gecko-dev/ipc/ipcd/util/public/ipcMessageWriter.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** 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 Mozilla IPC.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 2003
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Conrad Carlen <ccarlen@netscape.com>
*
* 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 ipcMessageWriter_h__
#define ipcMessageWriter_h__
#include "prtypes.h"
//*****************************************************************************
// ipcMessageWriter
//
// Creates a block of memory and resizes it in order to hold writes. The
// block will be freed when this object is destroyed. Bytes are written in
// native endianess, as ipcMessageReader reads them in native endianess.
//*****************************************************************************
class ipcMessageWriter
{
public:
ipcMessageWriter(PRUint32 initialCapacity) :
mBuf(NULL),
mBufPtr(NULL), mBufEnd(NULL),
mCapacity(0),
mError(PR_FALSE)
{
EnsureCapacity(initialCapacity);
}
~ipcMessageWriter();
// Returns PR_TRUE if an error has occured at any point
// during the lifetime of this object, due to the buffer
// not being able to be grown to the required size.
PRBool HasError()
{ return mError; }
void PutInt8(PRUint8 val);
void PutInt16(PRUint16 val);
void PutInt32(PRUint32 val);
PRUint32 PutBytes(const void* src, PRUint32 n);
// Returns the beginning of the buffer. Do not free this.
PRUint8* GetBuffer()
{ return mBuf; }
PRInt32 GetSize()
{ return mBufPtr - mBuf; }
private:
PRBool EnsureCapacity(PRInt32 sizeNeeded)
{
return (mBuf && ((mBufPtr + sizeNeeded) <= mBufEnd)) ?
PR_TRUE : GrowCapacity(sizeNeeded);
}
PRBool GrowCapacity(PRInt32 sizeNeeded);
private:
PRUint8 *mBuf;
PRUint8 *mBufPtr, *mBufEnd;
PRInt32 mCapacity;
PRBool mError;
};
#endif // ipcMessageWriter_h__