1 files changed, 98 insertions, 0 deletions
diff --git a/zen/long_path_prefix.h b/zen/long_path_prefix.h
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+++ b/zen/long_path_prefix.h
@@ -0,0 +1,98 @@
+// **************************************************************************
+// * This file is part of the FreeFileSync project. It is distributed under *
+// * GNU General Public License: http://www.gnu.org/licenses/gpl.html       *
+// * Copyright (C) 2008-2011 ZenJu (zhnmju123 AT gmx.de)                    *
+// **************************************************************************
+
+#ifndef LONGPATHPREFIX_H_INCLUDED
+#define LONGPATHPREFIX_H_INCLUDED
+
+#include "zstring.h"
+
+namespace zen
+{
+//handle filenames longer-equal 260 (== MAX_PATH) characters by applying \\?\-prefix (Reference: http://msdn.microsoft.com/en-us/library/aa365247(VS.85).aspx#maxpath)
+/*
+1. path must be absolute
+2. if path is smaller than MAX_PATH nothing is changed!
+3. path may already contain \\?\-prefix
+*/
+Zstring applyLongPathPrefix(const Zstring& path); //throw()
+Zstring applyLongPathPrefixCreateDir(const Zstring& path); //throw() -> special rule for ::CreateDirectoryEx(): MAX_PATH - 12(=^ 8.3 filename) is threshold
+
+Zstring removeLongPathPrefix(const Zstring& path); //throw()
+}
+
+
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+
+
+//################## implementation ##################
+
+//there are two flavors of long path prefix: one for UNC paths, one for regular paths
+const Zstring LONG_PATH_PREFIX     = L"\\\\?\\";
+const Zstring LONG_PATH_PREFIX_UNC = L"\\\\?\\UNC";
+
+template <size_t max_path> inline
+Zstring applyLongPathPrefixImpl(const Zstring& path)
+{
+    assert(!path.empty()); //nicely check almost all WinAPI accesses!
+
+    if (path.length() >= max_path &&    //maximum allowed path length without prefix is (MAX_PATH - 1)
+        !zen::startsWith(path, LONG_PATH_PREFIX))
+    {
+        if (zen::startsWith(path, L"\\\\")) //UNC-name, e.g. \\zenju-pc\Users
+            return LONG_PATH_PREFIX_UNC + zen::afterFirst(path, L'\\'); //convert to \\?\UNC\zenju-pc\Users
+        else
+            return LONG_PATH_PREFIX + path; //prepend \\?\ prefix
+    }
+    return path; //fallback
+}
+
+
+inline
+Zstring zen::applyLongPathPrefix(const Zstring& path)
+{
+    return applyLongPathPrefixImpl<MAX_PATH>(path);
+}
+
+
+inline
+Zstring zen::applyLongPathPrefixCreateDir(const Zstring& path) //throw()
+{
+    //special rule for ::CreateDirectoryEx(): MAX_PATH - 12(=^ 8.3 filename) is threshold
+    return applyLongPathPrefixImpl<MAX_PATH - 12> (path);
+}
+
+
+inline
+Zstring zen::removeLongPathPrefix(const Zstring& path) //throw()
+{
+    if (zen::startsWith(path, LONG_PATH_PREFIX))
+    {
+        if (zen::startsWith(path, LONG_PATH_PREFIX_UNC)) //UNC-name
+            return replaceCpy(path, LONG_PATH_PREFIX_UNC, Zstr("\\"), false);
+        else
+            return replaceCpy(path, LONG_PATH_PREFIX, Zstr(""), false);
+    }
+    return path; //fallback
+}
+
+#endif //LONGPATHPREFIX_H_INCLUDED