security/nss/lib/dbm/include/page.h@b8a032363ba2
security/nss/lib/dbm/include/page.h
Thu, 22 Jan 2015 13:21:57 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Thu, 22 Jan 2015 13:21:57 +0100
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
- permissions
- -rw-r--r--
Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6
1 /*-
2 * Copyright (c) 1990, 1993, 1994
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Margo Seltzer.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. ***REMOVED*** - see
17 * ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)page.h 8.2 (Berkeley) 5/31/94
35 */
37 /*
38 * Definitions for hashing page file format.
39 */
41 /*
42 * routines dealing with a data page
43 *
44 * page format:
45 * +------------------------------+
46 * p | n | keyoff | datoff | keyoff |
47 * +------------+--------+--------+
48 * | datoff | free | ptr | --> |
49 * +--------+---------------------+
50 * | F R E E A R E A |
51 * +--------------+---------------+
52 * | <---- - - - | data |
53 * +--------+-----+----+----------+
54 * | key | data | key |
55 * +--------+----------+----------+
56 *
57 * Pointer to the free space is always: p[p[0] + 2]
58 * Amount of free space on the page is: p[p[0] + 1]
59 */
61 /*
62 * How many bytes required for this pair?
63 * 2 shorts in the table at the top of the page + room for the
64 * key and room for the data
65 *
66 * We prohibit entering a pair on a page unless there is also room to append
67 * an overflow page. The reason for this it that you can get in a situation
68 * where a single key/data pair fits on a page, but you can't append an
69 * overflow page and later you'd have to split the key/data and handle like
70 * a big pair.
71 * You might as well do this up front.
72 */
73 #ifndef PAGE_H
74 #define PAGE_H
76 #define PAIRSIZE(K,D) (2*sizeof(uint16) + (K)->size + (D)->size)
77 #define BIGOVERHEAD (4*sizeof(uint16))
78 #define KEYSIZE(K) (4*sizeof(uint16) + (K)->size);
79 #define OVFLSIZE (2*sizeof(uint16))
80 #define FREESPACE(P) ((P)[(P)[0]+1])
81 #define OFFSET(P) ((P)[(P)[0]+2])
82 #define PAIRFITS(P,K,D) \
83 (((P)[2] >= REAL_KEY) && \
84 (PAIRSIZE((K),(D)) + OVFLSIZE) <= FREESPACE((P)))
85 #define PAGE_META(N) (((N)+3) * sizeof(uint16))
87 typedef struct {
88 BUFHEAD *newp;
89 BUFHEAD *oldp;
90 BUFHEAD *nextp;
91 uint16 next_addr;
92 } SPLIT_RETURN;
93 #endif
