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Diffstat (limited to 'dom/base/nsPropertyTable.h')
| -rw-r--r-- | dom/base/nsPropertyTable.h | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/dom/base/nsPropertyTable.h b/dom/base/nsPropertyTable.h new file mode 100644 index 0000000000..7fb90f6b9f --- /dev/null +++ b/dom/base/nsPropertyTable.h @@ -0,0 +1,166 @@ +/* -*- 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 |