1 /*- 2 * See the file LICENSE for redistribution information. 3 * 4 * Copyright (c) 1996, 1997, 1998 5 * Sleepycat Software. All rights reserved. 6 */ 7 8 #include "config.h" 9 10 #ifndef lint 11 static const char sccsid[] = "@(#)os_fid.c 10.12 (Sleepycat) 7/21/98"; 12 #endif /* not lint */ 13 14 #ifndef NO_SYSTEM_INCLUDES 15 #include <sys/types.h> 16 #include <sys/stat.h> 17 18 #include <errno.h> 19 #include <string.h> 20 #include <time.h> 21 #endif 22 23 #include "db_int.h" 24 #include "common_ext.h" 25 26 /* 27 * __os_fileid -- 28 * Return a unique identifier for a file. 29 * 30 * PUBLIC: int __os_fileid __P((DB_ENV *, const char *, int, u_int8_t *)); 31 */ 32 int 33 __os_fileid(dbenv, fname, timestamp, fidp) 34 DB_ENV *dbenv; 35 const char *fname; 36 int timestamp; 37 u_int8_t *fidp; 38 { 39 struct stat sb; 40 size_t i; 41 time_t now; 42 u_int8_t *p; 43 44 /* Clear the buffer. */ 45 memset(fidp, 0, DB_FILE_ID_LEN); 46 47 /* Check for the unthinkable. */ 48 if (sizeof(sb.st_ino) + 49 sizeof(sb.st_dev) + sizeof(time_t) > DB_FILE_ID_LEN) 50 return (EINVAL); 51 52 /* On UNIX, use a dev/inode pair. */ 53 if (stat(fname, &sb)) { 54 __db_err(dbenv, "%s: %s", fname, strerror(errno)); 55 return (errno); 56 } 57 58 /* 59 * Use the inode first and in reverse order, hopefully putting the 60 * distinguishing information early in the string. 61 */ 62 for (p = (u_int8_t *)&sb.st_ino + 63 sizeof(sb.st_ino), i = 0; i < sizeof(sb.st_ino); ++i) 64 *fidp++ = *--p; 65 for (p = (u_int8_t *)&sb.st_dev + 66 sizeof(sb.st_dev), i = 0; i < sizeof(sb.st_dev); ++i) 67 *fidp++ = *--p; 68 69 if (timestamp) { 70 (void)time(&now); 71 for (p = (u_int8_t *)&now + 72 sizeof(now), i = 0; i < sizeof(now); ++i) 73 *fidp++ = *--p; 74 } 75 return (0); 76 } 77