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 #if defined(USE_XCB)
  35 # include <X11/Xlib-xcb.h>
  36 # include <xcb/xcb.h>
  37 # include <xcb/glx.h>
  38 #endif
  39
  40 /**
  41  * GLX protocol structure for the ficticious "GXLGenericGetString" request.
  42  *
  43  * This is a non-existant protocol packet.  It just so happens that all of
  44  * the real protocol packets used to request a string from the server have
  45  * an identical binary layout.  The only difference between them is the
  46  * meaning of the \c for_whom field and the value of the \c glxCode.
  47  */
  48 typedef struct GLXGenericGetString
  49 {
  50    CARD8 reqType;
  51    CARD8 glxCode;
  52    CARD16 length B16;
  53    CARD32 for_whom B32;
  54    CARD32 name B32;
  55 } xGLXGenericGetStringReq;
  56
  57 /* These defines are only needed to make the GetReq macro happy.
  58  */
  59 #define sz_xGLXGenericGetStringReq 12
  60 #define X_GLXGenericGetString 0
  61
  62 /**
  63  * Query the Server GLX string.
  64  * This routine will allocate the necessay space for the string.
  65  */
  66 char *
  67 __glXGetStringFromServer(Display * dpy, int opcode, CARD32 glxCode,
  68                          CARD32 for_whom, CARD32 name)
  69 {
  70    xGLXGenericGetStringReq *req;
  71    xGLXSingleReply reply;
  72    int length;
  73    int numbytes;
  74    char *buf;
  75
  76
  77    LockDisplay(dpy);
  78
  79
  80    /* All of the GLX protocol requests for getting a string from the server
  81     * look the same.  The exact meaning of the for_whom field is usually
  82     * either the screen number (for glXQueryServerString) or the context tag
  83     * (for GLXSingle).
  84     */
  85
  86    GetReq(GLXGenericGetString, req);
  87    req->reqType = opcode;
  88    req->glxCode = glxCode;
  89    req->for_whom = for_whom;
  90    req->name = name;
  91
  92    _XReply(dpy, (xReply *) & reply, 0, False);
  93
  94    length = reply.length * 4;
  95    numbytes = reply.size;
  96
  97    buf = (char *) Xmalloc(numbytes);
  98    if (buf != NULL) {
  99       _XRead(dpy, buf, numbytes);
 100       length -= numbytes;
 101    }
 102
 103    _XEatData(dpy, length);
 104
 105    UnlockDisplay(dpy);
 106    SyncHandle();
 107
 108    return buf;
 109 }
 110
 111 #ifdef USE_XCB
 112 char *
 113 __glXQueryServerString(Display* dpy,
 114                        CARD32 screen,
 115                        CARD32 name)
 116 {
 117    xcb_connection_t *c = XGetXCBConnection(dpy);
 118    xcb_glx_query_server_string_reply_t* reply =
 119       xcb_glx_query_server_string_reply(c,
 120                                         xcb_glx_query_server_string(c,
 121                                                                     screen,
 122                                                                     name),
 123                                         NULL);
 124
 125    /* The spec doesn't mention this, but the Xorg server replies with
 126     * a string already terminated with '\0'. */
 127    uint32_t len = xcb_glx_query_server_string_string_length(reply);
 128    char* buf = Xmalloc(len);
 129    memcpy(buf, xcb_glx_query_server_string_string(reply), len);
 130    free(reply);
 131
 132    return buf;
 133 }
 134 #endif /* USE_XCB */