- def readfrom(self, offset, size, num_retries):
- """Read upto `size` bytes from the file starting at `offset`."""
+
+ def readfrom(self, offset, size, num_retries, exact=False):
+ """Read up to `size` bytes from the file starting at `offset`.
+
+ :exact:
+ If False (default), return less data than requested if the read
+ crosses a block boundary and the next block isn't cached. If True,
+ only return less data than requested when hitting EOF.
+ """