Getting both Metadata and Content with a Single request

[tsawada]

I might be wrong but looking at our distributed traces, it seems following code will send two GET (JSON API) requests to stogare.googleapis.com

Blob blob = storage.get(blobId);
byte[] content = blob.getContent();

Is there a way to get both the content and (some) metadata with a single request? There's Storage.readAllBytes but it does not return metadata.
We are specifically interested in Content-Encoding, Content-Type and a few other standard headers (Cache-Control, Content-Length, etc).

We have millions of small objects, and it'd be great if we can cut both the latency and the cost by half.

[tsawada]

I guess the v2 API readObjectCallable is what I am looking for?

[BenWhitehead]

We have this information internally to the library, but are constrained on exposing it due to some historically janky api decisions.

ReadChannel is a common interface from the google-cloud-core library. Unfortunately we can't add the BlobInfo resource to that interface without adding generics and causing warnings for existing users of the interface. And we can't change Storage#reader to return a more specialized implementation of the interface without breaking binary compatibility.

There are already many different "download" methods on the library leading to confusion for some customers (specific example: some customers don't use Storage#readAllBytes even though they don't need any metadata instead doing Storage.get(id).getContent()).

There are some new features in the works that are expected later this year that might be a good time for us to add another method with new functionality rather than simply yet another download method along with all the others.

At this time we don't recommend customers use the v2/storage StorageClient directly themselves. There's lots of sharp edges (no automatic retries among them) that the com.google.cloud.storage.GrpcStorageOptions based instance of Storage smooths over.

I hope to be able to provide more of an update on the feature implementation within the next couple of months.