Rosetta Implementation - pt4 (Stage 3.4 of Node API Overhaul)

[Daniel-VDM]

Stage 3.4 of Node API Overhaul

TLDR: This PR implements Rosetta's Construction API as well as correct some small bugs in the Node API found during the integration test of the Construction API. The integration test was done using the rosetta-cli using this configuration. Lastly, some refactoring of the block transaction formatter was done to make it more general so that the Construction API could consume said formatter.

Constriction API Details

For reference, this is the flow of the Construction API:

                               Caller (i.e. Coinbase)                + Construction API Implementation
                              +---------------------------------------------------------------------------------+
                                                                     |
                               Derive Address   +----------------------------> /construction/derive
                               from Public Key                       |
                                                                     |
                             X                                       |
                             X Create Metadata Request +---------------------> /construction/preprocess
                             X (array of operations)                 |                    +
    Get metadata needed      X                                       |                    |
    to construct transaction X            +-----------------------------------------------+
                             X            v                          |
                             X Fetch Online Metadata +-----------------------> /construction/metadata (online)
                             X                                       
                                                                     |
                             X                                       |
                             X Construct Payloads to Sign +------------------> /construction/payloads
                             X (array of operations)                 |                   +
                             X                                       |                   |
 Create unsigned transaction X          +------------------------------------------------+
                             X          v                            |
                             X Parse Unsigned Transaction +------------------> /construction/parse
                             X to Confirm Correctness                |
                             X                                       |
                                                                     |
                             X                                       |
                             X Sign Payload(s) +-----------------------------> /construction/combine
                             X (using caller's own detached signer)  |                 +
                             X                                       |                 |
   Create signed transaction X         +-----------------------------------------------+
                             X         v                             |
                             X Parse Signed Transaction +--------------------> /construction/parse
                             X to Confirm Correctness                |
                             X                                       |
                                                                     |
                             X                                       |
                             X Get hash of signed transaction +--------------> /construction/hash
Broadcast Signed Transaction X to monitor status                     |
                             X                                       |
                             X Submit Transaction +--------------------------> /construction/submit (online)
                             X                                       |
                                                                     +

All endpoints do NOT have access to the current state of the chain/pool unless specified that it is 'online'.

/construction/derive | Implementation

An Address Identifier can be derived from a compressed secp256k1 public key. The key's bytes given to this endpoint are assumed to be said compressed key.

/construction/preprocess | Implementation

One can determine if a set of operations creates a valid Harmony Transaction by using this endpoint. The underlying function(s) to check the operation(s) can be found here. Once the operations are validated, all metadata options (and curred data) are packaged into this struct and returned to the client to be forwarded (unchanged) on to the /construction/metadata endpoint.

/construction/metadata | Implementation

This endpoint is considered to be 'online'. Given the metadata option struct from /construction/preprocess, it fetches the correct nonce & gas fee estimation and returns it in this struct to the client to be forwarded (unchanged) on to the /construction/payloads endpoint.

/construction/payloads | Implementation

This endpoint actually constructs the Harmony transaction given the metadata from /construction/metadata and OperationComponents from the given operations. The returned payload to be signed by the client is the 'signer' (EIP115 Signer) hash of a Harmony transaction (i.e: this). Note that the returned harmony transaction object is wrapped in this struct.

/construction/parse | Implementation

One can check that an unsigned or signed (wrapped) transaction results in the intended rosetta operations using this endpoint. Note that parsing uses the same formatting functions as in the /block endpoint of the Node API. Logic for unpacking and checking the wrapped transaction can be found here.

/construction/combine | Implementation

One can get a signed (wrapped) transaction object by giving the signed payload to this endpoint (along with the unsigned wrapped transaction).

/construction/hash | Implementation

One can get the hash of a signed (wrapped) transaction using this endpoint.

/construction/submit | Implementation

This endpoint is considered to be 'online'. One can submit a signed (wrapped) transaction to the pool using this endpoint.

Misc Details

The transaction formatting needed to be changed to not error on unsigned transactions. Hence the introduction of the DefaultSenderAddress.

Moreover, all error messages now also return the line number, file, and node version to help with debugging.

Testing

Lots of effort was put into writing unit tests. Moreover, test scenarios were written for the rosetta-cli to test the construction API. One can run these scenarios by downloading and installing the rosetta-cli, and running the tests with the following command once localnet is started:

./rosetta-cli check:construction --configuration-file ./examples/configuration/harmony.json

The scenario file is here

Here is a screenshot of the successful tests:

Note that this also checks a large part of the Node API as it uses it to ensure that transactions are finalized.

TODO

Once merged, all functionalities of the constriction endpoint will be tested on testnet.

[LeoHChen]

did a quick review, in general looks good to me with lots of good unit tests.

[rlan35]

for contract creation, you could still send token along to the contract address right? By making the contract constructor payable.

[Daniel-VDM]

correct, but then the amount should be negative for the rosetta spec as it would deduct funds from the contract deployer.

[rlan35]

any risk that these new codes will cause issues for mainnet validators? Seems very separated.

[Daniel-VDM]

any risk that these new codes will cause issues for mainnet validators? Seems very separated.

Rosetta is only enabled by default on the explorer node. Validators have to manually enable it, therefore there shouldn't be any issues.

[LeoHChen]

LGTM in general, thanks for the work.