gecko-dev/ipc/ipcd/util/public/ipcMessageReader.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 ipcMessageReader_h__
#define ipcMessageReader_h__
#include "prtypes.h"
//*****************************************************************************
// ipcMessageReader
//
// Reads from a const buffer supplied to it. Does not take ownership of the
// buffer. Bytes are read in native endianess, as ipcMessageWriter writes them
// in native endianess.
//*****************************************************************************
class ipcMessageReader
{
public:
ipcMessageReader(const PRUint8* inBuffer, PRUint32 bufferSize) :
mBuf(inBuffer), mBufEnd(inBuffer + bufferSize),
mBufPtr(mBuf),
mError(PR_FALSE)
{ }
~ipcMessageReader()
{ }
// Returns PR_TRUE if an error has occured at any point
// during the lifetime of this object. Any read operation
// will safely return 0 on an error condition.
PRBool HasError()
{ return mError; }
PRUint8 GetInt8();
PRUint16 GetInt16();
PRUint32 GetInt32();
PRInt32 GetBytes(void* destBuffer, PRInt32 n);
// Returns data at the current read position.
const PRUint8* GetPtr()
{ return mBufPtr; }
// Returns PR_TRUE if the new position is within the buffer.
// Returns PR_FALSE and sets error state if not.
PRBool AdvancePtr(PRInt32 n);
private:
const PRUint8 *mBuf, *mBufEnd;
const PRUint8 *mBufPtr;
PRBool mError;
};
#endif // ipcMessageReader_h__