diff options
Diffstat (limited to 'db/btree/bt_open.c')
| -rw-r--r-- | db/btree/bt_open.c | 458 |
1 files changed, 0 insertions, 458 deletions
diff --git a/db/btree/bt_open.c b/db/btree/bt_open.c deleted file mode 100644 index 8c2f48ebf5..0000000000 --- a/db/btree/bt_open.c +++ /dev/null @@ -1,458 +0,0 @@ -/*- - * Copyright (c) 1990, 1993, 1994 - * The Regents of the University of California. All rights reserved. - * - * This code is derived from software contributed to Berkeley by - * Mike Olson. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * This product includes software developed by the University of - * California, Berkeley and its contributors. - * 4. Neither the name of the University nor the names of its contributors - * may be used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - */ - -#if defined(LIBC_SCCS) && !defined(lint) -static char sccsid[] = "@(#)bt_open.c 8.10 (Berkeley) 8/17/94"; -#endif /* LIBC_SCCS and not lint */ - -/* - * Implementation of btree access method for 4.4BSD. - * - * The design here was originally based on that of the btree access method - * used in the Postgres database system at UC Berkeley. This implementation - * is wholly independent of the Postgres code. - */ - -#include <sys/param.h> -#include <sys/stat.h> - -#include <errno.h> -#include <fcntl.h> -#include <limits.h> -#include <signal.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <unistd.h> - -#include <db.h> -#include "btree.h" - -#ifdef DEBUG -#undef MINPSIZE -#define MINPSIZE 128 -#endif - -static int byteorder __P((void)); -static int nroot __P((BTREE *)); -static int tmp __P((void)); - -/* - * __BT_OPEN -- Open a btree. - * - * Creates and fills a DB struct, and calls the routine that actually - * opens the btree. - * - * Parameters: - * fname: filename (NULL for in-memory trees) - * flags: open flag bits - * mode: open permission bits - * b: BTREEINFO pointer - * - * Returns: - * NULL on failure, pointer to DB on success. - * - */ -DB * -__bt_open(fname, flags, mode, openinfo, dflags) - const char *fname; - int flags, mode, dflags; - const BTREEINFO *openinfo; -{ - struct stat sb; - BTMETA m; - BTREE *t; - BTREEINFO b; - DB *dbp; - pgno_t ncache; - ssize_t nr; - int machine_lorder; - - t = NULL; - - /* - * Intention is to make sure all of the user's selections are okay - * here and then use them without checking. Can't be complete, since - * we don't know the right page size, lorder or flags until the backing - * file is opened. Also, the file's page size can cause the cachesize - * to change. - */ - machine_lorder = byteorder(); - if (openinfo) { - b = *openinfo; - - /* Flags: R_DUP. */ - if (b.flags & ~(R_DUP)) - goto einval; - - /* - * Page size must be indx_t aligned and >= MINPSIZE. Default - * page size is set farther on, based on the underlying file - * transfer size. - */ - if (b.psize && - (b.psize < MINPSIZE || b.psize > MAX_PAGE_OFFSET + 1 || - b.psize & (sizeof(indx_t) - 1))) - goto einval; - - /* Minimum number of keys per page; absolute minimum is 2. */ - if (b.minkeypage) { - if (b.minkeypage < 2) - goto einval; - } else - b.minkeypage = DEFMINKEYPAGE; - - /* If no comparison, use default comparison and prefix. */ - if (b.compare == NULL) { - b.compare = __bt_defcmp; - if (b.prefix == NULL) - b.prefix = __bt_defpfx; - } - - if (b.lorder == 0) - b.lorder = machine_lorder; - } else { - b.compare = __bt_defcmp; - b.cachesize = 0; - b.flags = 0; - b.lorder = machine_lorder; - b.minkeypage = DEFMINKEYPAGE; - b.prefix = __bt_defpfx; - b.psize = 0; - } - - /* Check for the ubiquitous PDP-11. */ - if (b.lorder != BIG_ENDIAN && b.lorder != LITTLE_ENDIAN) - goto einval; - - /* Allocate and initialize DB and BTREE structures. */ - if ((t = (BTREE *)malloc(sizeof(BTREE))) == NULL) - goto err; - memset(t, 0, sizeof(BTREE)); - t->bt_fd = -1; /* Don't close unopened fd on error. */ - t->bt_lorder = b.lorder; - t->bt_order = NOT; - t->bt_cmp = b.compare; - t->bt_pfx = b.prefix; - t->bt_rfd = -1; - - if ((t->bt_dbp = dbp = (DB *)malloc(sizeof(DB))) == NULL) - goto err; - memset(t->bt_dbp, 0, sizeof(DB)); - if (t->bt_lorder != machine_lorder) - F_SET(t, B_NEEDSWAP); - - dbp->type = DB_BTREE; - dbp->internal = t; - dbp->close = __bt_close; - dbp->del = __bt_delete; - dbp->fd = __bt_fd; - dbp->get = __bt_get; - dbp->put = __bt_put; - dbp->seq = __bt_seq; - dbp->sync = __bt_sync; - - /* - * If no file name was supplied, this is an in-memory btree and we - * open a backing temporary file. Otherwise, it's a disk-based tree. - */ - if (fname) { - switch (flags & O_ACCMODE) { - case O_RDONLY: - F_SET(t, B_RDONLY); - break; - case O_RDWR: - break; - case O_WRONLY: - default: - goto einval; - } - - if ((t->bt_fd = open(fname, flags, mode)) < 0) - goto err; - - } else { - if ((flags & O_ACCMODE) != O_RDWR) - goto einval; - if ((t->bt_fd = tmp()) == -1) - goto err; - F_SET(t, B_INMEM); - } - - if (fcntl(t->bt_fd, F_SETFD, 1) == -1) - goto err; - - if (fstat(t->bt_fd, &sb)) - goto err; - if (sb.st_size) { - if ((nr = read(t->bt_fd, &m, sizeof(BTMETA))) < 0) - goto err; - if (nr != sizeof(BTMETA)) - goto eftype; - - /* - * Read in the meta-data. This can change the notion of what - * the lorder, page size and flags are, and, when the page size - * changes, the cachesize value can change too. If the user - * specified the wrong byte order for an existing database, we - * don't bother to return an error, we just clear the NEEDSWAP - * bit. - */ - if (m.magic == BTREEMAGIC) - F_CLR(t, B_NEEDSWAP); - else { - F_SET(t, B_NEEDSWAP); - M_32_SWAP(m.magic); - M_32_SWAP(m.version); - M_32_SWAP(m.psize); - M_32_SWAP(m.free); - M_32_SWAP(m.nrecs); - M_32_SWAP(m.flags); - } - if (m.magic != BTREEMAGIC || m.version != BTREEVERSION) - goto eftype; - if (m.psize < MINPSIZE || m.psize > MAX_PAGE_OFFSET + 1 || - m.psize & (sizeof(indx_t) - 1)) - goto eftype; - if (m.flags & ~SAVEMETA) - goto eftype; - b.psize = m.psize; - F_SET(t, m.flags); - t->bt_free = m.free; - t->bt_nrecs = m.nrecs; - } else { - /* - * Set the page size to the best value for I/O to this file. - * Don't overflow the page offset type. - */ - if (b.psize == 0) { -#ifdef _STATBUF_ST_BLKSIZE - b.psize = sb.st_blksize; -#endif - if (b.psize < MINPSIZE) - b.psize = MINPSIZE; - if (b.psize > MAX_PAGE_OFFSET + 1) - b.psize = MAX_PAGE_OFFSET + 1; - } - - /* Set flag if duplicates permitted. */ - if (!(b.flags & R_DUP)) - F_SET(t, B_NODUPS); - - t->bt_free = P_INVALID; - t->bt_nrecs = 0; - F_SET(t, B_METADIRTY); - } - - t->bt_psize = b.psize; - - /* Set the cache size; must be a multiple of the page size. */ - if (b.cachesize && b.cachesize & (b.psize - 1)) - b.cachesize += (~b.cachesize & (b.psize - 1)) + 1; - if (b.cachesize < b.psize * MINCACHE) - b.cachesize = b.psize * MINCACHE; - - /* Calculate number of pages to cache. */ - ncache = (b.cachesize + t->bt_psize - 1) / t->bt_psize; - - /* - * The btree data structure requires that at least two keys can fit on - * a page, but other than that there's no fixed requirement. The user - * specified a minimum number per page, and we translated that into the - * number of bytes a key/data pair can use before being placed on an - * overflow page. This calculation includes the page header, the size - * of the index referencing the leaf item and the size of the leaf item - * structure. Also, don't let the user specify a minkeypage such that - * a key/data pair won't fit even if both key and data are on overflow - * pages. - */ - t->bt_ovflsize = (t->bt_psize - BTDATAOFF) / b.minkeypage - - (sizeof(indx_t) + NBLEAFDBT(0, 0)); - if (t->bt_ovflsize < NBLEAFDBT(NOVFLSIZE, NOVFLSIZE) + sizeof(indx_t)) - t->bt_ovflsize = - NBLEAFDBT(NOVFLSIZE, NOVFLSIZE) + sizeof(indx_t); - - /* Initialize the buffer pool. */ - if ((t->bt_mp = - mpool_open(NULL, t->bt_fd, t->bt_psize, ncache)) == NULL) - goto err; - if (!F_ISSET(t, B_INMEM)) - mpool_filter(t->bt_mp, __bt_pgin, __bt_pgout, t); - - /* Create a root page if new tree. */ - if (nroot(t) == RET_ERROR) - goto err; - - /* Global flags. */ - if (dflags & DB_LOCK) - F_SET(t, B_DB_LOCK); - if (dflags & DB_SHMEM) - F_SET(t, B_DB_SHMEM); - if (dflags & DB_TXN) - F_SET(t, B_DB_TXN); - - return (dbp); - -einval: errno = EINVAL; - goto err; - -eftype: errno = EFTYPE; - goto err; - -err: if (t) { - if (t->bt_dbp) - free(t->bt_dbp); - if (t->bt_fd != -1) - (void)close(t->bt_fd); - free(t); - } - return (NULL); -} - -/* - * NROOT -- Create the root of a new tree. - * - * Parameters: - * t: tree - * - * Returns: - * RET_ERROR, RET_SUCCESS - */ -static int -nroot(t) - BTREE *t; -{ - PAGE *meta, *root; - pgno_t npg; - - if ((meta = mpool_get(t->bt_mp, 0, 0)) != NULL) { - mpool_put(t->bt_mp, meta, 0); - return (RET_SUCCESS); - } - if (errno != EINVAL) /* It's OK to not exist. */ - return (RET_ERROR); - errno = 0; - - if ((meta = mpool_new(t->bt_mp, &npg)) == NULL) - return (RET_ERROR); - - if ((root = mpool_new(t->bt_mp, &npg)) == NULL) - return (RET_ERROR); - - if (npg != P_ROOT) - return (RET_ERROR); - root->pgno = npg; - root->prevpg = root->nextpg = P_INVALID; - root->lower = BTDATAOFF; - root->upper = t->bt_psize; - root->flags = P_BLEAF; - memset(meta, 0, t->bt_psize); - mpool_put(t->bt_mp, meta, MPOOL_DIRTY); - mpool_put(t->bt_mp, root, MPOOL_DIRTY); - return (RET_SUCCESS); -} - -static int -tmp() -{ - sigset_t set, oset; - int fd; - const char *envtmp; - char *path; - static const char fmt[] = "%s/bt.XXXXXX"; - size_t n; - - envtmp = getenv("TMPDIR"); - if (!envtmp) - envtmp = "/tmp"; - n = strlen (envtmp) + sizeof fmt; -#ifdef __GNUC__ - path = __builtin_alloca(n); -#else - path = malloc(n); -#endif - (void)snprintf(path, n, fmt, envtmp ? envtmp : "/tmp"); - - (void)sigfillset(&set); - (void)sigprocmask(SIG_BLOCK, &set, &oset); - if ((fd = mkstemp(path)) != -1) - (void)unlink(path); - (void)sigprocmask(SIG_SETMASK, &oset, NULL); -#ifndef __GNUC__ - free(path); -#endif - return(fd); -} - -static int -byteorder() -{ - u_int32_t x; - u_char *p; - - x = 0x01020304; - p = (u_char *)&x; - switch (*p) { - case 1: - return (BIG_ENDIAN); - case 4: - return (LITTLE_ENDIAN); - default: - return (0); - } -} - -int -__bt_fd(dbp) - const DB *dbp; -{ - BTREE *t; - - t = dbp->internal; - - /* Toss any page pinned across calls. */ - if (t->bt_pinned != NULL) { - mpool_put(t->bt_mp, t->bt_pinned, 0); - t->bt_pinned = NULL; - } - - /* In-memory database can't have a file descriptor. */ - if (F_ISSET(t, B_INMEM)) { - errno = ENOENT; - return (-1); - } - return (t->bt_fd); -} |