diff options
Diffstat (limited to 'storage/bdb/os/os_fid.c')
-rw-r--r-- | storage/bdb/os/os_fid.c | 135 |
1 files changed, 0 insertions, 135 deletions
diff --git a/storage/bdb/os/os_fid.c b/storage/bdb/os/os_fid.c deleted file mode 100644 index 9d5633a43d7..00000000000 --- a/storage/bdb/os/os_fid.c +++ /dev/null @@ -1,135 +0,0 @@ -/*- - * See the file LICENSE for redistribution information. - * - * Copyright (c) 1996-2005 - * Sleepycat Software. All rights reserved. - * - * $Id: os_fid.c,v 12.4 2005/10/14 15:33:08 bostic Exp $ - */ - -#include "db_config.h" - -#ifndef NO_SYSTEM_INCLUDES -#include <sys/types.h> -#include <sys/stat.h> - -#include <stdlib.h> -#include <string.h> -#endif - -#include "db_int.h" - -/* - * __os_fileid -- - * Return a unique identifier for a file. The structure - * of a fileid is: ino(4) dev(4) time(4) pid(4) extra(4). - * For real files, which have a backing inode and device, the first - * 16 bytes are filled in and the extra bytes are left 0. For - * temporary files, the inode and device fields are left blank and - * the extra four bytes are filled in with a random value. - * - * PUBLIC: int __os_fileid __P((DB_ENV *, const char *, int, u_int8_t *)); - */ -int -__os_fileid(dbenv, fname, unique_okay, fidp) - DB_ENV *dbenv; - const char *fname; - int unique_okay; - u_int8_t *fidp; -{ - pid_t pid; - db_threadid_t tid; - struct stat sb; - size_t i; - int ret; - u_int32_t tmp; - u_int8_t *p; - - /* Clear the buffer. */ - memset(fidp, 0, DB_FILE_ID_LEN); - - /* On POSIX/UNIX, use a dev/inode pair. */ -#ifdef HAVE_VXWORKS - RETRY_CHK((stat((char *)fname, &sb)), ret); -#else - RETRY_CHK((stat(fname, &sb)), ret); -#endif - if (ret != 0) { - __db_err(dbenv, "%s: %s", fname, strerror(ret)); - return (ret); - } - - /* - * !!! - * Nothing is ever big enough -- on Sparc V9, st_ino, st_dev and the - * time_t types are all 8 bytes. As DB_FILE_ID_LEN is only 20 bytes, - * we convert to a (potentially) smaller fixed-size type and use it. - * - * We don't worry about byte sexing or the actual variable sizes. - * - * When this routine is called from the DB access methods, it's only - * called once -- whatever ID is generated when a database is created - * is stored in the database file's metadata, and that is what is - * saved in the mpool region's information to uniquely identify the - * file. - * - * When called from the mpool layer this routine will be called each - * time a new thread of control wants to share the file, which makes - * things tougher. As far as byte sexing goes, since the mpool region - * lives on a single host, there's no issue of that -- the entire - * region is byte sex dependent. As far as variable sizes go, we make - * the simplifying assumption that 32-bit and 64-bit processes will - * get the same 32-bit values if we truncate any returned 64-bit value - * to a 32-bit value. When we're called from the mpool layer, though, - * we need to be careful not to include anything that isn't - * reproducible for a given file, such as the timestamp or serial - * number. - */ - tmp = (u_int32_t)sb.st_ino; - for (p = (u_int8_t *)&tmp, i = sizeof(u_int32_t); i > 0; --i) - *fidp++ = *p++; - - tmp = (u_int32_t)sb.st_dev; - for (p = (u_int8_t *)&tmp, i = sizeof(u_int32_t); i > 0; --i) - *fidp++ = *p++; - - if (unique_okay) { - static u_int32_t fid_serial = 0; - - /* Add in 32-bits of (hopefully) unique number. */ - __os_unique_id(dbenv, &tmp); - for (p = (u_int8_t *)&tmp, i = sizeof(u_int32_t); i > 0; --i) - *fidp++ = *p++; - - /* - * Initialize/increment the serial number we use to help - * avoid fileid collisions. Note we don't bother with - * locking; it's unpleasant to do from down in here, and - * if we race on this no real harm will be done, since the - * finished fileid has so many other components. - * - * We use the bottom 32-bits of the process ID, hoping they - * are more random than the top 32-bits (should we be on a - * machine with 64-bit process IDs). - * - * We increment by 100000 on each call as a simple way of - * randomizing; simply incrementing seems potentially less - * useful if pids are also simply incremented, since this - * is process-local and we may be one of a set of processes - * starting up. 100000 pushes us out of pid space on most - * 32-bit platforms, and has few interesting properties in - * base 2. - */ - if (fid_serial == 0) { - dbenv->thread_id(dbenv, &pid, &tid); - fid_serial = (u_int32_t)pid; - } else - fid_serial += 100000; - - for (p = - (u_int8_t *)&fid_serial, i = sizeof(u_int32_t); i > 0; --i) - *fidp++ = *p++; - } - - return (0); -} |