(aInitSize)
1.38 + {
1.39 + }
1.40 +
1.41 + /**
1.42 + * @copydoc nsBaseHashtable::Get
1.43 + * @param pData This is an XPCOM getter, so pData is already_addrefed.
1.44 + * If the key doesn't exist, pData will be set to nullptr.
1.45 + */
1.46 + bool Get(KeyType aKey, UserDataType* pData) const;
1.47 +
1.48 + /**
1.49 + * Gets a weak reference to the hashtable entry.
1.50 + * @param aFound If not nullptr, will be set to true if the entry is found,
1.51 + * to false otherwise.
1.52 + * @return The entry, or nullptr if not found. Do not release this pointer!
1.53 + */
1.54 + RefPtr* GetWeak(KeyType aKey, bool* aFound = nullptr) const;
1.55 +
1.56 + // Overload Remove, rather than overriding it.
1.57 + using base_type::Remove;
1.58 +
1.59 + /**
1.60 + * Remove the data for the associated key, swapping the current value into
1.61 + * pData, thereby avoiding calls to AddRef and Release.
1.62 + * @param aKey the key to remove from the hashtable
1.63 + * @param pData This is an XPCOM getter, so pData is already_addrefed.
1.64 + * If the key doesn't exist, pData will be set to nullptr. Must be non-null.
1.65 + */
1.66 + bool Remove(KeyType aKey, UserDataType* pData);
1.67 +};
1.68 +
1.69 +template <typename K, typename T>
1.70 +inline void
1.71 +ImplCycleCollectionUnlink(nsRefPtrHashtable<K, T>& aField)
1.72 +{
1.73 + aField.Clear();
1.74 +}
1.75 +
1.76 +template <typename K, typename T>
1.77 +inline void
1.78 +ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,
1.79 + nsRefPtrHashtable<K, T>& aField,
1.80 + const char* aName,
1.81 + uint32_t aFlags = 0)
1.82 +{
1.83 + nsBaseHashtableCCTraversalData userData(aCallback, aName, aFlags);
1.84 +
1.85 + aField.EnumerateRead(ImplCycleCollectionTraverse_EnumFunc<typename K::KeyType,T*>,
1.86 + &userData);
1.87 +}
1.88 +
1.89 +//
1.90 +// nsRefPtrHashtable definitions
1.91 +//
1.92 +
1.93 +template<class KeyClass, class RefPtr>
1.94 +bool
1.95 +nsRefPtrHashtable<KeyClass,RefPtr>::Get
1.96 + (KeyType aKey, UserDataType* pRefPtr) const
1.97 +{
1.98 + typename base_type::EntryType* ent = this->GetEntry(aKey);
1.99 +
1.100 + if (ent) {
1.101 + if (pRefPtr) {
1.102 + *pRefPtr = ent->mData;
1.103 +
1.104 + NS_IF_ADDREF(*pRefPtr);
1.105 + }
1.106 +
1.107 + return true;
1.108 + }
1.109 +
1.110 + // if the key doesn't exist, set *pRefPtr to null
1.111 + // so that it is a valid XPCOM getter
1.112 + if (pRefPtr) {
1.113 + *pRefPtr = nullptr;
1.114 + }
1.115 +
1.116 + return false;
1.117 +}
1.118 +
1.119 +template<class KeyClass, class RefPtr>
1.120 +RefPtr*
1.121 +nsRefPtrHashtable<KeyClass,RefPtr>::GetWeak
1.122 + (KeyType aKey, bool* aFound) const
1.123 +{
1.124 + typename base_type::EntryType* ent = this->GetEntry(aKey);
1.125 +
1.126 + if (ent) {
1.127 + if (aFound) {
1.128 + *aFound = true;
1.129 + }
1.130 +
1.131 + return ent->mData;
1.132 + }
1.133 +
1.134 + // Key does not exist, return nullptr and set aFound to false
1.135 + if (aFound) {
1.136 + *aFound = false;
1.137 + }
1.138 +
1.139 + return nullptr;
1.140 +}
1.141 +
1.142 +template<class KeyClass, class RefPtr>
1.143 +bool
1.144 +nsRefPtrHashtable<KeyClass,RefPtr>::Remove(KeyType aKey,
1.145 + UserDataType* pRefPtr)
1.146 +{
1.147 + MOZ_ASSERT(pRefPtr);
1.148 + typename base_type::EntryType* ent = this->GetEntry(aKey);
1.149 +
1.150 + if (ent) {
1.151 + ent->mData.forget(pRefPtr);
1.152 + this->Remove(aKey);
1.153 + return true;
1.154 + }
1.155 +
1.156 + // If the key doesn't exist, set *pRefPtr to null
1.157 + // so that it is a valid XPCOM getter.
1.158 + *pRefPtr = nullptr;
1.159 + return false;
1.160 +}
1.161 +
1.162 +#endif // nsRefPtrHashtable_h__
