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-rw-r--r--xpcom/glue/nsInterfaceHashtable.h142
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diff --git a/xpcom/glue/nsInterfaceHashtable.h b/xpcom/glue/nsInterfaceHashtable.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsInterfaceHashtable_h__
+#define nsInterfaceHashtable_h__
+
+#include "nsBaseHashtable.h"
+#include "nsHashKeys.h"
+#include "nsCOMPtr.h"
+
+/**
+ * templated hashtable class maps keys to interface pointers.
+ * See nsBaseHashtable for complete declaration.
+ * @param KeyClass a wrapper-class for the hashtable key, see nsHashKeys.h
+ * for a complete specification.
+ * @param Interface the interface-type being wrapped
+ * @see nsDataHashtable, nsClassHashtable
+ */
+template<class KeyClass, class Interface>
+class nsInterfaceHashtable
+ : public nsBaseHashtable<KeyClass, nsCOMPtr<Interface>, Interface*>
+{
+public:
+ typedef typename KeyClass::KeyType KeyType;
+ typedef Interface* UserDataType;
+ typedef nsBaseHashtable<KeyClass, nsCOMPtr<Interface>, Interface*> base_type;
+
+ nsInterfaceHashtable() {}
+ explicit nsInterfaceHashtable(uint32_t aInitLength)
+ : nsBaseHashtable<KeyClass, nsCOMPtr<Interface>, Interface*>(aInitLength)
+ {
+ }
+
+ /**
+ * @copydoc nsBaseHashtable::Get
+ * @param aData This is an XPCOM getter, so aData is already_addrefed.
+ * If the key doesn't exist, aData will be set to nullptr.
+ */
+ bool Get(KeyType aKey, UserDataType* aData) const;
+
+ /**
+ * @copydoc nsBaseHashtable::Get
+ */
+ already_AddRefed<Interface> Get(KeyType aKey) const;
+
+ /**
+ * Gets a weak reference to the hashtable entry.
+ * @param aFound If not nullptr, will be set to true if the entry is found,
+ * to false otherwise.
+ * @return The entry, or nullptr if not found. Do not release this pointer!
+ */
+ Interface* GetWeak(KeyType aKey, bool* aFound = nullptr) const;
+};
+
+template<typename K, typename T>
+inline void
+ImplCycleCollectionUnlink(nsInterfaceHashtable<K, T>& aField)
+{
+ aField.Clear();
+}
+
+template<typename K, typename T>
+inline void
+ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,
+ const nsInterfaceHashtable<K, T>& aField,
+ const char* aName,
+ uint32_t aFlags = 0)
+{
+ for (auto iter = aField.ConstIter(); !iter.Done(); iter.Next()) {
+ CycleCollectionNoteChild(aCallback, iter.UserData(), aName, aFlags);
+ }
+}
+
+//
+// nsInterfaceHashtable definitions
+//
+
+template<class KeyClass, class Interface>
+bool
+nsInterfaceHashtable<KeyClass, Interface>::Get(KeyType aKey,
+ UserDataType* aInterface) const
+{
+ typename base_type::EntryType* ent = this->GetEntry(aKey);
+
+ if (ent) {
+ if (aInterface) {
+ *aInterface = ent->mData;
+
+ NS_IF_ADDREF(*aInterface);
+ }
+
+ return true;
+ }
+
+ // if the key doesn't exist, set *aInterface to null
+ // so that it is a valid XPCOM getter
+ if (aInterface) {
+ *aInterface = nullptr;
+ }
+
+ return false;
+}
+
+template<class KeyClass, class Interface>
+already_AddRefed<Interface>
+nsInterfaceHashtable<KeyClass, Interface>::Get(KeyType aKey) const
+{
+ typename base_type::EntryType* ent = this->GetEntry(aKey);
+ if (!ent) {
+ return nullptr;
+ }
+
+ nsCOMPtr<Interface> copy = ent->mData;
+ return copy.forget();
+}
+
+template<class KeyClass, class Interface>
+Interface*
+nsInterfaceHashtable<KeyClass, Interface>::GetWeak(KeyType aKey,
+ bool* aFound) const
+{
+ typename base_type::EntryType* ent = this->GetEntry(aKey);
+
+ if (ent) {
+ if (aFound) {
+ *aFound = true;
+ }
+
+ return ent->mData;
+ }
+
+ // Key does not exist, return nullptr and set aFound to false
+ if (aFound) {
+ *aFound = false;
+ }
+ return nullptr;
+}
+
+#endif // nsInterfaceHashtable_h__