This commit adds a new add option: "format".
This option specifies how IPFS Cluster is expected to build the DAG when
adding content. By default, it takes a "unixfs", which chunks and DAG-ifies as
it did before, resulting in a UnixFSv1 DAG.
Alternatively, it can be set to "car". In this case, Cluster will directly
read blocks from the CAR file and add them.
Adding CAR files or doing normal processing is independent from letting
cluster do sharding or not. If sharding is ever enabled, Cluster could
potentially shard a large CAR file among peers.
Currently, importing CAR files is limited to a single CAR file with a single
root (the one that is pinned). Future iterations may support multiple CARs
and/or multiple roots by transparently wrapping them.
I had thought of this for a very long time but there were no compelling
reasons to do it. Specifying RPC endpoint permissions becomes however
significantly nicer if each Component is a different RPC Service. This also
fixes some naming issues like having to prefix methods with the component name
to separate them from methods named in the same way in some other component
(Pin and IPFSPin).
This takes advantange of the latest features in go-cid, peer.ID and
go-multiaddr and makes the Go types serializable by default.
This means we no longer need to copy between Pin <-> PinSerial, or ID <->
IDSerial etc. We can now efficiently binary-encode these types using short
field keys and without parsing/stringifying (in many cases it just a cast).
We still get the same json output as before (with minor modifications for
Cids).
This should greatly improve Cluster performance and memory usage when dealing
with large collections of items.
License: MIT
Signed-off-by: Hector Sanjuan <hector@protocol.ai>
