gecko/netwerk/streamconv/converters/nsBinHexDecoder.h

154 lines
5.7 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 mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1999
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Scott MacGregor <mscott@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
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*
* ***** END LICENSE BLOCK ***** */
// A decoder for Mac Bin Hex 4.0.
// This decoder is currently only intended to be used on NON-Mac platforms. It isn't hooked up to
// code which would actually save the file to disk. As a result, we can't leverage the resource fork.
// This makes this decoder most unhelpful for the Mac. Our assumption is that if you save a bin hex file
// on the mac and try to open it, stuffit or some other tool is already going to be on the Mac which knows how
// to handle bin hex. On windows and unix, that's not the case. We need client code to strip out the data fork.
// So this decoder currently just strips out the data fork.
// Note: it's possible that we can eventually turn this decoder into both a decoder and into a file stream (much
// like the apple double decoder) so on the Mac, if we are saving to disk, we can invoke the decoder as a file stream
// and it will process the resource fork and do the right magic.
#ifndef nsBinHexDecoder_h__
#define nsBinHexDecoder_h__
#include "nsIStreamConverter.h"
#include "nsIChannel.h"
#include "nsIOutputStream.h"
#include "nsIInputStream.h"
#include "nsCOMPtr.h"
#include "nsString.h"
#define NS_BINHEXDECODER_CID \
{ /* 301DEA42-6850-4cda-8945-81F7DBC2186B */ \
0x301dea42, 0x6850, 0x4cda, \
{ 0x89, 0x45, 0x81, 0xf7, 0xdb, 0xc2, 0x18, 0x6b } \
}
typedef struct _binhex_header
{
PRUint32 type, creator;
PRUint16 flags;
PRInt32 dlen, rlen;
} binhex_header;
typedef union
{
unsigned char c[4];
PRUint32 val;
} longbuf;
#define BINHEX_STATE_START 0
#define BINHEX_STATE_FNAME 1
#define BINHEX_STATE_HEADER 2
#define BINHEX_STATE_HCRC 3
#define BINHEX_STATE_DFORK 4
#define BINHEX_STATE_DCRC 5
#define BINHEX_STATE_RFORK 6
#define BINHEX_STATE_RCRC 7
#define BINHEX_STATE_FINISH 8
#define BINHEX_STATE_DONE 9
/* #define BINHEX_STATE_ERROR 10 */
class nsBinHexDecoder : public nsIStreamConverter
{
public:
// nsISupports methods
NS_DECL_ISUPPORTS
// nsIStreamConverter methods
NS_DECL_NSISTREAMCONVERTER
// nsIStreamListener methods
NS_DECL_NSISTREAMLISTENER
// nsIRequestObserver methods
NS_DECL_NSIREQUESTOBSERVER
nsBinHexDecoder();
protected:
virtual ~nsBinHexDecoder();
PRInt16 GetNextChar(PRUint32 numBytesInBuffer);
nsresult ProcessNextChunk(nsIRequest * aRequest, nsISupports * aContext, PRUint32 numBytesInBuffer);
nsresult ProcessNextState(nsIRequest * aRequest, nsISupports * aContext);
nsresult SetContentType(nsIRequest * aRequest, const char * fileName);
protected:
nsCOMPtr<nsIStreamListener> mNextListener;
// the input and output streams form a pipe...they need to be passed around together..
nsCOMPtr<nsIOutputStream> mOutputStream; // output stream
nsCOMPtr<nsIInputStream> mInputStream;
PRInt16 mState; /* current state */
PRUint16 mCRC; /* cumulative CRC */
PRUint16 mFileCRC; /* CRC value from file */
longbuf mOctetBuf; /* buffer for decoded 6-bit values */
PRInt16 mOctetin; /* current input position in octetbuf */
PRInt16 mDonePos; /* ending position in octetbuf */
PRInt16 mInCRC; /* flag set when reading a CRC */
// Bin Hex Header Information
binhex_header mHeader;
char mName[64]; /* fsspec for the output file */
// unfortunately we are going to need 2 8K buffers here. One for the data we are currently digesting. Another
// for the outgoing decoded data. I tried getting them to share a buffer but things didn't work out so nicely.
char * mDataBuffer; // temporary holding pen for the incoming data.
char * mOutgoingBuffer; // temporary holding pen for the incoming data.
PRUint32 mPosInDataBuffer;
unsigned char mRlebuf; /* buffer for last run length encoding value */
PRInt32 mCount; /* generic counter */
PRInt16 mMarker; /* flag indicating maker */
PRInt32 mPosInbuff; /* the index of the inbuff. */
PRInt32 mPosOutputBuff; /* the position of the out buff. */
};
#endif /* nsBinHexDecoder_h__ */