xref: /freebsd/lib/libc/db/recno/rec_get.c (revision 1ca63a8219b88b752b064d19bd3428c61dbcf1f9)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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 #if defined(LIBC_SCCS) && !defined(lint)
33 static char sccsid[] = "@(#)rec_get.c	8.9 (Berkeley) 8/18/94";
34 #endif /* LIBC_SCCS and not lint */
35 #include <sys/types.h>
36 
37 #include <errno.h>
38 #include <stddef.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <unistd.h>
43 
44 #include <db.h>
45 #include "recno.h"
46 
47 /*
48  * __REC_GET -- Get a record from the btree.
49  *
50  * Parameters:
51  *	dbp:	pointer to access method
52  *	key:	key to find
53  *	data:	data to return
54  *	flag:	currently unused
55  *
56  * Returns:
57  *	RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
58  */
59 int
60 __rec_get(const DB *dbp, const DBT *key, DBT *data, u_int flags)
61 {
62 	BTREE *t;
63 	EPG *e;
64 	recno_t nrec;
65 	int status;
66 
67 	t = dbp->internal;
68 
69 	/* Toss any page pinned across calls. */
70 	if (t->bt_pinned != NULL) {
71 		mpool_put(t->bt_mp, t->bt_pinned, 0);
72 		t->bt_pinned = NULL;
73 	}
74 
75 	/* Get currently doesn't take any flags, and keys of 0 are illegal. */
76 	if (flags || (nrec = *(recno_t *)key->data) == 0) {
77 		errno = EINVAL;
78 		return (RET_ERROR);
79 	}
80 
81 	/*
82 	 * If we haven't seen this record yet, try to find it in the
83 	 * original file.
84 	 */
85 	if (nrec > t->bt_nrecs) {
86 		if (F_ISSET(t, R_EOF | R_INMEM))
87 			return (RET_SPECIAL);
88 		if ((status = t->bt_irec(t, nrec)) != RET_SUCCESS)
89 			return (status);
90 	}
91 
92 	--nrec;
93 	if ((e = __rec_search(t, nrec, SEARCH)) == NULL)
94 		return (RET_ERROR);
95 
96 	status = __rec_ret(t, e, 0, NULL, data);
97 	if (F_ISSET(t, B_DB_LOCK))
98 		mpool_put(t->bt_mp, e->page, 0);
99 	else
100 		t->bt_pinned = e->page;
101 	return (status);
102 }
103 
104 /*
105  * __REC_FPIPE -- Get fixed length records from a pipe.
106  *
107  * Parameters:
108  *	t:	tree
109  *	cnt:	records to read
110  *
111  * Returns:
112  *	RET_ERROR, RET_SUCCESS
113  */
114 int
115 __rec_fpipe(BTREE *t, recno_t top)
116 {
117 	DBT data;
118 	recno_t nrec;
119 	size_t len;
120 	int ch;
121 	u_char *p;
122 
123 	if (t->bt_rdata.size < t->bt_reclen) {
124 		t->bt_rdata.data = reallocf(t->bt_rdata.data, t->bt_reclen);
125 		if (t->bt_rdata.data == NULL)
126 			return (RET_ERROR);
127 		t->bt_rdata.size = t->bt_reclen;
128 	}
129 	data.data = t->bt_rdata.data;
130 	data.size = t->bt_reclen;
131 
132 	for (nrec = t->bt_nrecs; nrec < top;) {
133 		len = t->bt_reclen;
134 		for (p = t->bt_rdata.data;; *p++ = ch)
135 			if ((ch = getc(t->bt_rfp)) == EOF || !--len) {
136 				if (ch != EOF)
137 					*p = ch;
138 				if (len != 0)
139 					memset(p, t->bt_bval, len);
140 				if (__rec_iput(t,
141 				    nrec, &data, 0) != RET_SUCCESS)
142 					return (RET_ERROR);
143 				++nrec;
144 				break;
145 			}
146 		if (ch == EOF)
147 			break;
148 	}
149 	if (nrec < top) {
150 		F_SET(t, R_EOF);
151 		return (RET_SPECIAL);
152 	}
153 	return (RET_SUCCESS);
154 }
155 
156 /*
157  * __REC_VPIPE -- Get variable length records from a pipe.
158  *
159  * Parameters:
160  *	t:	tree
161  *	cnt:	records to read
162  *
163  * Returns:
164  *	RET_ERROR, RET_SUCCESS
165  */
166 int
167 __rec_vpipe(BTREE *t, recno_t top)
168 {
169 	DBT data;
170 	recno_t nrec;
171 	size_t len;
172 	size_t sz;
173 	int bval, ch;
174 	u_char *p;
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 				t->bt_rdata.data = reallocf(t->bt_rdata.data, t->bt_rdata.size);
194 				if (t->bt_rdata.data == NULL)
195 					return (RET_ERROR);
196 				p = (u_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
220 __rec_fmap(BTREE *t, recno_t top)
221 {
222 	DBT data;
223 	recno_t nrec;
224 	u_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 = (u_char *)t->bt_cmap;
237 	ep = (u_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
266 __rec_vmap(BTREE *t, recno_t top)
267 {
268 	DBT data;
269 	u_char *sp, *ep;
270 	recno_t nrec;
271 	int bval;
272 
273 	sp = (u_char *)t->bt_cmap;
274 	ep = (u_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 - (u_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