xref: /dragonfly/lib/libc/db/recno/rec_get.c (revision abd448c3)
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  * @(#)rec_get.c	8.9 (Berkeley) 8/18/94
30  * $FreeBSD: head/lib/libc/db/recno/rec_get.c 189387 2009-03-05 00:57:01Z delphij $
31  */
32 
33 #include <sys/types.h>
34 
35 #include <errno.h>
36 #include <stddef.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <unistd.h>
41 
42 #include <db.h>
43 #include "recno.h"
44 
45 /*
46  * __REC_GET -- Get a record from the btree.
47  *
48  * Parameters:
49  *	dbp:	pointer to access method
50  *	key:	key to find
51  *	data:	data to return
52  *	flag:	currently unused
53  *
54  * Returns:
55  *	RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
56  */
57 int
__rec_get(const DB * dbp,const DBT * key,DBT * data,unsigned int flags)58 __rec_get(const DB *dbp, const DBT *key, DBT *data, unsigned int flags)
59 {
60 	BTREE *t;
61 	EPG *e;
62 	recno_t nrec;
63 	int status;
64 
65 	t = dbp->internal;
66 
67 	/* Toss any page pinned across calls. */
68 	if (t->bt_pinned != NULL) {
69 		mpool_put(t->bt_mp, t->bt_pinned, 0);
70 		t->bt_pinned = NULL;
71 	}
72 
73 	/* Get currently doesn't take any flags, and keys of 0 are illegal. */
74 	if (flags || (nrec = *(recno_t *)key->data) == 0) {
75 		errno = EINVAL;
76 		return (RET_ERROR);
77 	}
78 
79 	/*
80 	 * If we haven't seen this record yet, try to find it in the
81 	 * original file.
82 	 */
83 	if (nrec > t->bt_nrecs) {
84 		if (F_ISSET(t, R_EOF | R_INMEM))
85 			return (RET_SPECIAL);
86 		if ((status = t->bt_irec(t, nrec)) != RET_SUCCESS)
87 			return (status);
88 	}
89 
90 	--nrec;
91 	if ((e = __rec_search(t, nrec, SEARCH)) == NULL)
92 		return (RET_ERROR);
93 
94 	status = __rec_ret(t, e, 0, NULL, data);
95 	if (F_ISSET(t, B_DB_LOCK))
96 		mpool_put(t->bt_mp, e->page, 0);
97 	else
98 		t->bt_pinned = e->page;
99 	return (status);
100 }
101 
102 /*
103  * __REC_FPIPE -- Get fixed length records from a pipe.
104  *
105  * Parameters:
106  *	t:	tree
107  *	cnt:	records to read
108  *
109  * Returns:
110  *	RET_ERROR, RET_SUCCESS
111  */
112 int
__rec_fpipe(BTREE * t,recno_t top)113 __rec_fpipe(BTREE *t, recno_t top)
114 {
115 	DBT data;
116 	recno_t nrec;
117 	size_t len;
118 	int ch;
119 	unsigned char *p;
120 
121 	if (t->bt_rdata.size < t->bt_reclen) {
122 		t->bt_rdata.data = reallocf(t->bt_rdata.data, t->bt_reclen);
123 		if (t->bt_rdata.data == NULL)
124 			return (RET_ERROR);
125 		t->bt_rdata.size = t->bt_reclen;
126 	}
127 	data.data = t->bt_rdata.data;
128 	data.size = t->bt_reclen;
129 
130 	for (nrec = t->bt_nrecs; nrec < top;) {
131 		len = t->bt_reclen;
132 		for (p = t->bt_rdata.data;; *p++ = ch)
133 			if ((ch = getc(t->bt_rfp)) == EOF || !--len) {
134 				if (ch != EOF)
135 					*p = ch;
136 				if (len != 0)
137 					memset(p, t->bt_bval, len);
138 				if (__rec_iput(t,
139 				    nrec, &data, 0) != RET_SUCCESS)
140 					return (RET_ERROR);
141 				++nrec;
142 				break;
143 			}
144 		if (ch == EOF)
145 			break;
146 	}
147 	if (nrec < top) {
148 		F_SET(t, R_EOF);
149 		return (RET_SPECIAL);
150 	}
151 	return (RET_SUCCESS);
152 }
153 
154 /*
155  * __REC_VPIPE -- Get variable length records from a pipe.
156  *
157  * Parameters:
158  *	t:	tree
159  *	cnt:	records to read
160  *
161  * Returns:
162  *	RET_ERROR, RET_SUCCESS
163  */
164 int
__rec_vpipe(BTREE * t,recno_t top)165 __rec_vpipe(BTREE *t, recno_t top)
166 {
167 	DBT data;
168 	recno_t nrec;
169 	size_t len;
170 	size_t sz;
171 	int bval, ch;
172 	unsigned char *p;
173 
174 	bval = t->bt_bval;
175 	for (nrec = t->bt_nrecs; nrec < top; ++nrec) {
176 		for (p = t->bt_rdata.data,
177 		    sz = t->bt_rdata.size;; *p++ = ch, --sz) {
178 			if ((ch = getc(t->bt_rfp)) == EOF || ch == bval) {
179 				data.data = t->bt_rdata.data;
180 				data.size = p -
181 				    (unsigned char *)t->bt_rdata.data;
182 				if (ch == EOF && data.size == 0)
183 					break;
184 				if (__rec_iput(t, nrec, &data, 0)
185 				    != RET_SUCCESS)
186 					return (RET_ERROR);
187 				break;
188 			}
189 			if (sz == 0) {
190 				len = p - (unsigned char *)t->bt_rdata.data;
191 				t->bt_rdata.size += (sz = 256);
192 				t->bt_rdata.data = reallocf(t->bt_rdata.data,
193 				    t->bt_rdata.size);
194 				if (t->bt_rdata.data == NULL)
195 					return (RET_ERROR);
196 				p = (unsigned 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
__rec_fmap(BTREE * t,recno_t top)220 __rec_fmap(BTREE *t, recno_t top)
221 {
222 	DBT data;
223 	recno_t nrec;
224 	unsigned 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 = (unsigned char *)t->bt_cmap;
237 	ep = (unsigned 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
__rec_vmap(BTREE * t,recno_t top)266 __rec_vmap(BTREE *t, recno_t top)
267 {
268 	DBT data;
269 	unsigned char *sp, *ep;
270 	recno_t nrec;
271 	int bval;
272 
273 	sp = (unsigned char *)t->bt_cmap;
274 	ep = (unsigned 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 - (unsigned 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