Graphsync 2.1 Metadata Only Request #371
Description
What
As we look to the future, one very useful way to use Graphsync is to discover the CIDs that make up a response to a selector query, but use another protocol (i.e. Bitswap likely) to actually get the data.
With this in mind, we would introduce a new Request type to the Graphsync message: a "Metadata" request type.
There are several steps here:
- Responder sends no blocks, just metadata #372
- Expose RequestMetadata method on graphsync client #373
- Extract the reconciled loader #374
- Support caching layer for metadata traversals on the responder to answer future requests quickly #375
- Backward compatibility for graphsync 2.1 protocol #376
- Include block size in metadata #377