tree c466f5854abe0d32d6e286d84f4a298669828036
parent cd7edbe3eeff0b4379649eea8308c325882407ff
author Amin Hassani <ahassani@google.com> 1504213755 -0700
committer chrome-bot <chrome-bot@chromium.org> 1506379959 -0700

update_engine: Add ExtentReader

Currently Each operation in DeltaPerformer has the responsibility of
reading from the source device by itself. Adding an
ExtentReader (similar to ExtentWriter) aggregates all these
responsibilities on DeltaPerformer.source_fd_. This simplifies the
design as each operation does not need to invent is own open/read/close
etc. This specially will be used in conjunction with bspatch and puffin.

BUG=chromium:761138
TEST=FEATURES="test" emerge-amd64-generic update_engine;

Change-Id: I2c7a21a02bd1df06bbaa7ebf374a13f654768721
Reviewed-on: https://chromium-review.googlesource.com/651336
Commit-Ready: Amin Hassani <ahassani@chromium.org>
Tested-by: Amin Hassani <ahassani@chromium.org>
Reviewed-by: Andrew de los Reyes <adlr@chromium.org>
Reviewed-by: Sen Jiang <senj@chromium.org>