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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
/**
* 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