about summary refs log tree commit diff
path: root/db2/include/hash.h
blob: cb8ea350f52fd2e9e834a156b13e8d9944cb16da (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1996, 1997
 *	Sleepycat Software.  All rights reserved.
 */
/*
 * Copyright (c) 1990, 1993, 1994
 *	Margo Seltzer.  All rights reserved.
 */
/*
 * Copyright (c) 1990, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Margo Seltzer.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)hash.h	10.6 (Sleepycat) 8/18/97
 */

/* Cursor structure definitions. */
typedef struct cursor_t {
	DBC		*db_cursor;
	db_pgno_t	bucket;		/* Bucket we are traversing. */
	DB_LOCK		lock;		/* Lock held on the current bucket. */
	PAGE		*pagep;		/* The current page. */
	db_pgno_t	pgno;		/* Current page number. */
	db_indx_t	bndx;		/* Index within the current page. */
	PAGE		*dpagep;	/* Duplicate page pointer. */
	db_pgno_t	dpgno;		/* Duplicate page number. */
	db_indx_t	dndx;		/* Index within a duplicate set. */
	db_indx_t	dup_off;	/* Offset within a duplicate set. */
	db_indx_t	dup_len;	/* Length of current duplicate. */
	db_indx_t	dup_tlen;	/* Total length of duplicate entry. */
	u_int32_t	seek_size;	/* Number of bytes we need for add. */
	db_pgno_t	seek_found_page;/* Page on which we can insert. */
	u_int32_t	big_keylen;	/* Length of big_key buffer. */
	void		*big_key;	/* Temporary buffer for big keys. */
	u_int32_t	big_datalen;	/* Length of big_data buffer. */
	void		*big_data;	/* Temporary buffer for big data. */
#define	H_OK		0x0001
#define	H_NOMORE	0x0002
#define	H_DELETED	0x0004
#define	H_ISDUP		0x0008
#define	H_EXPAND	0x0020
	u_int32_t	flags;		/* Is cursor inside a dup set. */
} HASH_CURSOR;

#define	IS_VALID(C) ((C)->bucket != BUCKET_INVALID)


typedef struct htab {		/* Memory resident data structure. */
	DB *dbp;		/* Pointer to parent db structure. */
	DB_LOCK hlock;		/* Metadata page lock. */
	HASHHDR *hdr;		/* Pointer to meta-data page. */
	u_int32_t (*hash) __P((const void *, u_int32_t)); /* Hash Function */
	PAGE *split_buf;	/* Temporary buffer for splits. */
	int local_errno;	/* Error Number -- for DBM compatability */
	u_long hash_accesses;	/* Number of accesses to this table. */
	u_long hash_collisions;	/* Number of collisions on search. */
	u_long hash_expansions;	/* Number of times we added a bucket. */
	u_long hash_overflows;	/* Number of overflow pages. */
	u_long hash_bigpages;	/* Number of big key/data pages. */
} HTAB;

/*
 * Macro used for interface functions to set the txnid in the DBP.
 */
#define	SET_LOCKER(D, T) ((D)->txn = (T))

/*
 * More interface macros used to get/release the meta data page.
 */
#define	GET_META(D, H) {						\
	int _r;								\
	if (F_ISSET(D, DB_AM_LOCKING) && !F_ISSET(D, DB_AM_RECOVER)) {	\
		(D)->lock.pgno = BUCKET_INVALID;			\
	    	if ((_r = lock_get((D)->dbenv->lk_info,			\
	    	    (D)->txn == NULL ? (D)->locker : (D)->txn->txnid,	\
		    0, &(D)->lock_dbt, DB_LOCK_READ,			\
		    &(H)->hlock)) != 0)					\
			return (_r < 0 ? EAGAIN : _r);			\
	}								\
	if ((_r = __ham_get_page(D, 0, (PAGE **)&((H)->hdr))) != 0) {	\
		if ((H)->hlock) {					\
			(void)lock_put((D)->dbenv->lk_info, (H)->hlock);\
			(H)->hlock = 0;					\
		}							\
		return (_r);						\
	}								\
}

#define	RELEASE_META(D, H) {						\
	if (!F_ISSET(D, DB_AM_RECOVER) &&				\
	    (D)->txn == NULL && (H)->hlock)				\
		(void)lock_put((H)->dbp->dbenv->lk_info, (H)->hlock);	\
	(H)->hlock = 0;							\
	if ((H)->hdr)							\
		(void)__ham_put_page(D, (PAGE *)(H)->hdr,		\
		    F_ISSET(D, DB_HS_DIRTYMETA) ? 1 : 0);		\
	(H)->hdr = NULL;						\
	F_CLR(D, DB_HS_DIRTYMETA);					\
}

#define	DIRTY_META(H, R) {						\
	if (F_ISSET((H)->dbp, DB_AM_LOCKING) &&				\
	    !F_ISSET((H)->dbp, DB_AM_RECOVER)) {			\
		DB_LOCK _tmp;						\
		(H)->dbp->lock.pgno = BUCKET_INVALID;			\
	    	if (((R) = lock_get((H)->dbp->dbenv->lk_info,		\
	    	    (H)->dbp->txn ? (H)->dbp->txn->txnid :		\
	    	    (H)->dbp->locker, 0, &(H)->dbp->lock_dbt,		\
	    	    DB_LOCK_WRITE, &_tmp)) == 0)			\
			(R) = lock_put((H)->dbp->dbenv->lk_info,	\
			    (H)->hlock);				\
		else if ((R) < 0)					\
			(R) = EAGAIN;					\
		(H)->hlock = _tmp;					\
	}								\
	F_SET((H)->dbp, DB_HS_DIRTYMETA);				\
}

/* Allocate and discard thread structures. */
#define	H_GETHANDLE(dbp, dbpp, ret)					\
	if (F_ISSET(dbp, DB_AM_THREAD))					\
		ret = __db_gethandle(dbp, __ham_hdup, dbpp);		\
	else {								\
		ret = 0;						\
		*dbpp = dbp;						\
	}

#define	H_PUTHANDLE(dbp) {						\
	if (F_ISSET(dbp, DB_AM_THREAD))					\
		__db_puthandle(dbp);					\
}

/* Test string. */
#define	CHARKEY			"%$sniglet^&"

/* Overflow management */
/*
 * Overflow page numbers are allocated per split point.  At each doubling of
 * the table, we can allocate extra pages.  We keep track of how many pages
 * we've allocated at each point to calculate bucket to page number mapping.
 */
#define	BUCKET_TO_PAGE(H, B) \
	((B) + 1 + ((B) ? (H)->hdr->spares[__db_log2((B)+1)-1] : 0))

#define	PGNO_OF(H, S, O) (BUCKET_TO_PAGE((H), (1 << (S)) - 1) + (O))

/* Constraints about number of pages and how much data goes on a page. */

#define	MAX_PAGES(H)	UINT32_T_MAX
#define	MINFILL		0.25
#define	ISBIG(H, N)	(((N) > ((H)->hdr->pagesize * MINFILL)) ? 1 : 0)

/* Shorthands for accessing structure */
#define	NDX_INVALID	0xFFFF
#define	BUCKET_INVALID	0xFFFFFFFF

/* On page duplicates are stored as a string of size-data-size triples. */
#define	DUP_SIZE(len)	((len) + 2 * sizeof(db_indx_t))

/* Log messages types (these are subtypes within a record type) */
#define	PAIR_KEYMASK		0x1
#define	PAIR_DATAMASK		0x2
#define	PAIR_ISKEYBIG(N)	(N & PAIR_KEYMASK)
#define	PAIR_ISDATABIG(N)	(N & PAIR_DATAMASK)
#define	OPCODE_OF(N)    	(N & ~(PAIR_KEYMASK | PAIR_DATAMASK))

#define	PUTPAIR		0x20
#define	DELPAIR		0x30
#define	PUTOVFL		0x40
#define	DELOVFL		0x50
#define	ALLOCPGNO	0x60
#define	DELPGNO		0x70
#define	SPLITOLD	0x80
#define	SPLITNEW	0x90

#include "hash_auto.h"
#include "hash_ext.h"
#include "db_am.h"
#include "common_ext.h"