Add begin_block function to contract

[frankbraun]

For the evm-bully we need a begin_block function.
The begin_block function should allow to set the necessary block context the evm-bully needs to replay transactions successfully (see aurora-is-near/evm-bully#3).
It should only be available in a testing version of the contract.

[artob]

@frankbraun Commits 3f15f06 and 78c7c1f added the parameter definition for begin_block:

aurora-engine/src/types.rs

Lines 50 to 65 in 78c7c1f

	/// Borsh-encoded parameters for the `begin_block` function.
	#[derive(BorshSerialize, BorshDeserialize)]
	pub struct BeginBlockArgs {
	/// The current block's hash (for replayer use).
	pub hash: RawU256,
	/// The current block's beneficiary address.
	pub coinbase: RawU256,
	/// The current block's timestamp (in seconds since the Unix epoch).
	pub timestamp: RawU256,
	/// The current block's number (the genesis block is number zero).
	pub number: RawU256,
	/// The current block's difficulty.
	pub difficulty: RawU256,
	/// The current block's gas limit.
	pub gaslimit: RawU256,
	}

Note that the input to the begin_block function is Borsh-encoded, not JSON-encoded.

[frankbraun]

This needs to be put behind a feature flag and, as @ilblackdragon noted, should only be callable by the owner.

[artob]

This needs to be put behind a feature flag and, as @ilblackdragon noted, should only be callable by the owner.

As of 529a751, these methods are now only callable by the owner.

[joshuajbouw]

Isn't this closed now?

[artob]

@frankbraun Can this be closed? Please close issues when they are done.

[frankbraun]

The evm-bully calls begin_block with the correct arguments and they are decoded in the function in the contract:

aurora-engine/src/lib.rs

Line 364 in 5144281

let _args: BeginBlockArgs = sdk::read_input_borsh().sdk_unwrap();

However, the engine state is not updated correctly yet. @joshuajbouw, could you take a stab at this please? You are deeper into the engine. Might be related to #122

[joshuajbouw]

Yes, still looking into it. @frankbraun

[mrLSD]

@frankbraun Is that Issue still should be open?

[joshuajbouw]

Considering that this functionality has been added and there are other issues that are in a succession of this, I'm going to close it.