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: head/lib/libc/db/recno/rec_open.c 189327 2009-03-04 00:58:04Z delphij $ 34 */ 35 36 #include "namespace.h" 37 #include <sys/types.h> 38 #include <sys/mman.h> 39 #include <sys/stat.h> 40 41 #include <errno.h> 42 #include <fcntl.h> 43 #include <limits.h> 44 #include <stddef.h> 45 #include <stdio.h> 46 #include <unistd.h> 47 #include "un-namespace.h" 48 49 #include <db.h> 50 #include "recno.h" 51 52 DB * 53 __rec_open(const char *fname, int flags, mode_t mode, const RECNOINFO *openinfo, 54 int dflags) 55 { 56 BTREE *t; 57 BTREEINFO btopeninfo; 58 DB *dbp; 59 PAGE *h; 60 struct stat sb; 61 int rfd, sverrno; 62 63 /* Open the user's file -- if this fails, we're done. */ 64 if (fname != NULL && (rfd = _open(fname, flags, mode)) < 0) 65 return (NULL); 66 67 /* Create a btree in memory (backed by disk). */ 68 dbp = NULL; 69 if (openinfo) { 70 if (openinfo->flags & ~(R_FIXEDLEN | R_NOKEY | R_SNAPSHOT)) 71 goto einval; 72 btopeninfo.flags = 0; 73 btopeninfo.cachesize = openinfo->cachesize; 74 btopeninfo.maxkeypage = 0; 75 btopeninfo.minkeypage = 0; 76 btopeninfo.psize = openinfo->psize; 77 btopeninfo.compare = NULL; 78 btopeninfo.prefix = NULL; 79 btopeninfo.lorder = openinfo->lorder; 80 dbp = __bt_open(openinfo->bfname, 81 O_RDWR, S_IRUSR | S_IWUSR, &btopeninfo, dflags); 82 } else 83 dbp = __bt_open(NULL, O_RDWR, S_IRUSR | S_IWUSR, NULL, dflags); 84 if (dbp == NULL) 85 goto err; 86 87 /* 88 * Some fields in the tree structure are recno specific. Fill them 89 * in and make the btree structure look like a recno structure. We 90 * don't change the bt_ovflsize value, it's close enough and slightly 91 * bigger. 92 */ 93 t = dbp->internal; 94 if (openinfo) { 95 if (openinfo->flags & R_FIXEDLEN) { 96 F_SET(t, R_FIXLEN); 97 t->bt_reclen = openinfo->reclen; 98 if (t->bt_reclen == 0) 99 goto einval; 100 } 101 t->bt_bval = openinfo->bval; 102 } else 103 t->bt_bval = '\n'; 104 105 F_SET(t, R_RECNO); 106 if (fname == NULL) 107 F_SET(t, R_EOF | R_INMEM); 108 else 109 t->bt_rfd = rfd; 110 111 if (fname != NULL) { 112 /* 113 * In 4.4BSD, stat(2) returns true for ISSOCK on pipes. 114 * Unfortunately, that's not portable, so we use lseek 115 * and check the errno values. 116 */ 117 errno = 0; 118 if (lseek(rfd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) { 119 switch (flags & O_ACCMODE) { 120 case O_RDONLY: 121 F_SET(t, R_RDONLY); 122 break; 123 default: 124 goto einval; 125 } 126 slow: if ((t->bt_rfp = fdopen(rfd, "r")) == NULL) 127 goto err; 128 F_SET(t, R_CLOSEFP); 129 t->bt_irec = 130 F_ISSET(t, R_FIXLEN) ? __rec_fpipe : __rec_vpipe; 131 } else { 132 switch (flags & O_ACCMODE) { 133 case O_RDONLY: 134 F_SET(t, R_RDONLY); 135 break; 136 case O_RDWR: 137 break; 138 default: 139 goto einval; 140 } 141 142 if (_fstat(rfd, &sb)) 143 goto err; 144 /* 145 * Kluge -- we'd like to test to see if the file is too 146 * big to mmap. Since, we don't know what size or type 147 * off_t's or size_t's are, what the largest unsigned 148 * integral type is, or what random insanity the local 149 * C compiler will perpetrate, doing the comparison in 150 * a portable way is flatly impossible. Hope that mmap 151 * fails if the file is too large. 152 */ 153 if (sb.st_size == 0) 154 F_SET(t, R_EOF); 155 else { 156 #ifdef MMAP_NOT_AVAILABLE 157 /* 158 * XXX 159 * Mmap doesn't work correctly on many current 160 * systems. In particular, it can fail subtly, 161 * with cache coherency problems. Don't use it 162 * for now. 163 */ 164 t->bt_msize = sb.st_size; 165 if ((t->bt_smap = mmap(NULL, t->bt_msize, 166 PROT_READ, MAP_PRIVATE, rfd, 167 (off_t)0)) == MAP_FAILED) 168 goto slow; 169 t->bt_cmap = t->bt_smap; 170 t->bt_emap = t->bt_smap + sb.st_size; 171 t->bt_irec = F_ISSET(t, R_FIXLEN) ? 172 __rec_fmap : __rec_vmap; 173 F_SET(t, R_MEMMAPPED); 174 #else 175 goto slow; 176 #endif 177 } 178 } 179 } 180 181 /* Use the recno routines. */ 182 dbp->close = __rec_close; 183 dbp->del = __rec_delete; 184 dbp->fd = __rec_fd; 185 dbp->get = __rec_get; 186 dbp->put = __rec_put; 187 dbp->seq = __rec_seq; 188 dbp->sync = __rec_sync; 189 190 /* If the root page was created, reset the flags. */ 191 if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL) 192 goto err; 193 if ((h->flags & P_TYPE) == P_BLEAF) { 194 F_CLR(h, P_TYPE); 195 F_SET(h, P_RLEAF); 196 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 197 } else 198 mpool_put(t->bt_mp, h, 0); 199 200 if (openinfo && openinfo->flags & R_SNAPSHOT && 201 !F_ISSET(t, R_EOF | R_INMEM) && 202 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR) 203 goto err; 204 return (dbp); 205 206 einval: errno = EINVAL; 207 err: sverrno = errno; 208 if (dbp != NULL) 209 __bt_close(dbp); 210 if (fname != NULL) 211 _close(rfd); 212 errno = sverrno; 213 return (NULL); 214 } 215 216 int 217 __rec_fd(const DB *dbp) 218 { 219 BTREE *t; 220 221 t = dbp->internal; 222 223 /* Toss any page pinned across calls. */ 224 if (t->bt_pinned != NULL) { 225 mpool_put(t->bt_mp, t->bt_pinned, 0); 226 t->bt_pinned = NULL; 227 } 228 229 /* In-memory database can't have a file descriptor. */ 230 if (F_ISSET(t, R_INMEM)) { 231 errno = ENOENT; 232 return (-1); 233 } 234 return (t->bt_rfd); 235 } 236