xref: /netbsd-src/lib/libc/db/recno/rec_get.c (revision 76dfffe33547c37f8bdd446e3e4ab0f3c16cea4b)
1 /*	$NetBSD: rec_get.c,v 1.8 1996/05/03 21:38:48 cgd 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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #if defined(LIBC_SCCS) && !defined(lint)
37 #if 0
38 static char sccsid[] = "@(#)rec_get.c	8.9 (Berkeley) 8/18/94";
39 #else
40 static char rcsid[] = "$NetBSD: rec_get.c,v 1.8 1996/05/03 21:38:48 cgd Exp $";
41 #endif
42 #endif /* LIBC_SCCS and not lint */
43 
44 #include <sys/types.h>
45 
46 #include <errno.h>
47 #include <stddef.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 
53 #include <db.h>
54 #include "recno.h"
55 
56 /*
57  * __REC_GET -- Get a record from the btree.
58  *
59  * Parameters:
60  *	dbp:	pointer to access method
61  *	key:	key to find
62  *	data:	data to return
63  *	flag:	currently unused
64  *
65  * Returns:
66  *	RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
67  */
68 int
69 __rec_get(dbp, key, data, flags)
70 	const DB *dbp;
71 	const DBT *key;
72 	DBT *data;
73 	u_int flags;
74 {
75 	BTREE *t;
76 	EPG *e;
77 	recno_t nrec;
78 	int status;
79 
80 	t = dbp->internal;
81 
82 	/* Toss any page pinned across calls. */
83 	if (t->bt_pinned != NULL) {
84 		mpool_put(t->bt_mp, t->bt_pinned, 0);
85 		t->bt_pinned = NULL;
86 	}
87 
88 	/* Get currently doesn't take any flags, and keys of 0 are illegal. */
89 	if (flags || (nrec = *(recno_t *)key->data) == 0) {
90 		errno = EINVAL;
91 		return (RET_ERROR);
92 	}
93 
94 	/*
95 	 * If we haven't seen this record yet, try to find it in the
96 	 * original file.
97 	 */
98 	if (nrec > t->bt_nrecs) {
99 		if (F_ISSET(t, R_EOF | R_INMEM))
100 			return (RET_SPECIAL);
101 		if ((status = t->bt_irec(t, nrec)) != RET_SUCCESS)
102 			return (status);
103 	}
104 
105 	--nrec;
106 	if ((e = __rec_search(t, nrec, SEARCH)) == NULL)
107 		return (RET_ERROR);
108 
109 	status = __rec_ret(t, e, 0, NULL, data);
110 	if (F_ISSET(t, B_DB_LOCK))
111 		mpool_put(t->bt_mp, e->page, 0);
112 	else
113 		t->bt_pinned = e->page;
114 	return (status);
115 }
116 
117 /*
118  * __REC_FPIPE -- Get fixed length records from a pipe.
119  *
120  * Parameters:
121  *	t:	tree
122  *	cnt:	records to read
123  *
124  * Returns:
125  *	RET_ERROR, RET_SUCCESS
126  */
127 int
128 __rec_fpipe(t, top)
129 	BTREE *t;
130 	recno_t top;
131 {
132 	DBT data;
133 	recno_t nrec;
134 	size_t len;
135 	int ch;
136 	u_char *p;
137 
138 	if (t->bt_rdata.size < t->bt_reclen) {
139 		t->bt_rdata.data = t->bt_rdata.data == NULL ?
140 		    malloc(t->bt_reclen) :
141 		    realloc(t->bt_rdata.data, t->bt_reclen);
142 		if (t->bt_rdata.data == NULL)
143 			return (RET_ERROR);
144 		t->bt_rdata.size = t->bt_reclen;
145 	}
146 	data.data = t->bt_rdata.data;
147 	data.size = t->bt_reclen;
148 
149 	for (nrec = t->bt_nrecs; nrec < top;) {
150 		len = t->bt_reclen;
151 		for (p = t->bt_rdata.data;; *p++ = ch)
152 			if ((ch = getc(t->bt_rfp)) == EOF || !--len) {
153 				if (ch != EOF)
154 					*p = ch;
155 				if (len != 0)
156 					memset(p, t->bt_bval, len);
157 				if (__rec_iput(t,
158 				    nrec, &data, 0) != RET_SUCCESS)
159 					return (RET_ERROR);
160 				++nrec;
161 				break;
162 			}
163 		if (ch == EOF)
164 			break;
165 	}
166 	if (nrec < top) {
167 		F_SET(t, R_EOF);
168 		return (RET_SPECIAL);
169 	}
170 	return (RET_SUCCESS);
171 }
172 
173 /*
174  * __REC_VPIPE -- Get variable length records from a pipe.
175  *
176  * Parameters:
177  *	t:	tree
178  *	cnt:	records to read
179  *
180  * Returns:
181  *	RET_ERROR, RET_SUCCESS
182  */
183 int
184 __rec_vpipe(t, top)
185 	BTREE *t;
186 	recno_t top;
187 {
188 	DBT data;
189 	recno_t nrec;
190 	indx_t len;
191 	size_t sz;
192 	int bval, ch;
193 	u_char *p;
194 
195 	bval = t->bt_bval;
196 	for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
197 		for (p = t->bt_rdata.data,
198 		    sz = t->bt_rdata.size;; *p++ = ch, --sz) {
199 			if ((ch = getc(t->bt_rfp)) == EOF || ch == bval) {
200 				data.data = t->bt_rdata.data;
201 				data.size = p - (u_char *)t->bt_rdata.data;
202 				if (ch == EOF && data.size == 0)
203 					break;
204 				if (__rec_iput(t, nrec, &data, 0)
205 				    != RET_SUCCESS)
206 					return (RET_ERROR);
207 				break;
208 			}
209 			if (sz == 0) {
210 				len = p - (u_char *)t->bt_rdata.data;
211 				t->bt_rdata.size += (sz = 256);
212 				t->bt_rdata.data = t->bt_rdata.data == NULL ?
213 				    malloc(t->bt_rdata.size) :
214 				    realloc(t->bt_rdata.data, t->bt_rdata.size);
215 				if (t->bt_rdata.data == NULL)
216 					return (RET_ERROR);
217 				p = (u_char *)t->bt_rdata.data + len;
218 			}
219 		}
220 		if (ch == EOF)
221 			break;
222 	}
223 	if (nrec < top) {
224 		F_SET(t, R_EOF);
225 		return (RET_SPECIAL);
226 	}
227 	return (RET_SUCCESS);
228 }
229 
230 /*
231  * __REC_FMAP -- Get fixed length records from a file.
232  *
233  * Parameters:
234  *	t:	tree
235  *	cnt:	records to read
236  *
237  * Returns:
238  *	RET_ERROR, RET_SUCCESS
239  */
240 int
241 __rec_fmap(t, top)
242 	BTREE *t;
243 	recno_t top;
244 {
245 	DBT data;
246 	recno_t nrec;
247 	u_char *sp, *ep, *p;
248 	size_t len;
249 
250 	if (t->bt_rdata.size < t->bt_reclen) {
251 		t->bt_rdata.data = t->bt_rdata.data == NULL ?
252 		    malloc(t->bt_reclen) :
253 		    realloc(t->bt_rdata.data, t->bt_reclen);
254 		if (t->bt_rdata.data == NULL)
255 			return (RET_ERROR);
256 		t->bt_rdata.size = t->bt_reclen;
257 	}
258 	data.data = t->bt_rdata.data;
259 	data.size = t->bt_reclen;
260 
261 	sp = (u_char *)t->bt_cmap;
262 	ep = (u_char *)t->bt_emap;
263 	for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
264 		if (sp >= ep) {
265 			F_SET(t, R_EOF);
266 			return (RET_SPECIAL);
267 		}
268 		len = t->bt_reclen;
269 		for (p = t->bt_rdata.data;
270 		    sp < ep && len > 0; *p++ = *sp++, --len);
271 		if (len != 0)
272 			memset(p, t->bt_bval, len);
273 		if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
274 			return (RET_ERROR);
275 	}
276 	t->bt_cmap = (caddr_t)sp;
277 	return (RET_SUCCESS);
278 }
279 
280 /*
281  * __REC_VMAP -- Get variable length records from a file.
282  *
283  * Parameters:
284  *	t:	tree
285  *	cnt:	records to read
286  *
287  * Returns:
288  *	RET_ERROR, RET_SUCCESS
289  */
290 int
291 __rec_vmap(t, top)
292 	BTREE *t;
293 	recno_t top;
294 {
295 	DBT data;
296 	u_char *sp, *ep;
297 	recno_t nrec;
298 	int bval;
299 
300 	sp = (u_char *)t->bt_cmap;
301 	ep = (u_char *)t->bt_emap;
302 	bval = t->bt_bval;
303 
304 	for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
305 		if (sp >= ep) {
306 			F_SET(t, R_EOF);
307 			return (RET_SPECIAL);
308 		}
309 		for (data.data = sp; sp < ep && *sp != bval; ++sp);
310 		data.size = sp - (u_char *)data.data;
311 		if (__rec_iput(t, nrec, &data, 0) != RET_SUCCESS)
312 			return (RET_ERROR);
313 		++sp;
314 	}
315 	t->bt_cmap = (caddr_t)sp;
316 	return (RET_SUCCESS);
317 }
318