Transactions should be optimized

[turbolent]

Issue To Be Solved

EVM transactions are currently submitted by wrapping them in a Cadence transaction.

The Cadence transaction sends the EVM transaction as a [UInt8] value, see

flow-evm-gateway/services/requester/cadence/run.cdc

Line 3 in 816b5b7

transaction(encodedTx: [UInt8]) {

The current encoding of such values in the current format, JSON, is very inefficient.

Suggest A Solution

Until we add support for the new, more efficient, Cadence value encoding format, CCF, it might be best to send the EVM transaction in a more efficient manner. For example, it could be sent as a hex-encoded string, then decoded in the transaction.

[m-Peter]

That's a good point 👍 Thanks for the report 🙏
The change is rather straightforward to do, and in fact it might be easier to construct a cadence.String from the []byte data containing the RLP-encoded tx (see https://github.com/onflow/flow-evm-gateway/blob/main/services/requester/requester.go#L162)

[turbolent]

Note that Cadence Strings are required to be valid UTF-8, so it's not possible to use them for arbitrary byte arrays.

[m-Peter]

The byte array will first pass through hex.EncodeToString(data) (where data is the byte array), and that string value will be used to construct a value of cadence.String.