rec_open.c revision 71579
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. 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 * $FreeBSD: head/lib/libc/db/recno/rec_open.c 71579 2001-01-24 13:01:12Z deischen $ 37 */ 38 39#if defined(LIBC_SCCS) && !defined(lint) 40static char sccsid[] = "@(#)rec_open.c 8.10 (Berkeley) 9/1/94"; 41#endif /* LIBC_SCCS and not lint */ 42 43#include "namespace.h" 44#include <sys/types.h> 45#include <sys/mman.h> 46#include <sys/stat.h> 47 48#include <errno.h> 49#include <fcntl.h> 50#include <limits.h> 51#include <stddef.h> 52#include <stdio.h> 53#include <unistd.h> 54#include "un-namespace.h" 55 56#include <db.h> 57#include "recno.h" 58 59DB * 60__rec_open(fname, flags, mode, openinfo, dflags) 61 const char *fname; 62 int flags, mode, dflags; 63 const RECNOINFO *openinfo; 64{ 65 BTREE *t; 66 BTREEINFO btopeninfo; 67 DB *dbp; 68 PAGE *h; 69 struct stat sb; 70 int rfd, sverrno; 71 72 /* Open the user's file -- if this fails, we're done. */ 73 if (fname != NULL && (rfd = _open(fname, flags, mode)) < 0) 74 return (NULL); 75 76 /* Create a btree in memory (backed by disk). */ 77 dbp = NULL; 78 if (openinfo) { 79 if (openinfo->flags & ~(R_FIXEDLEN | R_NOKEY | R_SNAPSHOT)) 80 goto einval; 81 btopeninfo.flags = 0; 82 btopeninfo.cachesize = openinfo->cachesize; 83 btopeninfo.maxkeypage = 0; 84 btopeninfo.minkeypage = 0; 85 btopeninfo.psize = openinfo->psize; 86 btopeninfo.compare = NULL; 87 btopeninfo.prefix = NULL; 88 btopeninfo.lorder = openinfo->lorder; 89 dbp = __bt_open(openinfo->bfname, 90 O_RDWR, S_IRUSR | S_IWUSR, &btopeninfo, dflags); 91 } else 92 dbp = __bt_open(NULL, O_RDWR, S_IRUSR | S_IWUSR, NULL, dflags); 93 if (dbp == NULL) 94 goto err; 95 96 /* 97 * Some fields in the tree structure are recno specific. Fill them 98 * in and make the btree structure look like a recno structure. We 99 * don't change the bt_ovflsize value, it's close enough and slightly 100 * bigger. 101 */ 102 t = dbp->internal; 103 if (openinfo) { 104 if (openinfo->flags & R_FIXEDLEN) { 105 F_SET(t, R_FIXLEN); 106 t->bt_reclen = openinfo->reclen; 107 if (t->bt_reclen == 0) 108 goto einval; 109 } 110 t->bt_bval = openinfo->bval; 111 } else 112 t->bt_bval = '\n'; 113 114 F_SET(t, R_RECNO); 115 if (fname == NULL) 116 F_SET(t, R_EOF | R_INMEM); 117 else 118 t->bt_rfd = rfd; 119 120 if (fname != NULL) { 121 /* 122 * In 4.4BSD, stat(2) returns true for ISSOCK on pipes. 123 * Unfortunately, that's not portable, so we use lseek 124 * and check the errno values. 125 */ 126 errno = 0; 127 if (lseek(rfd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) { 128 switch (flags & O_ACCMODE) { 129 case O_RDONLY: 130 F_SET(t, R_RDONLY); 131 break; 132 default: 133 goto einval; 134 } 135slow: if ((t->bt_rfp = fdopen(rfd, "r")) == NULL) 136 goto err; 137 F_SET(t, R_CLOSEFP); 138 t->bt_irec = 139 F_ISSET(t, R_FIXLEN) ? __rec_fpipe : __rec_vpipe; 140 } else { 141 switch (flags & O_ACCMODE) { 142 case O_RDONLY: 143 F_SET(t, R_RDONLY); 144 break; 145 case O_RDWR: 146 break; 147 default: 148 goto einval; 149 } 150 151 if (_fstat(rfd, &sb)) 152 goto err; 153 /* 154 * Kluge -- we'd like to test to see if the file is too 155 * big to mmap. Since, we don't know what size or type 156 * off_t's or size_t's are, what the largest unsigned 157 * integral type is, or what random insanity the local 158 * C compiler will perpetrate, doing the comparison in 159 * a portable way is flatly impossible. Hope that mmap 160 * fails if the file is too large. 161 */ 162 if (sb.st_size == 0) 163 F_SET(t, R_EOF); 164 else { 165#ifdef MMAP_NOT_AVAILABLE 166 /* 167 * XXX 168 * Mmap doesn't work correctly on many current 169 * systems. In particular, it can fail subtly, 170 * with cache coherency problems. Don't use it 171 * for now. 172 */ 173 t->bt_msize = sb.st_size; 174 if ((t->bt_smap = mmap(NULL, t->bt_msize, 175 PROT_READ, MAP_PRIVATE, rfd, 176 (off_t)0)) == MAP_FAILED) 177 goto slow; 178 t->bt_cmap = t->bt_smap; 179 t->bt_emap = t->bt_smap + sb.st_size; 180 t->bt_irec = F_ISSET(t, R_FIXLEN) ? 181 __rec_fmap : __rec_vmap; 182 F_SET(t, R_MEMMAPPED); 183#else 184 goto slow; 185#endif 186 } 187 } 188 } 189 190 /* Use the recno routines. */ 191 dbp->close = __rec_close; 192 dbp->del = __rec_delete; 193 dbp->fd = __rec_fd; 194 dbp->get = __rec_get; 195 dbp->put = __rec_put; 196 dbp->seq = __rec_seq; 197 dbp->sync = __rec_sync; 198 199 /* If the root page was created, reset the flags. */ 200 if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL) 201 goto err; 202 if ((h->flags & P_TYPE) == P_BLEAF) { 203 F_CLR(h, P_TYPE); 204 F_SET(h, P_RLEAF); 205 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 206 } else 207 mpool_put(t->bt_mp, h, 0); 208 209 if (openinfo && openinfo->flags & R_SNAPSHOT && 210 !F_ISSET(t, R_EOF | R_INMEM) && 211 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR) 212 goto err; 213 return (dbp); 214 215einval: errno = EINVAL; 216err: sverrno = errno; 217 if (dbp != NULL) 218 (void)__bt_close(dbp); 219 if (fname != NULL) 220 (void)_close(rfd); 221 errno = sverrno; 222 return (NULL); 223} 224 225int 226__rec_fd(dbp) 227 const DB *dbp; 228{ 229 BTREE *t; 230 231 t = dbp->internal; 232 233 /* Toss any page pinned across calls. */ 234 if (t->bt_pinned != NULL) { 235 mpool_put(t->bt_mp, t->bt_pinned, 0); 236 t->bt_pinned = NULL; 237 } 238 239 /* In-memory database can't have a file descriptor. */ 240 if (F_ISSET(t, R_INMEM)) { 241 errno = ENOENT; 242 return (-1); 243 } 244 return (t->bt_rfd); 245} 246