1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/xpcom/glue/nsInterfaceHashtable.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,144 @@
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 nsInterfaceHashtable_h__
1.10 +#define nsInterfaceHashtable_h__
1.11 +
1.12 +#include "nsBaseHashtable.h"
1.13 +#include "nsHashKeys.h"
1.14 +#include "nsCOMPtr.h"
1.15 +
1.16 +/**
1.17 + * templated hashtable class maps keys to interface 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 Interface the interface-type being wrapped
1.22 + * @see nsDataHashtable, nsClassHashtable
1.23 + */
1.24 +template<class KeyClass,class Interface>
1.25 +class nsInterfaceHashtable :
1.26 + public nsBaseHashtable< KeyClass, nsCOMPtr<Interface> , Interface* >
1.27 +{
1.28 +public:
1.29 + typedef typename KeyClass::KeyType KeyType;
1.30 + typedef Interface* UserDataType;
1.31 + typedef nsBaseHashtable< KeyClass, nsCOMPtr<Interface> , Interface* >
1.32 + base_type;
1.33 +
1.34 + nsInterfaceHashtable()
1.35 + {
1.36 + }
1.37 + explicit nsInterfaceHashtable(uint32_t aInitSize)
1.38 + : nsBaseHashtable<KeyClass,nsCOMPtr<Interface>,Interface*>(aInitSize)
1.39 + {
1.40 + }
1.41 +
1.42 + /**
1.43 + * @copydoc nsBaseHashtable::Get
1.44 + * @param pData This is an XPCOM getter, so pData is already_addrefed.
1.45 + * If the key doesn't exist, pData will be set to nullptr.
1.46 + */
1.47 + bool Get(KeyType aKey, UserDataType* pData) const;
1.48 +
1.49 + /**
1.50 + * @copydoc nsBaseHashtable::Get
1.51 + */
1.52 + already_AddRefed<Interface> Get(KeyType aKey) const;
1.53 +
1.54 + /**
1.55 + * Gets a weak reference to the hashtable entry.
1.56 + * @param aFound If not nullptr, will be set to true if the entry is found,
1.57 + * to false otherwise.
1.58 + * @return The entry, or nullptr if not found. Do not release this pointer!
1.59 + */
1.60 + Interface* GetWeak(KeyType aKey, bool* aFound = nullptr) const;
1.61 +};
1.62 +
1.63 +template <typename K, typename T>
1.64 +inline void
1.65 +ImplCycleCollectionUnlink(nsInterfaceHashtable<K, T>& aField)
1.66 +{
1.67 + aField.Clear();
1.68 +}
1.69 +
1.70 +template <typename K, typename T>
1.71 +inline void
1.72 +ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,
1.73 + const nsInterfaceHashtable<K, T>& aField,
1.74 + const char* aName,
1.75 + uint32_t aFlags = 0)
1.76 +{
1.77 + nsBaseHashtableCCTraversalData userData(aCallback, aName, aFlags);
1.78 +
1.79 + aField.EnumerateRead(ImplCycleCollectionTraverse_EnumFunc<typename K::KeyType,T*>,
1.80 + &userData);
1.81 +}
1.82 +
1.83 +//
1.84 +// nsInterfaceHashtable definitions
1.85 +//
1.86 +
1.87 +template<class KeyClass,class Interface>
1.88 +bool
1.89 +nsInterfaceHashtable<KeyClass,Interface>::Get
1.90 + (KeyType aKey, UserDataType* pInterface) const
1.91 +{
1.92 + typename base_type::EntryType* ent = this->GetEntry(aKey);
1.93 +
1.94 + if (ent)
1.95 + {
1.96 + if (pInterface)
1.97 + {
1.98 + *pInterface = ent->mData;
1.99 +
1.100 + NS_IF_ADDREF(*pInterface);
1.101 + }
1.102 +
1.103 + return true;
1.104 + }
1.105 +
1.106 + // if the key doesn't exist, set *pInterface to null
1.107 + // so that it is a valid XPCOM getter
1.108 + if (pInterface)
1.109 + *pInterface = nullptr;
1.110 +
1.111 + return false;
1.112 +}
1.113 +
1.114 +template<class KeyClass, class Interface>
1.115 +already_AddRefed<Interface>
1.116 +nsInterfaceHashtable<KeyClass,Interface>::Get(KeyType aKey) const
1.117 +{
1.118 + typename base_type::EntryType* ent = this->GetEntry(aKey);
1.119 + if (!ent)
1.120 + return nullptr;
1.121 +
1.122 + nsCOMPtr<Interface> copy = ent->mData;
1.123 + return copy.forget();
1.124 +}
1.125 +
1.126 +template<class KeyClass,class Interface>
1.127 +Interface*
1.128 +nsInterfaceHashtable<KeyClass,Interface>::GetWeak
1.129 + (KeyType aKey, bool* aFound) const
1.130 +{
1.131 + typename base_type::EntryType* ent = this->GetEntry(aKey);
1.132 +
1.133 + if (ent)
1.134 + {
1.135 + if (aFound)
1.136 + *aFound = true;
1.137 +
1.138 + return ent->mData;
1.139 + }
1.140 +
1.141 + // Key does not exist, return nullptr and set aFound to false
1.142 + if (aFound)
1.143 + *aFound = false;
1.144 + return nullptr;
1.145 +}
1.146 +
1.147 +#endif // nsInterfaceHashtable_h__
