XCrAssoc.c   [plain text]

/* $Xorg: XCrAssoc.c,v 1.4 2001/02/09 02:04:05 xorgcvs Exp $ */
/*

Copyright 1985, 1998 The Open Group.

Permission to use, copy, modify, distribute, and sell this software and its
documentation for any purpose is hereby granted without fee, provided that
the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation.

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of The Open Group shall not be
used in advertising or otherwise to promote the sale, use or other dealings
in this Software without prior written authorization from The Open Group.

*/

#include "Xlibint.h"
#include "X10.h"

/*
 * XCreateAssocTable - Create an XAssocTable.  The size argument should be
 * a power of two for efficiency reasons.  Some size suggestions: use 32
 * buckets per 100 objects;  a reasonable maximum number of object per
 * buckets is 8.  If there is an error creating the XAssocTable, a NULL
 * pointer is returned.
 */
XAssocTable *XCreateAssocTable(size)
	register int size;		/* Desired size of the table. */
{
	register XAssocTable *table;	/* XAssocTable to be initialized. */
	register XAssoc *buckets;	/* Pointer to the first bucket in */
					/* the bucket array. */
	
	/* XMalloc the XAssocTable. */
	if ((table = (XAssocTable *)Xmalloc(sizeof(XAssocTable))) == NULL) {
		/* XMalloc call failed! */
		errno = ENOMEM;
		return(NULL);
	}
	
	/* XMalloc the buckets (actually just their headers). */
	buckets = (XAssoc *)Xcalloc((unsigned)size, (unsigned)sizeof(XAssoc));
	if (buckets == NULL) {
		/* XCalloc call failed! */
		errno = ENOMEM;
		return(NULL);
	}

	/* Insert table data into the XAssocTable structure. */
	table->buckets = buckets;
	table->size = size;

	while (--size >= 0) {
		/* Initialize each bucket. */
		buckets->prev = buckets;
		buckets->next = buckets;
		buckets++;
	}

	return(table);
}