rec_open.c revision 1.4
1 /*- 2 * Copyright (c) 1990, 1993 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. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #if defined(LIBC_SCCS) && !defined(lint) 38 /* from: static char sccsid[] = "@(#)rec_open.c 8.4 (Berkeley) 9/7/93"; */ 39 static char *rcsid = "$Id: rec_open.c,v 1.4 1993/09/09 02:42:25 cgd Exp $"; 40 #endif /* LIBC_SCCS and not lint */ 41 42 #include <sys/types.h> 43 #include <sys/mman.h> 44 #include <sys/stat.h> 45 46 #include <errno.h> 47 #include <fcntl.h> 48 #include <limits.h> 49 #include <stddef.h> 50 #include <stdio.h> 51 #include <unistd.h> 52 53 #define __DBINTERFACE_PRIVATE 54 #include <db.h> 55 #include "recno.h" 56 57 DB * 58 __rec_open(fname, flags, mode, openinfo, dflags) 59 const char *fname; 60 int flags, mode, dflags; 61 const RECNOINFO *openinfo; 62 { 63 BTREE *t; 64 BTREEINFO btopeninfo; 65 DB *dbp; 66 PAGE *h; 67 struct stat sb; 68 int rfd, sverrno; 69 70 /* Open the user's file -- if this fails, we're done. */ 71 if (fname != NULL && (rfd = open(fname, flags, mode)) < 0) 72 return (NULL); 73 74 /* Create a btree in memory (backed by disk). */ 75 dbp = NULL; 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 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 SET(t, R_RECNO); 113 if (fname == NULL) 114 SET(t, R_EOF | R_INMEM); 115 else 116 t->bt_rfd = rfd; 117 t->bt_rcursor = 0; 118 119 /* 120 * In 4.4BSD stat(2) returns true for ISSOCK on pipes. Until 121 * then, this is fairly close. Pipes are read-only. 122 */ 123 if (fname != NULL) { 124 if (lseek(rfd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) { 125 switch (flags & O_ACCMODE) { 126 case O_RDONLY: 127 SET(t, R_RDONLY); 128 break; 129 default: 130 goto einval; 131 } 132 slow: if ((t->bt_rfp = fdopen(rfd, "r")) == NULL) 133 goto err; 134 SET(t, R_CLOSEFP); 135 t->bt_irec = 136 ISSET(t, R_FIXLEN) ? __rec_fpipe : __rec_vpipe; 137 } else { 138 switch (flags & O_ACCMODE) { 139 case O_RDONLY: 140 SET(t, R_RDONLY); 141 break; 142 case O_RDWR: 143 break; 144 default: 145 goto einval; 146 } 147 148 if (fstat(rfd, &sb)) 149 goto err; 150 /* 151 * Kluge -- we'd like to test to see if the file is too 152 * big to mmap. Since, we don't know what size or type 153 * off_t's or size_t's are, what the largest unsigned 154 * integral type is, or what random insanity the local 155 * C compiler will perpetrate, doing the comparison in 156 * a portable way is flatly impossible. Hope that mmap 157 * fails if the file is too large. 158 */ 159 if (sb.st_size == 0) 160 SET(t, R_EOF); 161 else { 162 t->bt_msize = sb.st_size; 163 if ((t->bt_smap = mmap(NULL, t->bt_msize, 164 PROT_READ, MAP_PRIVATE, rfd, 165 (off_t)0)) == (caddr_t)-1) 166 goto slow; 167 t->bt_cmap = t->bt_smap; 168 t->bt_emap = t->bt_smap + sb.st_size; 169 t->bt_irec = ISSET(t, R_FIXLEN) ? 170 __rec_fmap : __rec_vmap; 171 SET(t, R_MEMMAPPED); 172 } 173 } 174 } 175 176 /* Use the recno routines. */ 177 dbp->close = __rec_close; 178 dbp->del = __rec_delete; 179 dbp->fd = __rec_fd; 180 dbp->get = __rec_get; 181 dbp->put = __rec_put; 182 dbp->seq = __rec_seq; 183 dbp->sync = __rec_sync; 184 185 /* If the root page was created, reset the flags. */ 186 if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL) 187 goto err; 188 if ((h->flags & P_TYPE) == P_BLEAF) { 189 h->flags = h->flags & ~P_TYPE | P_RLEAF; 190 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 191 } else 192 mpool_put(t->bt_mp, h, 0); 193 194 if (openinfo && openinfo->flags & R_SNAPSHOT && 195 !ISSET(t, R_EOF | R_INMEM) && 196 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR) 197 goto err; 198 return (dbp); 199 200 einval: errno = EINVAL; 201 err: sverrno = errno; 202 if (dbp != NULL) 203 (void)__bt_close(dbp); 204 if (fname != NULL) 205 (void)close(rfd); 206 errno = sverrno; 207 return (NULL); 208 } 209 210 int 211 __rec_fd(dbp) 212 const DB *dbp; 213 { 214 BTREE *t; 215 216 t = dbp->internal; 217 218 /* Toss any page pinned across calls. */ 219 if (t->bt_pinned != NULL) { 220 mpool_put(t->bt_mp, t->bt_pinned, 0); 221 t->bt_pinned = NULL; 222 } 223 224 /* In-memory database can't have a file descriptor. */ 225 if (ISSET(t, R_INMEM)) { 226 errno = ENOENT; 227 return (-1); 228 } 229 return (t->bt_rfd); 230 } 231
Indexes created Thu Sep 25 16:09:42 GMT 2025