EEVM.Handler.PreExecution (eevm v0.1.0)

Copy Markdown View Source

Steps 4-7 of the transaction pipeline (Yellow Paper §6):

  • Charge upfront — debit gas_limit * max_price from the sender, plus the EIP-4844 blob gas fee, which is burned and never refunded. The value portion is not debited here; it is moved by Execution when the call frame is set up so the same wei is not deducted twice.
  • Intrinsic gas — verify tx.gas_limit >= IntrinsicGas.calculate(tx, hardfork) and compute the gas available to the EVM as the difference.
  • Bump nonce — increment the sender's nonce.
  • Apply authorizations (EIP-7702) — write delegation designators for each valid authorization tuple. These writes happen before execution and persist even if the call reverts.
  • Pre-warm access set — seed accessed_addresses and accessed_storage_keys with EIP-2929 / EIP-3651 entries plus the transaction's access list.

Also exposes gas_upfront/1 and effective_gas_price/2 because both PostExecution settlement and the upfront balance check share the same fee-market formula, and blob_gas_fee/2 for runners that settle fees themselves.

Summary

Types

authorization_outcome()

Result of applying an EIP-7702 authorization list: every authority whose signature recovered (warm for the rest of the transaction) and the gas refund owed for authorities that already existed.

Functions

apply_authorizations(db, tx, chain_id)

Apply the EIP-7702 authorization list of tx to db, after the sender's nonce bump and before execution.

blob_gas_fee(transaction, block)

EIP-4844 blob gas fee: GAS_PER_BLOB * blob count * blob_base_fee. Zero for transactions without blobs.

charge_upfront(db, tx, block)

Debit the maximum gas fee from the sender after checking that the balance also covers tx.value and that the effective gas price meets the basefee.

effective_gas_price(tx, block)

Price per gas the sender pays: min(max_fee, basefee + priority_fee) for EIP-1559-style transactions (EIP-1559), or the legacy gas price.

gas_upfront(tx)

Maximum gas fee debited upfront: gas_limit times the fee cap (or gas price).

initial_accessed_addresses(tx, config, contract_ctx, block)

Addresses warm at transaction start (EIP-2929, EIP-2930, EIP-3651): the callee, caller, origin, coinbase, precompiles, and access-list entries.

initial_accessed_storage_keys(tx)

Storage keys warm at transaction start: every access-list slot (EIP-2930).

prepare_execution(db, tx, hardfork)

Verify intrinsic gas, bump the sender nonce, and return the gas available to the EVM.

Types

authorization_outcome()

@type authorization_outcome() :: %{
  authorities: MapSet.t(non_neg_integer()),
  refund: non_neg_integer()
}

Result of applying an EIP-7702 authorization list: every authority whose signature recovered (warm for the rest of the transaction) and the gas refund owed for authorities that already existed.

Functions

apply_authorizations(db, tx, chain_id)

@spec apply_authorizations(
  EEVM.Database.t(),
  EEVM.Context.Transaction.t(),
  non_neg_integer()
) ::
  {EEVM.Database.t(), authorization_outcome()}

Apply the EIP-7702 authorization list of tx to db, after the sender's nonce bump and before execution.

Each tuple is skipped, without failing the transaction, when its chain id is neither 0 nor chain_id, its nonce is 2^64 - 1, its signature does not recover, the authority has code other than a designator, or the authority's nonce differs. Otherwise the authority's code becomes a designator for address (or is cleared when address is zero) and its nonce is incremented. Tuples apply in order, so a later tuple from the same authority sees the earlier one's nonce bump.

blob_gas_fee(transaction, block)

@spec blob_gas_fee(EEVM.Context.Transaction.t(), EEVM.Context.Block.t()) ::
  non_neg_integer()

EIP-4844 blob gas fee: GAS_PER_BLOB * blob count * blob_base_fee. Zero for transactions without blobs.

Example

iex> tx = EEVM.Context.Transaction.new(type: :eip4844, blob_hashes: [1, 2])
iex> EEVM.Handler.PreExecution.blob_gas_fee(tx, EEVM.Context.Block.new(blob_base_fee: 3))
786_432

charge_upfront(db, tx, block)

@spec charge_upfront(
  EEVM.Database.t(),
  EEVM.Context.Transaction.t(),
  EEVM.Context.Block.t()
) ::
  {:ok, EEVM.Database.t()} | {:error, atom()}

Debit the maximum gas fee from the sender after checking that the balance also covers tx.value and that the effective gas price meets the basefee.

effective_gas_price(tx, block)

@spec effective_gas_price(EEVM.Context.Transaction.t(), EEVM.Context.Block.t()) ::
  non_neg_integer()

Price per gas the sender pays: min(max_fee, basefee + priority_fee) for EIP-1559-style transactions (EIP-1559), or the legacy gas price.

gas_upfront(tx)

@spec gas_upfront(EEVM.Context.Transaction.t()) :: non_neg_integer()

Maximum gas fee debited upfront: gas_limit times the fee cap (or gas price).

initial_accessed_addresses(tx, config, contract_ctx, block)

@spec initial_accessed_addresses(
  EEVM.Context.Transaction.t(),
  EEVM.Config.t(),
  EEVM.Context.Contract.t(),
  EEVM.Context.Block.t()
) :: MapSet.t(non_neg_integer())

Addresses warm at transaction start (EIP-2929, EIP-2930, EIP-3651): the callee, caller, origin, coinbase, precompiles, and access-list entries.

initial_accessed_storage_keys(tx)

@spec initial_accessed_storage_keys(EEVM.Context.Transaction.t()) ::
  MapSet.t({non_neg_integer(), non_neg_integer()})

Storage keys warm at transaction start: every access-list slot (EIP-2930).

prepare_execution(db, tx, hardfork)

@spec prepare_execution(
  EEVM.Database.t(),
  EEVM.Context.Transaction.t(),
  EEVM.HardforkConfig.t()
) ::
  {:ok, EEVM.Database.t(), non_neg_integer()} | {:error, :intrinsic_gas_too_low}

Verify intrinsic gas, bump the sender nonce, and return the gas available to the EVM.