mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-25 22:01:30 +00:00
128 lines
3.8 KiB
C++
128 lines
3.8 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
|
/* ***** BEGIN LICENSE BLOCK *****
|
|
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
|
|
*
|
|
* The contents of this file are subject to the Mozilla Public License Version
|
|
* 1.1 (the "License"); you may not use this file except in compliance with
|
|
* the License. You may obtain a copy of the License at
|
|
* http://www.mozilla.org/MPL/
|
|
*
|
|
* Software distributed under the License is distributed on an "AS IS" basis,
|
|
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
|
|
* for the specific language governing rights and limitations under the
|
|
* License.
|
|
*
|
|
* The Original Code is auto buffer template.
|
|
*
|
|
* The Initial Developer of the Original Code is
|
|
* Conrad Carlen <ccarlen@mac.com>.
|
|
* Portions created by the Initial Developer are Copyright (C) 2004
|
|
* the Initial Developer. All Rights Reserved.
|
|
*
|
|
* Contributor(s):
|
|
* Jungshik Shin <jshin@mailaps.org>
|
|
*
|
|
* Alternatively, the contents of this file may be used under the terms of
|
|
* either the GNU General Public License Version 2 or later (the "GPL"), or
|
|
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
|
|
* in which case the provisions of the GPL or the LGPL are applicable instead
|
|
* of those above. If you wish to allow use of your version of this file only
|
|
* under the terms of either the GPL or the LGPL, and not to allow others to
|
|
* use your version of this file under the terms of the MPL, indicate your
|
|
* decision by deleting the provisions above and replace them with the notice
|
|
* and other provisions required by the GPL or the LGPL. If you do not delete
|
|
* the provisions above, a recipient may use your version of this file under
|
|
* the terms of any one of the MPL, the GPL or the LGPL.
|
|
*
|
|
* ***** END LICENSE BLOCK ***** */
|
|
|
|
#ifndef nsAutoBuffer_h__
|
|
#define nsAutoBuffer_h__
|
|
|
|
#ifndef nsMemory_h__
|
|
#include "nsMemory.h"
|
|
#endif
|
|
|
|
/**
|
|
* A buffer which will use stack space if the requested size will
|
|
* fit in the stack buffer and allocate from the heap if not.
|
|
*
|
|
* Below is a usage example :
|
|
*
|
|
* typedef nsAutoBuffer<PRUnichar, 256> nsAutoUnicharBuffer;
|
|
*
|
|
* nsAutoUnicharBuffer buffer;
|
|
*
|
|
* if (!buffer.EnsureElemCapacity(initialLength))
|
|
* return NS_ERROR_OUT_OF_MEMORY;
|
|
*
|
|
* PRUnichar *unicharPtr = buffer.get();
|
|
*
|
|
* // add PRUnichar's to the buffer pointed to by |unicharPtr| as long as
|
|
* // the number of PRUnichar's is less than |intialLength|
|
|
*
|
|
* // increase the capacity
|
|
* if (!buffer.AddElemCapacity(extraLength))
|
|
* return NS_ERROR_OUT_OF_MEMORY
|
|
*
|
|
* unicharPtr = buffer.get() + initialLength;
|
|
*
|
|
* //continue to add PRUnichar's....
|
|
*/
|
|
|
|
template <class T, PRInt32 sz>
|
|
class nsAutoBuffer
|
|
{
|
|
public:
|
|
nsAutoBuffer() :
|
|
mBufferPtr(mStackBuffer),
|
|
mCurElemCapacity(sz)
|
|
{
|
|
}
|
|
|
|
~nsAutoBuffer()
|
|
{
|
|
if (mBufferPtr != mStackBuffer)
|
|
nsMemory::Free(mBufferPtr);
|
|
}
|
|
|
|
PRBool EnsureElemCapacity(PRInt32 inElemCapacity)
|
|
{
|
|
if (inElemCapacity <= mCurElemCapacity)
|
|
return PR_TRUE;
|
|
|
|
T* newBuffer;
|
|
|
|
if (mBufferPtr != mStackBuffer)
|
|
newBuffer = (T*)nsMemory::Realloc((void *)mBufferPtr, inElemCapacity * sizeof(T));
|
|
else
|
|
newBuffer = (T*)nsMemory::Alloc(inElemCapacity * sizeof(T));
|
|
|
|
if (!newBuffer)
|
|
return PR_FALSE;
|
|
|
|
if (mBufferPtr != mStackBuffer)
|
|
nsMemory::Free(mBufferPtr);
|
|
|
|
mBufferPtr = newBuffer;
|
|
mCurElemCapacity = inElemCapacity;
|
|
return PR_TRUE;
|
|
}
|
|
|
|
PRBool AddElemCapacity(PRInt32 inElemCapacity)
|
|
{
|
|
return EnsureElemCapacity(mCurElemCapacity + inElemCapacity);
|
|
}
|
|
|
|
T* get() const { return mBufferPtr; }
|
|
PRInt32 GetElemCapacity() const { return mCurElemCapacity; }
|
|
|
|
protected:
|
|
|
|
T *mBufferPtr;
|
|
T mStackBuffer[sz];
|
|
PRInt32 mCurElemCapacity;
|
|
};
|
|
|
|
#endif // nsAutoBuffer_h__
|