oldXMenu/XCrAssoc.c

   1 /* Copyright    Massachusetts Institute of Technology    1985   */
   2 #include "copyright.h"
   3
   4
   5 #include <config.h>
   6 #include <X11/Xlib.h>
   7 #include <errno.h>
   8 #include "X10.h"
   9
  10 #ifndef NULL
  11 #define NULL 0
  12 #endif
  13
  14 /*
  15  * XCreateAssocTable - Create an XAssocTable.  The size argument should be
  16  * a power of two for efficiency reasons.  Some size suggestions: use 32
  17  * buckets per 100 objects;  a reasonable maximum number of object per
  18  * buckets is 8.  If there is an error creating the XAssocTable, a NULL
  19  * pointer is returned.
  20  */
  21 XAssocTable *XCreateAssocTable(register int size)
  22                                         /* Desired size of the table. */
  23 {
  24         register XAssocTable *table;    /* XAssocTable to be initialized. */
  25         register XAssoc *buckets;       /* Pointer to the first bucket in */
  26                                         /* the bucket array. */
  27
  28         /* Malloc the XAssocTable. */
  29         if ((table = (XAssocTable *)malloc(sizeof(XAssocTable))) == NULL) {
  30                 /* malloc call failed! */
  31                 errno = ENOMEM;
  32                 return(NULL);
  33         }
  34
  35         /* calloc the buckets (actually just their headers). */
  36         buckets = (XAssoc *)calloc((unsigned)size, (unsigned)sizeof(XAssoc));
  37         if (buckets == NULL) {
  38                 /* calloc call failed! */
  39                 errno = ENOMEM;
  40                 return(NULL);
  41         }
  42
  43         /* Insert table data into the XAssocTable structure. */
  44         table->buckets = buckets;
  45         table->size = size;
  46
  47         while (--size >= 0) {
  48                 /* Initialize each bucket. */
  49                 buckets->prev = buckets;
  50                 buckets->next = buckets;
  51                 buckets++;
  52         }
  53
  54         return(table);
  55 }
  56