Backport fix for Bug#8672 from trunk
[emacs.git] / oldXMenu / XMakeAssoc.c
blobe46674db605d50622ce3f556cdd0b9f3f2bc0355
1 /* Copyright Massachusetts Institute of Technology 1985 */
3 #include "copyright.h"
6 #include <config.h>
7 #include <X11/Xlib.h>
8 #include <X11/Xresource.h>
9 #include "X10.h"
10 #include <errno.h>
12 #ifndef NULL
13 #define NULL 0
14 #endif
16 extern int errno;
18 void emacs_insque();
19 struct qelem {
20 struct qelem *q_forw;
21 struct qelem *q_back;
22 char q_data[1];
25 * XMakeAssoc - Insert data into an XAssocTable keyed on an XId.
26 * Data is inserted into the table only once. Redundant inserts are
27 * meaningless (but cause no problems). The queue in each association
28 * bucket is sorted (lowest XId to highest XId).
30 void
31 XMakeAssoc(dpy, table, x_id, data)
32 register Display *dpy;
33 register XAssocTable *table;
34 register XID x_id;
35 register caddr_t data;
37 int hash;
38 register XAssoc *bucket;
39 register XAssoc *Entry;
40 register XAssoc *new_entry;
42 /* Hash the XId to get the bucket number. */
43 hash = x_id & (table->size - 1);
44 /* Look up the bucket to get the entries in that bucket. */
45 bucket = &table->buckets[hash];
46 /* Get the first entry in the bucket. */
47 Entry = bucket->next;
49 /* If (Entry != bucket), the bucket is empty so make */
50 /* the new entry the first entry in the bucket. */
51 /* if (Entry == bucket), the we have to search the */
52 /* bucket. */
53 if (Entry != bucket) {
54 /* The bucket isn't empty, begin searching. */
55 /* If we leave the for loop then we have either passed */
56 /* where the entry should be or hit the end of the bucket. */
57 /* In either case we should then insert the new entry */
58 /* before the current value of "Entry". */
59 for (; Entry != bucket; Entry = Entry->next) {
60 if (Entry->x_id == x_id) {
61 /* Entry has the same XId... */
62 if (Entry->display == dpy) {
63 /* Entry has the same Display... */
64 /* Therefore there is already an */
65 /* entry with this XId and Display, */
66 /* reset its data value and return. */
67 Entry->data = data;
68 return;
70 /* We found an association with the right */
71 /* id but the wrong display! */
72 continue;
74 /* If the current entry's XId is greater than the */
75 /* XId of the entry to be inserted then we have */
76 /* passed the location where the new XId should */
77 /* be inserted. */
78 if (Entry->x_id > x_id) break;
82 /* If we are here then the new entry should be inserted just */
83 /* before the current value of "Entry". */
84 /* Create a new XAssoc and load it with new provided data. */
85 new_entry = (XAssoc *) malloc(sizeof(XAssoc));
86 new_entry->display = dpy;
87 new_entry->x_id = x_id;
88 new_entry->data = data;
90 /* Insert the new entry. */
91 emacs_insque((struct qelem *)new_entry, (struct qelem *)Entry->prev);
94 /* arch-tag: d7e3fb8a-f3b3-4c5d-a307-75ca67ec1b49
95 (do not change this comment) */