further simplify machine (#10472)

* removed AuxiliaryRequest from Machin trait

* removed AncestryAction from Machine trait

* removed AuxiliaryData from Machine trait

* removed LocalizedMachine trait

ethcore/src/engines/mod.rs

@@ -49,13 +49,12 @@ use spec::CommonParams;
 use types::transaction::{self, UnverifiedTransaction, SignedTransaction};
 
 use ethkey::{Signature};
-use machine::{Machine, LocalizedMachine as Localized};
+use machine::{self, Machine, AuxiliaryRequest, AuxiliaryData};
 use ethereum_types::{H256, U256, Address};
 use unexpected::{Mismatch, OutOfBounds};
 use bytes::Bytes;
 use types::ancestry_action::AncestryAction;
 use block::ExecutedBlock;
-use machine;
 
 /// Default EIP-210 contract code.
 /// As defined in https://github.com/ethereum/EIPs/pull/210
@@ -177,8 +176,7 @@ pub type PendingTransitionStore<'a> = Fn(H256) -> Option<epoch::PendingTransitio
 /// Proof dependent on state.
 pub trait StateDependentProof<M: Machine>: Send + Sync {
 	/// Generate a proof, given the state.
-	// TODO: make this into an &M::StateContext
-	fn generate_proof<'a>(&self, state: &<M as Localized<'a>>::StateContext) -> Result<Vec<u8>, String>;
+	fn generate_proof<'a>(&self, state: &machine::Call) -> Result<Vec<u8>, String>;
 	/// Check a proof generated elsewhere (potentially by a peer).
 	// `engine` needed to check state proofs, while really this should
 	// just be state machine params.
@@ -218,7 +216,7 @@ impl<'a, M: Machine> ConstructedVerifier<'a, M> {
 /// Results of a query of whether an epoch change occurred at the given block.
 pub enum EpochChange<M: Machine> {
 	/// Cannot determine until more data is passed.
-	Unsure(M::AuxiliaryRequest),
+	Unsure(AuxiliaryRequest),
 	/// No epoch change.
 	No,
 	/// The epoch will change, with proof.
@@ -310,7 +308,7 @@ pub trait Engine<M: Machine>: Sync + Send {
 	fn verify_block_external(&self, _header: &Header) -> Result<(), M::Error> { Ok(()) }
 
 	/// Genesis epoch data.
-	fn genesis_epoch_data<'a>(&self, _header: &Header, _state: &<M as Localized<'a>>::StateContext) -> Result<Vec<u8>, String> { Ok(Vec::new()) }
+	fn genesis_epoch_data<'a>(&self, _header: &Header, _state: &machine::Call) -> Result<Vec<u8>, String> { Ok(Vec::new()) }
 
 	/// Whether an epoch change is signalled at the given header but will require finality.
 	/// If a change can be enacted immediately then return `No` from this function but
@@ -321,7 +319,7 @@ pub trait Engine<M: Machine>: Sync + Send {
 	/// Return `Yes` or `No` when the answer is definitively known.
 	///
 	/// Should not interact with state.
-	fn signals_epoch_end<'a>(&self, _header: &Header, _aux: <M as Localized<'a>>::AuxiliaryData)
+	fn signals_epoch_end<'a>(&self, _header: &Header, _aux: AuxiliaryData<'a>)
 		-> EpochChange<M>
 	{
 		EpochChange::No

ethcore/src/machine/impls.rs

@@ -430,8 +430,6 @@ pub enum AuxiliaryRequest {
 
 impl super::Machine for EthereumMachine {
 	type EngineClient = ::client::EngineClient;
-	type AuxiliaryRequest = AuxiliaryRequest;
-	type AncestryAction = ::types::ancestry_action::AncestryAction;
 
 	type Error = Error;
 
@@ -444,11 +442,6 @@ impl super::Machine for EthereumMachine {
 	}
 }
 
-impl<'a> super::LocalizedMachine<'a> for EthereumMachine {
-	type StateContext = Call<'a>;
-	type AuxiliaryData = AuxiliaryData<'a>;
-}
-
 // Try to round gas_limit a bit so that:
 // 1) it will still be in desired range
 // 2) it will be a nearest (with tendency to increase) multiple of PARITY_GAS_LIMIT_DETERMINANT

ethcore/src/machine/traits.rs

@@ -21,13 +21,9 @@ use ethereum_types::{U256, Address};
 use block::ExecutedBlock;
 
 /// Generalization of types surrounding blockchain-suitable state machines.
-pub trait Machine: for<'a> LocalizedMachine<'a> {
+pub trait Machine: Send + Sync {
 	/// A handle to a blockchain client for this machine.
 	type EngineClient: ?Sized;
-	/// A description of needed auxiliary data.
-	type AuxiliaryRequest;
-	/// Actions taken on ancestry blocks when commiting a new block.
-	type AncestryAction;
 
 	/// Errors which can occur when querying or interacting with the machine.
 	type Error;
@@ -39,13 +35,3 @@ pub trait Machine: for<'a> LocalizedMachine<'a> {
 	/// Increment the balance of an account in the state of the live block.
 	fn add_balance(&self, live: &mut ExecutedBlock, address: &Address, amount: &U256) -> Result<(), Self::Error>;
 }
-
-/// Machine-related types localized to a specific lifetime.
-// TODO: this is a workaround for a lack of associated type constructors in the language.
-pub trait LocalizedMachine<'a>: Sync + Send {
-	/// Definition of auxiliary data associated to a specific block.
-	type AuxiliaryData: 'a;
-	/// A context providing access to the state in a controlled capacity.
-	/// Generally also provides verifiable proofs.
-	type StateContext: ?Sized + 'a;
-}