Mercurial > trustbridge > nss-cmake-static
comparison nss/lib/dbm/include/page.h @ 3:150b72113545
Add DBM and legacydb support
| author | Andre Heinecke <andre.heinecke@intevation.de> |
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| date | Tue, 05 Aug 2014 18:32:02 +0200 |
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| 2:a945361df361 | 3:150b72113545 |
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| 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 */ | |
| 36 | |
| 37 /* | |
| 38 * Definitions for hashing page file format. | |
| 39 */ | |
| 40 | |
| 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 */ | |
| 60 | |
| 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 | |
| 75 | |
| 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)) | |
| 86 | |
| 87 typedef struct { | |
| 88 BUFHEAD *newp; | |
| 89 BUFHEAD *oldp; | |
| 90 BUFHEAD *nextp; | |
| 91 uint16 next_addr; | |
| 92 } SPLIT_RETURN; | |
| 93 #endif | |
| 94 |