1 /*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * 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 5.16 (Berkeley) 03/23/93"; 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) 31 const char *fname; 32 int flags, mode; 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 = 0; 56 btopeninfo.compare = NULL; 57 btopeninfo.prefix = NULL; 58 btopeninfo.lorder = openinfo->lorder; 59 dbp = __bt_open(NULL, O_RDWR, S_IRUSR | S_IWUSR, &btopeninfo); 60 } else 61 dbp = __bt_open(NULL, O_RDWR, S_IRUSR | S_IWUSR, NULL); 62 if (dbp == NULL) 63 goto err; 64 65 /* 66 * Some fields in the tree structure are recno specific. Fill them 67 * in and make the btree structure look like a recno structure. We 68 * don't change the bt_ovflsize value, it's close enough and slightly 69 * bigger. 70 */ 71 t = dbp->internal; 72 if (openinfo) { 73 if (openinfo->flags & R_FIXEDLEN) { 74 SET(t, BTF_FIXEDLEN); 75 t->bt_reclen = openinfo->reclen; 76 if (t->bt_reclen == 0) 77 goto einval; 78 } 79 t->bt_bval = openinfo->bval; 80 } else 81 t->bt_bval = '\n'; 82 83 SET(t, BTF_RECNO); 84 if (fname == NULL) 85 SET(t, BTF_EOF | BTF_RINMEM); 86 else 87 t->bt_rfd = rfd; 88 t->bt_rcursor = 0; 89 90 /* 91 * In 4.4BSD stat(2) returns true for ISSOCK on pipes. Until 92 * then, this is fairly close. Pipes are read-only. 93 */ 94 if (fname != NULL) { 95 if (lseek(rfd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) { 96 switch (flags & O_ACCMODE) { 97 case O_RDONLY: 98 SET(t, BTF_RDONLY); 99 break; 100 default: 101 goto einval; 102 } 103 slow: if ((t->bt_rfp = fdopen(rfd, "r")) == NULL) 104 goto err; 105 SET(t, BTF_CLOSEFP); 106 t->bt_irec = 107 ISSET(t, BTF_FIXEDLEN) ? __rec_fpipe : __rec_vpipe; 108 } else { 109 switch (flags & O_ACCMODE) { 110 case O_RDONLY: 111 SET(t, BTF_RDONLY); 112 break; 113 case O_RDWR: 114 break; 115 default: 116 goto einval; 117 } 118 119 if (fstat(rfd, &sb)) 120 goto err; 121 if (sb.st_size > (off_t)SIZE_T_MAX) { 122 errno = EFBIG; 123 goto err; 124 } 125 if (sb.st_size == 0) 126 SET(t, BTF_EOF); 127 else { 128 t->bt_msize = sb.st_size; 129 if ((t->bt_smap = 130 mmap(NULL, t->bt_msize, PROT_READ, 0, rfd, 131 (off_t)0)) == (caddr_t)-1) 132 goto slow; 133 t->bt_cmap = t->bt_smap; 134 t->bt_emap = t->bt_smap + sb.st_size; 135 t->bt_irec = ISSET(t, BTF_FIXEDLEN) ? 136 __rec_fmap : __rec_vmap; 137 SET(t, BTF_MEMMAPPED); 138 } 139 } 140 } 141 142 /* Use the recno routines. */ 143 dbp->close = __rec_close; 144 dbp->del = __rec_delete; 145 dbp->get = __rec_get; 146 dbp->put = __rec_put; 147 dbp->seq = __rec_seq; 148 dbp->sync = __rec_sync; 149 150 /* If the root page was created, reset the flags. */ 151 if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL) 152 goto err; 153 if ((h->flags & P_TYPE) == P_BLEAF) { 154 h->flags = h->flags & ~P_TYPE | P_RLEAF; 155 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 156 } else 157 mpool_put(t->bt_mp, h, 0); 158 159 if (openinfo && openinfo->flags & R_SNAPSHOT && 160 !ISSET(t, BTF_EOF | BTF_RINMEM) && 161 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR) 162 goto err; 163 return (dbp); 164 165 einval: errno = EINVAL; 166 err: sverrno = errno; 167 if (dbp != NULL) 168 (void)__bt_close(dbp); 169 if (fname != NULL) 170 (void)close(rfd); 171 errno = sverrno; 172 return (NULL); 173 } 174