xref: /titanic_41/usr/src/lib/krb5/plugins/kdb/db2/libdb2/hash/hash.h (revision 54925bf60766fbb4f1f2d7c843721406a7b7a3fb)
1 /*
2  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 #ifndef _KRB5_DB2_HASH_H
7 #define	_KRB5_DB2_HASH_H
8 
9 #pragma ident	"%Z%%M%	%I%	%E% SMI"
10 
11 #ifdef	__cplusplus
12 extern "C" {
13 #endif
14 
15 /*-
16  * Copyright (c) 1990, 1993, 1994
17  *	The Regents of the University of California.  All rights reserved.
18  *
19  * This code is derived from software contributed to Berkeley by
20  * Margo Seltzer.
21  *
22  * Redistribution and use in source and binary forms, with or without
23  * modification, are permitted provided that the following conditions
24  * are met:
25  * 1. Redistributions of source code must retain the above copyright
26  *    notice, this list of conditions and the following disclaimer.
27  * 2. Redistributions in binary form must reproduce the above copyright
28  *    notice, this list of conditions and the following disclaimer in the
29  *    documentation and/or other materials provided with the distribution.
30  * 3. All advertising materials mentioning features or use of this software
31  *    must display the following acknowledgement:
32  *	This product includes software developed by the University of
33  *	California, Berkeley and its contributors.
34  * 4. Neither the name of the University nor the names of its contributors
35  *    may be used to endorse or promote products derived from this software
36  *    without specific prior written permission.
37  *
38  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
39  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
40  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
41  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
42  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
43  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
44  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
45  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
46  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
47  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
48  * SUCH DAMAGE.
49  *
50  *	@(#)hash.h	8.4 (Berkeley) 11/2/95
51  */
52 
53 #include "mpool.h"
54 #include "db-queue.h"
55 
56 /* Operations */
57 typedef enum {
58 	HASH_GET, HASH_PUT, HASH_PUTNEW, HASH_DELETE, HASH_FIRST, HASH_NEXT
59 } ACTION;
60 
61 /* cursor structure */
62 typedef struct cursor_t {
63 	TAILQ_ENTRY(cursor_t) queue;
64 	int (*get)	__P((const DB *, struct cursor_t *, DBT *, DBT *, \
65 			     u_int32_t));
66 	int (*delete) __P((const DB *, struct cursor_t *, u_int32_t));
67 	db_pgno_t	bucket;
68 	db_pgno_t	pgno;
69 	indx_t	ndx;
70 	indx_t	pgndx;
71 	u_int16_t *pagep;
72 	void *internal;
73 } CURSOR;
74 
75 
76 #define IS_BUCKET(X)	((X) & BUF_BUCKET)
77 #define IS_VALID(X)     (!((X) & BUF_INVALID))
78 
79 /* Hash Table Information */
80 typedef struct hashhdr {	/* Disk resident portion */
81 	int32_t	magic;		/* Magic NO for hash tables */
82 	int32_t	version;	/* Version ID */
83 	int32_t	lorder;		/* Byte Order */
84 	int32_t	bsize;		/* Bucket/Page Size */
85 	int32_t	bshift;		/* Bucket shift */
86 	int32_t	ovfl_point;	/* Where overflow pages are being allocated */
87 	int32_t	last_freed;	/* Last overflow page freed */
88 	int32_t	max_bucket;	/* ID of Maximum bucket in use */
89 	int32_t	high_mask;	/* Mask to modulo into entire table */
90 	int32_t	low_mask;	/* Mask to modulo into lower half of table */
91 	int32_t	ffactor;	/* Fill factor */
92 	int32_t	nkeys;		/* Number of keys in hash table */
93 	int32_t	hdrpages;	/* Size of table header */
94 	int32_t	h_charkey;	/* value of hash(CHARKEY) */
95 #define NCACHED	32		/* number of bit maps and spare points */
96 	int32_t	spares[NCACHED];/* spare pages for overflow */
97 	u_int16_t	bitmaps[NCACHED];	/* address of overflow page bitmaps */
98 } HASHHDR;
99 
100 typedef struct htab {		/* Memory resident data structure */
101 	TAILQ_HEAD(_cursor_queue, cursor_t) curs_queue;
102 	HASHHDR hdr;		/* Header */
103 	u_int32_t (*hash) __P((const void *, size_t)); /* Hash Function */
104 	int32_t	flags;		/* Flag values */
105 	int32_t	fp;		/* File pointer */
106 	const char *fname;        	/* File path */
107 	u_int8_t *bigdata_buf;	/* Temporary Buffer for BIG data */
108 	u_int8_t *bigkey_buf;	/* Temporary Buffer for BIG keys */
109 	u_int16_t  *split_buf;	/* Temporary buffer for splits */
110 	CURSOR	*seq_cursor;	/* Cursor used for hash_seq */
111 	int32_t	local_errno;	/* Error Number -- for DBM compatability */
112 	int32_t	new_file;	/* Indicates if fd is backing store or no */
113 	int32_t	save_file;	/* Indicates whether we need to flush file at
114 				 * exit */
115 	u_int32_t *mapp[NCACHED];/* Pointers to page maps */
116 	int32_t	nmaps;		/* Initial number of bitmaps */
117 	MPOOL	*mp;		/* mpool for buffer management */
118 } HTAB;
119 
120 /*
121  * Constants
122  */
123 #define	MAX_BSIZE		65536		/* 2^16 */
124 #define MIN_BUFFERS		6
125 #define MINHDRSIZE		512
126 #define DEF_CACHESIZE	65536
127 #define DEF_BUCKET_SHIFT	12		/* log2(BUCKET) */
128 #define DEF_BUCKET_SIZE		(1<<DEF_BUCKET_SHIFT)
129 #define DEF_SEGSIZE_SHIFT	8		/* log2(SEGSIZE)	 */
130 #define DEF_SEGSIZE		(1<<DEF_SEGSIZE_SHIFT)
131 #define DEF_DIRSIZE		256
132 #define DEF_FFACTOR		65536
133 #define MIN_FFACTOR		4
134 #define SPLTMAX			8
135 #define CHARKEY			"%$sniglet^&"
136 #define NUMKEY			1038583
137 #define BYTE_SHIFT		3
138 #define INT32_T_TO_BYTE		2
139 #define INT32_T_BYTE_SHIFT		5
140 #define ALL_SET			((u_int32_t)0xFFFFFFFF)
141 #define ALL_CLEAR		0
142 
143 #define PTROF(X)	((BUFHEAD *)((ptr_t)(X)&~0x3))
144 #define ISMOD(X)	((ptr_t)(X)&0x1)
145 #define DOMOD(X)	((X) = (int8_t *)((ptr_t)(X)|0x1))
146 #define ISDISK(X)	((ptr_t)(X)&0x2)
147 #define DODISK(X)	((X) = (int8_t *)((ptr_t)(X)|0x2))
148 
149 #define BITS_PER_MAP	32
150 
151 /* Given the address of the beginning of a big map, clear/set the nth bit */
152 #define CLRBIT(A, N)	((A)[(N)/BITS_PER_MAP] &= ~(1<<((N)%BITS_PER_MAP)))
153 #define SETBIT(A, N)	((A)[(N)/BITS_PER_MAP] |= (1<<((N)%BITS_PER_MAP)))
154 #define ISSET(A, N)	((A)[(N)/BITS_PER_MAP] & (1<<((N)%BITS_PER_MAP)))
155 
156 /* Overflow management */
157 /*
158  * Overflow page numbers are allocated per split point.  At each doubling of
159  * the table, we can allocate extra pages.  So, an overflow page number has
160  * the top 5 bits indicate which split point and the lower 11 bits indicate
161  * which page at that split point is indicated (pages within split points are
162  * numberered starting with 1).
163  */
164 
165 #define SPLITSHIFT	11
166 #define SPLITMASK	0x7FF
167 #define SPLITNUM(N)	(((u_int32_t)(N)) >> SPLITSHIFT)
168 #define OPAGENUM(N)	((N) & SPLITMASK)
169 #define	OADDR_OF(S,O)	((u_int32_t)((u_int32_t)(S) << SPLITSHIFT) + (O))
170 
171 #define BUCKET_TO_PAGE(B) \
172 	((B) + hashp->hdr.hdrpages + ((B) \
173 	    ? hashp->hdr.spares[__log2((B)+1)-1] : 0))
174 #define OADDR_TO_PAGE(B) 	\
175 	(BUCKET_TO_PAGE ( (1 << SPLITNUM((B))) -1 ) + OPAGENUM((B)))
176 
177 #define POW2(N)  (1 << (N))
178 
179 #define MAX_PAGES(H) (DB_OFF_T_MAX / (H)->hdr.bsize)
180 
181 /* Shorthands for accessing structure */
182 #define METADATA_PGNO 0
183 #define SPLIT_PGNO 0xFFFF
184 
185 typedef struct item_info {
186 	db_pgno_t 		pgno;
187 	db_pgno_t		bucket;
188 	indx_t		ndx;
189 	indx_t		pgndx;
190 	u_int8_t	status;
191 	int32_t		seek_size;
192 	db_pgno_t		seek_found_page;
193 	indx_t		key_off;
194 	indx_t		data_off;
195 	u_int8_t	caused_expand;
196 } ITEM_INFO;
197 
198 
199 #define	ITEM_ERROR	0
200 #define	ITEM_OK		1
201 #define	ITEM_NO_MORE	2
202 
203 #define	ITEM_GET_FIRST	0
204 #define	ITEM_GET_NEXT	1
205 #define	ITEM_GET_RESET	2
206 #define	ITEM_GET_DONE	3
207 #define	ITEM_GET_N	4
208 
209 #define	UNKNOWN		0xffffffff		/* for num_items */
210 #define	NO_EXPAND	0xfffffffe
211 
212 #ifdef	__cplusplus
213 }
214 #endif
215 
216 #endif	/* !_KRB5_DB2_HASH_H */
217