xref: /freebsd/lib/libc/db/recno/rec_get.c (revision 1b6c76a2fe091c74f08427e6c870851025a9cf67)
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. 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	8.9 (Berkeley) 8/18/94";
36 #endif /* LIBC_SCCS and not lint */
37 
38 #if !defined(lint)
39 static char rcsid[] = "$FreeBSD$";
40 #endif
41 
42 #include <sys/types.h>
43 
44 #include <errno.h>
45 #include <stddef.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <unistd.h>
50 
51 #include <db.h>
52 #include "recno.h"
53 
54 /*
55  * __REC_GET -- Get a record from the btree.
56  *
57  * Parameters:
58  *	dbp:	pointer to access method
59  *	key:	key to find
60  *	data:	data to return
61  *	flag:	currently unused
62  *
63  * Returns:
64  *	RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
65  */
66 int
67 __rec_get(dbp, key, data, flags)
68 	const DB *dbp;
69 	const DBT *key;
70 	DBT *data;
71 	u_int flags;
72 {
73 	BTREE *t;
74 	EPG *e;
75 	recno_t nrec;
76 	int status;
77 
78 	t = dbp->internal;
79 
80 	/* Toss any page pinned across calls. */
81 	if (t->bt_pinned != NULL) {
82 		mpool_put(t->bt_mp, t->bt_pinned, 0);
83 		t->bt_pinned = NULL;
84 	}
85 
86 	/* Get currently doesn't take any flags, and keys of 0 are illegal. */
87 	if (flags || (nrec = *(recno_t *)key->data) == 0) {
88 		errno = EINVAL;
89 		return (RET_ERROR);
90 	}
91 
92 	/*
93 	 * If we haven't seen this record yet, try to find it in the
94 	 * original file.
95 	 */
96 	if (nrec > t->bt_nrecs) {
97 		if (F_ISSET(t, R_EOF | R_INMEM))
98 			return (RET_SPECIAL);
99 		if ((status = t->bt_irec(t, nrec)) != RET_SUCCESS)
100 			return (status);
101 	}
102 
103 	--nrec;
104 	if ((e = __rec_search(t, nrec, SEARCH)) == NULL)
105 		return (RET_ERROR);
106 
107 	status = __rec_ret(t, e, 0, NULL, data);
108 	if (F_ISSET(t, B_DB_LOCK))
109 		mpool_put(t->bt_mp, e->page, 0);
110 	else
111 		t->bt_pinned = e->page;
112 	return (status);
113 }
114 
115 /*
116  * __REC_FPIPE -- Get fixed length records from a pipe.
117  *
118  * Parameters:
119  *	t:	tree
120  *	cnt:	records to read
121  *
122  * Returns:
123  *	RET_ERROR, RET_SUCCESS
124  */
125 int
126 __rec_fpipe(t, top)
127 	BTREE *t;
128 	recno_t top;
129 {
130 	DBT data;
131 	recno_t nrec;
132 	size_t len;
133 	int ch;
134 	u_char *p;
135 
136 	if (t->bt_rdata.size < t->bt_reclen) {
137 		t->bt_rdata.data = t->bt_rdata.data == NULL ?
138 		    malloc(t->bt_reclen) :
139 		    reallocf(t->bt_rdata.data, t->bt_reclen);
140 		if (t->bt_rdata.data == NULL)
141 			return (RET_ERROR);
142 		t->bt_rdata.size = t->bt_reclen;
143 	}
144 	data.data = t->bt_rdata.data;
145 	data.size = t->bt_reclen;
146 
147 	for (nrec = t->bt_nrecs; nrec < top;) {
148 		len = t->bt_reclen;
149 		for (p = t->bt_rdata.data;; *p++ = ch)
150 			if ((ch = getc(t->bt_rfp)) == EOF || !--len) {
151 				if (ch != EOF)
152 					*p = ch;
153 				if (len != 0)
154 					memset(p, t->bt_bval, len);
155 				if (__rec_iput(t,
156 				    nrec, &data, 0) != RET_SUCCESS)
157 					return (RET_ERROR);
158 				++nrec;
159 				break;
160 			}
161 		if (ch == EOF)
162 			break;
163 	}
164 	if (nrec < top) {
165 		F_SET(t, R_EOF);
166 		return (RET_SPECIAL);
167 	}
168 	return (RET_SUCCESS);
169 }
170 
171 /*
172  * __REC_VPIPE -- Get variable length records from a pipe.
173  *
174  * Parameters:
175  *	t:	tree
176  *	cnt:	records to read
177  *
178  * Returns:
179  *	RET_ERROR, RET_SUCCESS
180  */
181 int
182 __rec_vpipe(t, top)
183 	BTREE *t;
184 	recno_t top;
185 {
186 	DBT data;
187 	recno_t nrec;
188 	size_t len;
189 	size_t sz;
190 	int bval, ch;
191 	u_char *p;
192 
193 	bval = t->bt_bval;
194 	for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
195 		for (p = t->bt_rdata.data,
196 		    sz = t->bt_rdata.size;; *p++ = ch, --sz) {
197 			if ((ch = getc(t->bt_rfp)) == EOF || ch == bval) {
198 				data.data = t->bt_rdata.data;
199 				data.size = p - (u_char *)t->bt_rdata.data;
200 				if (ch == EOF && data.size == 0)
201 					break;
202 				if (__rec_iput(t, nrec, &data, 0)
203 				    != RET_SUCCESS)
204 					return (RET_ERROR);
205 				break;
206 			}
207 			if (sz == 0) {
208 				len = p - (u_char *)t->bt_rdata.data;
209 				t->bt_rdata.size += (sz = 256);
210 				t->bt_rdata.data = t->bt_rdata.data == NULL ?
211 				    malloc(t->bt_rdata.size) :
212 				    reallocf(t->bt_rdata.data, t->bt_rdata.size);
213 				if (t->bt_rdata.data == NULL)
214 					return (RET_ERROR);
215 				p = (u_char *)t->bt_rdata.data + len;
216 			}
217 		}
218 		if (ch == EOF)
219 			break;
220 	}
221 	if (nrec < top) {
222 		F_SET(t, R_EOF);
223 		return (RET_SPECIAL);
224 	}
225 	return (RET_SUCCESS);
226 }
227 
228 /*
229  * __REC_FMAP -- Get fixed length records from a file.
230  *
231  * Parameters:
232  *	t:	tree
233  *	cnt:	records to read
234  *
235  * Returns:
236  *	RET_ERROR, RET_SUCCESS
237  */
238 int
239 __rec_fmap(t, top)
240 	BTREE *t;
241 	recno_t top;
242 {
243 	DBT data;
244 	recno_t nrec;
245 	u_char *sp, *ep, *p;
246 	size_t len;
247 
248 	if (t->bt_rdata.size < t->bt_reclen) {
249 		t->bt_rdata.data = t->bt_rdata.data == NULL ?
250 		    malloc(t->bt_reclen) :
251 		    reallocf(t->bt_rdata.data, t->bt_reclen);
252 		if (t->bt_rdata.data == NULL)
253 			return (RET_ERROR);
254 		t->bt_rdata.size = t->bt_reclen;
255 	}
256 	data.data = t->bt_rdata.data;
257 	data.size = t->bt_reclen;
258 
259 	sp = (u_char *)t->bt_cmap;
260 	ep = (u_char *)t->bt_emap;
261 	for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
262 		if (sp >= ep) {
263 			F_SET(t, R_EOF);
264 			return (RET_SPECIAL);
265 		}
266 		len = t->bt_reclen;
267 		for (p = t->bt_rdata.data;
268 		    sp < ep && len > 0; *p++ = *sp++, --len);
269 		if (len != 0)
270 			memset(p, t->bt_bval, len);
271 		if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
272 			return (RET_ERROR);
273 	}
274 	t->bt_cmap = (caddr_t)sp;
275 	return (RET_SUCCESS);
276 }
277 
278 /*
279  * __REC_VMAP -- Get variable length records from a file.
280  *
281  * Parameters:
282  *	t:	tree
283  *	cnt:	records to read
284  *
285  * Returns:
286  *	RET_ERROR, RET_SUCCESS
287  */
288 int
289 __rec_vmap(t, top)
290 	BTREE *t;
291 	recno_t top;
292 {
293 	DBT data;
294 	u_char *sp, *ep;
295 	recno_t nrec;
296 	int bval;
297 
298 	sp = (u_char *)t->bt_cmap;
299 	ep = (u_char *)t->bt_emap;
300 	bval = t->bt_bval;
301 
302 	for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
303 		if (sp >= ep) {
304 			F_SET(t, R_EOF);
305 			return (RET_SPECIAL);
306 		}
307 		for (data.data = sp; sp < ep && *sp != bval; ++sp);
308 		data.size = sp - (u_char *)data.data;
309 		if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
310 			return (RET_ERROR);
311 		++sp;
312 	}
313 	t->bt_cmap = (caddr_t)sp;
314 	return (RET_SUCCESS);
315 }
316