1 /*-
2 * Copyright (c) 1990, 1993, 1994
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * @(#)rec_get.c 8.9 (Berkeley) 8/18/94
30 * $FreeBSD: head/lib/libc/db/recno/rec_get.c 189387 2009-03-05 00:57:01Z delphij $
31 */
32
33 #include <sys/types.h>
34
35 #include <errno.h>
36 #include <stddef.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <unistd.h>
41
42 #include <db.h>
43 #include "recno.h"
44
45 /*
46 * __REC_GET -- Get a record from the btree.
47 *
48 * Parameters:
49 * dbp: pointer to access method
50 * key: key to find
51 * data: data to return
52 * flag: currently unused
53 *
54 * Returns:
55 * RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
56 */
57 int
__rec_get(const DB * dbp,const DBT * key,DBT * data,unsigned int flags)58 __rec_get(const DB *dbp, const DBT *key, DBT *data, unsigned int flags)
59 {
60 BTREE *t;
61 EPG *e;
62 recno_t nrec;
63 int status;
64
65 t = dbp->internal;
66
67 /* Toss any page pinned across calls. */
68 if (t->bt_pinned != NULL) {
69 mpool_put(t->bt_mp, t->bt_pinned, 0);
70 t->bt_pinned = NULL;
71 }
72
73 /* Get currently doesn't take any flags, and keys of 0 are illegal. */
74 if (flags || (nrec = *(recno_t *)key->data) == 0) {
75 errno = EINVAL;
76 return (RET_ERROR);
77 }
78
79 /*
80 * If we haven't seen this record yet, try to find it in the
81 * original file.
82 */
83 if (nrec > t->bt_nrecs) {
84 if (F_ISSET(t, R_EOF | R_INMEM))
85 return (RET_SPECIAL);
86 if ((status = t->bt_irec(t, nrec)) != RET_SUCCESS)
87 return (status);
88 }
89
90 --nrec;
91 if ((e = __rec_search(t, nrec, SEARCH)) == NULL)
92 return (RET_ERROR);
93
94 status = __rec_ret(t, e, 0, NULL, data);
95 if (F_ISSET(t, B_DB_LOCK))
96 mpool_put(t->bt_mp, e->page, 0);
97 else
98 t->bt_pinned = e->page;
99 return (status);
100 }
101
102 /*
103 * __REC_FPIPE -- Get fixed length records from a pipe.
104 *
105 * Parameters:
106 * t: tree
107 * cnt: records to read
108 *
109 * Returns:
110 * RET_ERROR, RET_SUCCESS
111 */
112 int
__rec_fpipe(BTREE * t,recno_t top)113 __rec_fpipe(BTREE *t, recno_t top)
114 {
115 DBT data;
116 recno_t nrec;
117 size_t len;
118 int ch;
119 unsigned char *p;
120
121 if (t->bt_rdata.size < t->bt_reclen) {
122 t->bt_rdata.data = reallocf(t->bt_rdata.data, t->bt_reclen);
123 if (t->bt_rdata.data == NULL)
124 return (RET_ERROR);
125 t->bt_rdata.size = t->bt_reclen;
126 }
127 data.data = t->bt_rdata.data;
128 data.size = t->bt_reclen;
129
130 for (nrec = t->bt_nrecs; nrec < top;) {
131 len = t->bt_reclen;
132 for (p = t->bt_rdata.data;; *p++ = ch)
133 if ((ch = getc(t->bt_rfp)) == EOF || !--len) {
134 if (ch != EOF)
135 *p = ch;
136 if (len != 0)
137 memset(p, t->bt_bval, len);
138 if (__rec_iput(t,
139 nrec, &data, 0) != RET_SUCCESS)
140 return (RET_ERROR);
141 ++nrec;
142 break;
143 }
144 if (ch == EOF)
145 break;
146 }
147 if (nrec < top) {
148 F_SET(t, R_EOF);
149 return (RET_SPECIAL);
150 }
151 return (RET_SUCCESS);
152 }
153
154 /*
155 * __REC_VPIPE -- Get variable length records from a pipe.
156 *
157 * Parameters:
158 * t: tree
159 * cnt: records to read
160 *
161 * Returns:
162 * RET_ERROR, RET_SUCCESS
163 */
164 int
__rec_vpipe(BTREE * t,recno_t top)165 __rec_vpipe(BTREE *t, recno_t top)
166 {
167 DBT data;
168 recno_t nrec;
169 size_t len;
170 size_t sz;
171 int bval, ch;
172 unsigned char *p;
173
174 bval = t->bt_bval;
175 for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
176 for (p = t->bt_rdata.data,
177 sz = t->bt_rdata.size;; *p++ = ch, --sz) {
178 if ((ch = getc(t->bt_rfp)) == EOF || ch == bval) {
179 data.data = t->bt_rdata.data;
180 data.size = p -
181 (unsigned char *)t->bt_rdata.data;
182 if (ch == EOF && data.size == 0)
183 break;
184 if (__rec_iput(t, nrec, &data, 0)
185 != RET_SUCCESS)
186 return (RET_ERROR);
187 break;
188 }
189 if (sz == 0) {
190 len = p - (unsigned char *)t->bt_rdata.data;
191 t->bt_rdata.size += (sz = 256);
192 t->bt_rdata.data = reallocf(t->bt_rdata.data,
193 t->bt_rdata.size);
194 if (t->bt_rdata.data == NULL)
195 return (RET_ERROR);
196 p = (unsigned char *)t->bt_rdata.data + len;
197 }
198 }
199 if (ch == EOF)
200 break;
201 }
202 if (nrec < top) {
203 F_SET(t, R_EOF);
204 return (RET_SPECIAL);
205 }
206 return (RET_SUCCESS);
207 }
208
209 /*
210 * __REC_FMAP -- Get fixed length records from a file.
211 *
212 * Parameters:
213 * t: tree
214 * cnt: records to read
215 *
216 * Returns:
217 * RET_ERROR, RET_SUCCESS
218 */
219 int
__rec_fmap(BTREE * t,recno_t top)220 __rec_fmap(BTREE *t, recno_t top)
221 {
222 DBT data;
223 recno_t nrec;
224 unsigned char *sp, *ep, *p;
225 size_t len;
226
227 if (t->bt_rdata.size < t->bt_reclen) {
228 t->bt_rdata.data = reallocf(t->bt_rdata.data, t->bt_reclen);
229 if (t->bt_rdata.data == NULL)
230 return (RET_ERROR);
231 t->bt_rdata.size = t->bt_reclen;
232 }
233 data.data = t->bt_rdata.data;
234 data.size = t->bt_reclen;
235
236 sp = (unsigned char *)t->bt_cmap;
237 ep = (unsigned char *)t->bt_emap;
238 for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
239 if (sp >= ep) {
240 F_SET(t, R_EOF);
241 return (RET_SPECIAL);
242 }
243 len = t->bt_reclen;
244 for (p = t->bt_rdata.data;
245 sp < ep && len > 0; *p++ = *sp++, --len);
246 if (len != 0)
247 memset(p, t->bt_bval, len);
248 if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
249 return (RET_ERROR);
250 }
251 t->bt_cmap = (caddr_t)sp;
252 return (RET_SUCCESS);
253 }
254
255 /*
256 * __REC_VMAP -- Get variable length records from a file.
257 *
258 * Parameters:
259 * t: tree
260 * cnt: records to read
261 *
262 * Returns:
263 * RET_ERROR, RET_SUCCESS
264 */
265 int
__rec_vmap(BTREE * t,recno_t top)266 __rec_vmap(BTREE *t, recno_t top)
267 {
268 DBT data;
269 unsigned char *sp, *ep;
270 recno_t nrec;
271 int bval;
272
273 sp = (unsigned char *)t->bt_cmap;
274 ep = (unsigned char *)t->bt_emap;
275 bval = t->bt_bval;
276
277 for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
278 if (sp >= ep) {
279 F_SET(t, R_EOF);
280 return (RET_SPECIAL);
281 }
282 for (data.data = sp; sp < ep && *sp != bval; ++sp);
283 data.size = sp - (unsigned char *)data.data;
284 if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
285 return (RET_ERROR);
286 ++sp;
287 }
288 t->bt_cmap = (caddr_t)sp;
289 return (RET_SUCCESS);
290 }
291