1 files changed, 108 insertions, 0 deletions
diff --git a/db-4.8.30/os_windows/os_unlink.c b/db-4.8.30/os_windows/os_unlink.c
new file mode 100644
index 0000000..7b5544c
--- /dev/null
+++ b/db-4.8.30/os_windows/os_unlink.c
@@ -0,0 +1,108 @@
+/*-
+ * See the file LICENSE for redistribution information.
+ *
+ * Copyright (c) 1997-2009 Oracle.  All rights reserved.
+ *
+ * $Id$
+ */
+
+#include "db_config.h"
+
+#include "db_int.h"
+
+/*
+ * __os_unlink --
+ *	Remove a file.
+ */
+int
+__os_unlink(env, path, overwrite_test)
+	ENV *env;
+	const char *path;
+	int overwrite_test;
+{
+	DB_ENV *dbenv;
+	HANDLE h;
+	_TCHAR *tpath, *orig_tpath, buf[DB_MAXPATHLEN];
+	u_int32_t id;
+	int ret, t_ret;
+
+	dbenv = env == NULL ? NULL : env->dbenv;
+
+	if (dbenv != NULL &&
+	    FLD_ISSET(dbenv->verbose, DB_VERB_FILEOPS | DB_VERB_FILEOPS_ALL))
+		__db_msg(env, "fileops: unlink %s", path);
+
+	/* Optionally overwrite the contents of the file to enhance security. */
+	if (dbenv != NULL && overwrite_test && F_ISSET(dbenv, DB_ENV_OVERWRITE))
+		(void)__db_file_multi_write(env, path);
+
+	TO_TSTRING(env, path, tpath, ret);
+	if (ret != 0)
+		return (ret);
+	orig_tpath = tpath;
+
+	LAST_PANIC_CHECK_BEFORE_IO(env);
+
+	/*
+	 * Windows NT and its descendants 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(env, &id);
+		_sntprintf(buf, DB_MAXPATHLEN, _T("%s.del.%010u"), tpath, id);
+		if (MoveFile(tpath, buf))
+			tpath = buf;
+		else {
+			ret = __os_get_syserr();
+			if (__os_posix_err(ret) != ENOENT)
+				__db_err(env, ret,
+				    "MoveFile: rename %s to temporary file",
+				    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 | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
+		    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(env, 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 ENV->remove) that we
+	 * are expecting not to be there.  Reporting errors in these cases
+	 * is annoying.
+	 */
+	if (ret != 0) {
+		if ((t_ret = __os_posix_err(ret)) != ENOENT)
+			__db_syserr(env, ret, "DeleteFile: %s", path);
+		ret = t_ret;
+	}
+
+	return (ret);
+}