Initial sketch of Block struct.

src/block.rs

@@ -0,0 +1,146 @@
+use transaction::*;
+use engine::*;
+use env_info::*;
+
+/// A transaction/receipt execution entry.
+pub struct Entry {
+	transaction: Transaction,
+	receipt: Receipt,
+}
+
+/// Internal type for a block's common elements.
+pub struct Block {
+	header: Header,
+
+	/// State is the most final state in the block.
+	state: State,
+
+	archive: Vec<Entry>,
+	archive_set: HashSet<H256>,
+}
+
+impl Block {
+	fn new(header: Header, state: State) -> Block {
+		Block {
+			header: Header:new(),
+			state: state,
+			archive: Vec::new(),
+			archive_set: HashSet::new(),
+		}
+	}
+
+	pub fn state_mut(&mut self) -> &mut State { self.state }
+}
+
+/// Trait for a object that is_a `Block`.
+trait IsBlock {
+	/// Get the block associated with this object.
+	fn block(&self) -> &Block;
+
+	/// Get the header associated with this object's block.
+	pub fn header(&self) -> &Header { self.block().header }
+
+	/// Get the final state associated with this object's block.
+	pub fn state(&self) -> &State { self.block().state }
+
+	/// Get all information on transactions in this block.
+	pub fn archive(&self) -> &Vec<Entry> { self.block().archive }
+}
+
+impl IsBlock for Block {
+	fn block(&self) -> &Block { self }
+	fn block_mut(&self) -> &mut Block { self }
+}
+
+/// Block that is ready for transactions to be added.
+///
+/// It's a bit like a Vec<Transaction>, eccept that whenever a transaction is pushed, we execute it and
+/// maintain the system `state()`. We also archive execution receipts in preparation for later block creation.
+pub struct OpenBlock {
+	block: Block,
+	engine: &Engine,
+	last_hashes: LastHashes,
+}
+
+/// Just like OpenBlock, except that we've applied `Engine::on_close_block`, finished up the non-seal header fields,
+/// and collected the uncles.
+///
+/// There is no function available to push a transaction. If you want that you'll need to `reopen()` it.
+pub struct ClosedBlock {
+	open_block: OpenBlock,
+	uncles: Vec<Header>,
+}
+
+/// A block that has a valid seal.
+///
+/// The block's header has valid seal arguments. The block cannot be reversed into a ClosedBlock or OpenBlock.
+pub struct SealedBlock {
+	block: Block,
+	bytes: Bytes,
+}
+
+impl OpenBlock {
+	pub fn new(engine: &Engine, mut db: OverlayDB, parent: &Header, last_hashes: LastHashes) -> OpenBlock {
+		let mut r = OpenBlock {
+			block: Block::new(State::new_existing(db, parent.state_root.clone(), engine.account_start_nonce())),
+			engine: engine,
+			last_hashes: last_hashes,
+		}
+
+		engine.populate_from_parent(r.block.header, parent);
+		engine.on_init_block(&mut r);
+		r
+	}
+
+	/// Turn this into a `ClosedBlock`. A BlockChain must be provided in order to figure ou the uncles.
+	pub fn push_transaction(&mut self, t: Transaction, mut h: Option<H256>) -> Result<&Receipt, EthcoreError> {
+		let env_info = EnvInfo{
+			number: self.header.number,
+			author: self.header.author,
+			timestamp: self.header.timestamp,
+			difficulty: self.header.difficulty,
+			last_hashes: self.last_hashes.clone(),
+			gas_used: if let Some(ref t) = self.archive.last() {t.receipt.gas_used} else {U256::from(0)},
+		};
+		match self.state.apply(env_info, self.engine, t, true) {
+			Ok(x) => {
+				self.transactionHashes.insert(h.unwrap_or_else(||t.sha3()));
+				self.transactions.push(BlockTransaction{t, x.receipt});
+				Ok(&self.transactions.last().unwrap().receipt)
+			}
+			Err(x) => Err(x)
+		}
+	}
+
+	/// Turn this into a `ClosedBlock`. A BlockChain must be provided in order to figure ou the uncles.
+	pub fn close(self, bc: &BlockChain) -> ClosedBlock { unimplemented!(); }
+}
+
+impl IsBlock for OpenBlock {
+	fn block(&self) -> &Block { self.block }
+	fn block_mut(&self) -> &mut Block { self.block }
+}
+
+impl ClosedBlock {
+	/// Get the hash of the header without seal arguments.
+	pub fn preseal_hash(&self) -> H256 { unimplemented!(); }
+
+	/// Turn this into a `ClosedBlock`. A BlockChain must be provided in order to figure ou the uncles.
+	pub fn seal(self, seal_fields: Vec<Bytes>) -> SealedBlock { unimplemented!(); }
+
+	/// Turn this back into an `OpenBlock`.
+	pub fn reopen(self) -> OpenBlock { unimplemented!(); }
+}
+
+impl IsBlock for ClosedBlock {
+	fn block(&self) -> &Block { self.open_block.block }
+	fn block_mut(&self) -> &mut Block { self.open_block.block }
+}
+
+impl SealedBlock {
+}
+
+impl IsBlock for SealedBlock {
+	fn block(&self) -> &Block { self.block }
+	fn block_mut(&self) -> &mut Block { self.block.block }
+}

src/builtin.rs

@@ -58,6 +58,12 @@ impl Builtin {
 		}
 		None
 	}
+
+	/// Simple forwarder for cost.
+	pub fn cost(&self, s: usize) -> U256 { (*self.cost)(s) }
+
+	/// Simple forwarder for execute.
+	pub fn execute(&self, input: &[u8], output: &mut[u8]) { (*self.execute)(input, output); }
 }
 
 pub fn copy_to(src: &[u8], dest: &mut[u8]) {

src/engine.rs

@@ -1,5 +1,6 @@
 use std::collections::hash_map::*;
 use util::bytes::*;
+use util::hash::*;
 use util::uint::*;
 use util::rlp::*;
 use util::semantic_version::*;
@@ -35,18 +36,16 @@ pub trait Engine {
 	/// Some intrinsic operation parameters; by default they take their value from the `spec()`'s `engine_params`.
 	fn maximum_extra_data_size(&self, _env_info: &EnvInfo) -> usize { decode(&self.spec().engine_params.get("maximum_extra_data_size").unwrap()) }
 	fn account_start_nonce(&self, _env_info: &EnvInfo) -> U256 { decode(&self.spec().engine_params.get("account_start_nonce").unwrap()) }
-	// TODO: refactor in terms of `on_preseal_block`
-	fn block_reward(&self, _env_info: &EnvInfo) -> U256 { decode(&self.spec().engine_params.get("block_reward").unwrap()) }
 
 	/// Block transformation functions, before and after the transactions.
-//	fn on_new_block(&self, _env_info: &EnvInfo, _block: &mut Block) -> Result<(), EthcoreError> {}
-//	fn on_preseal_block(&self, _env_info: &EnvInfo, _block: &mut Block) -> Result<(), EthcoreError> {}
+	fn on_new_block(&self, _block: &mut Block) -> Result<(), EthcoreError> { Ok(()) }
+	fn on_close_block(&self, _block: &mut Block) -> Result<(), EthcoreError> { Ok(()) }
 
 	/// 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.
 	// TODO: consider including State in the params.
-	fn verify(&self, _header: &Header, _parent: Option<&Header>, _block: Option<&[u8]>) -> Result<(), EthcoreError> { Ok(()) }
+	fn verify_block(&self, _header: &Header, _parent: Option<&Header>, _block: Option<&[u8]>) -> Result<(), EthcoreError> { Ok(()) }
 
 	/// Additional verification for transactions in blocks.
 	// TODO: Add flags for which bits of the transaction to check.
@@ -59,10 +58,9 @@ pub trait Engine {
 
 	// TODO: builtin contract routing - to do this properly, it will require removing the built-in configuration-reading logic
 	// from Spec into here and removing the Spec::builtins field.
-/*	fn is_builtin(&self, a: Address) -> bool;
-	fn cost_of_builtin(&self, a: Address, in: &[u8]) -> bignum;
-	fn execute_builtin(&self, a: Address, in: &[u8], out: &mut [u8]);
-*/
+	fn is_builtin(&self, a: &Address) -> bool { self.spec().builtins.contains_key(a) }
+	fn cost_of_builtin(&self, a: &Address, input: &[u8]) -> U256 { self.spec().builtins.get(a).unwrap().cost(input.len()) }
+	fn execute_builtin(&self, a: &Address, input: &[u8], output: &mut [u8]) { self.spec().builtins.get(a).unwrap().execute(input, output); }
 
 	// TODO: sealing stuff - though might want to leave this for later.
 }

src/ethash.rs

@@ -19,4 +19,10 @@ impl Engine for Ethash {
 	fn name(&self) -> &str { "Ethash" }
 	fn spec(&self) -> &Spec { &self.spec }
 	fn evm_schedule(&self, _env_info: &EnvInfo) -> EvmSchedule { EvmSchedule::new_frontier() }
+
+	/// Apply the block reward on finalisation of the block.
+	fn on_close_block(&self, block: &mut Block) -> Result<(), EthcoreError> {
+		let a = block.header().author.clone();
+		block.state_mut().add_balance(a, decode(&self.spec().engine_params.get("block_reward").unwrap()));
+	}
 }

src/spec.rs

@@ -370,9 +370,8 @@ mod tests {
 	use super::*;
 
 	#[test]
-	fn all() {
+	fn morden_manual() {
 		let morden = Spec::new_morden_manual();
-//		let engine = morden.to_engine();	// Ethash doesn't exist as an engine yet, so would fail.
 
 		assert_eq!(*morden.state_root(), H256::from_str("f3f4696bbf3b3b07775128eb7a3763279a394e382130f27c21e70233e04946a9").unwrap());
 		let genesis = morden.genesis_block();
@@ -386,8 +385,6 @@ mod tests {
 		assert_eq!(*morden.state_root(), H256::from_str("f3f4696bbf3b3b07775128eb7a3763279a394e382130f27c21e70233e04946a9").unwrap());
 		let genesis = morden.genesis_block();
 		assert_eq!(BlockView::new(&genesis).header_view().sha3(), H256::from_str("0cd786a2425d16f152c658316c423e6ce1181e15c3295826d7c9904cba9ce303").unwrap());
-		
-		let engine = morden.to_engine();
 	}
 
 	#[test]

src/state.rs

@@ -15,7 +15,11 @@ use env_info::EnvInfo;
 use engine::Engine;
 
 /// Information concerning the result of the `State::apply` operation.
-pub struct ApplyResult;	// TODO
+pub struct ApplyInfo {
+	r: Receipt,
+}
+
+type ApplyResult = Result<ApplyInfo, EthcoreError>;
 
 /// Representation of the entire state of all accounts in the system.
 pub struct State {
@@ -131,7 +135,7 @@ impl State {
 
 	/// Execute a given transaction.
 	/// This will change the state accordingly.
-	pub fn apply(_env_info: &EnvInfo, _engine: &Engine, _t: &Transaction, _is_permanent: bool) -> (ApplyResult, Receipt) {
+	pub fn apply(_env_info: &EnvInfo, _engine: &Engine, _t: &Transaction, _is_permanent: bool) -> ApplyResult {
 		unimplemented!();
 	}
 

src/transaction.rs

@@ -3,6 +3,10 @@ use util::bytes::*;
 use util::uint::*;
 use util::rlp::*;
 
+struct Receipt {
+	gas_used: U256,
+}
+
 /// A set of information describing an externally-originating message call
 /// or contract creation operation.
 pub struct Transaction {