diff options
Diffstat (limited to 'storage/bdb/os_win32/os_fid.c')
| -rw-r--r-- | storage/bdb/os_win32/os_fid.c | 148 |
1 files changed, 0 insertions, 148 deletions
diff --git a/storage/bdb/os_win32/os_fid.c b/storage/bdb/os_win32/os_fid.c deleted file mode 100644 index b2e2340b67e..00000000000 --- a/storage/bdb/os_win32/os_fid.c +++ /dev/null @@ -1,148 +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 2005/10/11 18:17:00 bostic Exp $ - */ - -#include "db_config.h" - -#include "db_int.h" - -#define SERIAL_INIT 0 -static u_int32_t fid_serial = SERIAL_INIT; - -/* - * __os_fileid -- - * Return a unique identifier for a file. - */ -int -__os_fileid(dbenv, fname, unique_okay, fidp) - DB_ENV *dbenv; - const char *fname; - int unique_okay; - u_int8_t *fidp; -{ - db_threadid_t tid; - pid_t pid; - size_t i; - u_int32_t tmp; - u_int8_t *p; - int ret; - - /* - * 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. - */ - DB_FH *fhp; - BY_HANDLE_FILE_INFORMATION fi; - BOOL retval = FALSE; - - DB_ASSERT(fname != NULL); - - /* Clear the buffer. */ - memset(fidp, 0, DB_FILE_ID_LEN); - - /* - * Initialize/increment the serial number we use to help avoid - * fileid collisions. Note that 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 platforms, and has few - * interesting properties in base 2. - */ - if (fid_serial == SERIAL_INIT) { - __os_id(dbenv, &pid, &tid); - fid_serial = pid; - } else - fid_serial += 100000; - - /* - * First we open the file, because we're not given a handle to it. - * If we can't open it, we're in trouble. - */ - if ((ret = __os_open(dbenv, fname, DB_OSO_RDONLY, _S_IREAD, &fhp)) != 0) - return (ret); - - /* File open, get its info */ - if ((retval = GetFileInformationByHandle(fhp->handle, &fi)) == FALSE) - ret = __os_get_errno(); - (void)__os_closehandle(dbenv, fhp); - - if (retval == FALSE) - return (ret); - - /* - * 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. - * - * 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. - */ - tmp = (u_int32_t)fi.nFileIndexLow; - for (p = (u_int8_t *)&tmp, i = sizeof(u_int32_t); i > 0; --i) - *fidp++ = *p++; - tmp = (u_int32_t)fi.nFileIndexHigh; - for (p = (u_int8_t *)&tmp, i = sizeof(u_int32_t); i > 0; --i) - *fidp++ = *p++; - - if (unique_okay) { - /* - * Use the system time to try to get a unique value - * within this process. A millisecond counter - * overflows 32 bits in about 49 days. So we use 8 - * bytes, and don't bother with the volume ID, which - * is not very useful for our purposes. - */ - SYSTEMTIME st; - - GetSystemTime(&st); - tmp = (st.wYear - 1900) * 12 + (st.wMonth - 1); - for (p = (u_int8_t *)&tmp, i = sizeof(u_int32_t); i > 0; --i) - *fidp++ = *p++; - tmp = ((((st.wDay - 1) * 24 + st.wHour) * 60 + - st.wMinute) * 60 + st.wSecond) * 1000 + - st.wMilliseconds; - for (p = (u_int8_t *)&tmp, i = sizeof(u_int32_t); i > 0; --i) - *fidp++ = *p++; - for (p = (u_int8_t *)&fid_serial, i = sizeof(u_int32_t); - i > 0; --i) - *fidp++ = *p++; - } else { - tmp = (u_int32_t)fi.dwVolumeSerialNumber; - for (p = (u_int8_t *)&tmp, i = sizeof(u_int32_t); i > 0; --i) - *fidp++ = *p++; - } - - return (0); -} |