mariadb/storage/bdb/os_win32/os_unlink.c
2005-12-05 10:27:46 -08:00

115 lines
2.9 KiB
C

/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1997-2005
* Sleepycat Software. All rights reserved.
*
* $Id: os_unlink.c,v 12.7 2005/10/20 18:57:08 bostic Exp $
*/
#include "db_config.h"
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#include <string.h>
#endif
#include "db_int.h"
/*
* __os_region_unlink --
* Remove a shared memory object file.
*/
int
__os_region_unlink(dbenv, path)
DB_ENV *dbenv;
const char *path;
{
if (F_ISSET(dbenv, DB_ENV_OVERWRITE))
(void)__db_file_multi_write(dbenv, path);
return (__os_unlink(dbenv, path));
}
/*
* __os_unlink --
* Remove a file.
*
* PUBLIC: int __os_unlink __P((DB_ENV *, const char *));
*/
int
__os_unlink(dbenv, path)
DB_ENV *dbenv;
const char *path;
{
HANDLE h;
_TCHAR *tpath, *orig_tpath, buf[MAXPATHLEN];
u_int32_t id;
int ret;
if (DB_GLOBAL(j_unlink) != NULL) {
ret = DB_GLOBAL(j_unlink)(path);
goto done;
}
TO_TSTRING(dbenv, path, tpath, ret);
if (ret != 0)
return (ret);
orig_tpath = tpath;
/*
* Windows NT and its descendents allow removal of open files, but the
* DeleteFile Win32 system call isn't equivalent to a POSIX unlink.
* Firstly, it only succeeds if FILE_SHARE_DELETE is set when the file
* is opened. Secondly, it leaves the file in a "zombie" state, where
* it can't be opened again, but a new file with the same name can't be
* created either.
*
* Since we depend on being able to recreate files (during recovery,
* say), we have to first rename the file, and then delete it. It
* still hangs around, but with a name we don't care about. The rename
* will fail if the file doesn't exist, which isn't a problem, but if
* it fails for some other reason, we need to know about it or a
* subsequent open may fail for no apparent reason.
*/
if (__os_is_winnt()) {
__os_unique_id(dbenv, &id);
_sntprintf(buf, MAXPATHLEN, _T("%s.del.%010u"), tpath, id);
if (MoveFile(tpath, buf))
tpath = buf;
else if (__os_get_errno() != ENOENT)
__db_err(dbenv,
"unlink: rename %s to temporary file failed", path);
/*
* Try removing the file using the delete-on-close flag. This
* plays nicer with files that are still open than DeleteFile.
*/
h = CreateFile(tpath, 0, FILE_SHARE_READ, NULL, OPEN_EXISTING,
FILE_FLAG_DELETE_ON_CLOSE, 0);
if (h != INVALID_HANDLE_VALUE) {
(void)CloseHandle (h);
if (GetFileAttributes(tpath) == INVALID_FILE_ATTRIBUTES)
goto skipdel;
}
}
RETRY_CHK((!DeleteFile(tpath)), ret);
skipdel:
FREE_STRING(dbenv, orig_tpath);
/*
* XXX
* We shouldn't be testing for an errno of ENOENT here, but ENOENT
* signals that a file is missing, and we attempt to unlink things
* (such as v. 2.x environment regions, in DB_ENV->remove) that we
* are expecting not to be there. Reporting errors in these cases
* is annoying.
*/
done: if (ret != 0 && ret != ENOENT)
__db_err(dbenv, "unlink: %s: %s", path, strerror(ret));
return (ret);
}