XLookAssoc.c 1.56 KB
Newer Older
Dave Love's avatar
#  
Dave Love committed
1 2
/* Copyright    Massachusetts Institute of Technology    1985	*/

3 4
#include "copyright.h"

5
#include <config.h>
Dave Love's avatar
#  
Dave Love committed
6 7 8 9 10 11 12 13
#include <X11/Xlib.h>
#include <X11/Xresource.h>
#include "X10.h"

#ifndef NULL
#define NULL 0
#endif

14
/*
Dave Love's avatar
#  
Dave Love committed
15 16 17 18 19 20
 * XLookUpAssoc - Retrieve the data stored in an XAssocTable by its XId.
 * If an appropriately matching XId can be found in the table the routine will
 * return apointer to the data associated with it. If the XId can not be found
 * in the table the routine will return a NULL pointer.  All XId's are relative
 * to the currently active Display.
 */
21 22 23
caddr_t XLookUpAssoc(Display *dpy,
		     XAssocTable *table,  /* XAssocTable to search in. */
		     XID x_id)		  /* XId to search for. */
Dave Love's avatar
#  
Dave Love committed
24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56
{
	int hash;
	register XAssoc *bucket;
	register XAssoc *Entry;

	/* Hash the XId to get the bucket number. */
	hash = x_id & (table->size - 1);
	/* Look up the bucket to get the entries in that bucket. */
	bucket = &table->buckets[hash];
	/* Get the first entry in the bucket. */
	Entry = bucket->next;

	/* Scan through the entries in the bucket for the right XId. */
	for (; Entry != bucket; Entry = Entry->next) {
		if (Entry->x_id == x_id) {
			/* We have the right XId. */
			if (Entry->display == dpy) {
				/* We have the right display. */
				/* We have the right entry! */
				return(Entry->data);
			}
			/* Oops, identical XId's on different displays! */
			continue;
		}
		if (Entry->x_id > x_id) {
			/* We have gone past where it should be. */
			/* It is apparently not in the table. */
			return(NULL);
		}
	}
	/* It is apparently not in the table. */
	return(NULL);
}