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 {
  44    CARD8 reqType;
  45    CARD8 glxCode;
  46    CARD16 length B16;
  47    CARD32 for_whom B32;
  48    CARD32 name B32;
  49 } xGLXGenericGetStringReq;
  50
  51 /* These defines are only needed to make the GetReq macro happy.
  52  */
  53 #define sz_xGLXGenericGetStringReq 12
  54 #define X_GLXGenericGetString 0
  55
  56 /**
  57  * Query the Server GLX string.
  58  * This routine will allocate the necessay space for the string.
  59  */
  60 char *
  61 __glXGetStringFromServer(Display * dpy, int opcode, CARD32 glxCode,
  62                          CARD32 for_whom, CARD32 name)
  63 {
  64    xGLXGenericGetStringReq *req;
  65    xGLXSingleReply reply;
  66    int length;
  67    int numbytes;
  68    char *buf;
  69
  70
  71    LockDisplay(dpy);
  72
  73
  74    /* All of the GLX protocol requests for getting a string from the server
  75     * look the same.  The exact meaning of the for_whom field is usually
  76     * either the screen number (for glXQueryServerString) or the context tag
  77     * (for GLXSingle).
  78     */
  79
  80    GetReq(GLXGenericGetString, req);
  81    req->reqType = opcode;
  82    req->glxCode = glxCode;
  83    req->for_whom = for_whom;
  84    req->name = name;
  85
  86    _XReply(dpy, (xReply *) & reply, 0, False);
  87
  88    length = reply.length * 4;
  89    numbytes = reply.size;
  90
  91    buf = (char *) Xmalloc(numbytes);
  92    if (buf != NULL) {
  93       _XRead(dpy, buf, numbytes);
  94       length -= numbytes;
  95    }
  96
  97    _XEatData(dpy, length);
  98
  99    UnlockDisplay(dpy);
 100    SyncHandle();
 101
 102    return buf;
 103 }