46     // namespace for extended user attributes
  47     private static final String USER_NAMESPACE = "user.";
  48 
  49     // maximum bytes in extended attribute name (includes namespace)
  50     private static final int XATTR_NAME_MAX = 255;
  51 
  52     private byte[] nameAsBytes(UnixPath file, String name) throws IOException {
  53         if (name == null)
  54             throw new NullPointerException("'name' is null");
  55         name = USER_NAMESPACE + name;
  56         byte[] bytes = name.getBytes();
  57         if (bytes.length > XATTR_NAME_MAX) {
  58             throw new FileSystemException(file.getPathForExecptionMessage(),
  59                 null, "'" + name + "' is too big");
  60         }
  61         return bytes;
  62     }
  63 
  64     // Parses buffer as array of NULL-terminated C strings.
  65     private List<String> asList(long address, int size) {
  66         final List<String> list = new ArrayList<String>();
  67         int start = 0;
  68         int pos = 0;
  69         while (pos < size) {
  70             if (unsafe.getByte(address + pos) == 0) {
  71                 int len = pos - start;
  72                 byte[] value = new byte[len];
  73                 unsafe.copyMemory(null, address+start, value,
  74                     Unsafe.ARRAY_BYTE_BASE_OFFSET, len);
  75                 String s = new String(value);
  76                 if (s.startsWith(USER_NAMESPACE)) {
  77                     s = s.substring(USER_NAMESPACE.length());
  78                     list.add(s);
  79                 }
  80                 start = pos + 1;
  81             }
  82             pos++;
  83         }
  84         return list;
  85     }
  86 

  46     // namespace for extended user attributes
  47     private static final String USER_NAMESPACE = "user.";
  48 
  49     // maximum bytes in extended attribute name (includes namespace)
  50     private static final int XATTR_NAME_MAX = 255;
  51 
  52     private byte[] nameAsBytes(UnixPath file, String name) throws IOException {
  53         if (name == null)
  54             throw new NullPointerException("'name' is null");
  55         name = USER_NAMESPACE + name;
  56         byte[] bytes = name.getBytes();
  57         if (bytes.length > XATTR_NAME_MAX) {
  58             throw new FileSystemException(file.getPathForExecptionMessage(),
  59                 null, "'" + name + "' is too big");
  60         }
  61         return bytes;
  62     }
  63 
  64     // Parses buffer as array of NULL-terminated C strings.
  65     private List<String> asList(long address, int size) {
  66         final List<String> list = new ArrayList<>();
  67         int start = 0;
  68         int pos = 0;
  69         while (pos < size) {
  70             if (unsafe.getByte(address + pos) == 0) {
  71                 int len = pos - start;
  72                 byte[] value = new byte[len];
  73                 unsafe.copyMemory(null, address+start, value,
  74                     Unsafe.ARRAY_BYTE_BASE_OFFSET, len);
  75                 String s = new String(value);
  76                 if (s.startsWith(USER_NAMESPACE)) {
  77                     s = s.substring(USER_NAMESPACE.length());
  78                     list.add(s);
  79                 }
  80                 start = pos + 1;
  81             }
  82             pos++;
  83         }
  84         return list;
  85     }
  86