x_hil.h

早期freebsd实现

#ifndef X_HIL_H
#define X_HIL_H
/* $Header: /host/kaukau/disk2/X11R5/R5-hp300/mit/server/ddx/hpbsd/input/RCS/x_hil.h,v 1.1 1992/09/30 03:14:10 root Exp $ */
/*

Copyright (c) 1986, 1987 by Hewlett-Packard Company
Copyright (c) 1986, 1987 by the Massachusetts Institute of Technology

Permission to use, copy, modify, and distribute this
software and its documentation for any purpose and without
fee is hereby granted, provided that the above copyright
notice appear in all copies and that both that copyright
notice and this permission notice appear in supporting
documentation, and that the name of M.I.T. not be used in
advertising or publicity pertaining to distribution of the
software without specific, written prior permission.

HEWLETT-PACKARD MAKES NO WARRANTY OF ANY KIND WITH REGARD
TO THIS SOFWARE, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 
PURPOSE.  Hewlett-Packard shall not be liable for errors 
contained herein or direct, indirect, special, incidental or 
consequential damages in connection with the furnishing, 
performance, or use of this material.

This software is not subject to any license of the American
Telephone and Telegraph Company or of the Regents of the
University of California.

*/

#include "hpext.h"

/* MAXHILEVENTS is the maximum number of X events that can
   be put on the events queue as the result of reading a 
   single HIL data packet.  The HIL definition is that 
   a packet may contain one motion event and up to 8 bytes
   of key data.  If the key device is a barcode reader in 
   ASCII mode, we translate each ASCII code into up to 6
   keycodes.  The maximum number of X events that can be 
   generated from a single HIL packet is therefore 49.

   MAX_EVENTS is the size of the server's internal queue of
   input events.  X input is a two-step process, with the 
   first step consisting of reading input events from the 
   device and putting them on this internal queue.  Later
   in the dispatch loop, that queue is emptied and all the
   events are routed by DIX to the appropriate clients.

   The size of the event queue is not as large as the 
   theoretical maximum, but motion events are compressed
   into a single event until a key or button is seen.

   The worst at all reasonable case is alternating key and
   motion data, which would result in less than 50 events.
   A more reasonable guess is 20 events per device.
   Our queue size therefore allows for the worst case on 
   5 - 10 devices simultaneously.
*/

#define MAXHILEVENTS		49
#define MOTION_BUFFER_SIZE	100
#define MAX_EVENTS		256
#define WR_EVENTS		MAX_EVENTS-1

struct	x11EventQueue
	{
	xHPEvent *events;
	int	size;
	int	head;
	int	tail;
	};		

#endif