michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef nsInterfaceHashtable_h__
michael@0: #define nsInterfaceHashtable_h__
michael@0: 
michael@0: #include "nsBaseHashtable.h"
michael@0: #include "nsHashKeys.h"
michael@0: #include "nsCOMPtr.h"
michael@0: 
michael@0: /**
michael@0:  * templated hashtable class maps keys to interface pointers.
michael@0:  * See nsBaseHashtable for complete declaration.
michael@0:  * @param KeyClass a wrapper-class for the hashtable key, see nsHashKeys.h
michael@0:  *   for a complete specification.
michael@0:  * @param Interface the interface-type being wrapped
michael@0:  * @see nsDataHashtable, nsClassHashtable
michael@0:  */
michael@0: template<class KeyClass,class Interface>
michael@0: class nsInterfaceHashtable :
michael@0:   public nsBaseHashtable< KeyClass, nsCOMPtr<Interface> , Interface* >
michael@0: {
michael@0: public:
michael@0:   typedef typename KeyClass::KeyType KeyType;
michael@0:   typedef Interface* UserDataType;
michael@0:   typedef nsBaseHashtable< KeyClass, nsCOMPtr<Interface> , Interface* >
michael@0:           base_type;
michael@0: 
michael@0:   nsInterfaceHashtable()
michael@0:   {
michael@0:   }
michael@0:   explicit nsInterfaceHashtable(uint32_t aInitSize)
michael@0:     : nsBaseHashtable<KeyClass,nsCOMPtr<Interface>,Interface*>(aInitSize)
michael@0:   {
michael@0:   }
michael@0: 
michael@0:   /**
michael@0:    * @copydoc nsBaseHashtable::Get
michael@0:    * @param pData This is an XPCOM getter, so pData is already_addrefed.
michael@0:    *   If the key doesn't exist, pData will be set to nullptr.
michael@0:    */
michael@0:   bool Get(KeyType aKey, UserDataType* pData) const;
michael@0: 
michael@0:   /**
michael@0:    * @copydoc nsBaseHashtable::Get
michael@0:    */
michael@0:   already_AddRefed<Interface> Get(KeyType aKey) const;
michael@0: 
michael@0:   /**
michael@0:    * Gets a weak reference to the hashtable entry.
michael@0:    * @param aFound If not nullptr, will be set to true if the entry is found,
michael@0:    *               to false otherwise.
michael@0:    * @return The entry, or nullptr if not found. Do not release this pointer!
michael@0:    */
michael@0:   Interface* GetWeak(KeyType aKey, bool* aFound = nullptr) const;
michael@0: };
michael@0: 
michael@0: template <typename K, typename T>
michael@0: inline void
michael@0: ImplCycleCollectionUnlink(nsInterfaceHashtable<K, T>& aField)
michael@0: {
michael@0:   aField.Clear();
michael@0: }
michael@0: 
michael@0: template <typename K, typename T>
michael@0: inline void
michael@0: ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,
michael@0:                             const nsInterfaceHashtable<K, T>& aField,
michael@0:                             const char* aName,
michael@0:                             uint32_t aFlags = 0)
michael@0: {
michael@0:   nsBaseHashtableCCTraversalData userData(aCallback, aName, aFlags);
michael@0: 
michael@0:   aField.EnumerateRead(ImplCycleCollectionTraverse_EnumFunc<typename K::KeyType,T*>,
michael@0:                        &userData);
michael@0: }
michael@0: 
michael@0: //
michael@0: // nsInterfaceHashtable definitions
michael@0: //
michael@0: 
michael@0: template<class KeyClass,class Interface>
michael@0: bool
michael@0: nsInterfaceHashtable<KeyClass,Interface>::Get
michael@0:   (KeyType aKey, UserDataType* pInterface) const
michael@0: {
michael@0:   typename base_type::EntryType* ent = this->GetEntry(aKey);
michael@0: 
michael@0:   if (ent)
michael@0:   {
michael@0:     if (pInterface)
michael@0:     {
michael@0:       *pInterface = ent->mData;
michael@0: 
michael@0:       NS_IF_ADDREF(*pInterface);
michael@0:     }
michael@0: 
michael@0:     return true;
michael@0:   }
michael@0: 
michael@0:   // if the key doesn't exist, set *pInterface to null
michael@0:   // so that it is a valid XPCOM getter
michael@0:   if (pInterface)
michael@0:     *pInterface = nullptr;
michael@0: 
michael@0:   return false;
michael@0: }
michael@0: 
michael@0: template<class KeyClass, class Interface>
michael@0: already_AddRefed<Interface>
michael@0: nsInterfaceHashtable<KeyClass,Interface>::Get(KeyType aKey) const
michael@0: {
michael@0:   typename base_type::EntryType* ent = this->GetEntry(aKey);
michael@0:   if (!ent)
michael@0:     return nullptr;
michael@0: 
michael@0:   nsCOMPtr<Interface> copy = ent->mData;
michael@0:   return copy.forget();
michael@0: }
michael@0: 
michael@0: template<class KeyClass,class Interface>
michael@0: Interface*
michael@0: nsInterfaceHashtable<KeyClass,Interface>::GetWeak
michael@0:   (KeyType aKey, bool* aFound) const
michael@0: {
michael@0:   typename base_type::EntryType* ent = this->GetEntry(aKey);
michael@0: 
michael@0:   if (ent)
michael@0:   {
michael@0:     if (aFound)
michael@0:       *aFound = true;
michael@0: 
michael@0:     return ent->mData;
michael@0:   }
michael@0: 
michael@0:   // Key does not exist, return nullptr and set aFound to false
michael@0:   if (aFound)
michael@0:     *aFound = false;
michael@0:   return nullptr;
michael@0: }
michael@0: 
michael@0: #endif // nsInterfaceHashtable_h__