Update checked in version of gsutil to version 4.6

gslib/third_party/storage_apitools/stream_slice.py

+"""Small helper class to provide a small slice of a stream."""
+
+from gslib.third_party.storage_apitools import exceptions
+
+class StreamSlice(object):
+
+  def __init__(self, stream, max_bytes):
+    self.__stream = stream
+    self.__remaining_bytes = max_bytes
+    self.__max_bytes = max_bytes
+
+  def __str__(self):
+    return 'Slice of stream %s with %s/%s bytes not yet read' % (
+        self.__stream, self.__remaining_bytes, self.__max_bytes)
+
+  def __len__(self):
+    return self.__max_bytes
+
+  def read(self, size=None):
+    if size is not None:
+      size = min(size, self.__remaining_bytes)
+    else:
+      size = self.__remaining_bytes
+    data = self.__stream.read(size)
+    if not data and self.__remaining_bytes:
+      raise exceptions.TransferInvalidError(
+        'Not enough bytes in stream; expected %d, stream exhasted after %d' % (
+          self.__max_bytes, self.__remaining_bytes))
+    self.__remaining_bytes -= len(data)
+    return data