gecko-dev/xpcom/ds/nsIArena.h

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/* -*- 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 nsIArena_h___
#define nsIArena_h___
#include "nscore.h"
#include "nsISupports.h"
#define NS_MIN_ARENA_BLOCK_SIZE 64
#define NS_DEFAULT_ARENA_BLOCK_SIZE 4096
/// Interface IID for nsIArena
#define NS_IARENA_IID \
{ 0xa24fdad0, 0x93b4, 0x11d1, \
{0x89, 0x5b, 0x00, 0x60, 0x08, 0x91, 0x1b, 0x81} }
/** Interface to a memory arena abstraction. Arena's use large blocks
* of memory to allocate smaller objects. Arena's provide no free
* operator; instead, all of the objects in the arena are deallocated
* by deallocating the arena (e.g. when it's reference count goes to
* zero)
*/
class nsIArena : public nsISupports {
public:
static const nsIID& GetIID() { static nsIID iid = NS_IARENA_IID; return iid; }
virtual void* Alloc(PRInt32 size) = 0;
};
/**
* Create a new arena using the desired block size for allocating the
* underlying memory blocks. The underlying memory blocks are allocated
* using the PR heap.
*/
extern NS_BASE nsresult NS_NewHeapArena(nsIArena** aInstancePtrResult,
PRInt32 aArenaBlockSize = 0);
#endif /* nsIArena_h___ */