xref: /freebsd/lib/libc/db/recno/rec_get.c (revision ca987d4641cdcd7f27e153db17c5bf064934faf5)
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 
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static char sccsid[] = "@(#)rec_get.c	8.9 (Berkeley) 8/18/94";
32 #endif /* LIBC_SCCS and not lint */
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include <sys/types.h>
37 
38 #include <errno.h>
39 #include <stddef.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <unistd.h>
44 
45 #include <db.h>
46 #include "recno.h"
47 
48 /*
49  * __REC_GET -- Get a record from the btree.
50  *
51  * Parameters:
52  *	dbp:	pointer to access method
53  *	key:	key to find
54  *	data:	data to return
55  *	flag:	currently unused
56  *
57  * Returns:
58  *	RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
59  */
60 int
61 __rec_get(const DB *dbp, const DBT *key, DBT *data, u_int flags)
62 {
63 	BTREE *t;
64 	EPG *e;
65 	recno_t nrec;
66 	int status;
67 
68 	t = dbp->internal;
69 
70 	/* Toss any page pinned across calls. */
71 	if (t->bt_pinned != NULL) {
72 		mpool_put(t->bt_mp, t->bt_pinned, 0);
73 		t->bt_pinned = NULL;
74 	}
75 
76 	/* Get currently doesn't take any flags, and keys of 0 are illegal. */
77 	if (flags || (nrec = *(recno_t *)key->data) == 0) {
78 		errno = EINVAL;
79 		return (RET_ERROR);
80 	}
81 
82 	/*
83 	 * If we haven't seen this record yet, try to find it in the
84 	 * original file.
85 	 */
86 	if (nrec > t->bt_nrecs) {
87 		if (F_ISSET(t, R_EOF | R_INMEM))
88 			return (RET_SPECIAL);
89 		if ((status = t->bt_irec(t, nrec)) != RET_SUCCESS)
90 			return (status);
91 	}
92 
93 	--nrec;
94 	if ((e = __rec_search(t, nrec, SEARCH)) == NULL)
95 		return (RET_ERROR);
96 
97 	status = __rec_ret(t, e, 0, NULL, data);
98 	if (F_ISSET(t, B_DB_LOCK))
99 		mpool_put(t->bt_mp, e->page, 0);
100 	else
101 		t->bt_pinned = e->page;
102 	return (status);
103 }
104 
105 /*
106  * __REC_FPIPE -- Get fixed length records from a pipe.
107  *
108  * Parameters:
109  *	t:	tree
110  *	cnt:	records to read
111  *
112  * Returns:
113  *	RET_ERROR, RET_SUCCESS
114  */
115 int
116 __rec_fpipe(BTREE *t, recno_t top)
117 {
118 	DBT data;
119 	recno_t nrec;
120 	size_t len;
121 	int ch;
122 	u_char *p;
123 
124 	if (t->bt_rdata.size < t->bt_reclen) {
125 		t->bt_rdata.data = reallocf(t->bt_rdata.data, t->bt_reclen);
126 		if (t->bt_rdata.data == NULL)
127 			return (RET_ERROR);
128 		t->bt_rdata.size = t->bt_reclen;
129 	}
130 	data.data = t->bt_rdata.data;
131 	data.size = t->bt_reclen;
132 
133 	for (nrec = t->bt_nrecs; nrec < top;) {
134 		len = t->bt_reclen;
135 		for (p = t->bt_rdata.data;; *p++ = ch)
136 			if ((ch = getc(t->bt_rfp)) == EOF || !--len) {
137 				if (ch != EOF)
138 					*p = ch;
139 				if (len != 0)
140 					memset(p, t->bt_bval, len);
141 				if (__rec_iput(t,
142 				    nrec, &data, 0) != RET_SUCCESS)
143 					return (RET_ERROR);
144 				++nrec;
145 				break;
146 			}
147 		if (ch == EOF)
148 			break;
149 	}
150 	if (nrec < top) {
151 		F_SET(t, R_EOF);
152 		return (RET_SPECIAL);
153 	}
154 	return (RET_SUCCESS);
155 }
156 
157 /*
158  * __REC_VPIPE -- Get variable length records from a pipe.
159  *
160  * Parameters:
161  *	t:	tree
162  *	cnt:	records to read
163  *
164  * Returns:
165  *	RET_ERROR, RET_SUCCESS
166  */
167 int
168 __rec_vpipe(BTREE *t, recno_t top)
169 {
170 	DBT data;
171 	recno_t nrec;
172 	size_t len;
173 	size_t sz;
174 	int bval, ch;
175 	u_char *p;
176 
177 	bval = t->bt_bval;
178 	for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
179 		for (p = t->bt_rdata.data,
180 		    sz = t->bt_rdata.size;; *p++ = ch, --sz) {
181 			if ((ch = getc(t->bt_rfp)) == EOF || ch == bval) {
182 				data.data = t->bt_rdata.data;
183 				data.size = p - (u_char *)t->bt_rdata.data;
184 				if (ch == EOF && data.size == 0)
185 					break;
186 				if (__rec_iput(t, nrec, &data, 0)
187 				    != RET_SUCCESS)
188 					return (RET_ERROR);
189 				break;
190 			}
191 			if (sz == 0) {
192 				len = p - (u_char *)t->bt_rdata.data;
193 				t->bt_rdata.size += (sz = 256);
194 				t->bt_rdata.data = reallocf(t->bt_rdata.data, t->bt_rdata.size);
195 				if (t->bt_rdata.data == NULL)
196 					return (RET_ERROR);
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
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 
228 	if (t->bt_rdata.size < t->bt_reclen) {
229 		t->bt_rdata.data = reallocf(t->bt_rdata.data, t->bt_reclen);
230 		if (t->bt_rdata.data == NULL)
231 			return (RET_ERROR);
232 		t->bt_rdata.size = t->bt_reclen;
233 	}
234 	data.data = t->bt_rdata.data;
235 	data.size = t->bt_reclen;
236 
237 	sp = (u_char *)t->bt_cmap;
238 	ep = (u_char *)t->bt_emap;
239 	for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
240 		if (sp >= ep) {
241 			F_SET(t, R_EOF);
242 			return (RET_SPECIAL);
243 		}
244 		len = t->bt_reclen;
245 		for (p = t->bt_rdata.data;
246 		    sp < ep && len > 0; *p++ = *sp++, --len);
247 		if (len != 0)
248 			memset(p, t->bt_bval, len);
249 		if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
250 			return (RET_ERROR);
251 	}
252 	t->bt_cmap = (caddr_t)sp;
253 	return (RET_SUCCESS);
254 }
255 
256 /*
257  * __REC_VMAP -- Get variable length records from a file.
258  *
259  * Parameters:
260  *	t:	tree
261  *	cnt:	records to read
262  *
263  * Returns:
264  *	RET_ERROR, RET_SUCCESS
265  */
266 int
267 __rec_vmap(BTREE *t, recno_t top)
268 {
269 	DBT data;
270 	u_char *sp, *ep;
271 	recno_t nrec;
272 	int bval;
273 
274 	sp = (u_char *)t->bt_cmap;
275 	ep = (u_char *)t->bt_emap;
276 	bval = t->bt_bval;
277 
278 	for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
279 		if (sp >= ep) {
280 			F_SET(t, R_EOF);
281 			return (RET_SPECIAL);
282 		}
283 		for (data.data = sp; sp < ep && *sp != bval; ++sp);
284 		data.size = sp - (u_char *)data.data;
285 		if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
286 			return (RET_ERROR);
287 		++sp;
288 	}
289 	t->bt_cmap = (caddr_t)sp;
290 	return (RET_SUCCESS);
291 }
292