gecko-dev/xpcom/ds/nsISizeOfHandler.h
1999-05-26 01:38:36 +00:00

67 lines
2.3 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* The contents of this file are subject to the Netscape Public License
* Version 1.0 (the "NPL"); you may not use this file except in
* compliance with the NPL. You may obtain a copy of the NPL at
* http://www.mozilla.org/NPL/
*
* Software distributed under the NPL is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
* for the specific language governing rights and limitations under the
* NPL.
*
* The Initial Developer of this code under the NPL is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All Rights
* Reserved.
*/
#ifndef nsISizeOfHandler_h___
#define nsISizeOfHandler_h___
#include "nscore.h"
#include "nsISupports.h"
/* c028d1f0-fc9e-11d1-89e4-006008911b81 */
#define NS_ISIZEOF_HANDLER_IID \
{ 0xc028d1f0, 0xfc9e, 0x11d1, {0x89, 0xe4, 0x00, 0x60, 0x08, 0x91, 0x1b, 0x81}}
/**
* An API to managing a sizeof computation of an arbitrary graph.
* The handler is responsible for remembering which objects have been
* seen before. Note that the handler doesn't hold references to
* nsISupport's objects; the assumption is that the objects being
* sized are stationary and will not be modified during the sizing
* computation and therefore do not need an extra reference count.
*/
class nsISizeOfHandler : public nsISupports {
public:
/**
* Add in a simple size value to the running total.
* Always returns NS_OK.
*/
NS_IMETHOD Add(size_t aSize) = 0;
/**
* Update aResult with PR_TRUE if the object has been traversed
* by the sizeof computation before. Otherwise aResult is set to
* PR_FALSE and the object is added to the internal database
* of objects that have been traversed. It's ok to pass a null
* pointer in; aResult will be set to PR_TRUE so you won't accidently
* try to traverse through null pointer.
*
* Note: This violates the COM API standard on purpose; so there!
*/
virtual PRBool HaveSeen(void* anObject) = 0;
/**
* Return the currently computed size.
* Always returns NS_OK.
*/
NS_IMETHOD GetSize(PRUint32& aResult) = 0;
};
extern NS_COM nsresult
NS_NewSizeOfHandler(nsISizeOfHandler** aInstancePtrResult);
#endif /* nsISizeofHandler_h___ */