We previously kept the trait of a BlobService sync.
This however had some annoying consequences:
- It became more and more complicated to track when we're in a context
with an async runtime in the context or not, producing bugs like
https://b.tvl.fyi/issues/304
- The sync trait shielded away async clients from async worloads,
requiring manual block_on code inside the gRPC client code, and
spawn_blocking calls in consumers of the trait, even if they were
async (like the gRPC server)
- We had to write our own custom glue code (SyncReadIntoAsyncRead)
to convert a sync io::Read into a tokio::io::AsyncRead, which already
existed in tokio internally, but upstream ia hesitant to expose.
This now makes the BlobService trait async (via the async_trait macro,
like we already do in various gRPC parts), and replaces the sync readers
and writers with their async counterparts.
Tests interacting with a BlobService now need to have an async runtime
available, the easiest way for this is to mark the test functions
with the tokio::test macro, allowing us to directly .await in the test
function.
In places where we don't have an async runtime available from context
(like tvix-cli), we can pass one down explicitly.
Now that we don't provide a sync interface anymore, the (sync) FUSE
library now holds a pointer to a tokio runtime handle, and needs to at
least have 2 threads available when talking to a blob service (which is
why some of the tests now use the multi_thread flavor).
The FUSE tests got a bit more verbose, as we couldn't use the
setup_and_mount function accepting a callback anymore. We can hopefully
move some of the test fixture setup to rstest in the future to make this
less repetitive.
Co-Authored-By: Connor Brewster <cbrewster@hey.com>
Change-Id: Ia0501b606e32c852d0108de9c9016b21c94a3c05
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9329
Reviewed-by: Connor Brewster <cbrewster@hey.com>
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
da6cbb4a45