michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: // A decoder for Mac Bin Hex 4.0.
michael@0: 
michael@0: // This decoder is currently only intended to be used on NON-Mac platforms. It isn't hooked up to
michael@0: // code which would actually save the file to disk. As a result, we can't leverage the resource fork.
michael@0: // This makes this decoder most unhelpful for the Mac. Our assumption is that if you save a bin hex file
michael@0: // on the mac and try to open it, stuffit or some other tool is already going to be on the Mac which knows how
michael@0: // to handle bin hex. On windows and unix, that's not the case. We need client code to strip out the data fork.
michael@0: // So this decoder currently just strips out the data fork.
michael@0: 
michael@0: // Note: it's possible that we can eventually turn this decoder into both a decoder and into a file stream (much
michael@0: // like the apple double decoder) so on the Mac, if we are saving to disk, we can invoke the decoder as a file stream
michael@0: // and it will process the resource fork and do the right magic.
michael@0: 
michael@0: #ifndef nsBinHexDecoder_h__
michael@0: #define nsBinHexDecoder_h__
michael@0: 
michael@0: #include "nsIStreamConverter.h"
michael@0: #include "nsIChannel.h"
michael@0: #include "nsIOutputStream.h"
michael@0: #include "nsIInputStream.h"
michael@0: 
michael@0: #include "nsCOMPtr.h"
michael@0: #include "nsString.h"
michael@0: 
michael@0: #define NS_BINHEXDECODER_CID                         \
michael@0: { /* 301DEA42-6850-4cda-8945-81F7DBC2186B */         \
michael@0:   0x301dea42, 0x6850, 0x4cda,                        \
michael@0:   { 0x89, 0x45, 0x81, 0xf7, 0xdb, 0xc2, 0x18, 0x6b } \
michael@0: }
michael@0: 
michael@0: typedef struct _binhex_header
michael@0: {
michael@0:   uint32_t type, creator;
michael@0:   uint16_t flags;
michael@0:   int32_t dlen, rlen;
michael@0: } binhex_header;
michael@0: 
michael@0: typedef union
michael@0: {
michael@0:   unsigned char c[4];
michael@0:   uint32_t      val;
michael@0: } longbuf;
michael@0: 
michael@0: #define BINHEX_STATE_START    0
michael@0: #define BINHEX_STATE_FNAME    1
michael@0: #define BINHEX_STATE_HEADER   2
michael@0: #define BINHEX_STATE_HCRC     3
michael@0: #define BINHEX_STATE_DFORK    4
michael@0: #define BINHEX_STATE_DCRC     5
michael@0: #define BINHEX_STATE_RFORK    6
michael@0: #define BINHEX_STATE_RCRC     7
michael@0: #define BINHEX_STATE_FINISH   8
michael@0: #define BINHEX_STATE_DONE     9
michael@0: /* #define BINHEX_STATE_ERROR  10 */
michael@0: 
michael@0: class nsBinHexDecoder : public nsIStreamConverter
michael@0: {
michael@0: public:
michael@0:   // nsISupports methods
michael@0:   NS_DECL_ISUPPORTS
michael@0: 
michael@0:   // nsIStreamConverter methods
michael@0:   NS_DECL_NSISTREAMCONVERTER
michael@0: 
michael@0:   // nsIStreamListener methods
michael@0:   NS_DECL_NSISTREAMLISTENER
michael@0: 
michael@0:   // nsIRequestObserver methods
michael@0:   NS_DECL_NSIREQUESTOBSERVER
michael@0: 
michael@0:   nsBinHexDecoder();
michael@0: 
michael@0: protected:
michael@0:   virtual ~nsBinHexDecoder();
michael@0: 
michael@0:   int16_t  GetNextChar(uint32_t numBytesInBuffer);
michael@0:   nsresult ProcessNextChunk(nsIRequest * aRequest, nsISupports * aContext, uint32_t numBytesInBuffer);
michael@0:   nsresult ProcessNextState(nsIRequest * aRequest, nsISupports * aContext);
michael@0:   nsresult DetectContentType(nsIRequest * aRequest, const nsAFlatCString &aFilename);
michael@0: 
michael@0: protected:
michael@0:   nsCOMPtr<nsIStreamListener> mNextListener;
michael@0: 
michael@0:   // the input and output streams form a pipe...they need to be passed around together..
michael@0:   nsCOMPtr<nsIOutputStream>     mOutputStream;     // output stream
michael@0:   nsCOMPtr<nsIInputStream>      mInputStream;
michael@0: 
michael@0:   int16_t   mState;      /* current state */
michael@0:   uint16_t  mCRC;        /* cumulative CRC */
michael@0:   uint16_t  mFileCRC;    /* CRC value from file */
michael@0:   longbuf   mOctetBuf;   /* buffer for decoded 6-bit values     */
michael@0:   int16_t   mOctetin;    /* current input position in octetbuf */
michael@0:   int16_t   mDonePos;    /* ending position in octetbuf */
michael@0:   int16_t   mInCRC;      /* flag set when reading a CRC */
michael@0: 
michael@0:   // Bin Hex Header Information
michael@0:   binhex_header mHeader;
michael@0:   nsCString mName;       /* fsspec for the output file */
michael@0: 
michael@0:   // unfortunately we are going to need 2 8K buffers here. One for the data we are currently digesting. Another
michael@0:   // for the outgoing decoded data. I tried getting them to share a buffer but things didn't work out so nicely.
michael@0:   char * mDataBuffer; // temporary holding pen for the incoming data.
michael@0:   char * mOutgoingBuffer; // temporary holding pen for the incoming data.
michael@0:   uint32_t mPosInDataBuffer;
michael@0: 
michael@0:   unsigned char mRlebuf;  /* buffer for last run length encoding value */
michael@0: 
michael@0:   uint32_t mCount;        /* generic counter */
michael@0:   int16_t mMarker;        /* flag indicating maker */
michael@0: 
michael@0:   int32_t mPosInbuff;     /* the index of the inbuff.  */
michael@0:   int32_t mPosOutputBuff; /* the position of the out buff.    */
michael@0: };
michael@0: 
michael@0: #endif /* nsBinHexDecoder_h__ */