rec_open.c revision 1.7.2.1
1 /* $NetBSD: rec_open.c,v 1.7.2.1 1996/09/16 18:40:02 jtc 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. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #if defined(LIBC_SCCS) && !defined(lint) 40 #if 0 41 static char sccsid[] = "@(#)rec_open.c 8.10 (Berkeley) 9/1/94"; 42 #else 43 static char rcsid[] = "$NetBSD: rec_open.c,v 1.7.2.1 1996/09/16 18:40:02 jtc Exp $"; 44 #endif 45 #endif /* LIBC_SCCS and not lint */ 46 47 #include "namespace.h" 48 #include <sys/types.h> 49 #include <sys/mman.h> 50 #include <sys/stat.h> 51 52 #include <errno.h> 53 #include <fcntl.h> 54 #include <limits.h> 55 #include <stddef.h> 56 #include <stdio.h> 57 #include <unistd.h> 58 59 #include <db.h> 60 #include "recno.h" 61 62 DB * 63 __rec_open(fname, flags, mode, openinfo, dflags) 64 const char *fname; 65 int flags, mode, dflags; 66 const RECNOINFO *openinfo; 67 { 68 BTREE *t; 69 BTREEINFO btopeninfo; 70 DB *dbp; 71 PAGE *h; 72 struct stat sb; 73 int rfd, sverrno; 74 75 /* Open the user's file -- if this fails, we're done. */ 76 if (fname != NULL && (rfd = open(fname, flags, mode)) < 0) 77 return (NULL); 78 79 /* Create a btree in memory (backed by disk). */ 80 dbp = NULL; 81 if (openinfo) { 82 if (openinfo->flags & ~(R_FIXEDLEN | R_NOKEY | R_SNAPSHOT)) 83 goto einval; 84 btopeninfo.flags = 0; 85 btopeninfo.cachesize = openinfo->cachesize; 86 btopeninfo.maxkeypage = 0; 87 btopeninfo.minkeypage = 0; 88 btopeninfo.psize = openinfo->psize; 89 btopeninfo.compare = NULL; 90 btopeninfo.prefix = NULL; 91 btopeninfo.lorder = openinfo->lorder; 92 dbp = __bt_open(openinfo->bfname, 93 O_RDWR, S_IRUSR | S_IWUSR, &btopeninfo, dflags); 94 } else 95 dbp = __bt_open(NULL, O_RDWR, S_IRUSR | S_IWUSR, NULL, dflags); 96 if (dbp == NULL) 97 goto err; 98 99 /* 100 * Some fields in the tree structure are recno specific. Fill them 101 * in and make the btree structure look like a recno structure. We 102 * don't change the bt_ovflsize value, it's close enough and slightly 103 * bigger. 104 */ 105 t = dbp->internal; 106 if (openinfo) { 107 if (openinfo->flags & R_FIXEDLEN) { 108 F_SET(t, R_FIXLEN); 109 t->bt_reclen = openinfo->reclen; 110 if (t->bt_reclen == 0) 111 goto einval; 112 } 113 t->bt_bval = openinfo->bval; 114 } else 115 t->bt_bval = '\n'; 116 117 F_SET(t, R_RECNO); 118 if (fname == NULL) 119 F_SET(t, R_EOF | R_INMEM); 120 else 121 t->bt_rfd = rfd; 122 123 if (fname != NULL) { 124 /* 125 * In 4.4BSD, stat(2) returns true for ISSOCK on pipes. 126 * Unfortunately, that's not portable, so we use lseek 127 * and check the errno values. 128 */ 129 errno = 0; 130 if (lseek(rfd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) { 131 switch (flags & O_ACCMODE) { 132 case O_RDONLY: 133 F_SET(t, R_RDONLY); 134 break; 135 default: 136 goto einval; 137 } 138 slow: if ((t->bt_rfp = fdopen(rfd, "r")) == NULL) 139 goto err; 140 F_SET(t, R_CLOSEFP); 141 t->bt_irec = 142 F_ISSET(t, R_FIXLEN) ? __rec_fpipe : __rec_vpipe; 143 } else { 144 switch (flags & O_ACCMODE) { 145 case O_RDONLY: 146 F_SET(t, R_RDONLY); 147 break; 148 case O_RDWR: 149 break; 150 default: 151 goto einval; 152 } 153 154 if (fstat(rfd, &sb)) 155 goto err; 156 /* 157 * Kluge -- we'd like to test to see if the file is too 158 * big to mmap. Since, we don't know what size or type 159 * off_t's or size_t's are, what the largest unsigned 160 * integral type is, or what random insanity the local 161 * C compiler will perpetrate, doing the comparison in 162 * a portable way is flatly impossible. Hope that mmap 163 * fails if the file is too large. 164 */ 165 if (sb.st_size == 0) 166 F_SET(t, R_EOF); 167 else { 168 #ifdef MMAP_NOT_AVAILABLE 169 /* 170 * XXX 171 * Mmap doesn't work correctly on many current 172 * systems. In particular, it can fail subtly, 173 * with cache coherency problems. Don't use it 174 * for now. 175 */ 176 t->bt_msize = sb.st_size; 177 if ((t->bt_smap = mmap(NULL, t->bt_msize, 178 PROT_READ, MAP_PRIVATE, rfd, 179 (off_t)0)) == (caddr_t)-1) 180 goto slow; 181 t->bt_cmap = t->bt_smap; 182 t->bt_emap = t->bt_smap + sb.st_size; 183 t->bt_irec = F_ISSET(t, R_FIXLEN) ? 184 __rec_fmap : __rec_vmap; 185 F_SET(t, R_MEMMAPPED); 186 #else 187 goto slow; 188 #endif 189 } 190 } 191 } 192 193 /* Use the recno routines. */ 194 dbp->close = __rec_close; 195 dbp->del = __rec_delete; 196 dbp->fd = __rec_fd; 197 dbp->get = __rec_get; 198 dbp->put = __rec_put; 199 dbp->seq = __rec_seq; 200 dbp->sync = __rec_sync; 201 202 /* If the root page was created, reset the flags. */ 203 if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL) 204 goto err; 205 if ((h->flags & P_TYPE) == P_BLEAF) { 206 F_CLR(h, P_TYPE); 207 F_SET(h, P_RLEAF); 208 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 209 } else 210 mpool_put(t->bt_mp, h, 0); 211 212 if (openinfo && openinfo->flags & R_SNAPSHOT && 213 !F_ISSET(t, R_EOF | R_INMEM) && 214 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR) 215 goto err; 216 return (dbp); 217 218 einval: errno = EINVAL; 219 err: sverrno = errno; 220 if (dbp != NULL) 221 (void)__bt_close(dbp); 222 if (fname != NULL) 223 (void)close(rfd); 224 errno = sverrno; 225 return (NULL); 226 } 227 228 int 229 __rec_fd(dbp) 230 const DB *dbp; 231 { 232 BTREE *t; 233 234 t = dbp->internal; 235 236 /* Toss any page pinned across calls. */ 237 if (t->bt_pinned != NULL) { 238 mpool_put(t->bt_mp, t->bt_pinned, 0); 239 t->bt_pinned = NULL; 240 } 241 242 /* In-memory database can't have a file descriptor. */ 243 if (F_ISSET(t, R_INMEM)) { 244 errno = ENOENT; 245 return (-1); 246 } 247 return (t->bt_rfd); 248 } 249
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