rec_open.c revision 1573
155714Skris/*- 255714Skris * Copyright (c) 1990, 1993 355714Skris * The Regents of the University of California. All rights reserved. 455714Skris * 555714Skris * This code is derived from software contributed to Berkeley by 655714Skris * Mike Olson. 755714Skris * 855714Skris * Redistribution and use in source and binary forms, with or without 955714Skris * modification, are permitted provided that the following conditions 1055714Skris * are met: 1155714Skris * 1. Redistributions of source code must retain the above copyright 1255714Skris * notice, this list of conditions and the following disclaimer. 1355714Skris * 2. Redistributions in binary form must reproduce the above copyright 1455714Skris * notice, this list of conditions and the following disclaimer in the 1555714Skris * documentation and/or other materials provided with the distribution. 1655714Skris * 3. All advertising materials mentioning features or use of this software 1755714Skris * must display the following acknowledgement: 1855714Skris * This product includes software developed by the University of 1955714Skris * California, Berkeley and its contributors. 2055714Skris * 4. Neither the name of the University nor the names of its contributors 2155714Skris * may be used to endorse or promote products derived from this software 2255714Skris * without specific prior written permission. 2355714Skris * 2455714Skris * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 2555714Skris * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2655714Skris * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2755714Skris * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 2855714Skris * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2955714Skris * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 3055714Skris * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 3155714Skris * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 3255714Skris * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 3355714Skris * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3455714Skris * SUCH DAMAGE. 3555714Skris */ 36 37#if defined(LIBC_SCCS) && !defined(lint) 38static char sccsid[] = "@(#)rec_open.c 8.6 (Berkeley) 2/22/94"; 39#endif /* LIBC_SCCS and not lint */ 40 41#include <sys/types.h> 42#include <sys/mman.h> 43#include <sys/stat.h> 44 45#include <errno.h> 46#include <fcntl.h> 47#include <limits.h> 48#include <stddef.h> 49#include <stdio.h> 50#include <unistd.h> 51 52#include <db.h> 53#include "recno.h" 54 55DB * 56__rec_open(fname, flags, mode, openinfo, dflags) 57 const char *fname; 58 int flags, mode, dflags; 59 const RECNOINFO *openinfo; 60{ 61 BTREE *t; 62 BTREEINFO btopeninfo; 63 DB *dbp; 64 PAGE *h; 65 struct stat sb; 66 int rfd, sverrno; 67 68 /* Open the user's file -- if this fails, we're done. */ 69 if (fname != NULL && (rfd = open(fname, flags, mode)) < 0) 70 return (NULL); 71 72 /* Create a btree in memory (backed by disk). */ 73 dbp = NULL; 74 if (openinfo) { 75 if (openinfo->flags & ~(R_FIXEDLEN | R_NOKEY | R_SNAPSHOT)) 76 goto einval; 77 btopeninfo.flags = 0; 78 btopeninfo.cachesize = openinfo->cachesize; 79 btopeninfo.maxkeypage = 0; 80 btopeninfo.minkeypage = 0; 81 btopeninfo.psize = openinfo->psize; 82 btopeninfo.compare = NULL; 83 btopeninfo.prefix = NULL; 84 btopeninfo.lorder = openinfo->lorder; 85 dbp = __bt_open(openinfo->bfname, 86 O_RDWR, S_IRUSR | S_IWUSR, &btopeninfo, dflags); 87 } else 88 dbp = __bt_open(NULL, O_RDWR, S_IRUSR | S_IWUSR, NULL, dflags); 89 if (dbp == NULL) 90 goto err; 91 92 /* 93 * Some fields in the tree structure are recno specific. Fill them 94 * in and make the btree structure look like a recno structure. We 95 * don't change the bt_ovflsize value, it's close enough and slightly 96 * bigger. 97 */ 98 t = dbp->internal; 99 if (openinfo) { 100 if (openinfo->flags & R_FIXEDLEN) { 101 SET(t, R_FIXLEN); 102 t->bt_reclen = openinfo->reclen; 103 if (t->bt_reclen == 0) 104 goto einval; 105 } 106 t->bt_bval = openinfo->bval; 107 } else 108 t->bt_bval = '\n'; 109 110 SET(t, R_RECNO); 111 if (fname == NULL) 112 SET(t, R_EOF | R_INMEM); 113 else 114 t->bt_rfd = rfd; 115 t->bt_rcursor = 0; 116 117 if (fname != NULL) { 118 /* 119 * In 4.4BSD, stat(2) returns true for ISSOCK on pipes. 120 * Unfortunately, that's not portable, so we use lseek 121 * and check the errno values. 122 */ 123 errno = 0; 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 } 132slow: 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 200einval: errno = EINVAL; 201err: 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 210int 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