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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/. */
+
+/**
+ * nsPropertyTable allows a set of arbitrary key/value pairs to be stored
+ * for any number of nodes, in a global hashtable rather than on the nodes
+ * themselves. Nodes can be any type of object; the hashtable keys are
+ * nsAtom pointers, and the values are void pointers.
+ */
+
+#ifndef nsPropertyTable_h_
+#define nsPropertyTable_h_
+
+#include "mozilla/MemoryReporting.h"
+#include "nscore.h"
+
+class nsAtom;
+
+using NSPropertyFunc = void (*)(void* aObject, nsAtom* aPropertyName,
+ void* aPropertyValue, void* aData);
+
+/**
+ * Callback type for property destructors. |aObject| is the object
+ * the property is being removed for, |aPropertyName| is the property
+ * being removed, |aPropertyValue| is the value of the property, and |aData|
+ * is the opaque destructor data that was passed to SetProperty().
+ **/
+using NSPropertyDtorFunc = NSPropertyFunc;
+class nsINode;
+class nsIFrame;
+
+class nsPropertyOwner {
+ public:
+ nsPropertyOwner(const nsPropertyOwner& aOther) = default;
+
+ // These are the types of objects that can own properties. No object should
+ // inherit more then one of these classes.
+ // To add support for more types just add to this list.
+ MOZ_IMPLICIT nsPropertyOwner(const nsINode* aObject) : mObject(aObject) {}
+ MOZ_IMPLICIT nsPropertyOwner(const nsIFrame* aObject) : mObject(aObject) {}
+
+ operator const void*() { return mObject; }
+ const void* get() { return mObject; }
+
+ private:
+ const void* mObject;
+};
+
+class nsPropertyTable {
+ public:
+ /**
+ * Get the value of the property |aPropertyName| for node |aObject|.
+ * |aResult|, if supplied, is filled in with a return status code.
+ **/
+ void* GetProperty(const nsPropertyOwner& aObject, const nsAtom* aPropertyName,
+ nsresult* aResult = nullptr) {
+ return GetPropertyInternal(aObject, aPropertyName, false, aResult);
+ }
+
+ /**
+ * Set the value of the property |aPropertyName| to
+ * |aPropertyValue| for node |aObject|. |aDtor| is a destructor for the
+ * property value to be called if the property is removed. It can be null
+ * if no destructor is required. |aDtorData| is an optional pointer to an
+ * opaque context to be passed to the property destructor. Note that the
+ * destructor is global for each property name regardless of node; it is an
+ * error to set a given property with a different destructor than was used
+ * before (this will return NS_ERROR_INVALID_ARG). If |aTransfer| is true
+ * the property will be transfered to the new table when the property table
+ * for |aObject| changes (currently the tables for nodes are owned by their
+ * ownerDocument, so if the ownerDocument for a node changes, its property
+ * table changes too). If |aTransfer| is false the property will just be
+ * deleted instead.
+ */
+ nsresult SetProperty(const nsPropertyOwner& aObject, nsAtom* aPropertyName,
+ void* aPropertyValue, NSPropertyDtorFunc aDtor,
+ void* aDtorData, bool aTransfer = false) {
+ return SetPropertyInternal(aObject, aPropertyName, aPropertyValue, aDtor,
+ aDtorData, aTransfer);
+ }
+
+ /**
+ * Remove the property |aPropertyName| in the global category for object
+ * |aObject|. The property's destructor function will be called.
+ */
+ nsresult RemoveProperty(nsPropertyOwner aObject, const nsAtom* aPropertyName);
+
+ /**
+ * Remove the property |aPropertyName| in the global category for object
+ * |aObject|, but do not call the property's destructor function. The
+ * property value is returned.
+ */
+ void* TakeProperty(const nsPropertyOwner& aObject,
+ const nsAtom* aPropertyName, nsresult* aStatus = nullptr) {
+ return GetPropertyInternal(aObject, aPropertyName, true, aStatus);
+ }
+
+ /**
+ * Removes all of the properties for object |aObject|, calling the destructor
+ * function for each property.
+ */
+ void RemoveAllPropertiesFor(nsPropertyOwner aObject);
+
+ /**
+ * Transfers all properties for object |aObject| that were set with the
+ * |aTransfer| argument as true to |aTable|. Removes the other properties for
+ * object |aObject|, calling the destructor function for each property.
+ * If transfering a property fails, this deletes all the properties for object
+ * |aObject|.
+ */
+ nsresult TransferOrRemoveAllPropertiesFor(nsPropertyOwner aObject,
+ nsPropertyTable& aOtherTable);
+
+ /**
+ * Enumerate the properties for object |aObject|.
+ * For every property |aCallback| will be called with as arguments |aObject|,
+ * the property name, the property value and |aData|.
+ */
+ void Enumerate(nsPropertyOwner aObject, NSPropertyFunc aCallback,
+ void* aData);
+
+ /**
+ * Enumerate all the properties.
+ * For every property |aCallback| will be called with arguments the owner,
+ * the property name, the property value and |aData|.
+ */
+ void EnumerateAll(NSPropertyFunc aCallback, void* aData);
+
+ /**
+ * Removes all of the properties for all objects in the property table,
+ * calling the destructor function for each property.
+ */
+ void RemoveAllProperties();
+
+ nsPropertyTable() : mPropertyList(nullptr) {}
+ ~nsPropertyTable() { RemoveAllProperties(); }
+
+ /**
+ * Function useable as destructor function for property data that is
+ * XPCOM objects. The function will call NS_IF_RELASE on the value
+ * to destroy it.
+ */
+ static void SupportsDtorFunc(void* aObject, nsAtom* aPropertyName,
+ void* aPropertyValue, void* aData);
+
+ class PropertyList;
+
+ size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
+ size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
+
+ private:
+ void DestroyPropertyList();
+ PropertyList* GetPropertyListFor(const nsAtom* aPropertyName) const;
+ void* GetPropertyInternal(nsPropertyOwner aObject,
+ const nsAtom* aPropertyName, bool aRemove,
+ nsresult* aStatus);
+ nsresult SetPropertyInternal(nsPropertyOwner aObject, nsAtom* aPropertyName,
+ void* aPropertyValue, NSPropertyDtorFunc aDtor,
+ void* aDtorData, bool aTransfer);
+
+ PropertyList* mPropertyList;
+};
+#endif