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Member "xorg-server-1.20.5/dix/atom.c" (30 May 2019, 5885 Bytes) of package /linux/misc/xorg-server-1.20.5.tar.bz2:


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    1 /***********************************************************
    2 
    3 Copyright 1987, 1998  The Open Group
    4 
    5 Permission to use, copy, modify, distribute, and sell this software and its
    6 documentation for any purpose is hereby granted without fee, provided that
    7 the above copyright notice appear in all copies and that both that
    8 copyright notice and this permission notice appear in supporting
    9 documentation.
   10 
   11 The above copyright notice and this permission notice shall be included in
   12 all copies or substantial portions of the Software.
   13 
   14 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   15 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   16 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
   17 OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
   18 AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
   19 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   20 
   21 Except as contained in this notice, the name of The Open Group shall not be
   22 used in advertising or otherwise to promote the sale, use or other dealings
   23 in this Software without prior written authorization from The Open Group.
   24 
   25 Copyright 1987 by Digital Equipment Corporation, Maynard, Massachusetts.
   26 
   27                         All Rights Reserved
   28 
   29 Permission to use, copy, modify, and distribute this software and its
   30 documentation for any purpose and without fee is hereby granted,
   31 provided that the above copyright notice appear in all copies and that
   32 both that copyright notice and this permission notice appear in
   33 supporting documentation, and that the name of Digital not be
   34 used in advertising or publicity pertaining to distribution of the
   35 software without specific, written prior permission.
   36 
   37 DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
   38 ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
   39 DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
   40 ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
   41 WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
   42 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
   43 SOFTWARE.
   44 
   45 ******************************************************************/
   46 
   47 #ifdef HAVE_DIX_CONFIG_H
   48 #include <dix-config.h>
   49 #endif
   50 
   51 #include <X11/X.h>
   52 #include <X11/Xatom.h>
   53 #include <stdio.h>
   54 #include <string.h>
   55 #include "misc.h"
   56 #include "resource.h"
   57 #include "dix.h"
   58 
   59 #define InitialTableSize 256
   60 
   61 typedef struct _Node {
   62     struct _Node *left, *right;
   63     Atom a;
   64     unsigned int fingerPrint;
   65     const char *string;
   66 } NodeRec, *NodePtr;
   67 
   68 static Atom lastAtom = None;
   69 static NodePtr atomRoot = NULL;
   70 static unsigned long tableLength;
   71 static NodePtr *nodeTable;
   72 
   73 Atom
   74 MakeAtom(const char *string, unsigned len, Bool makeit)
   75 {
   76     NodePtr *np;
   77     unsigned i;
   78     int comp;
   79     unsigned int fp = 0;
   80 
   81     np = &atomRoot;
   82     for (i = 0; i < (len + 1) / 2; i++) {
   83         fp = fp * 27 + string[i];
   84         fp = fp * 27 + string[len - 1 - i];
   85     }
   86     while (*np != NULL) {
   87         if (fp < (*np)->fingerPrint)
   88             np = &((*np)->left);
   89         else if (fp > (*np)->fingerPrint)
   90             np = &((*np)->right);
   91         else {                  /* now start testing the strings */
   92             comp = strncmp(string, (*np)->string, (int) len);
   93             if ((comp < 0) || ((comp == 0) && (len < strlen((*np)->string))))
   94                 np = &((*np)->left);
   95             else if (comp > 0)
   96                 np = &((*np)->right);
   97             else
   98                 return (*np)->a;
   99         }
  100     }
  101     if (makeit) {
  102         NodePtr nd;
  103 
  104         nd = malloc(sizeof(NodeRec));
  105         if (!nd)
  106             return BAD_RESOURCE;
  107         if (lastAtom < XA_LAST_PREDEFINED) {
  108             nd->string = string;
  109         }
  110         else {
  111             nd->string = strndup(string, len);
  112             if (!nd->string) {
  113                 free(nd);
  114                 return BAD_RESOURCE;
  115             }
  116         }
  117         if ((lastAtom + 1) >= tableLength) {
  118             NodePtr *table;
  119 
  120             table = reallocarray(nodeTable, tableLength, 2 * sizeof(NodePtr));
  121             if (!table) {
  122                 if (nd->string != string) {
  123                     /* nd->string has been strdup'ed */
  124                     free((char *) nd->string);
  125                 }
  126                 free(nd);
  127                 return BAD_RESOURCE;
  128             }
  129             tableLength <<= 1;
  130             nodeTable = table;
  131         }
  132         *np = nd;
  133         nd->left = nd->right = NULL;
  134         nd->fingerPrint = fp;
  135         nd->a = ++lastAtom;
  136         nodeTable[lastAtom] = nd;
  137         return nd->a;
  138     }
  139     else
  140         return None;
  141 }
  142 
  143 Bool
  144 ValidAtom(Atom atom)
  145 {
  146     return (atom != None) && (atom <= lastAtom);
  147 }
  148 
  149 const char *
  150 NameForAtom(Atom atom)
  151 {
  152     NodePtr node;
  153 
  154     if (atom > lastAtom)
  155         return 0;
  156     if ((node = nodeTable[atom]) == NULL)
  157         return 0;
  158     return node->string;
  159 }
  160 
  161 void
  162 AtomError(void)
  163 {
  164     FatalError("initializing atoms");
  165 }
  166 
  167 static void
  168 FreeAtom(NodePtr patom)
  169 {
  170     if (patom->left)
  171         FreeAtom(patom->left);
  172     if (patom->right)
  173         FreeAtom(patom->right);
  174     if (patom->a > XA_LAST_PREDEFINED) {
  175         /*
  176          * All strings above XA_LAST_PREDEFINED are strdup'ed, so it's safe to
  177          * cast here
  178          */
  179         free((char *) patom->string);
  180     }
  181     free(patom);
  182 }
  183 
  184 void
  185 FreeAllAtoms(void)
  186 {
  187     if (atomRoot == NULL)
  188         return;
  189     FreeAtom(atomRoot);
  190     atomRoot = NULL;
  191     free(nodeTable);
  192     nodeTable = NULL;
  193     lastAtom = None;
  194 }
  195 
  196 void
  197 InitAtoms(void)
  198 {
  199     FreeAllAtoms();
  200     tableLength = InitialTableSize;
  201     nodeTable = xallocarray(InitialTableSize, sizeof(NodePtr));
  202     if (!nodeTable)
  203         AtomError();
  204     nodeTable[None] = NULL;
  205     MakePredeclaredAtoms();
  206     if (lastAtom != XA_LAST_PREDEFINED)
  207         AtomError();
  208 }