xref: /freebsd/lib/libc/db/recno/rec_get.c (revision afe61c15161c324a7af299a9b8457aba5afc92db)
1 /*-
2  * Copyright (c) 1990, 1993
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. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)rec_get.c	8.4 (Berkeley) 3/1/94";
36 #endif /* LIBC_SCCS and not lint */
37 
38 #include <sys/types.h>
39 
40 #include <errno.h>
41 #include <stddef.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 
47 #include <db.h>
48 #include "recno.h"
49 
50 /*
51  * __REC_GET -- Get a record from the btree.
52  *
53  * Parameters:
54  *	dbp:	pointer to access method
55  *	key:	key to find
56  *	data:	data to return
57  *	flag:	currently unused
58  *
59  * Returns:
60  *	RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
61  */
62 int
63 __rec_get(dbp, key, data, flags)
64 	const DB *dbp;
65 	const DBT *key;
66 	DBT *data;
67 	u_int flags;
68 {
69 	BTREE *t;
70 	EPG *e;
71 	recno_t nrec;
72 	int status;
73 
74 	t = dbp->internal;
75 
76 	/* Toss any page pinned across calls. */
77 	if (t->bt_pinned != NULL) {
78 		mpool_put(t->bt_mp, t->bt_pinned, 0);
79 		t->bt_pinned = NULL;
80 	}
81 
82 	/* Get currently doesn't take any flags, and keys of 0 are illegal. */
83 	if (flags || (nrec = *(recno_t *)key->data) == 0) {
84 		errno = EINVAL;
85 		return (RET_ERROR);
86 	}
87 
88 	/*
89 	 * If we haven't seen this record yet, try to find it in the
90 	 * original file.
91 	 */
92 	if (nrec > t->bt_nrecs) {
93 		if (ISSET(t, R_EOF | R_INMEM))
94 			return (RET_SPECIAL);
95 		if ((status = t->bt_irec(t, nrec)) != RET_SUCCESS)
96 			return (status);
97 	}
98 
99 	--nrec;
100 	if ((e = __rec_search(t, nrec, SEARCH)) == NULL)
101 		return (RET_ERROR);
102 
103 	status = __rec_ret(t, e, 0, NULL, data);
104 	if (ISSET(t, B_DB_LOCK))
105 		mpool_put(t->bt_mp, e->page, 0);
106 	else
107 		t->bt_pinned = e->page;
108 	return (status);
109 }
110 
111 /*
112  * __REC_FPIPE -- Get fixed length records from a pipe.
113  *
114  * Parameters:
115  *	t:	tree
116  *	cnt:	records to read
117  *
118  * Returns:
119  *	RET_ERROR, RET_SUCCESS
120  */
121 int
122 __rec_fpipe(t, top)
123 	BTREE *t;
124 	recno_t top;
125 {
126 	DBT data;
127 	recno_t nrec;
128 	size_t len;
129 	int ch;
130 	char *p;
131 
132 	if (t->bt_dbufsz < t->bt_reclen) {
133 		if ((t->bt_dbuf =
134 		    (char *)realloc(t->bt_dbuf, t->bt_reclen)) == NULL)
135 			return (RET_ERROR);
136 		t->bt_dbufsz = t->bt_reclen;
137 	}
138 	data.data = t->bt_dbuf;
139 	data.size = t->bt_reclen;
140 
141 	for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
142 		len = t->bt_reclen;
143 		for (p = t->bt_dbuf;; *p++ = ch)
144 			if ((ch = getc(t->bt_rfp)) == EOF || !len--) {
145 				if (__rec_iput(t, nrec, &data, 0)
146 				    != RET_SUCCESS)
147 					return (RET_ERROR);
148 				break;
149 			}
150 		if (ch == EOF)
151 			break;
152 	}
153 	if (nrec < top) {
154 		SET(t, R_EOF);
155 		return (RET_SPECIAL);
156 	}
157 	return (RET_SUCCESS);
158 }
159 
160 /*
161  * __REC_VPIPE -- Get variable length records from a pipe.
162  *
163  * Parameters:
164  *	t:	tree
165  *	cnt:	records to read
166  *
167  * Returns:
168  *	RET_ERROR, RET_SUCCESS
169  */
170 int
171 __rec_vpipe(t, top)
172 	BTREE *t;
173 	recno_t top;
174 {
175 	DBT data;
176 	recno_t nrec;
177 	indx_t len;
178 	size_t sz;
179 	int bval, ch;
180 	char *p;
181 
182 	bval = t->bt_bval;
183 	for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
184 		for (p = t->bt_dbuf, sz = t->bt_dbufsz;; *p++ = ch, --sz) {
185 			if ((ch = getc(t->bt_rfp)) == EOF || ch == bval) {
186 				data.data = t->bt_dbuf;
187 				data.size = p - t->bt_dbuf;
188 				if (ch == EOF && data.size == 0)
189 					break;
190 				if (__rec_iput(t, nrec, &data, 0)
191 				    != RET_SUCCESS)
192 					return (RET_ERROR);
193 				break;
194 			}
195 			if (sz == 0) {
196 				len = p - t->bt_dbuf;
197 				t->bt_dbufsz += (sz = 256);
198 				if ((t->bt_dbuf = (char *)realloc(t->bt_dbuf,
199 				    t->bt_dbufsz)) == NULL)
200 					return (RET_ERROR);
201 				p = t->bt_dbuf + len;
202 			}
203 		}
204 		if (ch == EOF)
205 			break;
206 	}
207 	if (nrec < top) {
208 		SET(t, R_EOF);
209 		return (RET_SPECIAL);
210 	}
211 	return (RET_SUCCESS);
212 }
213 
214 /*
215  * __REC_FMAP -- Get fixed length records from a file.
216  *
217  * Parameters:
218  *	t:	tree
219  *	cnt:	records to read
220  *
221  * Returns:
222  *	RET_ERROR, RET_SUCCESS
223  */
224 int
225 __rec_fmap(t, top)
226 	BTREE *t;
227 	recno_t top;
228 {
229 	DBT data;
230 	recno_t nrec;
231 	caddr_t sp, ep;
232 	size_t len;
233 	char *p;
234 
235 	if (t->bt_dbufsz < t->bt_reclen) {
236 		if ((t->bt_dbuf =
237 		    (char *)realloc(t->bt_dbuf, t->bt_reclen)) == NULL)
238 			return (RET_ERROR);
239 		t->bt_dbufsz = t->bt_reclen;
240 	}
241 	data.data = t->bt_dbuf;
242 	data.size = t->bt_reclen;
243 
244 	sp = t->bt_cmap;
245 	ep = t->bt_emap;
246 	for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
247 		if (sp >= ep) {
248 			SET(t, R_EOF);
249 			return (RET_SPECIAL);
250 		}
251 		len = t->bt_reclen;
252 		for (p = t->bt_dbuf; sp < ep && len--; *p++ = *sp++);
253 		memset(p, t->bt_bval, len);
254 		if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
255 			return (RET_ERROR);
256 	}
257 	t->bt_cmap = sp;
258 	return (RET_SUCCESS);
259 }
260 
261 /*
262  * __REC_VMAP -- Get variable length records from a file.
263  *
264  * Parameters:
265  *	t:	tree
266  *	cnt:	records to read
267  *
268  * Returns:
269  *	RET_ERROR, RET_SUCCESS
270  */
271 int
272 __rec_vmap(t, top)
273 	BTREE *t;
274 	recno_t top;
275 {
276 	DBT data;
277 	caddr_t sp, ep;
278 	recno_t nrec;
279 	int bval;
280 
281 	sp = t->bt_cmap;
282 	ep = t->bt_emap;
283 	bval = t->bt_bval;
284 
285 	for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
286 		if (sp >= ep) {
287 			SET(t, R_EOF);
288 			return (RET_SPECIAL);
289 		}
290 		for (data.data = sp; sp < ep && *sp != bval; ++sp);
291 		data.size = sp - (caddr_t)data.data;
292 		if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
293 			return (RET_ERROR);
294 		++sp;
295 	}
296 	t->bt_cmap = sp;
297 	return (RET_SUCCESS);
298 }
299