io.c

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	InsertIOV (padBuffer, padsize)

	errno = 0;
	if (trans_conn && (len = _XSERVTransWritev(trans_conn, iov, i)) >= 0)
	{
	    written += len;
	    notWritten -= len;
	    todo = notWritten;
	}
	else if (ETEST(errno)
#ifdef SUNSYSV /* check for another brain-damaged OS bug */
		 || (errno == 0)
#endif
#ifdef EMSGSIZE /* check for another brain-damaged OS bug */
		 || ((errno == EMSGSIZE) && (todo == 1))
#endif
		)
	{
	    /* If we've arrived here, then the client is stuffed to the gills
	       and not ready to accept more.  Make a note of it and buffer
	       the rest. */
	    FD_SET(connection, &ClientsWriteBlocked);
	    AnyClientsWriteBlocked = TRUE;

	    if (written < oco->count)
	    {
		if (written > 0)
		{
		    oco->count -= written;
		    memmove((char *)oco->buf,
			    (char *)oco->buf + written,
			  oco->count);
		    written = 0;
		}
	    }
	    else
	    {
		written -= oco->count;
		oco->count = 0;
	    }

	    if (notWritten > oco->size)
	    {
		unsigned char *obuf;

		obuf = (unsigned char *)xrealloc(oco->buf,
						 notWritten + BUFSIZE);
		if (!obuf)
		{
		    _XSERVTransDisconnect(oc->trans_conn);
		    _XSERVTransClose(oc->trans_conn);
		    oc->trans_conn = NULL;
		    MarkClientException(who);
		    oco->count = 0;
		    return(-1);
		}
		oco->size = notWritten + BUFSIZE;
		oco->buf = obuf;
	    }

	    /* If the amount written extended into the padBuffer, then the
	       difference "extraCount - written" may be less than 0 */
	    if ((len = extraCount - written) > 0)
		memmove ((char *)oco->buf + oco->count,
			 extraBuf + written,
		       len);

	    oco->count = notWritten; /* this will include the pad */
	    /* return only the amount explicitly requested */
	    return extraCount;
	}
#ifdef EMSGSIZE /* check for another brain-damaged OS bug */
	else if (errno == EMSGSIZE)
	{
	    todo >>= 1;
	}
#endif
	else
	{
	    if (oc->trans_conn)
	    {
		_XSERVTransDisconnect(oc->trans_conn);
		_XSERVTransClose(oc->trans_conn);
		oc->trans_conn = NULL;
	    }
	    MarkClientException(who);
	    oco->count = 0;
	    return(-1);
	}
    }

    /* everything was flushed out */
    oco->count = 0;
    /* check to see if this client was write blocked */
    if (AnyClientsWriteBlocked)
    {
	FD_CLR(oc->fd, &ClientsWriteBlocked);
 	if (! XFD_ANYSET(&ClientsWriteBlocked))
	    AnyClientsWriteBlocked = FALSE;
    }
    if (oco->size > BUFWATERMARK)
    {
	xfree(oco->buf);
	xfree(oco);
    }
    else
    {
	oco->next = FreeOutputs;
	FreeOutputs = oco;
    }
    oc->output = (ConnectionOutputPtr)NULL;
    return extraCount; /* return only the amount explicitly requested */
}

 /********************
 * FlushAllOutput()
 *    Flush all clients with output.  However, if some client still
 *    has input in the queue (more requests), then don't flush.  This
 *    will prevent the output queue from being flushed every time around
 *    the round robin queue.  Now, some say that it SHOULD be flushed
 *    every time around, but...
 *
 **********************/

void
FlushAllOutput()
{
    register int index, base;
    fd_mask mask;
    OsCommPtr oc;
    register ClientPtr client;
    Bool newoutput = NewOutputPending;
#ifdef WIN32
    fd_set newOutputPending;
#endif

    if (FlushCallback)
	CallCallbacks(&FlushCallback, NULL);

    if (!newoutput)
	return;

    /*
     * It may be that some client still has critical output pending,
     * but he is not yet ready to receive it anyway, so we will
     * simply wait for the select to tell us when he's ready to receive.
     */
    CriticalOutputPending = FALSE;
    NewOutputPending = FALSE;

#ifndef WIN32
    for (base = 0; base < howmany(XFD_SETSIZE, NFDBITS); base++)
    {
	mask = OutputPending.fds_bits[ base ];
	OutputPending.fds_bits[ base ] = 0;
	while (mask)
	{
	    index = ffsl(mask) - 1;
	    mask &= ~lowbit(mask);
	    if ((index = ConnectionTranslation[(base * sizeof(fd_mask) * 8) + index]) == 0)
		continue;
	    client = clients[index];
	    if (client->clientGone)
		continue;
	    oc = (OsCommPtr)client->osPrivate;
	    if (
#ifdef LBX
		!oc->proxy &&
#endif
		FD_ISSET(oc->fd, &ClientsWithInput))
	    {
		FD_SET(oc->fd, &OutputPending); /* set the bit again */
		NewOutputPending = TRUE;
	    }
	    else
		(void)FlushClient(client, oc, (char *)NULL, 0);
	}
    }
#else  /* WIN32 */
    FD_ZERO(&newOutputPending);
    for (base = 0; base < XFD_SETCOUNT(&OutputPending); base++)
    {
	    index = XFD_FD(&OutputPending, base);
	    if ((index = ConnectionTranslation[index]) == 0)
		continue;
	    client = clients[index];
	    if (client->clientGone)
		continue;
	    oc = (OsCommPtr)client->osPrivate;
	    if (
#ifdef LBX
		!oc->proxy &&
#endif
		FD_ISSET(oc->fd, &ClientsWithInput))
	    {
		FD_SET(oc->fd, &newOutputPending); /* set the bit again */
		NewOutputPending = TRUE;
	    }
	    else
		(void)FlushClient(client, oc, (char *)NULL, 0);
    }
    XFD_COPYSET(&newOutputPending, &OutputPending);
#endif /* WIN32 */
}

void
FlushIfCriticalOutputPending()
{
    if (CriticalOutputPending)
	FlushAllOutput();
}

void
SetCriticalOutputPending()
{
    CriticalOutputPending = TRUE;
}

/*****************
 * WriteToClient
 *    Copies buf into ClientPtr.buf if it fits (with padding), else
 *    flushes ClientPtr.buf and buf to client.  As of this writing,
 *    every use of WriteToClient is cast to void, and the result
 *    is ignored.  Potentially, this could be used by requests
 *    that are sending several chunks of data and want to break
 *    out of a loop on error.  Thus, we will leave the type of
 *    this routine as int.
 *****************/

int
WriteToClient (who, count, buf)
    ClientPtr who;
    char *buf;
    int count;
{
    OsCommPtr oc = (OsCommPtr)who->osPrivate;
    register ConnectionOutputPtr oco = oc->output;
    int padBytes;

    if (!count)
	return(0);

    if (!oco)
    {
	if (oco = FreeOutputs)
	{
	    FreeOutputs = oco->next;
	}
	else if (!(oco = AllocateOutputBuffer()))
	{
	    if (oc->trans_conn) {
		_XSERVTransDisconnect(oc->trans_conn);
		_XSERVTransClose(oc->trans_conn);
		oc->trans_conn = NULL;
	    }
	    MarkClientException(who);
	    return -1;
	}
	oc->output = oco;
    }

    padBytes = padlength[count & 3];

    if(ReplyCallback)
    {
        ReplyInfoRec replyinfo;

	replyinfo.client = who;
	replyinfo.replyData = buf;
	replyinfo.dataLenBytes = count + padBytes;
	if (who->replyBytesRemaining)
	{ /* still sending data of an earlier reply */
	    who->replyBytesRemaining -= count + padBytes;
	    replyinfo.startOfReply = FALSE;
	    replyinfo.bytesRemaining = who->replyBytesRemaining;
	    CallCallbacks((&ReplyCallback), (pointer)&replyinfo);
	}
	else if (who->clientState == ClientStateRunning
		 && buf[0] == X_Reply)
        { /* start of new reply */
	    CARD32 replylen;
	    unsigned long bytesleft;
	    char n;

	    replylen = ((xGenericReply *)buf)->length;
	    if (who->swapped)
		swapl(&replylen, n);
	    bytesleft = (replylen * 4) + SIZEOF(xReply) - count - padBytes;
	    replyinfo.startOfReply = TRUE;
	    replyinfo.bytesRemaining = who->replyBytesRemaining = bytesleft;
	    CallCallbacks((&ReplyCallback), (pointer)&replyinfo);
	} 	                      
    } 
  
    if (oco->count + count + padBytes > oco->size)
    {
	FD_CLR(oc->fd, &OutputPending);
	CriticalOutputPending = FALSE;
	NewOutputPending = FALSE;
	return FlushClient(who, oc, buf, count);
    }

    NewOutputPending = TRUE;
    FD_SET(oc->fd, &OutputPending);
    memmove((char *)oco->buf + oco->count, buf, count);
    oco->count += count + padBytes;
    return(count);
}

ConnectionInputPtr
AllocateInputBuffer()
{
    register ConnectionInputPtr oci;

    oci = (ConnectionInputPtr)xalloc(sizeof(ConnectionInput));
    if (!oci)
	return (ConnectionInputPtr)NULL;
    oci->buffer = (char *)xalloc(BUFSIZE);
    if (!oci->buffer)
    {
	xfree(oci);
	return (ConnectionInputPtr)NULL;
    }
    oci->size = BUFSIZE;
    oci->bufptr = oci->buffer;
    oci->bufcnt = 0;
    oci->lenLastReq = 0;
    return oci;
}

ConnectionOutputPtr
AllocateOutputBuffer()
{
    register ConnectionOutputPtr oco;

    oco = (ConnectionOutputPtr)xalloc(sizeof(ConnectionOutput));
    if (!oco)
	return (ConnectionOutputPtr)NULL;
    oco->buf = (unsigned char *) xalloc(BUFSIZE);
    if (!oco->buf)
    {
	xfree(oco);
	return (ConnectionOutputPtr)NULL;
    }
    oco->size = BUFSIZE;
    oco->count = 0;
#ifdef LBX
    oco->nocompress = FALSE;
#endif
    return oco;
}

void
FreeOsBuffers(oc)
    OsCommPtr oc;
{
    register ConnectionInputPtr oci;
    register ConnectionOutputPtr oco;

    if (AvailableInput == oc)
	AvailableInput = (OsCommPtr)NULL;
    if (oci = oc->input)
    {
	if (FreeInputs)
	{
	    xfree(oci->buffer);
	    xfree(oci);
	}
	else
	{
	    FreeInputs = oci;
	    oci->next = (ConnectionInputPtr)NULL;
	    oci->bufptr = oci->buffer;
	    oci->bufcnt = 0;
	    oci->lenLastReq = 0;
	}
    }
    if (oco = oc->output)
    {
	if (FreeOutputs)
	{
	    xfree(oco->buf);
	    xfree(oco);
	}
	else
	{
	    FreeOutputs = oco;
	    oco->next = (ConnectionOutputPtr)NULL;
	    oco->count = 0;
	}
    }
#ifdef LBX
    if (oci = oc->largereq) {
	xfree(oci->buffer);
	xfree(oci);
    }
#endif
}

void
ResetOsBuffers()
{
    register ConnectionInputPtr oci;
    register ConnectionOutputPtr oco;

    while (oci = FreeInputs)
    {
	FreeInputs = oci->next;
	xfree(oci->buffer);
	xfree(oci);
    }
    while (oco = FreeOutputs)
    {
	FreeOutputs = oco->next;
	xfree(oco->buf);
	xfree(oco);
    }
}