1 files changed, 98 insertions, 1 deletions

diff --git a/src/os_win/os_errno.c b/src/os_win/os_errno.c
index ce50106b0cc..00ee638fbe3 100644
--- a/src/os_win/os_errno.c
+++ b/src/os_win/os_errno.c
@@ -1,4 +1,5 @@
 /*-
+ * Copyright (c) 2014-2015 MongoDB, Inc.
  * Copyright (c) 2008-2014 WiredTiger, Inc.
  *	All rights reserved.
  *
@@ -7,6 +8,34 @@
 
 #include "wt_internal.h"
 
+static const int windows_error_offset = -29000;
+
+/*
+ * __wt_map_error_to_windows_error --
+ *	Return a negative integer, an encoded Windows error
+ * Standard C errors are positive integers from 0 - ~200
+ * Windows errors are from 0 - 15999 according to the documentation
+ */
+static DWORD
+__wt_map_error_to_windows_error(int error) {
+	/* Ensure we do not exceed the error range
+	   Also validate he do not get any COM errors
+	   (which are negative integers)
+	*/
+	WT_ASSERT(NULL, error > 0 && error > -(windows_error_offset));
+
+	return (error + -(windows_error_offset));
+}
+
+/*
+ * __wt_map_error_to_windows_error --
+ *	Return a positive integer, a decoded Windows error
+ */
+static int
+__wt_map_windows_error_to_error(DWORD winerr) {
+	return (winerr + windows_error_offset);
+}
+
 /*
  * __wt_errno --
  *	Return errno, or WT_ERROR if errno not set.
@@ -23,5 +52,73 @@ __wt_errno(void)
 	/* GetLastError should only be called if we hit an actual error */
 	WT_ASSERT(NULL, err != ERROR_SUCCESS);
 
-	return (err == ERROR_SUCCESS ? WT_ERROR : err);
+	return (err == ERROR_SUCCESS ?
+	    WT_ERROR : __wt_map_windows_error_to_error(err));
+}
+
+/*
+ * __wt_strerror --
+ *	Windows implementation of wiredtiger_strerror.
+ */
+const char *
+__wt_strerror(int error)
+{
+	const char *p;
+
+	/*
+	 * POSIX errors are non-negative integers; check for 0 explicitly
+	 * in-case the underlying strerror doesn't handle 0, some don't.
+	 */
+	if (error == 0)
+		return ("Successful return: 0");
+	if (error > 0 && (p = strerror(error)) != NULL)
+		return (p);
+	return (NULL);
+}
+
+/*
+ * __wt_strerror_r --
+ *	Windows implementation of wiredtiger_strerror_r.
+ */
+int
+__wt_strerror_r(int error, char *buf, size_t buflen)
+{
+	DWORD lasterror;
+	const char *p;
+
+	/* Require at least 2 bytes, printable character and trailing nul. */
+	if (buflen < 2)
+		return (ENOMEM);
+
+	/*
+	 * Check for POSIX errors, Windows errors, then fallback to something
+	 * generic.  Copy the string into the user's buffer, return success if
+	 * anything printed.
+	 */
+	p = __wt_strerror(error);
+	if (p != NULL && snprintf(buf, buflen, "%s", p) > 0)
+		return (0);
+
+	if (error < 0) {
+		error = __wt_map_error_to_windows_error(error);
+
+		lasterror = FormatMessageA(
+			FORMAT_MESSAGE_FROM_SYSTEM |
+			    FORMAT_MESSAGE_IGNORE_INSERTS,
+			NULL,
+			error,
+			0, /* let system choose the correct LANGID */
+			buf,
+			buflen,
+			NULL);
+
+		if (lasterror != 0)
+			return (0);
+
+		/* Fall through to the fallback error code */
+	}
+
+	/* Fallback to a generic message, then guess it's a memory problem. */
+	return (
+	    snprintf(buf, buflen, "error return: %d", error) > 0 ? 0 : ENOMEM);
 }