Repot & introduce various additional components for rest of consensus algorithm.

src/engine.rs

@@ -0,0 +1,129 @@
+use util::uint::*;
+use util::hash::*;
+use util::bytes::*;
+use header::Header;
+use std::collections::hash_map::*;
+use util::error::*;
+
+/// Definition of the cost schedule and other parameterisations for the EVM.
+pub struct EvmSchedule {
+	pub exceptional_failed_code_deposit: bool,
+	pub have_delegate_call: bool,
+	pub stack_limit: U256,
+	pub tier_step_gas: [U256; 8],
+	pub exp_gas: U256,
+	pub exp_byte_gas: U256,
+	pub sha3_gas: U256,
+	pub sha3_word_gas: U256,
+	pub sload_gas: U256,
+	pub sstore_set_gas: U256,
+	pub sstore_reset_gas: U256,
+	pub sstore_refund_gas: U256,
+	pub jumpdest_gas: U256,
+	pub log_gas: U256,
+	pub log_data_gas: U256,
+	pub log_topic_gas: U256,
+	pub create_gas: U256,
+	pub call_gas: U256,
+	pub call_stipend: U256,
+	pub call_value_transfer_gas: U256,
+	pub call_new_account_gas: U256,
+	pub suicide_refund_gas: U256,
+	pub memory_gas: U256,
+	pub quad_coeff_div: U256,
+	pub create_data_gas: U256,
+	pub tx_gas: U256,
+	pub tx_create_gas: U256,
+	pub tx_data_zero_gas: U256,
+	pub tx_data_non_zero_gas: U256,
+	pub copy_gas: U256,
+}
+
+/// Definition of a contract whose implementation is built-in. 
+pub struct Builtin {
+	/// The gas cost of running this built-in for the given size of input data.
+	pub cost: Box<Fn(usize) -> U256>,	// TODO: U256 should be bignum.
+	/// Run this built-in function with the input being the first argument and the output
+	/// being placed into the second.
+	pub execute: Box<Fn(&[u8], &mut [u8])>,
+}
+
+/// Parameters for a block chain; includes both those intrinsic to the design of the
+/// chain and those to be interpreted by the active chain engine.
+pub struct Params {
+	/*
+	TODO: std::unordered_map<Address, PrecompiledContract> precompiled;
+	*/
+	pub block_reward: U256,
+	pub maximum_extra_data_size: U256,
+	pub account_start_nonce: U256,
+	pub evm_schedule: EvmSchedule,
+	pub builtins: HashMap<Address, Builtin>,
+	pub misc: HashMap<String, String>,
+}
+
+// TODO: move to ethcore-util
+/// A version value with strict meaning.
+pub struct SemanticVersion {
+	/// Major version - API/feature removals & breaking changes.
+	pub major: u8,
+	/// Minor version - API/feature additions.
+	pub minor: u8,
+	/// Tiny version - bug fixes.
+	pub tiny: u8,
+}
+
+impl SemanticVersion {
+	/// Create a new object.
+	pub fn new(major: u8, minor: u8, tiny: u8) -> SemanticVersion { SemanticVersion{major: major, minor: minor, tiny: tiny} }
+
+	/// Convert to a `u32` representation.
+	pub fn as_u32(&self) -> u32 { ((self.major as u32) << 16u32) + ((self.minor as u32) << 8u32) + self.tiny as u32 }
+}
+
+// TODO: implement PartialOrdered for SemanticVersion.
+
+/// A consensus mechanism for the chain. Generally either proof-of-work or proof-of-stake-based.
+/// Provides hooks into each of the major parts of block import.
+pub trait Engine {
+	/// The name of this engine.
+	fn name(&self) -> &str;
+	/// The version of this engine. Should be of the form 
+	fn version(&self) -> SemanticVersion { SemanticVersion::new(0, 0 ,0) }
+
+	/// The number of additional header fields required for this engine.
+	fn seal_fields(&self) -> u32 { 0 }
+	/// Default values of the additional fields RLP-encoded in a raw (non-list) harness.
+	fn seal_rlp(&self) -> Bytes { vec![] }
+
+	/// Additional engine-specific information for the user/developer concerning `header`.
+	fn extra_info(&self, _header: &Header) -> HashMap<String, String> { HashMap::new() }
+
+	/// Verify that `header` is valid.
+	/// `parent` (the parent header) and `block` (the header's full block) may be provided for additional
+	/// checks. Returns either a null `Ok` or a general error detailing the problem with import.
+	fn verify(&self, _header: &Header, _parent: Option<&Header>, _block: Option<&[u8]>) -> Result<(), EthcoreError> { Ok(()) }
+/*
+	virtual void verify(Strictness _s, BlockHeader const& _bi, BlockHeader const& _parent = BlockHeader(), bytesConstRef _block = bytesConstRef()) const;
+	/// Additional verification for transactions in blocks.
+	virtual void verifyTransaction(ImportRequirements::value _ir, TransactionBase const& _t, BlockHeader const& _bi) const;
+	/// Don't forget to call Super::populateFromParent when subclassing & overriding.
+	virtual void populateFromParent(BlockHeader& _bi, BlockHeader const& _parent) const;
+*/
+
+	/// Get the general parameters of the chain.
+	fn params(&self) -> &Params;
+	/// Set the general parameters of the chain.
+	fn set_params(&mut self, p: Params);
+}
+
+/// An engine which does not provide any consensus mechanism.
+pub struct NullEngine {
+	params: Params,
+}
+
+impl Engine for NullEngine {
+	fn name(&self) -> &str { "NullEngine" }
+	fn params(&self) -> &Params { &self.params }
+	fn set_params(&mut self, params: Params) { self.params = params; }
+}

src/env_info.rs

@@ -0,0 +1,24 @@
+use util::uint::*;
+use util::hash::*;
+
+/// Simple vector of hashes, should be at most 256 items large, can be smaller if being used
+/// for a block whose number is less than 257.
+pub type LastHashes = Vec<H256>;
+
+/// Information concerning the execution environment for a message-call/contract-creation.
+pub struct EnvInfo {
+	/// The block number.
+	pub number: U256,
+	/// The block author.
+	pub author: Address,
+	/// The block timestamp.
+	pub timestamp: U256,
+	/// The block difficulty.
+	pub difficulty: U256,
+	/// The block gas limit.
+	pub gas_limit: U256,
+	/// The last 256 block hashes.
+	pub last_hashes: LastHashes,
+	/// The gas used.
+	pub gas_used: U256,
+}

src/lib.rs

@@ -84,10 +84,13 @@ pub use util::hash::*;
 pub use util::uint::*;
 pub use util::bytes::*;
 
+pub mod env_info;
+pub mod engine;
 pub mod state;
 pub mod account;
-pub mod blockheader;
+pub mod header;
 pub mod transaction;
+pub mod receipt;
 pub mod networkparams;
 pub mod denominations;
 

src/receipt.rs

@@ -0,0 +1,6 @@
+use util::hash::*;
+
+pub struct Receipt {
+	// TODO
+	pub state_root: H256,
+}

src/state.rs

@@ -9,28 +9,13 @@ use util::bytes::*;
 use util::rlp::*;
 use util::uint::*;
 use account::Account;
+use transaction::Transaction;
+use receipt::Receipt;
+use env_info::EnvInfo;
+use engine::Engine;
 
-/*
-enum ValueOrRef<'self, 'db: 'self> {
-	Value(OverlayDB),
-	Ref(&'db mut OverlayDB)
-}
-
-impl<'self, 'db> ValueOrRef<'self, 'db: 'self> {
-	pub fn get_mut(&mut self) -> &mut OverlayDB {
-		match self {
-			Value(ref mut x) => x,
-			Ref(x) => x,
-		}
-	}
-	pub fn get(&self) -> &OverlayDB {
-		match self {
-			Value(ref x) => x,
-			Ref(x) => x,
-		}
-	}
-}
-*/
+/// Information concerning the result of the `State::apply` operation.
+pub struct ApplyResult;	// TODO
 
 /// Representation of the entire state of all accounts in the system.
 pub struct State {
@@ -146,9 +131,9 @@ impl State {
 
 	/// Execute a given transaction.
 	/// This will change the state accordingly.
-/*	pub fn execute(_env_info: EnvInfo, _seal_engine: SealEngine, _t: Transaction, _p: Permanence) -> (ExecutionResult, TransactionReceipt) {
+	pub fn apply(_env_info: &EnvInfo, _engine: &Engine, _t: &Transaction, _is_permanent: bool) -> (ApplyResult, Receipt) {
 		unimplemented!();
-	}*/
+	}
 
 	/// Convert into a JSON representation.
 	pub fn as_json(&self) -> String {

src/transaction.rs

@@ -3,20 +3,23 @@ use util::bytes::*;
 use util::uint::*;
 use util::rlp::*;
 
+/// A set of information describing an externally-originating message call
+/// or contract creation operation.
 pub struct Transaction {
 	nonce: U256,
 	gas_price: U256,
 	gas: U256,
-	receive_address: Option<Address>,
+	to: Option<Address>,
 	value: U256,
 	data: Bytes,
 }
 
 impl Transaction {
+	/// Is this transaction meant to create a contract?
 	pub fn is_contract_creation(&self) -> bool {
-		self.receive_address.is_none()
+		self.to.is_none()
 	}
-
+	/// Is this transaction meant to send a message?
 	pub fn is_message_call(&self) -> bool {
 		!self.is_contract_creation()
 	}
@@ -28,7 +31,7 @@ impl Encodable for Transaction {
 			self.nonce.encode(e);
 			self.gas_price.encode(e);
 			self.gas.encode(e);
-			self.receive_address.encode(e);
+			self.to.encode(e);
 			self.value.encode(e);
 			self.data.encode(e);
 		})
@@ -36,14 +39,14 @@ impl Encodable for Transaction {
 }
 
 impl Decodable for Transaction {
-	fn decode<D>(decoder: &D) -> Result<Self, DecoderError>  where D: Decoder {
+	fn decode<D>(decoder: &D) -> Result<Self, DecoderError> where D: Decoder {
 		let d = try!(decoder.as_list());
 
 		let transaction = Transaction {
 			nonce: try!(Decodable::decode(&d[0])),
 			gas_price: try!(Decodable::decode(&d[1])),
 			gas: try!(Decodable::decode(&d[2])),
-			receive_address: try!(Decodable::decode(&d[3])),
+			to: try!(Decodable::decode(&d[3])),
 			value: try!(Decodable::decode(&d[4])),
 			data: try!(Decodable::decode(&d[5])),
 		};