rec_open.c revision 1.16
1 /* $NetBSD: rec_open.c,v 1.16 2008/09/10 17:52:36 joerg Exp $ */ 2 3 /*- 4 * Copyright (c) 1990, 1993, 1994 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Mike Olson. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 __RCSID("$NetBSD: rec_open.c,v 1.16 2008/09/10 17:52:36 joerg Exp $"); 37 38 #include "namespace.h" 39 #include <sys/types.h> 40 #include <sys/mman.h> 41 #include <sys/stat.h> 42 43 #include <assert.h> 44 #include <errno.h> 45 #include <fcntl.h> 46 #include <limits.h> 47 #include <stddef.h> 48 #include <stdio.h> 49 #include <unistd.h> 50 51 #include <db.h> 52 #include "recno.h" 53 54 DB * 55 __rec_open(const char *fname, int flags, mode_t mode, const RECNOINFO *openinfo, 56 int dflags) 57 { 58 BTREE *t; 59 BTREEINFO btopeninfo; 60 DB *dbp; 61 PAGE *h; 62 struct stat sb; 63 int rfd = -1; /* pacify gcc */ 64 int sverrno; 65 66 dbp = NULL; 67 /* Open the user's file -- if this fails, we're done. */ 68 if (fname != NULL) { 69 if ((rfd = open(fname, flags, mode)) == -1) 70 return (NULL); 71 if (fcntl(rfd, F_SETFD, FD_CLOEXEC) == -1) 72 goto err; 73 } 74 75 /* Create a btree in memory (backed by disk). */ 76 if (openinfo) { 77 if (openinfo->flags & ~(R_FIXEDLEN | R_NOKEY | R_SNAPSHOT)) 78 goto einval; 79 btopeninfo.flags = 0; 80 btopeninfo.cachesize = openinfo->cachesize; 81 btopeninfo.maxkeypage = 0; 82 btopeninfo.minkeypage = 0; 83 btopeninfo.psize = openinfo->psize; 84 btopeninfo.compare = NULL; 85 btopeninfo.prefix = NULL; 86 btopeninfo.lorder = openinfo->lorder; 87 dbp = __bt_open(openinfo->bfname, 88 O_RDWR, S_IRUSR | S_IWUSR, &btopeninfo, dflags); 89 } else 90 dbp = __bt_open(NULL, O_RDWR, S_IRUSR | S_IWUSR, NULL, dflags); 91 if (dbp == NULL) 92 goto err; 93 94 /* 95 * Some fields in the tree structure are recno specific. Fill them 96 * in and make the btree structure look like a recno structure. We 97 * don't change the bt_ovflsize value, it's close enough and slightly 98 * bigger. 99 */ 100 t = dbp->internal; 101 if (openinfo) { 102 if (openinfo->flags & R_FIXEDLEN) { 103 F_SET(t, R_FIXLEN); 104 t->bt_reclen = openinfo->reclen; 105 if (t->bt_reclen == 0) 106 goto einval; 107 } 108 t->bt_bval = openinfo->bval; 109 } else 110 t->bt_bval = '\n'; 111 112 F_SET(t, R_RECNO); 113 if (fname == NULL) 114 F_SET(t, R_EOF | R_INMEM); 115 else 116 t->bt_rfd = rfd; 117 118 if (fname != NULL) { 119 /* 120 * In 4.4BSD, stat(2) returns true for ISSOCK on pipes. 121 * Unfortunately, that's not portable, so we use lseek 122 * and check the errno values. 123 */ 124 errno = 0; 125 if (lseek(rfd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) { 126 switch (flags & O_ACCMODE) { 127 case O_RDONLY: 128 F_SET(t, R_RDONLY); 129 break; 130 default: 131 goto einval; 132 } 133 slow: if ((t->bt_rfp = fdopen(rfd, "r")) == NULL) 134 goto err; 135 F_SET(t, R_CLOSEFP); 136 t->bt_irec = 137 F_ISSET(t, R_FIXLEN) ? __rec_fpipe : __rec_vpipe; 138 } else { 139 switch (flags & O_ACCMODE) { 140 case O_RDONLY: 141 F_SET(t, R_RDONLY); 142 break; 143 case O_RDWR: 144 break; 145 default: 146 goto einval; 147 } 148 149 if (fstat(rfd, &sb)) 150 goto err; 151 /* 152 * Kluge -- we'd like to test to see if the file is too 153 * big to mmap. Since, we don't know what size or type 154 * off_t's or size_t's are, what the largest unsigned 155 * integral type is, or what random insanity the local 156 * C compiler will perpetrate, doing the comparison in 157 * a portable way is flatly impossible. Hope that mmap 158 * fails if the file is too large. 159 */ 160 if (sb.st_size == 0) 161 F_SET(t, R_EOF); 162 else { 163 #ifdef MMAP_NOT_AVAILABLE 164 /* 165 * XXX 166 * Mmap doesn't work correctly on many current 167 * systems. In particular, it can fail subtly, 168 * with cache coherency problems. Don't use it 169 * for now. 170 */ 171 t->bt_msize = sb.st_size; 172 if ((t->bt_smap = mmap(NULL, t->bt_msize, 173 PROT_READ, MAP_FILE | MAP_PRIVATE, rfd, 174 (off_t)0)) == (caddr_t)-1) 175 goto slow; 176 t->bt_cmap = t->bt_smap; 177 t->bt_emap = t->bt_smap + sb.st_size; 178 t->bt_irec = F_ISSET(t, R_FIXLEN) ? 179 __rec_fmap : __rec_vmap; 180 F_SET(t, R_MEMMAPPED); 181 #else 182 goto slow; 183 #endif 184 } 185 } 186 } 187 188 /* Use the recno routines. */ 189 dbp->close = __rec_close; 190 dbp->del = __rec_delete; 191 dbp->fd = __rec_fd; 192 dbp->get = __rec_get; 193 dbp->put = __rec_put; 194 dbp->seq = __rec_seq; 195 dbp->sync = __rec_sync; 196 197 /* If the root page was created, reset the flags. */ 198 if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL) 199 goto err; 200 if ((h->flags & P_TYPE) == P_BLEAF) { 201 F_CLR(h, P_TYPE); 202 F_SET(h, P_RLEAF); 203 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 204 } else 205 mpool_put(t->bt_mp, h, 0); 206 207 if (openinfo && openinfo->flags & R_SNAPSHOT && 208 !F_ISSET(t, R_EOF | R_INMEM) && 209 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR) 210 goto err; 211 return (dbp); 212 213 einval: errno = EINVAL; 214 err: sverrno = errno; 215 if (dbp != NULL) 216 (void)__bt_close(dbp); 217 if (fname != NULL) 218 (void)close(rfd); 219 errno = sverrno; 220 return (NULL); 221 } 222 223 int 224 __rec_fd(const DB *dbp) 225 { 226 BTREE *t; 227 228 t = dbp->internal; 229 230 /* Toss any page pinned across calls. */ 231 if (t->bt_pinned != NULL) { 232 mpool_put(t->bt_mp, t->bt_pinned, 0); 233 t->bt_pinned = NULL; 234 } 235 236 /* In-memory database can't have a file descriptor. */ 237 if (F_ISSET(t, R_INMEM)) { 238 errno = ENOENT; 239 return (-1); 240 } 241 return (t->bt_rfd); 242 } 243
Indexes created Sat Oct 11 19:10:01 GMT 2025