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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:49:04 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:49:04 +0000 |
commit | 16f504a9dca3fe3b70568f67b7d41241ae485288 (patch) | |
tree | c60f36ada0496ba928b7161059ba5ab1ab224f9d /src/libs/xpcom18a4/xpcom/ds/nsAutoBuffer.h | |
parent | Initial commit. (diff) | |
download | virtualbox-16f504a9dca3fe3b70568f67b7d41241ae485288.tar.xz virtualbox-16f504a9dca3fe3b70568f67b7d41241ae485288.zip |
Adding upstream version 7.0.6-dfsg.upstream/7.0.6-dfsgupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/libs/xpcom18a4/xpcom/ds/nsAutoBuffer.h')
-rw-r--r-- | src/libs/xpcom18a4/xpcom/ds/nsAutoBuffer.h | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/src/libs/xpcom18a4/xpcom/ds/nsAutoBuffer.h b/src/libs/xpcom18a4/xpcom/ds/nsAutoBuffer.h new file mode 100644 index 00000000..84011369 --- /dev/null +++ b/src/libs/xpcom18a4/xpcom/ds/nsAutoBuffer.h @@ -0,0 +1,127 @@ +/* -*- 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__ |