commit 4f000043ec4a5b1986eead39d48c291a118c4496
author Ben Reich <benreich@chromium.org> Tue Apr 23 00:44:36 2024
committer Chromium LUCI CQ <chromium-scoped@luci-project-accounts.iam.gserviceaccount.com> Tue Apr 23 00:44:36 2024
tree a63cbc828380af5e5d6a1b31bdfcfd34e6932b14
parent 2707037f1ca5b26d0e50210b9d8eafe4242c6fde

[FspCache] Ensure only bytes available locally are served from cache

There are a number of readers that always make requests for chunks of
512KiB despite the file not being that big OR the last chunk not being
that size. In the event this happens, currently we count that as a
cache miss (despite the underlying FSP serving the exact same data
that we have locally).

To get around this, extract the size from the `OpenFileCallback` and
use this to ensure the bytes that are known on disk are always served
if the same bytes that are known in the cloud are being served. Another
side effect of this is when a large file is being streamed (e.g. a
video being played by Gallery) this may be stopped mid way through
leaving only half the file on disk. If this occurs, the new logic
will ensure all local requests are served locally, whilst any data
that isn't available locally will be served via the FSP.

Bug: b/335548899
Test: unit_tests --gtest_filter=FileSystemProviderContentCacheImplTest*
Change-Id: I7cb84879158f8ae8fa5b7449ee23eb17afbccb01
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5465336
Reviewed-by: Cassy Chun-Crogan <cassycc@google.com>
Commit-Queue: Ben Reich <benreich@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1290996}