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comparison: security/nss/lib/dbm/include/hash.h

security/nss/lib/dbm/include/hash.h

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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 * @(#)hash.h 8.3 (Berkeley) 5/31/94
35 */
36
37 /* Operations */
38
39 #include <stdio.h>
40 #include "mcom_db.h"
41 typedef enum {
42 HASH_GET, HASH_PUT, HASH_PUTNEW, HASH_DELETE, HASH_FIRST, HASH_NEXT
43 } ACTION;
44
45 /* Buffer Management structures */
46 typedef struct _bufhead BUFHEAD;
47
48 struct _bufhead {
49 BUFHEAD *prev; /* LRU links */
50 BUFHEAD *next; /* LRU links */
51 BUFHEAD *ovfl; /* Overflow page buffer header */
52 uint32 addr; /* Address of this page */
53 char *page; /* Actual page data */
54 char is_disk;
55 char flags;
56 #define BUF_MOD 0x0001
57 #define BUF_DISK 0x0002
58 #define BUF_BUCKET 0x0004
59 #define BUF_PIN 0x0008
60 };
61
62 #define IS_BUCKET(X) ((X) & BUF_BUCKET)
63
64 typedef BUFHEAD **SEGMENT;
65
66 typedef int DBFILE_PTR;
67 #define NO_FILE -1
68 #ifdef macintosh
69 #define DBFILE_OPEN(path, flag,mode) open((path), flag)
70 #define EXISTS(path)
71 #else
72 #define DBFILE_OPEN(path, flag,mode) open((path), (flag), (mode))
73 #endif
74 /* Hash Table Information */
75 typedef struct hashhdr { /* Disk resident portion */
76 int32 magic; /* Magic NO for hash tables */
77 int32 version; /* Version ID */
78 uint32 lorder; /* Byte Order */
79 int32 bsize; /* Bucket/Page Size */
80 int32 bshift; /* Bucket shift */
81 int32 dsize; /* Directory Size */
82 int32 ssize; /* Segment Size */
83 int32 sshift; /* Segment shift */
84 int32 ovfl_point; /* Where overflow pages are being
85 * allocated */
86 int32 last_freed; /* Last overflow page freed */
87 int32 max_bucket; /* ID of Maximum bucket in use */
88 int32 high_mask; /* Mask to modulo into entire table */
89 int32 low_mask; /* Mask to modulo into lower half of
90 * table */
91 int32 ffactor; /* Fill factor */
92 int32 nkeys; /* Number of keys in hash table */
93 int32 hdrpages; /* Size of table header */
94 uint32 h_charkey; /* value of hash(CHARKEY) */
95 #define NCACHED 32 /* number of bit maps and spare
96 * points */
97 int32 spares[NCACHED];/* spare pages for overflow */
98 uint16 bitmaps[NCACHED]; /* address of overflow page
99 * bitmaps */
100 } HASHHDR;
101
102 typedef struct htab { /* Memory resident data structure */
103 HASHHDR hdr; /* Header */
104 int nsegs; /* Number of allocated segments */
105 int exsegs; /* Number of extra allocated
106 * segments */
107 uint32 /* Hash function */
108 (*hash)(const void *, size_t);
109 int flags; /* Flag values */
110 DBFILE_PTR fp; /* File pointer */
111 char *filename;
112 char *tmp_buf; /* Temporary Buffer for BIG data */
113 char *tmp_key; /* Temporary Buffer for BIG keys */
114 BUFHEAD *cpage; /* Current page */
115 int cbucket; /* Current bucket */
116 int cndx; /* Index of next item on cpage */
117 int dbmerrno; /* Error Number -- for DBM
118 * compatability */
119 int new_file; /* Indicates if fd is backing store
120 * or no */
121 int save_file; /* Indicates whether we need to flush
122 * file at
123 * exit */
124 uint32 *mapp[NCACHED]; /* Pointers to page maps */
125 int nmaps; /* Initial number of bitmaps */
126 int nbufs; /* Number of buffers left to
127 * allocate */
128 BUFHEAD bufhead; /* Header of buffer lru list */
129 SEGMENT *dir; /* Hash Bucket directory */
130 off_t file_size; /* in bytes */
131 char is_temp; /* unlink file on close */
132 char updateEOF; /* force EOF update on flush */
133 } HTAB;
134
135 /*
136 * Constants
137 */
138 #define DATABASE_CORRUPTED_ERROR -999 /* big ugly abort, delete database */
139 #define OLD_MAX_BSIZE 65536 /* 2^16 */
140 #define MAX_BSIZE 32l*1024l /* 2^15 */
141 #define MIN_BUFFERS 6
142 #define MINHDRSIZE 512
143 #define DEF_BUFSIZE 65536l /* 64 K */
144 #define DEF_BUCKET_SIZE 4096
145 #define DEF_BUCKET_SHIFT 12 /* log2(BUCKET) */
146 #define DEF_SEGSIZE 256
147 #define DEF_SEGSIZE_SHIFT 8 /* log2(SEGSIZE) */
148 #define DEF_DIRSIZE 256
149 #define DEF_FFACTOR 65536l
150 #define MIN_FFACTOR 4
151 #define SPLTMAX 8
152 #define CHARKEY "%$sniglet^&"
153 #define NUMKEY 1038583l
154 #define BYTE_SHIFT 3
155 #define INT_TO_BYTE 2
156 #define INT_BYTE_SHIFT 5
157 #define ALL_SET ((uint32)0xFFFFFFFF)
158 #define ALL_CLEAR 0
159
160 #define PTROF(X) ((ptrdiff_t)(X) == BUF_DISK ? 0 : (X))
161 #define ISDISK(X) ((X) ? ((ptrdiff_t)(X) == BUF_DISK ? BUF_DISK \
162 : (X)->is_disk) : 0)
163
164 #define BITS_PER_MAP 32
165
166 /* Given the address of the beginning of a big map, clear/set the nth bit */
167 #define CLRBIT(A, N) ((A)[(N)/BITS_PER_MAP] &= ~(1<<((N)%BITS_PER_MAP)))
168 #define SETBIT(A, N) ((A)[(N)/BITS_PER_MAP] |= (1<<((N)%BITS_PER_MAP)))
169 #define ISSET(A, N) ((A)[(N)/BITS_PER_MAP] & (1<<((N)%BITS_PER_MAP)))
170
171 /* Overflow management */
172 /*
173 * Overflow page numbers are allocated per split point. At each doubling of
174 * the table, we can allocate extra pages. So, an overflow page number has
175 * the top 5 bits indicate which split point and the lower 11 bits indicate
176 * which page at that split point is indicated (pages within split points are
177 * numberered starting with 1).
178 */
179
180 #define SPLITSHIFT 11
181 #define SPLITMASK 0x7FF
182 #define SPLITNUM(N) (((uint32)(N)) >> SPLITSHIFT)
183 #define OPAGENUM(N) ((N) & SPLITMASK)
184 #define OADDR_OF(S,O) ((uint32)((uint32)(S) << SPLITSHIFT) + (O))
185
186 #define BUCKET_TO_PAGE(B) \
187 (B) + hashp->HDRPAGES + ((B) ? hashp->SPARES[__log2((uint32)((B)+1))-1] : 0)
188 #define OADDR_TO_PAGE(B) \
189 BUCKET_TO_PAGE ( (1 << SPLITNUM((B))) -1 ) + OPAGENUM((B));
190
191 /*
192 * page.h contains a detailed description of the page format.
193 *
194 * Normally, keys and data are accessed from offset tables in the top of
195 * each page which point to the beginning of the key and data. There are
196 * four flag values which may be stored in these offset tables which indicate
197 * the following:
198 *
199 *
200 * OVFLPAGE Rather than a key data pair, this pair contains
201 * the address of an overflow page. The format of
202 * the pair is:
203 * OVERFLOW_PAGE_NUMBER OVFLPAGE
204 *
205 * PARTIAL_KEY This must be the first key/data pair on a page
206 * and implies that page contains only a partial key.
207 * That is, the key is too big to fit on a single page
208 * so it starts on this page and continues on the next.
209 * The format of the page is:
210 * KEY_OFF PARTIAL_KEY OVFL_PAGENO OVFLPAGE
211 *
212 * KEY_OFF -- offset of the beginning of the key
213 * PARTIAL_KEY -- 1
214 * OVFL_PAGENO - page number of the next overflow page
215 * OVFLPAGE -- 0
216 *
217 * FULL_KEY This must be the first key/data pair on the page. It
218 * is used in two cases.
219 *
220 * Case 1:
221 * There is a complete key on the page but no data
222 * (because it wouldn't fit). The next page contains
223 * the data.
224 *
225 * Page format it:
226 * KEY_OFF FULL_KEY OVFL_PAGENO OVFL_PAGE
227 *
228 * KEY_OFF -- offset of the beginning of the key
229 * FULL_KEY -- 2
230 * OVFL_PAGENO - page number of the next overflow page
231 * OVFLPAGE -- 0
232 *
233 * Case 2:
234 * This page contains no key, but part of a large
235 * data field, which is continued on the next page.
236 *
237 * Page format it:
238 * DATA_OFF FULL_KEY OVFL_PAGENO OVFL_PAGE
239 *
240 * KEY_OFF -- offset of the beginning of the data on
241 * this page
242 * FULL_KEY -- 2
243 * OVFL_PAGENO - page number of the next overflow page
244 * OVFLPAGE -- 0
245 *
246 * FULL_KEY_DATA
247 * This must be the first key/data pair on the page.
248 * There are two cases:
249 *
250 * Case 1:
251 * This page contains a key and the beginning of the
252 * data field, but the data field is continued on the
253 * next page.
254 *
255 * Page format is:
256 * KEY_OFF FULL_KEY_DATA OVFL_PAGENO DATA_OFF
257 *
258 * KEY_OFF -- offset of the beginning of the key
259 * FULL_KEY_DATA -- 3
260 * OVFL_PAGENO - page number of the next overflow page
261 * DATA_OFF -- offset of the beginning of the data
262 *
263 * Case 2:
264 * This page contains the last page of a big data pair.
265 * There is no key, only the tail end of the data
266 * on this page.
267 *
268 * Page format is:
269 * DATA_OFF FULL_KEY_DATA <OVFL_PAGENO> <OVFLPAGE>
270 *
271 * DATA_OFF -- offset of the beginning of the data on
272 * this page
273 * FULL_KEY_DATA -- 3
274 * OVFL_PAGENO - page number of the next overflow page
275 * OVFLPAGE -- 0
276 *
277 * OVFL_PAGENO and OVFLPAGE are optional (they are
278 * not present if there is no next page).
279 */
280
281 #define OVFLPAGE 0
282 #define PARTIAL_KEY 1
283 #define FULL_KEY 2
284 #define FULL_KEY_DATA 3
285 #define REAL_KEY 4
286
287 /* Short hands for accessing structure */
288 #undef BSIZE
289 #define BSIZE hdr.bsize
290 #undef BSHIFT
291 #define BSHIFT hdr.bshift
292 #define DSIZE hdr.dsize
293 #define SGSIZE hdr.ssize
294 #define SSHIFT hdr.sshift
295 #define LORDER hdr.lorder
296 #define OVFL_POINT hdr.ovfl_point
297 #define LAST_FREED hdr.last_freed
298 #define MAX_BUCKET hdr.max_bucket
299 #define FFACTOR hdr.ffactor
300 #define HIGH_MASK hdr.high_mask
301 #define LOW_MASK hdr.low_mask
302 #define NKEYS hdr.nkeys
303 #define HDRPAGES hdr.hdrpages
304 #define SPARES hdr.spares
305 #define BITMAPS hdr.bitmaps
306 #define VERSION hdr.version
307 #define MAGIC hdr.magic
308 #define NEXT_FREE hdr.next_free
309 #define H_CHARKEY hdr.h_charkey
310
311 extern uint32 (*__default_hash) (const void *, size_t);
312 void __buf_init(HTAB *hashp, int32 nbytes);
313 int __big_delete(HTAB *hashp, BUFHEAD *bufp);
314 BUFHEAD * __get_buf(HTAB *hashp, uint32 addr, BUFHEAD *prev_bp, int newpage);
315 uint32 __call_hash(HTAB *hashp, char *k, size_t len);
316 #include "page.h"
317 extern int __big_split(HTAB *hashp, BUFHEAD *op,BUFHEAD *np,
318 BUFHEAD *big_keyp,uint32 addr,uint32 obucket, SPLIT_RETURN *ret);
319 void __free_ovflpage(HTAB *hashp, BUFHEAD *obufp);
320 BUFHEAD * __add_ovflpage(HTAB *hashp, BUFHEAD *bufp);
321 int __big_insert(HTAB *hashp, BUFHEAD *bufp, const DBT *key, const DBT *val);
322 int __expand_table(HTAB *hashp);
323 uint32 __log2(uint32 num);
324 void __reclaim_buf(HTAB *hashp, BUFHEAD *bp);
325 int __get_page(HTAB *hashp, char * p, uint32 bucket, int is_bucket, int is_disk, int is_bitmap);
326 int __put_page(HTAB *hashp, char *p, uint32 bucket, int is_bucket, int is_bitmap);
327 int __ibitmap(HTAB *hashp, int pnum, int nbits, int ndx);
328 int __buf_free(HTAB *hashp, int do_free, int to_disk);
329 int __find_bigpair(HTAB *hashp, BUFHEAD *bufp, int ndx, char *key, int size);
330 uint16 __find_last_page(HTAB *hashp, BUFHEAD **bpp);
331 int __addel(HTAB *hashp, BUFHEAD *bufp, const DBT *key, const DBT * val);
332 int __big_return(HTAB *hashp, BUFHEAD *bufp, int ndx, DBT *val, int set_current);
333 int __delpair(HTAB *hashp, BUFHEAD *bufp, int ndx);
334 int __big_keydata(HTAB *hashp, BUFHEAD *bufp, DBT *key, DBT *val, int set);
335 int __split_page(HTAB *hashp, uint32 obucket, uint32 nbucket);

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