1 /* $OpenBSD: rec_get.c,v 1.11 2007/08/08 07:16:50 ray Exp $ */
2
3 /*-
4 * Copyright (c) 1990, 1993, 1994
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/types.h>
33
34 #include <errno.h>
35 #include <stddef.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <unistd.h>
40
41 #include <db.h>
42 #include "recno.h"
43
44 /*
45 * __REC_GET -- Get a record from the btree.
46 *
47 * Parameters:
48 * dbp: pointer to access method
49 * key: key to find
50 * data: data to return
51 * flag: currently unused
52 *
53 * Returns:
54 * RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
55 */
56 int
__rec_get(const DB * dbp,const DBT * key,DBT * data,u_int flags)57 __rec_get(const DB *dbp, const DBT *key, DBT *data, u_int flags)
58 {
59 BTREE *t;
60 EPG *e;
61 recno_t nrec;
62 int status;
63
64 t = dbp->internal;
65
66 /* Toss any page pinned across calls. */
67 if (t->bt_pinned != NULL) {
68 mpool_put(t->bt_mp, t->bt_pinned, 0);
69 t->bt_pinned = NULL;
70 }
71
72 /* Get currently doesn't take any flags, and keys of 0 are illegal. */
73 if (flags || (nrec = *(recno_t *)key->data) == 0) {
74 errno = EINVAL;
75 return (RET_ERROR);
76 }
77
78 /*
79 * If we haven't seen this record yet, try to find it in the
80 * original file.
81 */
82 if (nrec > t->bt_nrecs) {
83 if (F_ISSET(t, R_EOF | R_INMEM))
84 return (RET_SPECIAL);
85 if ((status = t->bt_irec(t, nrec)) != RET_SUCCESS)
86 return (status);
87 }
88
89 --nrec;
90 if ((e = __rec_search(t, nrec, SEARCH)) == NULL)
91 return (RET_ERROR);
92
93 status = __rec_ret(t, e, 0, NULL, data);
94 if (F_ISSET(t, B_DB_LOCK))
95 mpool_put(t->bt_mp, e->page, 0);
96 else
97 t->bt_pinned = e->page;
98 return (status);
99 }
100
101 /*
102 * __REC_FPIPE -- Get fixed length records from a pipe.
103 *
104 * Parameters:
105 * t: tree
106 * cnt: records to read
107 *
108 * Returns:
109 * RET_ERROR, RET_SUCCESS
110 */
111 int
__rec_fpipe(BTREE * t,recno_t top)112 __rec_fpipe(BTREE *t, recno_t top)
113 {
114 DBT data;
115 recno_t nrec;
116 size_t len;
117 int ch;
118 u_char *p;
119 void *tp;
120
121 if (t->bt_rdata.size < t->bt_reclen) {
122 tp = realloc(t->bt_rdata.data, t->bt_reclen);
123 if (tp == NULL)
124 return (RET_ERROR);
125 t->bt_rdata.data = tp;
126 t->bt_rdata.size = t->bt_reclen;
127 }
128 data.data = t->bt_rdata.data;
129 data.size = t->bt_reclen;
130
131 for (nrec = t->bt_nrecs; nrec < top;) {
132 len = t->bt_reclen;
133 for (p = t->bt_rdata.data;; *p++ = ch)
134 if ((ch = getc(t->bt_rfp)) == EOF || !--len) {
135 if (ch != EOF)
136 *p = ch;
137 if (len != 0)
138 memset(p, t->bt_bval, len);
139 if (__rec_iput(t,
140 nrec, &data, 0) != RET_SUCCESS)
141 return (RET_ERROR);
142 ++nrec;
143 break;
144 }
145 if (ch == EOF)
146 break;
147 }
148 if (nrec < top) {
149 F_SET(t, R_EOF);
150 return (RET_SPECIAL);
151 }
152 return (RET_SUCCESS);
153 }
154
155 /*
156 * __REC_VPIPE -- Get variable length records from a pipe.
157 *
158 * Parameters:
159 * t: tree
160 * cnt: records to read
161 *
162 * Returns:
163 * RET_ERROR, RET_SUCCESS
164 */
165 int
__rec_vpipe(BTREE * t,recno_t top)166 __rec_vpipe(BTREE *t, recno_t top)
167 {
168 DBT data;
169 recno_t nrec;
170 size_t len;
171 size_t sz;
172 int bval, ch;
173 u_char *p;
174 void *tp;
175
176 bval = t->bt_bval;
177 for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
178 for (p = t->bt_rdata.data,
179 sz = t->bt_rdata.size;; *p++ = ch, --sz) {
180 if ((ch = getc(t->bt_rfp)) == EOF || ch == bval) {
181 data.data = t->bt_rdata.data;
182 data.size = p - (u_char *)t->bt_rdata.data;
183 if (ch == EOF && data.size == 0)
184 break;
185 if (__rec_iput(t, nrec, &data, 0)
186 != RET_SUCCESS)
187 return (RET_ERROR);
188 break;
189 }
190 if (sz == 0) {
191 len = p - (u_char *)t->bt_rdata.data;
192 t->bt_rdata.size += (sz = 256);
193 tp = realloc(t->bt_rdata.data, t->bt_rdata.size);
194 if (tp == NULL)
195 return (RET_ERROR);
196 t->bt_rdata.data = tp;
197 p = (u_char *)t->bt_rdata.data + len;
198 }
199 }
200 if (ch == EOF)
201 break;
202 }
203 if (nrec < top) {
204 F_SET(t, R_EOF);
205 return (RET_SPECIAL);
206 }
207 return (RET_SUCCESS);
208 }
209
210 /*
211 * __REC_FMAP -- Get fixed length records from a file.
212 *
213 * Parameters:
214 * t: tree
215 * cnt: records to read
216 *
217 * Returns:
218 * RET_ERROR, RET_SUCCESS
219 */
220 int
__rec_fmap(BTREE * t,recno_t top)221 __rec_fmap(BTREE *t, recno_t top)
222 {
223 DBT data;
224 recno_t nrec;
225 u_char *sp, *ep, *p;
226 size_t len;
227 void *tp;
228
229 if (t->bt_rdata.size < t->bt_reclen) {
230 tp = realloc(t->bt_rdata.data, t->bt_reclen);
231 if (tp == NULL)
232 return (RET_ERROR);
233 t->bt_rdata.data = tp;
234 t->bt_rdata.size = t->bt_reclen;
235 }
236 data.data = t->bt_rdata.data;
237 data.size = t->bt_reclen;
238
239 sp = (u_char *)t->bt_cmap;
240 ep = (u_char *)t->bt_emap;
241 for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
242 if (sp >= ep) {
243 F_SET(t, R_EOF);
244 return (RET_SPECIAL);
245 }
246 len = t->bt_reclen;
247 for (p = t->bt_rdata.data;
248 sp < ep && len > 0; *p++ = *sp++, --len);
249 if (len != 0)
250 memset(p, t->bt_bval, len);
251 if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
252 return (RET_ERROR);
253 }
254 t->bt_cmap = (caddr_t)sp;
255 return (RET_SUCCESS);
256 }
257
258 /*
259 * __REC_VMAP -- Get variable length records from a file.
260 *
261 * Parameters:
262 * t: tree
263 * cnt: records to read
264 *
265 * Returns:
266 * RET_ERROR, RET_SUCCESS
267 */
268 int
__rec_vmap(BTREE * t,recno_t top)269 __rec_vmap(BTREE *t, recno_t top)
270 {
271 DBT data;
272 u_char *sp, *ep;
273 recno_t nrec;
274 int bval;
275
276 sp = (u_char *)t->bt_cmap;
277 ep = (u_char *)t->bt_emap;
278 bval = t->bt_bval;
279
280 for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
281 if (sp >= ep) {
282 F_SET(t, R_EOF);
283 return (RET_SPECIAL);
284 }
285 for (data.data = sp; sp < ep && *sp != bval; ++sp);
286 data.size = sp - (u_char *)data.data;
287 if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
288 return (RET_ERROR);
289 ++sp;
290 }
291 t->bt_cmap = (caddr_t)sp;
292 return (RET_SUCCESS);
293 }
294