path: root/include/lbx.h

/* $Xorg: lbx.h,v 1.4 2001/02/09 02:05:32 xorgcvs Exp $ */
/*

Copyright 1996, 1998  The Open Group

Permission to use, copy, modify, distribute, and sell this software and its
documentation for any purpose is hereby granted without fee, provided that
the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation.

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of The Open Group shall not be
used in advertising or otherwise to promote the sale, use or other dealings
in this Software without prior written authorization from The Open Group.

*/
/*
 * Copyright 1992 Network Computing Devices
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, 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 NCD. not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  NCD. makes no representations about the
 * suitability of this software for any purpose.  It is provided "as is"
 * without express or implied warranty.
 *
 * NCD. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL NCD.
 * BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN 
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 */
/* $XFree86$ */

#ifndef _LBX_H_
#define _LBX_H_
#include "misc.h"
#include "os.h"
#include "util.h"
#include "lbxstr.h"

/* we keep the ifdefs in the code as a guide to what's going on */
/* but we want the proxy to work with all possible servers */
#ifndef BIGREQS
#define BIGREQS
#endif

/* cache stuff */
#define MAX_ATOM_LENGTH 256	/* screw any large ones */
#define MAX_COLORNAME_LENGTH    256	/* screw any large ones */


typedef struct proptagdata {
    Atom        type;
    int         format;
    int         length;		/* in bytes */
    pointer     data;
}           PropertyTagDataRec, *PropertyTagDataPtr;

typedef struct _replystuff *ReplyStuffPtr;

typedef Bool (*ReplyFunc)(
    ClientPtr /*client*/,
    ReplyStuffPtr /*nr*/,
    char * /*data*/
);

typedef struct _replystuff {
    int         sequenceNumber;	/* expected sequence number */
    int         major;		/* major opcode */
    int         minor;		/* minor opcode */
    ReplyFunc	reply_func;	/* function to handle reply */
    union {			/* reply data */
	struct intern_data {
	    int         len;
	    char        str[MAX_ATOM_LENGTH];
	}           xintern;
	struct get_atom {
	    Atom        atom;
	}           xgetatom;
	struct colorname {
	    char        name[MAX_COLORNAME_LENGTH];
	    int         namelen;
	    VisualID    visual;
	}           xlookupcolor;
	struct allocnamedcolor {
	    char        name[MAX_COLORNAME_LENGTH];
	    int         namelen;
	    struct _cmap *pmap;
	}           xallocnamedcolor;
	struct alloccolorcells {
	    struct _cmap *pmap;
	}           xalloccolorcells;
	struct alloccolorplanes {
	    struct _cmap *pmap;
	}           xalloccolorplanes;
	struct grabcmap {
	    struct _cmap *pmap;
	    Bool	alloc_named;
	    CARD16      vred,
	                vgreen,
	                vblue;
	    CARD16      xred,
	                xgreen,
	                xblue;
	}           lbxgrabcmap;
	struct getkeymap {
	    int         count;
	    int         first;
	}           lbxgetkeymap;
	struct getprop {
	    CARD32      offset;
	    CARD32      length;
	}           lbxgetprop;
	struct changeprop {
	    PropertyTagDataRec ptd;
	}           lbxchangeprop;
	struct wingeom {
	    char got_geom_request;
	    char got_geom_reply;
	    CARD8 depth;
	    Window root B32;
	    INT16 x B16, y B16;
	    CARD16 width B16, height B16;
	    CARD16 borderWidth B16;
	}	    lbxWinGeom;
	struct queryextension {
	    char       *name;
	}           lbxqueryextension;
	struct getimage {
#ifdef LBX_STATS
	    Drawable	drawable;
	    INT16	x;
	    INT16	y;
#endif
	    CARD16      width;
	    CARD16      height;
	    CARD8	format;
	}           lbxgetimage;
	pointer     lbxextensiondata;
    }           request_info;
    ReplyStuffPtr next;
}           ReplyStuffRec;

typedef struct _replydata {
    int         dlen;
    xReply      reply;
    pointer     data;
    int         delay_seq_no;	/* what seq i'm waiting for */
    struct _replydata *next;
}           ReplyDataRec, *ReplyDataPtr;


#define LBX_LARGE_REQUEST_MIN_SIZE	1024
#define LBX_LARGE_REQUEST_CHUNK_SIZE	512

#define LARGE_REQUEST_QUEUE_LEN 16

typedef struct {
    ClientPtr client;
    Bool compressed;
    char *buf;
    unsigned totalBytes;
    unsigned bytesRead;
    unsigned bytesWritten;
} LbxLargeRequestRec;


typedef struct _ClientPublic {
    int             (*writeToClient) ();
    int             (*uncompressedWriteToClient) ();
    unsigned long   (*requestLength) ();
    int             (*readRequest)();
} ClientPublicRec, *ClientPublicPtr;

typedef struct _Client {
    int         index;
    XID         ridBase;
    XID         ridMask;
    pointer     requestBuffer;
    pointer     osPrivate;	/* for OS layer, including scheduler */
    Bool        swapped;
    void        (*pSwapReplyFunc) (
		ClientPtr	/* pClient */,
		int		/* size */,
		void *		/* pbuf */
);
    XID         errorValue;
    int         sequence;
    int         closeDownMode;
    int         clientGone;
    int         noClientException;	/* this client died or needs to be
					 * killed */
    XServerPtr  server;
    Drawable    serverID;
    GContext    lastGCID;
    pointer    *saveSet;
    int         awaitingSetup;
    int         (**requestVector) (
		ClientPtr /* pClient */
);
    CARD32	req_len;		/* length of current request */
    Bool	big_requests;		/* supports large requests */

#ifdef DEBUG
#define MAX_REQUEST_LOG 100
    unsigned char requestLog[MAX_REQUEST_LOG];
    int         requestLogIndex;
#endif

    ClientPublicRec public;
    int         lbxIndex;

    Bool        cache_safe;	/* safe to short circuit request? */
    Bool        can_delay_reply;/* safe to delay short-circuit request? */

    int         sequenceNumber;	/* what we've seen */
    int         sequence_lost;	/* requests short-circuited */
    int         lastForReply;   /* last request with reply known coming */
    int         lastForResponse;/* last request sent with event or reply */
    int         lastResponse;	/* last sequence number seen from server */

    int         yanked;		/* total requests short-circuited */

    KeyCode     minKeyCode,
                maxKeyCode;

    CARD8          imageByteOrder;        /* LSBFirst, MSBFirst */
    CARD8          bitmapBitOrder;        /* LeastSignificant, MostSign...*/
    CARD8          bitmapScanlineUnit,     /* 8, 16, 32 */
                   bitmapScanlinePad;     /* 8, 16, 32 */
    CARD8          ZbitsPerPixel1;	  /* for ZPixmap depth 1 */
    Window	   rootWindow;		  /* root window of screen 0 */

    ReplyStuffPtr replylist;	/* list of pending replies */
    ReplyDataPtr replydata;	/* list of delayed short-circuited replies */
    Drawable	drawableCache[GFX_CACHE_SIZE];
    GContext	gcontextCache[GFX_CACHE_SIZE];

    LbxLargeRequestRec *largeRequest;

}           ClientRec;


#define WriteToClient(client,len,buf)   (((client)->public.writeToClient)(client,len,buf))
#define ReadRequestFromClient(client)   ((client)->public.readRequest(client))
#define RequestLength(r,client,g,p)           (*(client)->public.requestLength) (r,client,g,p)

#define	LBXSequenceNumber(client)	((client->sequenceNumber) & 0xffff)
#define	LBXCacheSafe(client)	(client->cache_safe)
#define	LBXCanDelayReply(client) (client->can_delay_reply)
#define	LBXSequenceLost(client)	(client->sequence_lost)
#define	LBXYanked(client)	(client->yanked)
#define	LBXLastForReply(client)	(client->lastForReply)
#define	LBXLastForResponse(client)	(client->lastForResponse)
#define	LBXLastResponse(client)	(client->lastResponse)
#define	LBXReplyList(client)	(client->replylist)
#define	LBXReplyData(client)	(client->replydata)
#define	LBXMinKeyCode(client)	(client->minKeyCode)
#define	LBXMaxKeyCode(client)	(client->maxKeyCode)
#define	LBXImageByteOrder(client) (client->imageByteOrder)
#define	LBXBitmapBitOrder(client) (client->bitmapBitOrder)
#define	LBXBitmapScanlineUnit(client) (client->bitmapScanlineUnit)
#define	LBXBitmapScanlinePad(client) (client->bitmapScanlinePad)
#define	LBXZBitsPerPixel1(client) (client->ZbitsPerPixel1)
#define LBXRootWindow(client) (client->rootWindow)
#define	LBXDrawableCache(client)(client->drawableCache)
#define	LBXGContextCache(client)(client->gcontextCache)

extern ClientPtr *clients;
#define MAXCLIENTS       128
#define NullClient ((ClientPtr) 0)
extern int currentMaxClients;

extern LbxLargeRequestRec *largeRequestQueue[];
extern int numLargeRequestsInQueue;

/*
 * Notes on request short-circuiting
 *
 * X guarentees that any replies, events or errors generated by a
 * previous request will be sent before those of a later request.
 * this means that any requests that can be handled by the proxy
 * must have their reply sent after any previous events or errors.
 *
 * there are 3 possible stages implemented here:
 *
 * - fully correct protocol, where nothing can be out of order
 * - mostly correct protocol, where only errors can be out of order
 * - poor protocol, where events & errors can be out of order
 *
 * for most applications, poor is 'good enough', because they don't
 * depend on events coming in order, and instead let Xlib do
 * the work.
 *
 * depending on the type of protocol being used, the cache_safe
 * flag in the ClientRec will be set appropriately, and if TRUE,
 * the proxy is cleared to short-circuit a request.
 *
 * for full correct protocol, the flag is set if the previous request
 * was a round trip and the reply has come back.
 *
 * for a mostly correct protocol, the flag is set for the above
 * case, and for requests that can generate only errors (mostly
 * graphics)
 *
 * for a 'good enough' protocol, the flag is always on, and we let
 * the client sort things out.
 *
 * (note than in no case do we allow replies to come out of order.)
 *
 *
 * Note on Xlib's handling of sequences:
 *
 * Xlib usually waits for the reply to sync request before
 * issuing another -- its archetecture depends on it.  However,
 * this is not required.  Xlib itself misses this in at least one
 * case (XGetWindowAttributes, which uses both the GetWindowAttributes
 * and GetGeometry requests).
 *
 * The upshot is that the proxy has to be able to handle seeing
 * another request before it receives an expected reply.
 *
 * this means we can't assume a single pending reply, but many.
 * currently these get tacked onto a list.
 *
 *
 * Notes on how the proxy attempts to solve all of this:
 *
 * There are 4 request that it will attempt to short-circuit:
 * InternAtom, GetAtomName, LookupColor, AllocColor, and AllocNamedColor.
 * All the code to do this is in lbxfuncs.c, and all of it works in
 * essentially the same way -- whenever possible, it will try to respond 
 * to the client without sending the request all the way to the X server.
 * The goal is to remove a roudn-trip entirely -- even though not a lot of data
 * is involved, remving the roundtrip can make this useful.

 * Unfortunately, figuring out *when* its safe is very nasty.  First
 * there are all the possibile stages outlined above.  If the proxy
 * isn't waiting, thinking there might be pending data, it can always
 * short-circuit the request.  However, this is the rare case.  When
 * the proxy can't immediately respond, it attempts to short-circuit anyways,
 * delaying the reply until whatever it was waiting on arrives.  Often
 * it can't -- if the most paranoid type of checking is turned on, it'll
 * never work.  The complex part occurs with loose checking.  If it knows
 * a reply is coming back, it can delay the short-circuit until it gets
 * the reply.  This works fine for the core protocol, but breaks down 
 * again for extensions -- to be safe, any unknown extensions are assumed
 * to have replies -- but since they may never arrive, the delayed
 * short-circuit can never be flushed.  To avoid this, whether a reply
 * has been guessed at is tracked, and this info is used to decide
 * whether a short-circuit can be delayed -- if not, it always needs
 * to do the full round-trip.
 *
 * The complexity really makes me wonder if this stuff is worth the effort...
 */


/* short-circuiting protocol */

#define	PROTOCOL_FULL	0		/* DEFAULT - best w/ accuracy */
#define	PROTOCOL_MOST	1		/* cheat on errors */
#define	PROTOCOL_POOR	2		/* cheat on errors & events */

#undef	DEBUG

#undef	TRACE

/* possible states of request handlers.  some requests are short-circuited
 * (yanked), some are replaced with LBX requests, and some are let through
 * unchanged
 *
 * any replaced request expecting a reply needs to be sure the sequence
 * number isn't lagging before its sends its data
 */
#define	REQ_PASSTHROUGH	0	/* pass through */
#define	REQ_YANK	1	/* completely remove, reply sent */
#define REQ_YANKLATE	2	/* completely remove, reply not sent yet */
#define	REQ_REPLACE	3	/* replaced with 1way, reply sent */
#define	REQ_REPLACELATE	4	/* replaced with 1way, reply not sent yet */

/*
 * size of motion event queue
 *
 * this specifies the maximum number of motion events that the server
 * can spew out at once.  the proxy will send it NUM_MOTION_EVENTS
 * AllowMotion requests at startup, and then send a new one each time it
 * processes a Motion event.  this will prevent the wire from being
 * swamped by MotionNotify.
 */

/* XXX this should be a calculation based on the wire latency */

#define	NUM_MOTION_EVENTS	8


#ifdef LBX_STATS
extern int  intern_good,
            intern_miss;
extern int  getatom_good,
            getatom_miss;
extern int  luc_good,
            luc_miss;
extern int  ac_good,
            ac_miss;
extern int  anc_good,
            anc_miss;

extern int  getmodmap_tag,	/* tag only */
            getmodmap_full;
extern int  getkeymap_tag,	/* tag only */
            getkeymap_full;
extern int  queryfont_tag,	/* tag only */
            queryfont_full;
extern int  getsetup_tag,	/* tag only */
            getsetup_full;

extern int  getprop_tag,
            getprop_full;

extern int  tag_bytes_unsent;	/* approx data kept off wire by tags */


extern void DumpOtherStats();
extern void ZeroOtherStats();

#endif /* LBX_STATS */

extern void DumpCompressionStats();
extern void ZeroCompressionStats();

/* tables.c */
extern int ProcLBXInternAtom(
    ClientPtr /*client*/
);

extern int ProcLBXGetAtomName(
    ClientPtr /*client*/
);

extern int ProcLBXCreateColormap(
    ClientPtr /*client*/
);

extern int ProcLBXAllocColor(
    ClientPtr /*client*/
);

extern int ProcLBXAllocNamedColor(
    ClientPtr /*client*/
);

extern int ProcLBXFreeColormap(
    ClientPtr /*client*/
);

extern int ProcLBXCopyColormapAndFree(
    ClientPtr /*client*/
);

extern int ProcLBXFreeColors(
    ClientPtr /*client*/
);

extern int ProcLBXLookupColor(
    ClientPtr /*client*/
);

extern int ProcLBXGetModifierMapping(
    ClientPtr /*client*/
);

extern int ProcLBXGetKeyboardMapping(
    ClientPtr /*client*/
);

extern int ProcLBXQueryFont(
    ClientPtr /*client*/
);

extern void FinishLBXRequest(
    ClientPtr /*client*/,
    int /*yank*/
);

extern void DoLBXReply(
    ClientPtr /*client*/,
    char * /*data*/,
    int /*len*/
);

extern void WriteError(
    ClientPtr /*client*/,
    unsigned /*int majorCode*/,
    unsigned /*int minorCode*/,
    XID /*resId*/,
    int /*errorCode*/
);

extern void SendLbxSync(
    ClientPtr /*client*/
);

/* dispatch.c */

extern int Dispatch(
    void
);

extern void SendErrorToClient(
    ClientPtr /*client*/,
    unsigned int /*majorCode*/,
    unsigned int /*minorCode*/,
    XID /*resId*/,
    int /*errorCode*/
);

extern ClientPtr NextAvailableClient(
    pointer /*ospriv*/,
    int /* connect_fd */	/* the fd the client connected on */
);

extern int ProcInitialConnection(
    ClientPtr /*client*/
);

extern int ProcEstablishConnection(
    ClientPtr /*client*/
);

extern void CloseDownClient(
    ClientPtr /*client*/
);

extern int ProcStandardRequest(
    ClientPtr /*client*/
);

extern int ProcBadRequest(
    ClientPtr /*client*/
);

extern void AdjustProcVector(
    void
);

/* lbxutil.c */

extern ReplyStuffPtr NewReply(
    ClientPtr /*client*/,
    int /*major*/,
    int /*minor*/,
    ReplyFunc /*reply_func*/
);

extern void RemoveReply(
    ClientPtr /*client*/,
    ReplyStuffPtr /*rp*/
);

extern ReplyStuffPtr GetMatchingReply(
    ClientPtr /*client*/,
    int /*seqno*/,
    Bool /*flush_older*/
);

extern Bool AnyReplies(
    ClientPtr /*client*/
);

extern Bool SaveReplyData(
    ClientPtr /*client*/,
    xReply * /*rep*/,
    int /*len*/,
    pointer /*data*/
);

extern Bool FlushDelayedReplies(
    ClientPtr /*client*/
);

extern void BumpSequence(
    ClientPtr /*client*/
);

extern void ForceSequenceUpdate(
    ClientPtr /*client*/
);

extern void LbxFreeTag(
    XServerPtr /*server*/,
    XID /*tag*/,
    int /*tagtype*/
);

extern void LbxSendTagData(
    ClientPtr /*client*/,
    XID /*tag*/,
    int /*tagtype*/
);

extern void SendInitLBXPackets(
    XServerPtr /*server*/
);

extern void LbxCleanupSession(
    void
);

/* unsquish.c */

extern int EventLength(
    xEvent * /*ev*/,
    Bool /* squish */
);

extern Bool UnsquishEvent(
    xReply * /*rep*/,
    xEvent * /*ev*/,
    int * /*lenp*/
);

/* props.c */

extern int ProcLBXChangeProperty(
    ClientPtr /*client*/
);

extern int ProcLBXGetProperty(
    ClientPtr /*client*/
);

#endif