DA
Rollkit provides a wrapper for go-da, a generic data availability interface for modular blockchains, called DAClient with wrapper functionalities like SubmitBlocks and RetrieveBlocks to help block manager interact with DA more easily.
Details
DAClient can connect via either gRPC or JSON-RPC transports using the go-da proxy/grpc or proxy/jsonrpc implementations. The connection can be configured using the following cli flags:
--rollkit.da_address: url address of the DA service (default: "grpc://localhost:26650")--rollkit.da_auth_token: authentication token of the DA service--rollkit.da_namespace: namespace to use when submitting blobs to the DA service
Given a set of blocks to be submitted to DA by the block manager, the SubmitBlocks first encodes the blocks using protobuf (the encoded data are called blobs) and invokes the Submit method on the underlying DA implementation. On successful submission (StatusSuccess), the DA block height which included in the rollup blocks is returned.
To make sure that the serialised blocks don't exceed the underlying DA's blob limits, it fetches the blob size limit by calling Config which returns the limit as uint64 bytes, then includes serialised blocks until the limit is reached. If the limit is reached, it submits the partial set and returns the count of successfully submitted blocks as SubmittedCount. The caller should retry with the remaining blocks until all the blocks are submitted. If the first block itself is over the limit, it throws an error.
The Submit call may result in an error (StatusError) based on the underlying DA implementations on following scenarios:
- the total blobs size exceeds the underlying DA's limits (includes empty blobs)
- the implementation specific failures, e.g., for celestia-da, invalid namespace, unable to create the commitment or proof, setting low gas price, etc, could return error.
The RetrieveBlocks retrieves the rollup blocks for a given DA height using go-da GetIDs and Get methods. If there are no blocks available for a given DA height, StatusNotFound is returned (which is not an error case). The retrieved blobs are converted back to rollup blocks and returned on successful retrieval.
Both SubmitBlocks and RetrieveBlocks may be unsuccessful if the DA node and the DA blockchain that the DA implementation is using have failures. For example, failures such as, DA mempool is full, DA submit transaction is nonce clashing with other transaction from the DA submitter account, DA node is not synced, etc.
Implementation
References
[1] go-da
[2] celestia-da
[3] proxy/grpc
[4] proxy/jsonrpc