Improved ManagedContainer classes

1 files changed, 352 insertions, 168 deletions

diff --git a/src/core/managed/ManagedContainer.hpp b/src/core/managed/ManagedContainer.hpp
index 7b18bcd..1454608 100644
--- a/src/core/managed/ManagedContainer.hpp
+++ b/src/core/managed/ManagedContainer.hpp
@@ -16,6 +16,14 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+/**
+ * @file ManagedContainer.hpp
+ *
+ * Container classes for conviniently storing managed instances.
+ *
+ * @author Andreas Stöckel (astoecke@techfak.uni-bielefeld.de)
+ */
+
 #ifndef _OUSIA_MANAGED_CONTAINER_H_
 #define _OUSIA_MANAGED_CONTAINER_H_
 
@@ -31,48 +39,140 @@
 namespace ousia {
 
 /**
+ * Default accessor class for accessing the managed element within a list value
+ * type.
+ *
+ * @tparam ValueType is the list value type that should be accessed.
+ */
+template <class ValueType>
+struct ListAccessor {
+	Managed *getManaged(const ValueType &val) const { return val.get(); }
+};
+
+/**
+ * Default accessor class for accessing the managed element within a map value
+ * type.
+ *
+ * @tparam ValueType is the map value type that should be accessed.
+ */
+template <class ValueType>
+struct MapAccessor {
+	Managed *getManaged(const ValueType &val) const { return val.second.get(); }
+};
+
+/**
+ * Default implementation of a Listener class. With empty functions.
+ */
+template <class ValueType>
+struct DefaultListener {
+	void addElement(const ValueType &val, Managed *owner) {}
+	void deleteElement(const ValueType &val, Managed *owner) {}
+};
+
+/**
  * Template class which can be used to collect refrences to a certain type of
  * managed objects. Do not use this class directly, use ManagedMap or
  * ManagedVector instead. This class only provides functionality which is common
  * to list and map containers (iterators and state).
  *
- * @param T is the type of the Managed object that should be managed.
- * @param Collection should be a STL container of Owned<T>
+ * @tparam T is the type of the Managed object that should be managed.
+ * @tparam Collection is the underlying STL collection and should contain
+ * pointers of type T as value.
+ * @tparam Accessor is a type that allows to resolve the STL value type to the
+ * actual, underlying pointer to T -- this is important to generically support
+ * maps, where the value type is a pair of key type and the actual value.
+ * @tparam Listener is an optional type that allows to execute arbitrary code
+ * whenever data is read or written to the collection.
  */
-template <class T, class Collection>
-class ManagedContainer : Managed {
+template <class T, class Collection, class Accessor, class Listener>
+class ManagedContainer {
 public:
-	using collection_type = Collection;
-	using value_type = typename collection_type::value_type;
-	using reference = typename collection_type::reference;
-	using const_reference = typename collection_type::const_reference;
-	using iterator = typename collection_type::iterator;
-	using const_iterator = typename collection_type::const_iterator;
-	using size_type = typename collection_type::size_type;
+	using own_type = ManagedContainer<T, Collection, Accessor, Listener>;
+	using value_type = typename Collection::value_type;
+	using reference = typename Collection::reference;
+	using const_reference = typename Collection::const_reference;
+	using iterator = typename Collection::iterator;
+	using const_iterator = typename Collection::const_iterator;
+	using size_type = typename Collection::size_type;
 
-protected:
+private:
 	/**
 	 * Handle containing a reference to the owner of the collection.
 	 */
-	Handle<Managed> owner;
+	Managed *owner;
 
 	/**
-	 * Underlying STL collection.
+	 * Accessor used to access the managed instance inside a "reference type".
+	 */
+	Accessor accessor;
+
+	/**
+	 * Listener which is notified whenever an element is added to or removed
+	 * from the list.
+	 */
+	Listener listener;
+
+	/**
+	 * Calls the "addElement" function of each element and thus initializes
+	 * the references from the owner to the elements.
+	 */
+	void initialize()
+	{
+		for (const auto &elem : *this) {
+			addElement(elem);
+		}
+	}
+
+	/**
+	 * Calls the "deleteElement" function of each element and thus finalizes
+	 * the references from the owner to the elements.
 	 */
-	collection_type c;
+	void finalize()
+	{
+		if (owner) {
+			for (const auto &elem : *this) {
+				deleteElement(elem);
+			}
+		}
+	}
 
 protected:
 	/**
-	 * Function which can be overridden by child classes to execute special code
-	 * whenever a new element is added to the collection.
+	 * Underlying STL collection.
+	 */
+	Collection c;
+
+	/**
+	 * Function to be called whenever an element is added to the collection.
+	 * This function makes sure that the association from the owner to the added
+	 * element is established.
+	 *
+	 * @param managed is the managed instance that is being added to the
+	 * container.
+	 * @param elem is a reference to the actual element that is being added to
+	 * the underlying container.
 	 */
-	virtual void addElement(value_type h) {}
+	void addElement(const value_type &elem)
+	{
+		getManager().addRef(accessor.getManaged(elem), owner);
+		listener.addElement(elem, owner);
+	}
 
 	/**
-	 * Function which can be overriden by child classes to execute special code
-	 * whenever an element is removed from the collection.
+	 * Function to be called whenever an element is removed from the collection.
+	 * This function makes sure that the association from the owner to the added
+	 * element is removed.
+	 *
+	 * @param managed is the managed instance that is being deleted from the
+	 * container.
+	 * @param elem is a reference to the actual element that is being removed
+	 * from the underlying container.
 	 */
-	virtual void deleteElement(value_type h) {}
+	void deleteElement(const value_type &elem)
+	{
+		getManager().deleteRef(accessor.getManaged(elem), owner);
+		listener.deleteElement(elem, owner);
+	}
 
 public:
 	/**
@@ -81,15 +181,162 @@ public:
 	 * @param owner is the managed object which owns the collection and all
 	 * handles to other managed objects stored within.
 	 */
-	ManagedContainer(Handle<Managed> owner) : Managed(owner->getManager), owner(owner){};
+	ManagedContainer(Handle<Managed> owner) : owner(owner.get()){};
+
+	/**
+	 * Copy constructor. Creates a copy of the given container with the same
+	 * owner as the given container.
+	 *
+	 * @param other is the other coontainer that should be copied.
+	 */
+	ManagedContainer(const own_type &other) : owner(other.owner), c(other.c)
+	{
+		initialize();
+	}
+
+	/**
+	 * Copy constructor. Creates a copy of the given container with another
+	 * owner.
+	 *
+	 * @param other is the other container that should be copied.
+	 */
+	ManagedContainer(Handle<Managed> owner, const own_type &other)
+	    : owner(owner.get()), c(other.c)
+	{
+		initialize();
+	}
+
+	/**
+	 * Copy constructor. Creates a copy of the given container and takes over
+	 * ownership.
+	 */
+	ManagedContainer(Handle<Managed> owner, const Collection &collection)
+	    : owner(owner), c(collection)
+	{
+		initialize();
+	}
+
+	/**
+	 * Move constructor. Moves the other instance to this instance.
+	 *
+	 * @param other is the other container that should be moved.
+	 */
+	ManagedContainer(own_type &&other)
+	    : owner(other.owner), c(std::move(other.c))
+	{
+		other.owner = nullptr;
+	}
+
+	/**
+	 * Copy constructor. Creates a copy of the given container with another
+	 * owner.
+	 *
+	 * @param other is the other container that should be moved.
+	 */
+	ManagedContainer(Handle<Managed> owner, own_type &&other)
+	    : owner(owner.get()), c(std::move(other.c))
+	{
+		other.finalize();
+		other.owner = nullptr;
+		initialize();
+	}
+
+	/**
+	 * Copy constructor. Initialize with an iterator from another collection.
+	 *
+	 * @param owner is the managed object which owns the collection and all
+	 * handles to other managed objects stored within.
+	 * @param first is an iterator pointing at the first element to be copied
+	 * from some other collection.
+	 * @param last is an iterator pointing at the last element to be copied
+	 * from some other collection.
+	 */
+	template <class InputIterator>
+	ManagedContainer(Handle<Managed> owner, InputIterator first,
+	                 InputIterator last)
+	    : owner(owner.get())
+	{
+		auto it = end();
+		for (auto it2 = first; it2 != last; it2++) {
+			it = insert(it, *it2);
+			it++;
+		}
+	}
+
+	/**
+	 * Destructor of the ManagedContainer class. Calls the "deleteElement"
+	 * function for each element in the container.
+	 */
+	~ManagedContainer() { finalize(); };
+
+	/**
+	 * Copy assignment operator.
+	 *
+	 * @param other is the collection instance that should be copied.
+	 * @return this instance.
+	 */
+	own_type &operator=(const own_type &other)
+	{
+		finalize();
+		owner = other.owner;
+		c = other.c;
+		initialize();
+		return *this;
+	}
+
+	/**
+	 * Move assignment operator.
+	 *
+	 * @param other is the collection instance that should be moved;
+	 * @return this instance.
+	 */
+	own_type &operator=(own_type &&other)
+	{
+		finalize();
+		owner = other.owner;
+		c = std::move(other.c);
+		other.owner = nullptr;
+		return *this;
+	}
+
+	/**
+	 * Equality operator.
+	 */
+	bool operator==(const own_type &other) {
+		return (owner == other.owner) && (c == other.c);
+	}
+
+	/**
+	 * Inequality operator.
+	 */
+	bool operator!=(const own_type &other) {
+		return (owner != other.owner) || (c != other.c);
+	}
 
 	/**
-	 * Destructor of the ManagedContainer class.
+	 * Returns the owner of the ManagedContainer instance.
 	 */
-	virtual ~ManagedContainer() {};
+	Managed *getOwner() { return owner; }
+
+	/**
+	 * Returns the manager instance associated with the owner.
+	 */
+	Manager &getManager() { return owner->getManager(); }
 
 	/* State functions */
+
+	/**
+	 * Returns the size of the container.
+	 *
+	 * @return the number of elements in the container.
+	 */
 	size_type size() const noexcept { return c.size(); }
+
+	/**
+	 * Returns whether the container is empty.
+	 *
+	 * @return true if the container is empty, false otherwise.
+	 */
 	bool empty() const noexcept { return c.empty(); }
 
 	/* Iterators */
@@ -111,7 +358,9 @@ public:
 	const_iterator crbegin() const { return c.crbegin(); }
 	const_iterator crend() const { return c.crend(); }
 
-	/* Clear function */
+	/**
+	 * Removes all elements from the container.
+	 */
 	void clear() noexcept
 	{
 		for (const_iterator it = cbegin(); it != cend(); it++) {
@@ -119,6 +368,41 @@ public:
 		}
 		c.clear();
 	}
+
+	/**
+	 * Generic insert operation.
+	 */
+	iterator insert(const_iterator position, value_type val)
+	{
+		addElement(val);
+		return c.insert(position, val);
+	}
+
+	/**
+	 * Erases the element at the given position.
+	 *
+	 * @param position is the position at which the element should be removed.
+	 * @return an iterator to the element after the deleted element.
+	 */
+	iterator erase(iterator position)
+	{
+		deleteElement(*position);
+		return c.erase(position);
+	}
+
+	/**
+	 * Erases a range of elements from the collection.
+	 *
+	 * @param position is the position at which the element should be removed.
+	 * @return an iterator to the element after the deleted element.
+	 */
+	iterator erase(iterator first, iterator last)
+	{
+		for (const_iterator it = first; it != last; it++) {
+			this->deleteElement(*it);
+		}
+		return c.erase(first, last);
+	}
 };
 
 /**
@@ -128,16 +412,15 @@ public:
  * owner of this collection whenever a new element is added.
  *
  * @param T is the type of the Managed object that should be managed.
- * @param Collection should be a STL list container of Owned<T>
+ * @param Collection should be a STL list container of T*
  */
-template <class T, class Collection>
-class ManagedGenericList : public ManagedContainer<T, Collection> {
+template <class T, class Collection, class Accessor, class Listener>
+class ManagedGenericList
+    : public ManagedContainer<T, Collection, Accessor, Listener> {
 private:
-	using Base = ManagedContainer<T, Collection>;
+	using Base = ManagedContainer<T, Collection, Accessor, Listener>;
 
 public:
-	using Base::ManagedContainer;
-	using collection_type = typename Base::collection_type;
 	using value_type = typename Base::value_type;
 	using reference = typename Base::reference;
 	using const_reference = typename Base::const_reference;
@@ -145,40 +428,8 @@ public:
 	using const_iterator = typename Base::const_iterator;
 	using size_type = typename Base::size_type;
 
-	/**
-	 * Initialize with an iterator from another collection.
-	 *
-	 * @param owner is the managed object which owns the collection and all
-	 * handles to other managed objects stored within.
-	 * @param first is an iterator pointing at the first element to be copied
-	 * from some other collection.
-	 * @param last is an iterator pointing at the last element to be copied
-	 * from some other collection.
-	 */
-	template <class InputIterator>
-	ManagedGenericList(Handle<Managed> owner, InputIterator first,
-	                   InputIterator last)
-	    : ManagedContainer<T, Collection>(owner)
-	{
-		insert(Base::c.begin(), first, last);
-	}
-
-	/**
-	 * Initialize with another collection.
-	 *
-	 * @param owner is the managed object which owns the collection and all
-	 * handles to other managed objects stored within.
-	 * @param in is a reference at some other collection with content that
-	 * should be copied.
-	 */
-	template <class InputCollection>
-	ManagedGenericList(Handle<Managed> owner, const InputCollection &in)
-	    : ManagedContainer<T, Collection>(owner)
-	{
-		for (const auto &e : in) {
-			push_back(e);
-		}
-	}
+	using Base::ManagedContainer;
+	using Base::insert;
 
 	/* Front and back */
 	reference front() { return Base::c.front(); }
@@ -188,13 +439,6 @@ public:
 
 	/* Insert and delete operations */
 
-	iterator insert(const_iterator position, Handle<T> h)
-	{
-		value_type v = Base::owner->acquire(h);
-		addElement(v);
-		return Base::c.insert(position, v);
-	}
-
 	template <class InputIterator>
 	iterator insert(const_iterator position, InputIterator first,
 	                InputIterator last)
@@ -212,20 +456,20 @@ public:
 		return pos;
 	}
 
-	iterator find(const Handle<T> h)
+	iterator find(const value_type &val)
 	{
 		for (iterator it = Base::begin(); it != Base::end(); it++) {
-			if (*it == h) {
+			if (*it == val) {
 				return it;
 			}
 		}
 		return Base::end();
 	}
 
-	const_iterator find(const Handle<T> h) const
+	const_iterator find(const value_type &val) const
 	{
 		for (const_iterator it = Base::cbegin(); it != Base::cend(); it++) {
-			if (*it == h) {
+			if (*it == val) {
 				return it;
 			}
 		}
@@ -234,9 +478,8 @@ public:
 
 	void push_back(Handle<T> h)
 	{
-		value_type v = Base::owner->acquire(h);
-		this->addElement(v);
-		Base::c.push_back(v);
+		this->addElement(h.get());
+		Base::c.push_back(h.get());
 	}
 
 	void pop_back()
@@ -246,33 +489,18 @@ public:
 		}
 		Base::c.pop_back();
 	}
-
-	iterator erase(iterator position)
-	{
-		this->deleteElement(*position);
-		return Base::c.erase(position);
-	}
-
-	iterator erase(iterator first, iterator last)
-	{
-		for (const_iterator it = first; it != last; it++) {
-			this->deleteElement(*it);
-		}
-		return Base::c.erase(first, last);
-	}
 };
 
 /**
  * Special type of ManagedContainer based on an STL map.
  */
-template <class K, class T, class Collection>
-class ManagedGenericMap : public ManagedContainer<T, Collection> {
+template <class K, class T, class Collection, class Accessor, class Listener>
+class ManagedGenericMap
+    : public ManagedContainer<T, Collection, Accessor, Listener> {
 private:
-	using Base = ManagedContainer<T, Collection>;
+	using Base = ManagedContainer<T, Collection, Accessor, Listener>;
 
 public:
-	using Base::ManagedContainer;
-	using collection_type = typename Base::collection_type;
 	using value_type = typename Base::value_type;
 	using key_type = typename Collection::key_type;
 	using reference = typename Base::reference;
@@ -281,76 +509,30 @@ public:
 	using const_iterator = typename Base::const_iterator;
 	using size_type = typename Base::size_type;
 
-private:
-	value_type acquirePair(std::pair<K, Handle<T>> val)
-	{
-		return value_type{val.first, Base::owner->acquire(val.second)};
-	}
-
-public:
-	/**
-	 * Initialize with an iterator from another collection.
-	 *
-	 * @param owner is the managed object which owns the collection and all
-	 * handles to other managed objects stored within.
-	 * @param first is an iterator pointing at the first element to be copied
-	 * from some other collection.
-	 * @param last is an iterator pointing at the last element to be copied
-	 * from some other collection.
-	 */
-	template <class InputIterator>
-	ManagedGenericMap(Handle<Managed> owner, InputIterator first,
-	                  InputIterator last)
-	    : ManagedContainer<T, Collection>(owner)
-	{
-		insert(first, last);
-	}
-
-	/**
-	 * Initialize with another collection.
-	 *
-	 * @param owner is the managed object which owns the collection and all
-	 * handles to other managed objects stored within.
-	 * @param in is a reference at some other collection with content that
-	 * should be copied.
-	 */
-	template <class InputCollection>
-	ManagedGenericMap(Handle<Managed> owner, const InputCollection &in)
-	    : ManagedContainer<T, Collection>(owner)
-	{
-		for (const auto &e : in) {
-			insert(*in);
-		}
-	}
+	using Base::ManagedContainer;
+	using Base::erase;
+	using Base::insert;
 
-	std::pair<iterator, bool> insert(std::pair<K, Handle<T>> val)
+	std::pair<iterator, bool> insert(value_type val)
 	{
-		value_type v = acquirePair(val);
-		this->addElement(v);
-		return Base::c.insert(v);
+		this->addElement(val);
+		return Base::c.insert(val);
 	}
 
-	iterator insert(const_iterator position, std::pair<K, Handle<T>> val)
+	iterator insert(const_iterator position, value_type val)
 	{
-		value_type v = acquirePair(val);
-		this->addElement(v);
-		return Base::c.insert(position, v);
+		this->addElement(val);
+		return Base::c.insert(position, val);
 	}
 
 	template <class InputIterator>
 	void insert(InputIterator first, InputIterator last)
 	{
 		for (auto it = first; it != last; it++) {
-			insert(acquirePair);
+			insert(*it);
 		}
 	}
 
-	iterator erase(const_iterator position)
-	{
-		this->deleteElement(*position);
-		return Base::c.erase(position);
-	}
-
 	size_t erase(const key_type &k)
 	{
 		iterator pos = find(k);
@@ -361,14 +543,6 @@ public:
 		return 0;
 	}
 
-	iterator erase(const_iterator first, const_iterator last)
-	{
-		for (const_iterator it = first; it != last; it++) {
-			this->deleteElement(*it);
-		}
-		return Base::c.erase(first, last);
-	}
-
 	iterator find(const key_type &k) { return Base::c.find(k); }
 	const_iterator find(const key_type &k) const { return Base::c.find(k); }
 };
@@ -376,19 +550,29 @@ public:
 /**
  * Special type of ManagedGenericList based on an STL vector.
  */
-template <class T>
-class ManagedVector : public ManagedGenericList<T, std::vector<Owned<T>>> {
+template <class T, class Listener = DefaultListener<Handle<T>>>
+class ManagedVector
+    : public ManagedGenericList<T, std::vector<Handle<T>>,
+                                ListAccessor<Handle<T>>, Listener> {
 public:
-	using ManagedGenericList<T, std::vector<Owned<T>>>::ManagedGenericList;
+	using Base = ManagedGenericList<T, std::vector<Handle<T>>,
+	                                ListAccessor<Handle<T>>, Listener>;
+	using Base::ManagedGenericList;
 };
 
 /**
  * Special type of ManagedGenericMap based on an STL map.
  */
-template <class K, class T>
-class ManagedMap : public ManagedGenericMap<K, T, std::map<K, Owned<T>>> {
+template <class K, class T,
+          class Listener = DefaultListener<std::pair<K, Handle<T>>>>
+class ManagedMap
+    : public ManagedGenericMap<K, T, std::map<K, Handle<T>>,
+                               MapAccessor<std::pair<K, Handle<T>>>, Listener> {
 public:
-	using ManagedGenericMap<K, T, std::map<K, Owned<T>>>::ManagedGenericMap;
+	using Base =
+	    ManagedGenericMap<K, T, std::map<K, Handle<T>>,
+	                      MapAccessor<std::pair<K, Handle<T>>>, Listener>;
+	using Base::ManagedGenericMap;
 };
 }