tree 2e653344d2913f19892dfdbbe6c9f677fc1917f5
parent 927179d9190e15fa4b2829eb12a8aeb8f297afdf
author Darin Petkov <petkov@chromium.org> 1291330026 -0800
committer Darin Petkov <petkov@chromium.org> 1291330026 -0800

Restructure FilesystemCopierAction to use ping-pong buffers.

This would allow some parallel processing -- calculating hashes in parallel with
read in parallel with write. Performance benefit at this stage seems
marginal. The major reason for the change is to reuse the FilesystemCopierAction
for applied update verification -- hopefully speeding it up and making AU
responsive to D-Bus signals during that stage. That would be a separate CL
though.

BUG=9140
TEST=unit tests, tested update on the device

Change-Id: I9d07ebbf4d536362c0a955addcaa1d48d5e9b115

Review URL: http://codereview.chromium.org/5603001