oldXMenu/XMakeAssoc.c

   1 /* Copyright    Massachusetts Institute of Technology    1985   */
   2
   3 #include "copyright.h"
   4
   5
   6 #include <config.h>
   7 #include <X11/Xlib.h>
   8 #include <X11/Xresource.h>
   9 #include "X10.h"
  10 #include <errno.h>
  11
  12 #ifndef NULL
  13 #define NULL 0
  14 #endif
  15
  16 struct qelem {
  17         struct    qelem *q_forw;
  18         struct    qelem *q_back;
  19         char q_data[1];
  20 };
  21 void emacs_insque (struct qelem *elem, struct qelem *prev);
  22
  23 /*
  24  * XMakeAssoc - Insert data into an XAssocTable keyed on an XId.
  25  * Data is inserted into the table only once.  Redundant inserts are
  26  * meaningless (but cause no problems).  The queue in each association
  27  * bucket is sorted (lowest XId to highest XId).
  28  */
  29 void
  30 XMakeAssoc(register Display *dpy, register XAssocTable *table, register XID x_id, register caddr_t data)
  31 {
  32         int hash;
  33         register XAssoc *bucket;
  34         register XAssoc *Entry;
  35         register XAssoc *new_entry;
  36
  37         /* Hash the XId to get the bucket number. */
  38         hash = x_id & (table->size - 1);
  39         /* Look up the bucket to get the entries in that bucket. */
  40         bucket = &table->buckets[hash];
  41         /* Get the first entry in the bucket. */
  42         Entry = bucket->next;
  43
  44         /* If (Entry != bucket), the bucket is empty so make */
  45         /* the new entry the first entry in the bucket. */
  46         /* if (Entry == bucket), the we have to search the */
  47         /* bucket. */
  48         if (Entry != bucket) {
  49                 /* The bucket isn't empty, begin searching. */
  50                 /* If we leave the for loop then we have either passed */
  51                 /* where the entry should be or hit the end of the bucket. */
  52                 /* In either case we should then insert the new entry */
  53                 /* before the current value of "Entry". */
  54                 for (; Entry != bucket; Entry = Entry->next) {
  55                         if (Entry->x_id == x_id) {
  56                                 /* Entry has the same XId... */
  57                                 if (Entry->display == dpy) {
  58                                         /* Entry has the same Display... */
  59                                         /* Therefore there is already an */
  60                                         /* entry with this XId and Display, */
  61                                         /* reset its data value and return. */
  62                                         Entry->data = data;
  63                                         return;
  64                                 }
  65                                 /* We found an association with the right */
  66                                 /* id but the wrong display! */
  67                                 continue;
  68                         }
  69                         /* If the current entry's XId is greater than the */
  70                         /* XId of the entry to be inserted then we have */
  71                         /* passed the location where the new XId should */
  72                         /* be inserted. */
  73                         if (Entry->x_id > x_id) break;
  74                 }
  75         }
  76
  77         /* If we are here then the new entry should be inserted just */
  78         /* before the current value of "Entry". */
  79         /* Create a new XAssoc and load it with new provided data. */
  80         new_entry = (XAssoc *) malloc(sizeof(XAssoc));
  81         new_entry->display = dpy;
  82         new_entry->x_id = x_id;
  83         new_entry->data = data;
  84
  85         /* Insert the new entry. */
  86         emacs_insque((struct qelem *)new_entry, (struct qelem *)Entry->prev);
  87 }
  88