1 files changed, 133 insertions, 0 deletions
diff --git a/src/os_windows/os_config.c b/src/os_windows/os_config.c
new file mode 100644
index 00000000..4250dbd4
--- /dev/null
+++ b/src/os_windows/os_config.c
@@ -0,0 +1,133 @@
+/*-
+ * See the file LICENSE for redistribution information.
+ *
+ * Copyright (c) 1999, 2012 Oracle and/or its affiliates.  All rights reserved.
+ *
+ * $Id$
+ */
+
+#include "db_config.h"
+
+#include "db_int.h"
+
+/*
+ * __os_is_winnt --
+ *	Return 1 if Windows/NT, otherwise 0.
+ *
+ * PUBLIC: int __os_is_winnt __P((void));
+ */
+int
+__os_is_winnt()
+{
+#ifdef DB_WINCE
+	return (1);
+#else
+	static int __os_type = -1;
+
+	/*
+	 * The value of __os_type is computed only once, and cached to
+	 * avoid the overhead of repeated calls to GetVersion().
+	 */
+	if (__os_type == -1) {
+		if ((GetVersion() & 0x80000000) == 0)
+			__os_type = 1;
+		else
+			__os_type = 0;
+	}
+	return (__os_type);
+#endif
+}
+
+/*
+ * __os_fs_notzero --
+ *	Return 1 if allocated filesystem blocks are not zeroed.
+ */
+int
+__os_fs_notzero()
+{
+#ifdef DB_WINCE
+	return (1);
+#else
+	static int __os_notzero = -1;
+	OSVERSIONINFO osvi;
+
+	/*
+	 * Windows/NT zero-fills pages that were never explicitly written to
+	 * the file.  Note however that this is *NOT* documented.  In fact, the
+	 * Win32 documentation makes it clear that there are no guarantees that
+	 * uninitialized bytes will be zeroed:
+	 *
+	 *   If the file is extended, the contents of the file between the old
+	 *   EOF position and the new position are not defined.
+	 *
+	 * Experiments confirm that NT/2K/XP all zero fill for both NTFS and
+	 * FAT32.  Cygwin also relies on this behavior.  This is the relevant
+	 * comment from Cygwin:
+	 *
+	 *    Oops, this is the bug case - Win95 uses whatever is on the disk
+	 *    instead of some known (safe) value, so we must seek back and fill
+	 *    in the gap with zeros. - DJ
+	 *    Note: this bug doesn't happen on NT4, even though the
+	 *    documentation for WriteFile() says that it *may* happen on any OS.
+	 *
+	 * We're making a bet, here, but we made it a long time ago and haven't
+	 * yet seen any evidence that it was wrong.
+	 *
+	 * Windows 95/98 and On-Time give random garbage, and that breaks
+	 * Berkeley DB.
+	 *
+	 * The value of __os_notzero is computed only once, and cached to
+	 * avoid the overhead of repeated calls to GetVersion().
+	 */
+	if (__os_notzero == -1) {
+		if (__os_is_winnt()) {
+			osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
+			GetVersionEx(&osvi);
+			if (_tcscmp(osvi.szCSDVersion, _T("RTTarget-32")) == 0)
+				__os_notzero = 1;	/* On-Time */
+			else
+				__os_notzero = 0;	/* Windows/NT */
+		} else
+			__os_notzero = 1;		/* Not Windows/NT */
+	}
+	return (__os_notzero);
+#endif
+}
+
+/*
+ * __os_support_direct_io --
+ *	Check to see if we support direct I/O.
+ */
+int
+__os_support_direct_io()
+{
+	return (1);
+}
+
+/*
+ * __os_support_db_register --
+ *	Return 1 if the system supports DB_REGISTER.
+ */
+int
+__os_support_db_register()
+{
+#ifdef DB_WINCE
+	return (0);
+#else
+	return (__os_is_winnt());
+#endif
+}
+
+/*
+ * __os_support_replication --
+ *	Return 1 if the system supports replication.
+ */
+int
+__os_support_replication()
+{
+#ifdef DB_WINCE
+	return (0);
+#else
+	return (__os_is_winnt());
+#endif
+}