xref: /onnv-gate/usr/src/uts/common/fs/zfs/sys/unique.h (revision 4787:602d3f97842c)
1789Sahrens /*
2789Sahrens  * CDDL HEADER START
3789Sahrens  *
4789Sahrens  * The contents of this file are subject to the terms of the
5*4787Sahrens  * Common Development and Distribution License (the "License").
6*4787Sahrens  * You may not use this file except in compliance with the License.
7789Sahrens  *
8789Sahrens  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9789Sahrens  * or http://www.opensolaris.org/os/licensing.
10789Sahrens  * See the License for the specific language governing permissions
11789Sahrens  * and limitations under the License.
12789Sahrens  *
13789Sahrens  * When distributing Covered Code, include this CDDL HEADER in each
14789Sahrens  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15789Sahrens  * If applicable, add the following below this CDDL HEADER, with the
16789Sahrens  * fields enclosed by brackets "[]" replaced with your own identifying
17789Sahrens  * information: Portions Copyright [yyyy] [name of copyright owner]
18789Sahrens  *
19789Sahrens  * CDDL HEADER END
20789Sahrens  */
21789Sahrens /*
22*4787Sahrens  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23789Sahrens  * Use is subject to license terms.
24789Sahrens  */
25789Sahrens 
26789Sahrens #ifndef	_SYS_UNIQUE_H
27789Sahrens #define	_SYS_UNIQUE_H
28789Sahrens 
29789Sahrens #pragma ident	"%Z%%M%	%I%	%E% SMI"
30789Sahrens 
31789Sahrens #include <sys/zfs_context.h>
32789Sahrens 
33789Sahrens #ifdef	__cplusplus
34789Sahrens extern "C" {
35789Sahrens #endif
36789Sahrens 
37789Sahrens /* The number of significant bits in each unique value. */
38789Sahrens #define	UNIQUE_BITS	56
39789Sahrens 
40789Sahrens void unique_init(void);
41*4787Sahrens void unique_fini(void);
42789Sahrens 
43*4787Sahrens /*
44*4787Sahrens  * Return a new unique value (which will not be uniquified against until
45*4787Sahrens  * it is unique_insert()-ed.
46*4787Sahrens  */
47789Sahrens uint64_t unique_create(void);
48789Sahrens 
49789Sahrens /* Return a unique value, which equals the one passed in if possible. */
50789Sahrens uint64_t unique_insert(uint64_t value);
51789Sahrens 
52789Sahrens /* Indicate that this value no longer needs to be uniquified against. */
53789Sahrens void unique_remove(uint64_t value);
54789Sahrens 
55789Sahrens #ifdef	__cplusplus
56789Sahrens }
57789Sahrens #endif
58789Sahrens 
59789Sahrens #endif /* _SYS_UNIQUE_H */
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