rec_open.c revision 1.9
1 /* $NetBSD: rec_open.c,v 1.9 1997/07/21 14:06:45 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 #include <sys/cdefs.h> 40 #if defined(LIBC_SCCS) && !defined(lint) 41 #if 0 42 static char sccsid[] = "@(#)rec_open.c 8.10 (Berkeley) 9/1/94"; 43 #else 44 __RCSID("$NetBSD: rec_open.c,v 1.9 1997/07/21 14:06:45 jtc Exp $"); 45 #endif 46 #endif /* LIBC_SCCS and not lint */ 47 48 #include "namespace.h" 49 #include <sys/types.h> 50 #include <sys/mman.h> 51 #include <sys/stat.h> 52 53 #include <errno.h> 54 #include <fcntl.h> 55 #include <limits.h> 56 #include <stddef.h> 57 #include <stdio.h> 58 #include <unistd.h> 59 60 #include <db.h> 61 #include "recno.h" 62 63 DB * 64 __rec_open(fname, flags, mode, openinfo, dflags) 65 const char *fname; 66 int flags, mode, dflags; 67 const RECNOINFO *openinfo; 68 { 69 BTREE *t; 70 BTREEINFO btopeninfo; 71 DB *dbp; 72 PAGE *h; 73 struct stat sb; 74 int rfd = -1; /* pacify gcc */ 75 int sverrno; 76 77 /* Open the user's file -- if this fails, we're done. */ 78 if (fname != NULL && (rfd = open(fname, flags, mode)) < 0) 79 return (NULL); 80 81 /* Create a btree in memory (backed by disk). */ 82 dbp = NULL; 83 if (openinfo) { 84 if (openinfo->flags & ~(R_FIXEDLEN | R_NOKEY | R_SNAPSHOT)) 85 goto einval; 86 btopeninfo.flags = 0; 87 btopeninfo.cachesize = openinfo->cachesize; 88 btopeninfo.maxkeypage = 0; 89 btopeninfo.minkeypage = 0; 90 btopeninfo.psize = openinfo->psize; 91 btopeninfo.compare = NULL; 92 btopeninfo.prefix = NULL; 93 btopeninfo.lorder = openinfo->lorder; 94 dbp = __bt_open(openinfo->bfname, 95 O_RDWR, S_IRUSR | S_IWUSR, &btopeninfo, dflags); 96 } else 97 dbp = __bt_open(NULL, O_RDWR, S_IRUSR | S_IWUSR, NULL, dflags); 98 if (dbp == NULL) 99 goto err; 100 101 /* 102 * Some fields in the tree structure are recno specific. Fill them 103 * in and make the btree structure look like a recno structure. We 104 * don't change the bt_ovflsize value, it's close enough and slightly 105 * bigger. 106 */ 107 t = dbp->internal; 108 if (openinfo) { 109 if (openinfo->flags & R_FIXEDLEN) { 110 F_SET(t, R_FIXLEN); 111 t->bt_reclen = openinfo->reclen; 112 if (t->bt_reclen == 0) 113 goto einval; 114 } 115 t->bt_bval = openinfo->bval; 116 } else 117 t->bt_bval = '\n'; 118 119 F_SET(t, R_RECNO); 120 if (fname == NULL) 121 F_SET(t, R_EOF | R_INMEM); 122 else 123 t->bt_rfd = rfd; 124 125 if (fname != NULL) { 126 /* 127 * In 4.4BSD, stat(2) returns true for ISSOCK on pipes. 128 * Unfortunately, that's not portable, so we use lseek 129 * and check the errno values. 130 */ 131 errno = 0; 132 if (lseek(rfd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) { 133 switch (flags & O_ACCMODE) { 134 case O_RDONLY: 135 F_SET(t, R_RDONLY); 136 break; 137 default: 138 goto einval; 139 } 140 slow: if ((t->bt_rfp = fdopen(rfd, "r")) == NULL) 141 goto err; 142 F_SET(t, R_CLOSEFP); 143 t->bt_irec = 144 F_ISSET(t, R_FIXLEN) ? __rec_fpipe : __rec_vpipe; 145 } else { 146 switch (flags & O_ACCMODE) { 147 case O_RDONLY: 148 F_SET(t, R_RDONLY); 149 break; 150 case O_RDWR: 151 break; 152 default: 153 goto einval; 154 } 155 156 if (fstat(rfd, &sb)) 157 goto err; 158 /* 159 * Kluge -- we'd like to test to see if the file is too 160 * big to mmap. Since, we don't know what size or type 161 * off_t's or size_t's are, what the largest unsigned 162 * integral type is, or what random insanity the local 163 * C compiler will perpetrate, doing the comparison in 164 * a portable way is flatly impossible. Hope that mmap 165 * fails if the file is too large. 166 */ 167 if (sb.st_size == 0) 168 F_SET(t, R_EOF); 169 else { 170 #ifdef MMAP_NOT_AVAILABLE 171 /* 172 * XXX 173 * Mmap doesn't work correctly on many current 174 * systems. In particular, it can fail subtly, 175 * with cache coherency problems. Don't use it 176 * for now. 177 */ 178 t->bt_msize = sb.st_size; 179 if ((t->bt_smap = mmap(NULL, t->bt_msize, 180 PROT_READ, MAP_PRIVATE, rfd, 181 (off_t)0)) == (caddr_t)-1) 182 goto slow; 183 t->bt_cmap = t->bt_smap; 184 t->bt_emap = t->bt_smap + sb.st_size; 185 t->bt_irec = F_ISSET(t, R_FIXLEN) ? 186 __rec_fmap : __rec_vmap; 187 F_SET(t, R_MEMMAPPED); 188 #else 189 goto slow; 190 #endif 191 } 192 } 193 } 194 195 /* Use the recno routines. */ 196 dbp->close = __rec_close; 197 dbp->del = __rec_delete; 198 dbp->fd = __rec_fd; 199 dbp->get = __rec_get; 200 dbp->put = __rec_put; 201 dbp->seq = __rec_seq; 202 dbp->sync = __rec_sync; 203 204 /* If the root page was created, reset the flags. */ 205 if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL) 206 goto err; 207 if ((h->flags & P_TYPE) == P_BLEAF) { 208 F_CLR(h, P_TYPE); 209 F_SET(h, P_RLEAF); 210 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 211 } else 212 mpool_put(t->bt_mp, h, 0); 213 214 if (openinfo && openinfo->flags & R_SNAPSHOT && 215 !F_ISSET(t, R_EOF | R_INMEM) && 216 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR) 217 goto err; 218 return (dbp); 219 220 einval: errno = EINVAL; 221 err: sverrno = errno; 222 if (dbp != NULL) 223 (void)__bt_close(dbp); 224 if (fname != NULL) 225 (void)close(rfd); 226 errno = sverrno; 227 return (NULL); 228 } 229 230 int 231 __rec_fd(dbp) 232 const DB *dbp; 233 { 234 BTREE *t; 235 236 t = dbp->internal; 237 238 /* Toss any page pinned across calls. */ 239 if (t->bt_pinned != NULL) { 240 mpool_put(t->bt_mp, t->bt_pinned, 0); 241 t->bt_pinned = NULL; 242 } 243 244 /* In-memory database can't have a file descriptor. */ 245 if (F_ISSET(t, R_INMEM)) { 246 errno = ENOENT; 247 return (-1); 248 } 249 return (t->bt_rfd); 250 } 251
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