gecko-dev/netwerk/streamconv/converters/nsMultiMixedConv.h

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * The contents of this file are subject to the Netscape Public License
 * Version 1.0 (the "NPL"); you may not use this file except in
 * compliance with the NPL.  You may obtain a copy of the NPL at
 * http://www.mozilla.org/NPL/
 *
 * Software distributed under the NPL is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
 * for the specific language governing rights and limitations under the
 * NPL.
 *
 * The Initial Developer of this code under the NPL is Netscape
 * Communications Corporation.  Portions created by Netscape are
 * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
 * Reserved.
 */
#ifndef __nsmultimixedconv__h__
#define __nsmultimixedconv__h__

#include "nsIStreamConverter.h"
#include "nsIChannel.h"
#include "nsIURI.h"
#include "nsString2.h"

#include "nsIFactory.h"

#define NS_MULTIMIXEDCONVERTER_CID                         \
{ /* 7584CE90-5B25-11d3-A175-0050041CAF44 */         \
    0x7584ce90,                                      \
    0x5b25,                                          \
    0x11d3,                                          \
    {0xa1, 0x75, 0x0, 0x50, 0x4, 0x1c, 0xaf, 0x44}       \
}
static NS_DEFINE_CID(kMultiMixedConverterCID,          NS_MULTIMIXEDCONVERTER_CID);

// The nsMultiMixedConv stream converter converts a stream of type "multipart/x-mixed-replace"
// to it's subparts. There was some debate as to whether or not the functionality desired
// when HTTP confronted this type required a stream converter. After all, this type really
// prompts various viewer related actions rather than stream conversion. There simply needs
// to be a piece in place that can strip out the multiple parts of a stream of this type, and 
// "display" them accordingly.
//
// With that said, this "stream converter" spends more time packaging up the sub parts of the
// main stream and sending them off the destination stream listener, than doing any real
// stream parsing/converting.
//
// WARNING: This converter requires that it's destination stream listener be able to handle
//   multiple OnStartRequest(), OnDataAvailable(), and OnStopRequest() call combinations.
//   Each series represents the beginning, data production, and ending phase of each sub-
//   part of the original stream.
//
// NOTE: this MIME-type is used by HTTP, *not* SMTP, or IMAP.
//
// NOTE: For reference, a general description of how this MIME type should be handled via
//   HTTP, see http://home.netscape.com/assist/net_sites/pushpull.html

class nsMultiMixedConv : public nsIStreamConverter {
public:
    // nsISupports methods
    NS_DECL_ISUPPORTS

    // nsIStreamConverter methods
    NS_DECL_NSISTREAMCONVERTER

    // nsIStreamListener methods
    NS_DECL_NSISTREAMLISTENER

    // nsIStreamObserver methods
    NS_DECL_NSISTREAMOBSERVER

    // nsMultiMixedConv methods
    nsMultiMixedConv();
    virtual ~nsMultiMixedConv();
    nsresult Init();
    nsresult SendData(const char *aBuffer, nsIChannel *aChannel, nsISupports *aCtxt);
    nsresult BuildURI(nsIChannel *aChannel, nsIURI **_retval);

    // For factory creation.
    static NS_METHOD
    Create(nsISupports *aOuter, REFNSIID aIID, void **aResult) {
        nsresult rv;
        if (aOuter)
            return NS_ERROR_NO_AGGREGATION;

        nsMultiMixedConv* _s = new nsMultiMixedConv();
        if (_s == nsnull)
            return NS_ERROR_OUT_OF_MEMORY;
        NS_ADDREF(_s);
        rv = _s->Init();
        if (NS_FAILED(rv)) {
            delete _s;
            return rv;
        }
        rv = _s->QueryInterface(aIID, aResult);
        NS_RELEASE(_s);
        return rv;
    }

    // member data
    PRBool              mBoundaryStart;  // are we in the middle of a boundary?
    nsIStreamListener   *mFinalListener; // this guy gets the converted data via his OnDataAvailable()
    char                *mBoundaryCStr;
    PRInt32             mBoundaryStrLen;
    PRUint16            mPartCount;     // the number of parts we've seen so far
    nsIChannel          *mPartChannel;  // the channel for the given part we're processing.
                                        // one channel per part.
};

//////////////////////////////////////////////////
// FACTORY
class MultiMixedFactory : public nsIFactory
{
public:
    MultiMixedFactory(const nsCID &aClass, const char* className, const char* progID);

    // nsISupports methods
    NS_DECL_ISUPPORTS

    // nsIFactory methods
    NS_IMETHOD CreateInstance(nsISupports *aOuter,
                              const nsIID &aIID,
                              void **aResult);

    NS_IMETHOD LockFactory(PRBool aLock);

protected:
    virtual ~MultiMixedFactory();

protected:
    nsCID       mClassID;
    const char* mClassName;
    const char* mProgID;
};

#endif /* __nsmultimixedconv__h__ */