htfile.c

www工具包. 这是W3C官方支持的www支撑库. 其中提供通用目的的客户端的WebAPI: complete HTTP/1.1 (with caching, pipelining, PUT, POS

**	request		This is the request structure
** On exit,
**	returns		HT_ERROR	Error has occured in call back
**			HT_OK		Call back was OK
*/
PRIVATE int FileEvent (SOCKET soc, void * pVoid, HTEventType type);

PUBLIC int HTLoadFile (SOCKET soc, HTRequest * request)
{
    file_info *file;			      /* Specific access information */
    HTNet * net = HTRequest_net(request);
    HTParentAnchor * anchor = HTRequest_anchor(request);

    HTTRACE(PROT_TRACE, "HTLoadFile.. Looking for `%s\'\n" _ 
			    HTAnchor_physical(anchor));
    if ((file = (file_info *) HT_CALLOC(1, sizeof(file_info))) == NULL)
	HT_OUTOFMEM("HTLoadFILE");
    file->state = FS_BEGIN;
    file->net = net;
    HTNet_setContext(net, file);
    HTNet_setEventCallback(net, FileEvent);
    HTNet_setEventParam(net, file);  /* callbacks get http* */

    return FileEvent(soc, file, HTEvent_BEGIN);	    /* get it started - ops is ignored */
}

PRIVATE int ReturnEvent (HTTimer * timer, void * param, HTEventType type)
{
    file_info * file = (file_info *) param;
    if (timer != file->timer)
	HTDEBUGBREAK("File timer %p not in sync\n" _ timer);
    HTTRACE(PROT_TRACE, "HTLoadFile.. Continuing %p with timer %p\n" _ file _ timer);

    /*
    **  Delete the timer
    */
    HTTimer_delete(file->timer);
    file->timer = NULL;

    /*
    **  Now call the event again
    */
    return FileEvent(INVSOC, file, HTEvent_READ);
}


PRIVATE int FileEvent (SOCKET soc, void * pVoid, HTEventType type)
{
    file_info *file = pVoid;			      /* Specific access information */
    int status = HT_ERROR;
    HTNet * net = file->net;
    HTRequest * request = HTNet_request(net);
    HTParentAnchor * anchor = HTRequest_anchor(request);

    /*
    ** Initiate a new file structure and bind to request structure
    ** This is actually state FILE_BEGIN, but it can't be in the state
    ** machine as we need the structure first.
    */
    if (type == HTEvent_CLOSE) {				      /* Interrupted */
	HTRequest_addError(request, ERR_FATAL, NO, HTERR_INTERRUPTED,
			   NULL, 0, "HTLoadFile");
	FileCleanup(request, HT_INTERRUPTED);
	return HT_OK;
    }


    /* Now jump into the machine. We know the state from the previous run */
    while (1) {
	switch (file->state) {
	case FS_BEGIN:

	    /* We only support safe (GET, HEAD, etc) methods for the moment */
	    if (!HTMethod_isSafe(HTRequest_method(request))) {
		HTRequest_addError(request, ERR_FATAL, NO, HTERR_NOT_ALLOWED,
				   NULL, 0, "HTLoadFile");
		file->state = FS_ERROR;
		break;
	    }

	    /* Check whether we have access to local disk at all */
	    if (HTLib_secure()) {
		HTTRACE(PROT_TRACE, "LoadFile.... No access to local file system\n");
		file->state = FS_TRY_FTP;
		break;
	    }
	    file->local = HTWWWToLocal(HTAnchor_physical(anchor), "",
				       HTRequest_userProfile(request));
	    if (!file->local) {
		file->state = FS_TRY_FTP;
		break;
	    }

	    /* Create a new host object and link it to the net object */
	    {
		HTHost * host = NULL;
		if ((host = HTHost_new("localhost", 0)) == NULL) return HT_ERROR;
		HTNet_setHost(net, host);
		if (HTHost_addNet(host, net) == HT_PENDING) {
		    HTTRACE(PROT_TRACE, "HTLoadFile.. Pending...\n");
		    /* move to the hack state */
		    file->state = FS_PENDING;
		    return HT_OK;
		}
	    }
	    file->state = FS_DO_CN;
	    break;

	case FS_PENDING:
	    /*
	    ** 2000/08/10 JK : This is a funny state. Because of the
	    ** internal libwww stacks, when doing multiple local
	    ** requests (e.g., while using the Robot), we need to ask
	    ** again for the host object. If we had jumped directly to
	    ** the FS_DO_CN state, libwww would have blocked because
	    ** of socket starvation.
	    ** This state is similar to FS_BEGINNING, but just requests 
	    ** the host object. 
	    ** YES. THIS IS AN UGLY HACK!!
	    */
	    {
		HTHost * host = NULL;
		if ((host = HTHost_new("localhost", 0)) == NULL) return HT_ERROR;
		HTNet_setHost(net, host);
		if (HTHost_addNet(host, net) == HT_PENDING) {
		    HTTRACE(PROT_TRACE, "HTLoadFile.. Pending...\n");
		    file->state = FS_PENDING;
		    return HT_OK;
		}
	    }
	    file->state = FS_DO_CN;
	    break;

	case FS_DO_CN:
	    /*
	    ** If we have to do content negotiation then find the object that
	    ** fits best into either what the client has indicated in the
	    ** accept headers or what the client has registered on its own.
	    ** The object chosen can in fact be a directory! However, content
	    ** negotiation only makes sense if we can read the directory!
	    ** We stat the file in order to find the size and to see it if
	    ** exists.
	    */
	    if (HTRequest_negotiation(request) &&
		HTMethod_isSafe(HTRequest_method(request))) {
 		char * conneg = HTMulti(request, file->local,&file->stat_info);
		if (conneg) {
		    HT_FREE(file->local);
		    file->local = conneg;
		    HTAnchor_setPhysical(anchor, conneg);
		    HTTRACE(PROT_TRACE, "Load File... Found `%s\'\n" _ conneg);
		} else {
		    HTTRACE(PROT_TRACE, "Load File... Not found - even tried content negotiation\n");
		    HTRequest_addError(request, ERR_FATAL, NO, HTERR_NOT_FOUND,
				       NULL, 0, "HTLoadFile");
		    file->state = FS_ERROR;
		    break;
		}
	    } else {
		if (HT_STAT(file->local, &file->stat_info) == -1) {
		    HTTRACE(PROT_TRACE, "Load File... Not found `%s\'\n" _ file->local);
		    HTRequest_addError(request, ERR_FATAL, NO, HTERR_NOT_FOUND,
				       NULL, 0, "HTLoadFile");
		    file->state = FS_ERROR;
		    break;
		}
	    }

	    /*
	    ** Check to see if the 'localname' is in fact a directory.
	    ** Note that we can't do a HEAD on a directory
	    */
	    if (((file->stat_info.st_mode) & S_IFMT) == S_IFDIR) {
		if (HTRequest_method(request) == METHOD_GET)
		    file->state = FS_PARSE_DIR;
		else {
		    HTRequest_addError(request, ERR_INFO, NO, HTERR_NO_CONTENT,
				       NULL, 0, "HTLoadFile");
		    file->state = FS_NO_DATA;
		}
		break;
	    }

	    /*
	    ** If empty file then only serve it if it is editable. We also get
	    ** the bindings for the file suffixes in lack of better bindings
	    */
	    {
		BOOL editable = HTEditable(file->local, &file->stat_info);
		if (file_suffix_binding) HTBind_getAnchorBindings(anchor);
		if (editable) HTAnchor_appendAllow(anchor, METHOD_PUT);

		/* Set the file size */
		if (file->stat_info.st_size)
		    HTAnchor_setLength(anchor, file->stat_info.st_size);

		/* Set the file last modified time stamp */
		if (file->stat_info.st_mtime > 0)
		    HTAnchor_setLastModified(anchor, file->stat_info.st_mtime);

		/* Check to see if we can edit it */
		if (!editable && !file->stat_info.st_size) {
		    HTRequest_addError(request, ERR_INFO, NO, HTERR_NO_CONTENT,
				       NULL, 0, "HTLoadFile");
		    file->state = FS_NO_DATA;
		} else {
		    file->state = (HTRequest_method(request)==METHOD_GET) ? 
			FS_NEED_OPEN_FILE : FS_GOT_DATA;
		}
	    }
	    break;

	  case FS_NEED_OPEN_FILE:
	    status = HTFileOpen(net, file->local, HT_FB_RDONLY);
	    if (status == HT_OK) {
		/* 
		** Create the stream pipe FROM the channel to the application.
		** The target for the input stream pipe is set up using the
		** stream stack.
		*/
		{
		    HTStream * rstream = HTStreamStack(HTAnchor_format(anchor),
						       HTRequest_outputFormat(request),
						       HTRequest_outputStream(request),
						       request, YES);
		    HTNet_setReadStream(net, rstream);
		    HTRequest_setOutputConnected(request, YES);
		}

		/*
		** Create the stream pipe TO the channel from the application
		** and hook it up to the request object
		*/
		{
		    HTOutputStream * output = HTNet_getOutput(net, NULL, 0);
		    HTRequest_setInputStream(request, (HTStream *) output);
		}

		/*
		** Set up concurrent read/write if this request isn't the
		** source for a PUT or POST. As source we don't start reading
		** before all destinations are ready. If destination then
		** register the input stream and get ready for read
		*/
		if (HTRequest_isSource(request) && !HTRequest_destinationsReady(request))
		    return HT_OK;
		HTRequest_addError(request, ERR_INFO, NO, HTERR_OK, NULL, 0,
				   "HTLoadFile");
		file->state = FS_NEED_BODY;

		/* If we are _not_ using preemptive mode and we are Unix fd's
		** then return here to get the same effect as when we are
		** connecting to a socket. That way, HTFile acts just like any
		** other protocol module even though we are in fact doing
		** blocking connect
		*/
		if (HTEvent_isCallbacksRegistered()) {
		    if (!HTRequest_preemptive(request)) {
			if (!HTNet_preemptive(net)) {
			    HTTRACE(PROT_TRACE, "HTLoadFile.. Returning\n");
			    HTHost_register(HTNet_host(net), net, HTEvent_READ);
			} else if (!file->timer) {
			    HTTRACE(PROT_TRACE, "HTLoadFile.. Returning\n");
			    file->timer =
				HTTimer_new(NULL, ReturnEvent, file, 1, YES, NO);
			}
			return HT_OK;
		    }
		}
	    } else if (status == HT_WOULD_BLOCK || status == HT_PENDING)
		return HT_OK;
	    else {
		HTRequest_addError(request, ERR_INFO, NO, HTERR_INTERNAL,
				   NULL, 0, "HTLoadFile");
		file->state = FS_ERROR;		       /* Error or interrupt */
	    }
	    break;

	  case FS_NEED_BODY:
	    status = HTHost_read(HTNet_host(net), net);
	    if (status == HT_WOULD_BLOCK)
		return HT_OK;
	    else if (status == HT_LOADED || status == HT_CLOSED) {
		file->state = FS_GOT_DATA;
	    } else {
		HTRequest_addError(request, ERR_INFO, NO, HTERR_FORBIDDEN,
				   NULL, 0, "HTLoadFile");
		file->state = FS_ERROR;
	    }
	    break;

	  case FS_PARSE_DIR:
	    status = HTFile_readDir(request, file);
	    if (status == HT_LOADED)
		file->state = FS_GOT_DATA;
	    else
		file->state = FS_ERROR;
	    break;

	  case FS_TRY_FTP:
	    {
		char *url = HTAnchor_physical(anchor);
		HTAnchor *anchor;
		char *newname = NULL;
		StrAllocCopy(newname, "ftp:");
		if (!strncmp(url, "file:", 5))
		    StrAllocCat(newname, url+5);
		else
		    StrAllocCat(newname, url);
		anchor = HTAnchor_findAddress(newname);
		HTRequest_setAnchor(request, anchor);
		HT_FREE(newname);
		FileCleanup(request, HT_IGNORE);
		return HTLoad(request, YES);
	    }
	    break;

	  case FS_GOT_DATA:
	    FileCleanup(request, HT_LOADED);
	    return HT_OK;
	    break;

	  case FS_NO_DATA:
	    FileCleanup(request, HT_NO_DATA);
	    return HT_OK;
	    break;

	  case FS_RETRY:
	    FileCleanup(request, HT_RETRY);
	    return HT_OK;
	    break;

	  case FS_ERROR:
	    FileCleanup(request, HT_ERROR);
	    return HT_OK;
	    break;
	}
    } /* End of while(1) */
}