rec_open.c revision 1.2
1 /*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Mike Olson. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #if defined(LIBC_SCCS) && !defined(lint) 38 /*static char sccsid[] = "from: @(#)rec_open.c 8.1 (Berkeley) 6/4/93";*/ 39 static char rcsid[] = "$Id: rec_open.c,v 1.2 1993/08/01 18:43:13 mycroft Exp $"; 40 #endif /* LIBC_SCCS and not lint */ 41 42 #include <sys/types.h> 43 #include <sys/mman.h> 44 #include <sys/stat.h> 45 46 #include <errno.h> 47 #include <fcntl.h> 48 #include <limits.h> 49 #include <stddef.h> 50 #include <stdio.h> 51 #include <unistd.h> 52 53 #include <db.h> 54 #include "recno.h" 55 56 DB * 57 __rec_open(fname, flags, mode, openinfo) 58 const char *fname; 59 int flags, mode; 60 const RECNOINFO *openinfo; 61 { 62 BTREE *t; 63 BTREEINFO btopeninfo; 64 DB *dbp; 65 PAGE *h; 66 struct stat sb; 67 int rfd, sverrno; 68 69 /* Open the user's file -- if this fails, we're done. */ 70 if (fname != NULL && (rfd = open(fname, flags, mode)) < 0) 71 return (NULL); 72 73 /* Create a btree in memory (backed by disk). */ 74 dbp = NULL; 75 if (openinfo) { 76 if (openinfo->flags & ~(R_FIXEDLEN | R_NOKEY | R_SNAPSHOT)) 77 goto einval; 78 btopeninfo.flags = 0; 79 btopeninfo.cachesize = openinfo->cachesize; 80 btopeninfo.maxkeypage = 0; 81 btopeninfo.minkeypage = 0; 82 btopeninfo.psize = openinfo->psize; 83 btopeninfo.compare = NULL; 84 btopeninfo.prefix = NULL; 85 btopeninfo.lorder = openinfo->lorder; 86 dbp = __bt_open(openinfo->bfname, 87 O_RDWR, S_IRUSR | S_IWUSR, &btopeninfo); 88 } else 89 dbp = __bt_open(NULL, O_RDWR, S_IRUSR | S_IWUSR, NULL); 90 if (dbp == NULL) 91 goto err; 92 93 /* 94 * Some fields in the tree structure are recno specific. Fill them 95 * in and make the btree structure look like a recno structure. We 96 * don't change the bt_ovflsize value, it's close enough and slightly 97 * bigger. 98 */ 99 t = dbp->internal; 100 if (openinfo) { 101 if (openinfo->flags & R_FIXEDLEN) { 102 SET(t, R_FIXLEN); 103 t->bt_reclen = openinfo->reclen; 104 if (t->bt_reclen == 0) 105 goto einval; 106 } 107 t->bt_bval = openinfo->bval; 108 } else 109 t->bt_bval = '\n'; 110 111 SET(t, R_RECNO); 112 if (fname == NULL) 113 SET(t, R_EOF | R_INMEM); 114 else 115 t->bt_rfd = rfd; 116 t->bt_rcursor = 0; 117 118 /* 119 * In 4.4BSD stat(2) returns true for ISSOCK on pipes. Until 120 * then, this is fairly close. Pipes are read-only. 121 */ 122 if (fname != NULL) { 123 if (lseek(rfd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) { 124 switch (flags & O_ACCMODE) { 125 case O_RDONLY: 126 SET(t, R_RDONLY); 127 break; 128 default: 129 goto einval; 130 } 131 slow: if ((t->bt_rfp = fdopen(rfd, "r")) == NULL) 132 goto err; 133 SET(t, R_CLOSEFP); 134 t->bt_irec = 135 ISSET(t, R_FIXLEN) ? __rec_fpipe : __rec_vpipe; 136 } else { 137 switch (flags & O_ACCMODE) { 138 case O_RDONLY: 139 SET(t, R_RDONLY); 140 break; 141 case O_RDWR: 142 break; 143 default: 144 goto einval; 145 } 146 147 if (fstat(rfd, &sb)) 148 goto err; 149 /* 150 * Kluge -- we'd like to test to see if the file is too 151 * big to mmap. Since, we don't know what size or type 152 * off_t's or size_t's are, what the largest unsigned 153 * integral type is, or what random insanity the local 154 * C compiler will perpetrate, doing the comparison in 155 * a portable way is flatly impossible. Hope that mmap 156 * fails if the file is too large. 157 */ 158 if (sb.st_size == 0) 159 SET(t, R_EOF); 160 else { 161 t->bt_msize = sb.st_size; 162 if ((t->bt_smap = 163 mmap(NULL, t->bt_msize, PROT_READ, 0, rfd, 164 (off_t)0)) == (caddr_t)-1) 165 goto slow; 166 t->bt_cmap = t->bt_smap; 167 t->bt_emap = t->bt_smap + sb.st_size; 168 t->bt_irec = ISSET(t, R_FIXLEN) ? 169 __rec_fmap : __rec_vmap; 170 SET(t, R_MEMMAPPED); 171 } 172 } 173 } 174 175 /* Use the recno routines. */ 176 dbp->close = __rec_close; 177 dbp->del = __rec_delete; 178 dbp->fd = __rec_fd; 179 dbp->get = __rec_get; 180 dbp->put = __rec_put; 181 dbp->seq = __rec_seq; 182 dbp->sync = __rec_sync; 183 184 /* If the root page was created, reset the flags. */ 185 if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL) 186 goto err; 187 if ((h->flags & P_TYPE) == P_BLEAF) { 188 h->flags = h->flags & ~P_TYPE | P_RLEAF; 189 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 190 } else 191 mpool_put(t->bt_mp, h, 0); 192 193 if (openinfo && openinfo->flags & R_SNAPSHOT && 194 !ISSET(t, R_EOF | R_INMEM) && 195 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR) 196 goto err; 197 return (dbp); 198 199 einval: errno = EINVAL; 200 err: sverrno = errno; 201 if (dbp != NULL) 202 (void)__bt_close(dbp); 203 if (fname != NULL) 204 (void)close(rfd); 205 errno = sverrno; 206 return (NULL); 207 } 208 209 int 210 __rec_fd(dbp) 211 const DB *dbp; 212 { 213 BTREE *t; 214 215 t = dbp->internal; 216 217 if (ISSET(t, R_INMEM)) { 218 errno = ENOENT; 219 return (-1); 220 } 221 return (t->bt_rfd); 222 } 223
Indexes created Sat Oct 11 19:10:01 GMT 2025