1 /*- 2 * Copyright (c) 1990, 1993, 1994 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. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)rec_open.c 8.10 (Berkeley) 9/1/94 33 * $FreeBSD: src/lib/libc/db/recno/rec_open.c,v 1.4 2000/01/27 23:06:11 jasone Exp $ 34 * $DragonFly: src/lib/libc/db/recno/rec_open.c,v 1.6 2005/11/19 20:46:32 swildner Exp $ 35 */ 36 37 #include "namespace.h" 38 #include <sys/types.h> 39 #include <sys/mman.h> 40 #include <sys/stat.h> 41 42 #include <errno.h> 43 #include <fcntl.h> 44 #include <limits.h> 45 #include <stddef.h> 46 #include <stdio.h> 47 #include <unistd.h> 48 #include "un-namespace.h" 49 50 #include <db.h> 51 #include "recno.h" 52 53 DB * 54 __rec_open(const char *fname, int flags, int mode, const RECNOINFO *openinfo, 55 int dflags) 56 { 57 BTREE *t; 58 BTREEINFO btopeninfo; 59 DB *dbp; 60 PAGE *h; 61 struct stat sb; 62 int rfd, sverrno; 63 64 rfd = 0; 65 66 /* Open the user's file -- if this fails, we're done. */ 67 if (fname != NULL && (rfd = _open(fname, flags, mode)) < 0) 68 return (NULL); 69 70 /* Create a btree in memory (backed by disk). */ 71 dbp = NULL; 72 if (openinfo) { 73 if (openinfo->flags & ~(R_FIXEDLEN | R_NOKEY | R_SNAPSHOT)) 74 goto einval; 75 btopeninfo.flags = 0; 76 btopeninfo.cachesize = openinfo->cachesize; 77 btopeninfo.maxkeypage = 0; 78 btopeninfo.minkeypage = 0; 79 btopeninfo.psize = openinfo->psize; 80 btopeninfo.compare = NULL; 81 btopeninfo.prefix = NULL; 82 btopeninfo.lorder = openinfo->lorder; 83 dbp = __bt_open(openinfo->bfname, 84 O_RDWR, S_IRUSR | S_IWUSR, &btopeninfo, dflags); 85 } else 86 dbp = __bt_open(NULL, O_RDWR, S_IRUSR | S_IWUSR, NULL, dflags); 87 if (dbp == NULL) 88 goto err; 89 90 /* 91 * Some fields in the tree structure are recno specific. Fill them 92 * in and make the btree structure look like a recno structure. We 93 * don't change the bt_ovflsize value, it's close enough and slightly 94 * bigger. 95 */ 96 t = dbp->internal; 97 if (openinfo) { 98 if (openinfo->flags & R_FIXEDLEN) { 99 F_SET(t, R_FIXLEN); 100 t->bt_reclen = openinfo->reclen; 101 if (t->bt_reclen == 0) 102 goto einval; 103 } 104 t->bt_bval = openinfo->bval; 105 } else 106 t->bt_bval = '\n'; 107 108 F_SET(t, R_RECNO); 109 if (fname == NULL) 110 F_SET(t, R_EOF | R_INMEM); 111 else 112 t->bt_rfd = rfd; 113 114 if (fname != NULL) { 115 /* 116 * In 4.4BSD, stat(2) returns true for ISSOCK on pipes. 117 * Unfortunately, that's not portable, so we use lseek 118 * and check the errno values. 119 */ 120 errno = 0; 121 if (lseek(rfd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) { 122 switch (flags & O_ACCMODE) { 123 case O_RDONLY: 124 F_SET(t, R_RDONLY); 125 break; 126 default: 127 goto einval; 128 } 129 slow: if ((t->bt_rfp = fdopen(rfd, "r")) == NULL) 130 goto err; 131 F_SET(t, R_CLOSEFP); 132 t->bt_irec = 133 F_ISSET(t, R_FIXLEN) ? __rec_fpipe : __rec_vpipe; 134 } else { 135 switch (flags & O_ACCMODE) { 136 case O_RDONLY: 137 F_SET(t, R_RDONLY); 138 break; 139 case O_RDWR: 140 break; 141 default: 142 goto einval; 143 } 144 145 if (_fstat(rfd, &sb)) 146 goto err; 147 /* 148 * Kluge -- we'd like to test to see if the file is too 149 * big to mmap. Since, we don't know what size or type 150 * off_t's or size_t's are, what the largest unsigned 151 * integral type is, or what random insanity the local 152 * C compiler will perpetrate, doing the comparison in 153 * a portable way is flatly impossible. Hope that mmap 154 * fails if the file is too large. 155 */ 156 if (sb.st_size == 0) 157 F_SET(t, R_EOF); 158 else { 159 #ifdef MMAP_NOT_AVAILABLE 160 /* 161 * XXX 162 * Mmap doesn't work correctly on many current 163 * systems. In particular, it can fail subtly, 164 * with cache coherency problems. Don't use it 165 * for now. 166 */ 167 t->bt_msize = sb.st_size; 168 if ((t->bt_smap = mmap(NULL, t->bt_msize, 169 PROT_READ, MAP_PRIVATE, rfd, 170 (off_t)0)) == MAP_FAILED) 171 goto slow; 172 t->bt_cmap = t->bt_smap; 173 t->bt_emap = t->bt_smap + sb.st_size; 174 t->bt_irec = F_ISSET(t, R_FIXLEN) ? 175 __rec_fmap : __rec_vmap; 176 F_SET(t, R_MEMMAPPED); 177 #else 178 goto slow; 179 #endif 180 } 181 } 182 } 183 184 /* Use the recno routines. */ 185 dbp->close = __rec_close; 186 dbp->del = __rec_delete; 187 dbp->fd = __rec_fd; 188 dbp->get = __rec_get; 189 dbp->put = __rec_put; 190 dbp->seq = __rec_seq; 191 dbp->sync = __rec_sync; 192 193 /* If the root page was created, reset the flags. */ 194 if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL) 195 goto err; 196 if ((h->flags & P_TYPE) == P_BLEAF) { 197 F_CLR(h, P_TYPE); 198 F_SET(h, P_RLEAF); 199 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 200 } else 201 mpool_put(t->bt_mp, h, 0); 202 203 if (openinfo && openinfo->flags & R_SNAPSHOT && 204 !F_ISSET(t, R_EOF | R_INMEM) && 205 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR) 206 goto err; 207 return (dbp); 208 209 einval: errno = EINVAL; 210 err: sverrno = errno; 211 if (dbp != NULL) 212 __bt_close(dbp); 213 if (fname != NULL) 214 _close(rfd); 215 errno = sverrno; 216 return (NULL); 217 } 218 219 int 220 __rec_fd(const DB *dbp) 221 { 222 BTREE *t; 223 224 t = dbp->internal; 225 226 /* Toss any page pinned across calls. */ 227 if (t->bt_pinned != NULL) { 228 mpool_put(t->bt_mp, t->bt_pinned, 0); 229 t->bt_pinned = NULL; 230 } 231 232 /* In-memory database can't have a file descriptor. */ 233 if (F_ISSET(t, R_INMEM)) { 234 errno = ENOENT; 235 return (-1); 236 } 237 return (t->bt_rfd); 238 } 239