oldXMenu/XMakeAssoc.c

   1 /* Copyright    Massachusetts Institute of Technology    1985   */
   2
   3 #include "copyright.h"
   4
   5
   6 #include <config.h>
   7 #include "XMenuInt.h"
   8 #include <X11/Xresource.h>
   9 #include <errno.h>
  10
  11 #ifndef NULL
  12 #define NULL 0
  13 #endif
  14
  15 /*
  16  * XMakeAssoc - Insert data into an XAssocTable keyed on an XId.
  17  * Data is inserted into the table only once.  Redundant inserts are
  18  * meaningless (but cause no problems).  The queue in each association
  19  * bucket is sorted (lowest XId to highest XId).
  20  */
  21 void
  22 XMakeAssoc(register Display *dpy, register XAssocTable *table, register XID x_id, register void *data)
  23 {
  24         int hash;
  25         register XAssoc *bucket;
  26         register XAssoc *Entry;
  27         register XAssoc *new_entry;
  28
  29         /* Hash the XId to get the bucket number. */
  30         hash = x_id & (table->size - 1);
  31         /* Look up the bucket to get the entries in that bucket. */
  32         bucket = &table->buckets[hash];
  33         /* Get the first entry in the bucket. */
  34         Entry = bucket->next;
  35
  36         /* If (Entry != bucket), the bucket is empty so make */
  37         /* the new entry the first entry in the bucket. */
  38         /* if (Entry == bucket), the we have to search the */
  39         /* bucket. */
  40         if (Entry != bucket) {
  41                 /* The bucket isn't empty, begin searching. */
  42                 /* If we leave the for loop then we have either passed */
  43                 /* where the entry should be or hit the end of the bucket. */
  44                 /* In either case we should then insert the new entry */
  45                 /* before the current value of "Entry". */
  46                 for (; Entry != bucket; Entry = Entry->next) {
  47                         if (Entry->x_id == x_id) {
  48                                 /* Entry has the same XId... */
  49                                 if (Entry->display == dpy) {
  50                                         /* Entry has the same Display... */
  51                                         /* Therefore there is already an */
  52                                         /* entry with this XId and Display, */
  53                                         /* reset its data value and return. */
  54                                         Entry->data = data;
  55                                         return;
  56                                 }
  57                                 /* We found an association with the right */
  58                                 /* id but the wrong display! */
  59                                 continue;
  60                         }
  61                         /* If the current entry's XId is greater than the */
  62                         /* XId of the entry to be inserted then we have */
  63                         /* passed the location where the new XId should */
  64                         /* be inserted. */
  65                         if (Entry->x_id > x_id) break;
  66                 }
  67         }
  68
  69         /* If we are here then the new entry should be inserted just */
  70         /* before the current value of "Entry". */
  71         /* Create a new XAssoc and load it with new provided data. */
  72         new_entry = (XAssoc *) malloc(sizeof(XAssoc));
  73         new_entry->display = dpy;
  74         new_entry->x_id = x_id;
  75         new_entry->data = data;
  76
  77         /* Insert the new entry. */
  78         emacs_insque((struct qelem *)new_entry, (struct qelem *)Entry->prev);
  79 }