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 * %sccs.include.redist.c% 9 */ 10 11 #if defined(LIBC_SCCS) && !defined(lint) 12 static char sccsid[] = "@(#)rec_open.c 8.5 (Berkeley) 02/21/94"; 13 #endif /* LIBC_SCCS and not lint */ 14 15 #include <sys/types.h> 16 #include <sys/mman.h> 17 #include <sys/stat.h> 18 19 #include <errno.h> 20 #include <fcntl.h> 21 #include <limits.h> 22 #include <stddef.h> 23 #include <stdio.h> 24 #include <unistd.h> 25 26 #include <db.h> 27 #include "recno.h" 28 29 DB * 30 __rec_open(fname, flags, mode, openinfo, dflags) 31 const char *fname; 32 int flags, mode, dflags; 33 const RECNOINFO *openinfo; 34 { 35 BTREE *t; 36 BTREEINFO btopeninfo; 37 DB *dbp; 38 PAGE *h; 39 struct stat sb; 40 int rfd, sverrno; 41 42 /* Open the user's file -- if this fails, we're done. */ 43 if (fname != NULL && (rfd = open(fname, flags, mode)) < 0) 44 return (NULL); 45 46 /* Create a btree in memory (backed by disk). */ 47 dbp = NULL; 48 if (openinfo) { 49 if (openinfo->flags & ~(R_FIXEDLEN | R_NOKEY | R_SNAPSHOT)) 50 goto einval; 51 btopeninfo.flags = 0; 52 btopeninfo.cachesize = openinfo->cachesize; 53 btopeninfo.maxkeypage = 0; 54 btopeninfo.minkeypage = 0; 55 btopeninfo.psize = openinfo->psize; 56 btopeninfo.compare = NULL; 57 btopeninfo.prefix = NULL; 58 btopeninfo.lorder = openinfo->lorder; 59 dbp = __bt_open(openinfo->bfname, 60 O_RDWR, S_IRUSR | S_IWUSR, &btopeninfo, dflags); 61 } else 62 dbp = __bt_open(NULL, O_RDWR, S_IRUSR | S_IWUSR, NULL, dflags); 63 if (dbp == NULL) 64 goto err; 65 66 /* 67 * Some fields in the tree structure are recno specific. Fill them 68 * in and make the btree structure look like a recno structure. We 69 * don't change the bt_ovflsize value, it's close enough and slightly 70 * bigger. 71 */ 72 t = dbp->internal; 73 if (openinfo) { 74 if (openinfo->flags & R_FIXEDLEN) { 75 SET(t, R_FIXLEN); 76 t->bt_reclen = openinfo->reclen; 77 if (t->bt_reclen == 0) 78 goto einval; 79 } 80 t->bt_bval = openinfo->bval; 81 } else 82 t->bt_bval = '\n'; 83 84 SET(t, R_RECNO); 85 if (fname == NULL) 86 SET(t, R_EOF | R_INMEM); 87 else 88 t->bt_rfd = rfd; 89 t->bt_rcursor = 0; 90 91 /* 92 * In 4.4BSD stat(2) returns true for ISSOCK on pipes. Until 93 * then, this is fairly close. Pipes are read-only. 94 */ 95 if (fname != NULL) { 96 if (lseek(rfd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) { 97 switch (flags & O_ACCMODE) { 98 case O_RDONLY: 99 SET(t, R_RDONLY); 100 break; 101 default: 102 goto einval; 103 } 104 slow: if ((t->bt_rfp = fdopen(rfd, "r")) == NULL) 105 goto err; 106 SET(t, R_CLOSEFP); 107 t->bt_irec = 108 ISSET(t, R_FIXLEN) ? __rec_fpipe : __rec_vpipe; 109 } else { 110 switch (flags & O_ACCMODE) { 111 case O_RDONLY: 112 SET(t, R_RDONLY); 113 break; 114 case O_RDWR: 115 break; 116 default: 117 goto einval; 118 } 119 120 if (fstat(rfd, &sb)) 121 goto err; 122 /* 123 * Kluge -- we'd like to test to see if the file is too 124 * big to mmap. Since, we don't know what size or type 125 * off_t's or size_t's are, what the largest unsigned 126 * integral type is, or what random insanity the local 127 * C compiler will perpetrate, doing the comparison in 128 * a portable way is flatly impossible. Hope that mmap 129 * fails if the file is too large. 130 */ 131 if (sb.st_size == 0) 132 SET(t, R_EOF); 133 else { 134 t->bt_msize = sb.st_size; 135 if ((t->bt_smap = mmap(NULL, t->bt_msize, 136 PROT_READ, MAP_PRIVATE, rfd, 137 (off_t)0)) == (caddr_t)-1) 138 goto slow; 139 t->bt_cmap = t->bt_smap; 140 t->bt_emap = t->bt_smap + sb.st_size; 141 t->bt_irec = ISSET(t, R_FIXLEN) ? 142 __rec_fmap : __rec_vmap; 143 SET(t, R_MEMMAPPED); 144 } 145 } 146 } 147 148 /* Use the recno routines. */ 149 dbp->close = __rec_close; 150 dbp->del = __rec_delete; 151 dbp->fd = __rec_fd; 152 dbp->get = __rec_get; 153 dbp->put = __rec_put; 154 dbp->seq = __rec_seq; 155 dbp->sync = __rec_sync; 156 157 /* If the root page was created, reset the flags. */ 158 if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL) 159 goto err; 160 if ((h->flags & P_TYPE) == P_BLEAF) { 161 h->flags = h->flags & ~P_TYPE | P_RLEAF; 162 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 163 } else 164 mpool_put(t->bt_mp, h, 0); 165 166 if (openinfo && openinfo->flags & R_SNAPSHOT && 167 !ISSET(t, R_EOF | R_INMEM) && 168 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR) 169 goto err; 170 return (dbp); 171 172 einval: errno = EINVAL; 173 err: sverrno = errno; 174 if (dbp != NULL) 175 (void)__bt_close(dbp); 176 if (fname != NULL) 177 (void)close(rfd); 178 errno = sverrno; 179 return (NULL); 180 } 181 182 int 183 __rec_fd(dbp) 184 const DB *dbp; 185 { 186 BTREE *t; 187 188 t = dbp->internal; 189 190 /* Toss any page pinned across calls. */ 191 if (t->bt_pinned != NULL) { 192 mpool_put(t->bt_mp, t->bt_pinned, 0); 193 t->bt_pinned = NULL; 194 } 195 196 /* In-memory database can't have a file descriptor. */ 197 if (ISSET(t, R_INMEM)) { 198 errno = ENOENT; 199 return (-1); 200 } 201 return (t->bt_rfd); 202 } 203