diff options
Diffstat (limited to 'db2/os/db_os_fid.c')
-rw-r--r-- | db2/os/db_os_fid.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/db2/os/db_os_fid.c b/db2/os/db_os_fid.c new file mode 100644 index 0000000000..8fa55fa56c --- /dev/null +++ b/db2/os/db_os_fid.c @@ -0,0 +1,126 @@ +/*- + * See the file LICENSE for redistribution information. + * + * Copyright (c) 1996, 1997 + * Sleepycat Software. All rights reserved. + */ + +#include "config.h" + +#ifndef lint +static const char sccsid[] = "@(#)db_os_fid.c 10.7 (Sleepycat) 8/21/97"; +#endif /* not lint */ + +#ifndef NO_SYSTEM_INCLUDES +#include <sys/types.h> +#include <sys/stat.h> + +#include <errno.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> +#endif + +#include "db_int.h" +#include "db_page.h" +#include "os_ext.h" +#include "common_ext.h" + +/* + * __db_fileid -- + * Return a unique identifier for a file. + * + * PUBLIC: int __db_fileid __P((DB_ENV *, const char *, int, u_int8_t *)); + */ +int +__db_fileid(dbenv, fname, timestamp, fidp) + DB_ENV *dbenv; + const char *fname; + int timestamp; + u_int8_t *fidp; +{ + time_t now; + u_int8_t *p; + unsigned int i; + +#ifdef _WIN32 + /* + * The documentation for GetFileInformationByHandle() states that the + * inode-type numbers are not constant between processes. Actually, + * they are, they're the NTFS MFT indexes. So, this works on NTFS, + * but perhaps not on other platforms, and perhaps not over a network. + * Can't think of a better solution right now. + */ + int fd = 0; + HANDLE fh = 0; + BY_HANDLE_FILE_INFORMATION fi; + BOOL retval = FALSE; + + /* Clear the buffer. */ + memset(fidp, 0, DB_FILE_ID_LEN); + + /* first we open the file, because we're not given a handle to it */ + fd = open(fname,_O_RDONLY,_S_IREAD); + if (-1 == fd) { + /* If we can't open it, we're in trouble */ + return (errno); + } + + /* File open, get its info */ + fh = (HANDLE)_get_osfhandle(fd); + if ((HANDLE)(-1) != fh) { + retval = GetFileInformationByHandle(fh,&fi); + } + close(fd); + + /* + * We want the three 32-bit words which tell us the volume ID and + * the file ID. We make a crude attempt to copy the bytes over to + * the callers buffer. + * + * DBDB: really we should ensure that the bytes get packed the same + * way on all compilers, platforms etc. + */ + if ( ((HANDLE)(-1) != fh) && (TRUE == retval) ) { + memcpy(fidp, &fi.nFileIndexLow, sizeof(u_int32_t)); + fidp += sizeof(u_int32_t); + memcpy(fidp, &fi.nFileIndexHigh, sizeof(u_int32_t)); + fidp += sizeof(u_int32_t); + memcpy(fidp, &fi.dwVolumeSerialNumber, sizeof(u_int32_t)); + } +#else + struct stat sb; + + /* Clear the buffer. */ + memset(fidp, 0, DB_FILE_ID_LEN); + + /* Check for the unthinkable. */ + if (sizeof(sb.st_ino) + + sizeof(sb.st_dev) + sizeof(time_t) > DB_FILE_ID_LEN) + return (EINVAL); + + /* On UNIX, use a dev/inode pair. */ + if (stat(fname, &sb)) { + __db_err(dbenv, "%s: %s", fname, strerror(errno)); + return (errno); + } + + /* + * Use the inode first and in reverse order, hopefully putting the + * distinguishing information early in the string. + */ + for (p = (u_int8_t *)&sb.st_ino + + sizeof(sb.st_ino), i = 0; i < sizeof(sb.st_ino); ++i) + *fidp++ = *--p; + for (p = (u_int8_t *)&sb.st_dev + + sizeof(sb.st_dev), i = 0; i < sizeof(sb.st_dev); ++i) + *fidp++ = *--p; +#endif + if (timestamp) { + (void)time(&now); + for (p = (u_int8_t *)&now + + sizeof(now), i = 0; i < sizeof(now); ++i) + *fidp++ = *--p; + } + return (0); +} |