src/glx/x11/glx_query.c

   1 /*
   2  * (C) Copyright IBM Corporation 2004
   3  * All Rights Reserved.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * on the rights to use, copy, modify, merge, publish, distribute, sub
   9  * license, and/or sell copies of the Software, and to permit persons to whom
  10  * the Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice (including the next
  13  * paragraph) shall be included in all copies or substantial portions of the
  14  * Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
  19  * IBM AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  22  * DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 /**
  26  * \file glx_query.c
  27  * Generic utility functions to query internal data from the server.
  28  *
  29  * \author Ian Romanick <idr@us.ibm.com>
  30  */
  31
  32 #include "glxclient.h"
  33
  34 /**
  35  * GLX protocol structure for the ficticious "GXLGenericGetString" request.
  36  *
  37  * This is a non-existant protocol packet.  It just so happens that all of
  38  * the real protocol packets used to request a string from the server have
  39  * an identical binary layout.  The only difference between them is the
  40  * meaning of the \c for_whom field and the value of the \c glxCode.
  41  */
  42 typedef struct GLXGenericGetString {
  43     CARD8 reqType;
  44     CARD8 glxCode;
  45     CARD16 length B16;
  46     CARD32 for_whom B32;
  47     CARD32 name B32;
  48 } xGLXGenericGetStringReq;
  49
  50 /* These defines are only needed to make the GetReq macro happy.
  51  */
  52 #define sz_xGLXGenericGetStringReq 12
  53 #define X_GLXGenericGetString 0
  54
  55 /**
  56  * Query the Server GLX string and cache it in the display private.
  57  * This routine will allocate the necessay space for the string.
  58  */
  59 char *
  60 __glXGetStringFromServer( Display * dpy, int opcode, CARD32 glxCode,
  61                           CARD32 for_whom, CARD32 name )
  62 {
  63     xGLXGenericGetStringReq *req;
  64     xGLXSingleReply reply;
  65     int length;
  66     int numbytes;
  67     char * buf;
  68
  69
  70     LockDisplay( dpy );
  71
  72
  73     /* All of the GLX protocol requests for getting a string from the server
  74      * look the same.  The exact meaning of the for_whom field is usually
  75      * either the screen number (for glXQueryServerString) or the context tag
  76      * (for GLXSingle).
  77      */
  78
  79     GetReq( GLXGenericGetString, req );
  80     req->reqType = opcode;
  81     req->glxCode = glxCode;
  82     req->for_whom = for_whom;
  83     req->name = name;
  84
  85     _XReply( dpy, (xReply *) & reply, 0, False );
  86
  87     length = reply.length * 4;
  88     numbytes = reply.size;
  89
  90     buf = (char *) Xmalloc( numbytes );
  91     if ( buf != NULL ) {
  92         _XRead( dpy, buf, numbytes );
  93         length -= numbytes;
  94     }
  95
  96     _XEatData( dpy, length );
  97
  98     UnlockDisplay( dpy );
  99     SyncHandle();
 100
 101     return buf;
 102 }