engine changes

ethcore/src/block.rs

@@ -26,7 +26,7 @@ use util::error::{Mismatch, OutOfBounds};
 
 use basic_types::{LogBloom, Seal};
 use env_info::{EnvInfo, LastHashes};
-use engines::{Engine, ValidationProof};
+use engines::Engine;
 use error::{Error, BlockError, TransactionError};
 use factory::Factories;
 use header::Header;
@@ -488,11 +488,10 @@ impl LockedBlock {
 		self,
 		engine: &Engine,
 		seal: Vec<Bytes>,
-		proof: Option<ValidationProof>,
 	) -> Result<SealedBlock, (Error, LockedBlock)> {
 		let mut s = self;
 		s.block.header.set_seal(seal);
-		match engine.verify_block_seal(&s.block.header, proof) {
+		match engine.verify_block_seal(&s.block.header) {
 			Err(e) => Err((e, s)),
 			_ => Ok(SealedBlock { block: s.block, uncle_bytes: s.uncle_bytes }),
 		}

ethcore/src/engines/authority_round.rs

@@ -464,14 +464,14 @@ mod tests {
 
 		engine.set_signer(tap.clone(), addr1, "1".into());
 		if let Seal::Regular(seal) = engine.generate_seal(b1.block()) {
-			assert!(b1.clone().try_seal(engine, seal, None).is_ok());
+			assert!(b1.clone().try_seal(engine, seal).is_ok());
 			// Second proposal is forbidden.
 			assert!(engine.generate_seal(b1.block()) == Seal::None);
 		}
 
 		engine.set_signer(tap, addr2, "2".into());
 		if let Seal::Regular(seal) = engine.generate_seal(b2.block()) {
-			assert!(b2.clone().try_seal(engine, seal, None).is_ok());
+			assert!(b2.clone().try_seal(engine, seal).is_ok());
 			// Second proposal is forbidden.
 			assert!(engine.generate_seal(b2.block()) == Seal::None);
 		}

ethcore/src/engines/basic_authority.rs

@@ -258,7 +258,7 @@ mod tests {
 		let b = OpenBlock::new(engine, Default::default(), false, db, &genesis_header, last_hashes, addr, (3141562.into(), 31415620.into()), vec![]).unwrap();
 		let b = b.close_and_lock();
 		if let Seal::Regular(seal) = engine.generate_seal(b.block()) {
-			assert!(b.try_seal(engine, seal, None).is_ok());
+			assert!(b.try_seal(engine, seal).is_ok());
 		}
 	}
 

ethcore/src/engines/instant_seal.rs

@@ -89,7 +89,7 @@ mod tests {
 		let b = OpenBlock::new(engine, Default::default(), false, db, &genesis_header, last_hashes, Address::default(), (3141562.into(), 31415620.into()), vec![]).unwrap();
 		let b = b.close_and_lock();
 		if let Seal::Regular(seal) = engine.generate_seal(b.block()) {
-			assert!(b.try_seal(engine, seal, None).is_ok());
+			assert!(b.try_seal(engine, seal).is_ok());
 		}
 	}
 

ethcore/src/engines/mod.rs

@@ -44,6 +44,7 @@ use evm::Schedule;
 use header::Header;
 use spec::CommonParams;
 use transaction::{UnverifiedTransaction, SignedTransaction};
+use receipt::Receipt;
 
 use ethkey::Signature;
 use util::*;
@@ -61,8 +62,6 @@ pub enum EngineError {
 	UnexpectedMessage,
 	/// Seal field has an unexpected size.
 	BadSealFieldSize(OutOfBounds<usize>),
-	/// Needs a validation proof for the given block hash before verification can continue.
-	NeedsValidationProof(H256),
 }
 
 impl fmt::Display for EngineError {
@@ -74,7 +73,6 @@ impl fmt::Display for EngineError {
 			NotAuthorized(ref address) => format!("Signer {} is not authorized.", address),
 			UnexpectedMessage => "This Engine should not be fed messages.".into(),
 			BadSealFieldSize(ref oob) => format!("Seal field has an unexpected length: {}", oob),
-			NeedsValidationProof(ref hash) => format!("Needs validation proof of block {} to verify seal.", hash),
 		};
 
 		f.write_fmt(format_args!("Engine error ({})", msg))
@@ -92,12 +90,29 @@ pub enum Seal {
 	None,
 }
 
-/// A validation proof, required for validation of a block header.
-pub type ValidationProof = Vec<DBValue>;
-
 /// Type alias for a function we can make calls through synchronously.
 pub type Call = Fn(Address, Bytes) -> Result<Bytes, String>;
 
+/// Results of a query of whether a validation proof is necessary at a block.
+pub enum RequiresProof {
+	/// Cannot determine until more data is passed.
+	Unsure(Unsure),
+	/// Validation proof not required.
+	No,
+	/// Validation proof required.
+	Yes,
+}
+
+/// More data required to determine if a validation proof is required.
+pub enum Unsure {
+	/// Needs the body.
+	NeedsBody,
+	/// Needs the receipts.
+	NeedsReceipts,
+	/// Needs both body and receipts.
+	NeedsBoth,
+}
+
 /// 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 : Sync + Send {
@@ -191,23 +206,22 @@ pub trait Engine : Sync + Send {
 	/// Verify the seal of a block. This is an auxilliary method that actually just calls other `verify_` methods
 	/// to get the job done. By default it must pass `verify_basic` and `verify_block_unordered`. If more or fewer
 	/// methods are needed for an Engine, this may be overridden.
-	fn verify_block_seal(&self, header: &Header, _proof: Option<ValidationProof>) -> Result<(), Error> {
+	fn verify_block_seal(&self, header: &Header) -> Result<(), Error> {
 		self.verify_block_basic(header, None).and_then(|_| self.verify_block_unordered(header, None))
 	}
 
-	/// Generate a validation proof for the given block header.
+	/// Re-do all verification for a header with the given contract-calling interface
 	///
-	/// All values queried during execution of given  will go into the proof.
-	/// This may only be called for blocks indicated in "needs validation proof"
-	/// errors.
-	///
-	/// Engines which don't draw consensus information from the state (e.g. PoW)
-	/// don't need to change anything here.
-	///
-	/// Engines which do draw consensus information from the state may only do so
-	/// here.
-	fn generate_validation_proof(&self, header: &Header, _call: &Call) -> ValidationProof {
-		ValidationProof::default()
+	/// This will be used to generate proofs of validation as well as verify them.
+	fn verify_with_state(&self, _header: &Header, _call: &Call) -> Result<(), Error> {
+		Ok(())
+	}
+
+	/// Whether a proof is required for the given header.
+	fn proof_required(&self, _header: Header, _block: Option<&[u8]>, _receipts: Option<&[Receipt]>)
+		-> RequiresProof
+	{
+		RequiresProof::No
 	}
 
 	/// Populate a header's fields based on its parent's header.

ethcore/src/engines/tendermint/mod.rs

@@ -864,7 +864,7 @@ mod tests {
 		let proposer = insert_and_register(&tap, spec.engine.as_ref(), "1");
 
 		let (b, seal) = propose_default(&spec, proposer);
-		assert!(b.lock().try_seal(spec.engine.as_ref(), seal, None).is_ok());
+		assert!(b.lock().try_seal(spec.engine.as_ref(), seal).is_ok());
 	}
 
 	#[test]

ethcore/src/engines/validator_set/mod.rs

@@ -25,15 +25,12 @@ use std::sync::Weak;
 use util::{Address, H256};
 use ethjson::spec::ValidatorSet as ValidatorSpec;
 use client::Client;
-use receipt::Receipt;
 
 use self::simple_list::SimpleList;
 use self::contract::ValidatorContract;
 use self::safe_contract::ValidatorSafeContract;
 use self::multi::Multi;
 
-pub type Call = Fn(Address, Vec<u8>) -> Result<Vec<u8>, String>;
-
 /// Creates a validator set from spec.
 pub fn new_validator_set(spec: ValidatorSpec) -> Box<ValidatorSet> {
 	match spec {
@@ -48,10 +45,6 @@ pub fn new_validator_set(spec: ValidatorSpec) -> Box<ValidatorSet> {
 
 /// A validator set.
 pub trait ValidatorSet: Send + Sync {
-	/// Get this validator set as a flexible validator set.
-	/// Returning `None` indicates this is only usable for
-	/// full nodes.
-	fn as_memoized(&self) -> Option<&Memoized> { None }
 	/// Checks if a given address is a validator.
 	fn contains(&self, parent_block_hash: &H256, address: &Address) -> bool;
 	/// Draws an validator nonce modulo number of validators.
@@ -65,35 +58,3 @@ pub trait ValidatorSet: Send + Sync {
 	/// Allows blockchain state access.
 	fn register_contract(&self, _client: Weak<Client>) {}
 }
-
-/// A flexible validator set can track its changes.
-pub trait FlexibleValidatorSet: Send + Sync {
-	/// Whether a validator set may have changed at this header.
-	fn has_possibly_changed(&self, header: &Header) -> bool;
-
-	/// Whether a validator set has changed at this header, given the block receipts.
-	/// Called after `has_possibly_changed`.
-	/// `Some` indicates the validator set has changed at this header and the new
-	/// expected validator set.
-	/// `None` indicates no change.
-	fn has_changed(&self, header: &Header, receipts: &[Receipt]) -> Option<SimpleList>;
-
-	/// Fetch validators at a block synchronously.
-	fn fetch_validators(&self, header: &Header, call: &Call) -> Result<SimpleList, String>;
-}
-
-/// A memoized flexible validator set
-pub struct Memoized {
-	inner: Box<FlexibleValidatorSet>,
-	memo: Mutex<(SimpleList, (H256, u64))>,
-}
-
-impl Memoized {
-	/// Denote that the
-	pub fn use_memo_at(&self, list: SimpleList)
-}
-
-impl ValidatorSet for Memoized {
-	fn as_memoized(&self) -> Option<&Memoized> { Some(self) }
-}
-

ethcore/src/engines/validator_set/multi.rs

@@ -55,7 +55,7 @@ impl Multi {
 				) {
 			Ok((block, set)) => {
 				trace!(target: "engine", "Multi ValidatorSet retrieved for block {}.", block);
-				Some(&*set)
+				Some(&**set)
 			},
 			Err(e) => {
 				debug!(target: "engine", "ValidatorSet could not be recovered: {}", e);
@@ -66,21 +66,6 @@ impl Multi {
 }
 
 impl ValidatorSet for Multi {
-	fn has_possibly_changed(&self, header: &Header) -> bool {
-		// if the sets are the same for each header, compare those.
-		// otherwise, the sets have almost certainly changed.
-		match (self.correct_set(&header.hash()), self.correct_set(header.parent_hash())) {
-			(Some(a), Some(b)) if a as *const _ == b as *const _ => { a.has_possibly_changed(header) },
-			_ => true,
-		}
-	}
-
-	fn has_changed(&self, header: &Header, receipts: &[Receipt]) -> Option<Vec<Address>> {
-
-	}
-
-	fn fetch(&self) ->
-
 	fn contains(&self, bh: &H256, address: &Address) -> bool {
 		self.correct_set(bh).map_or(false, |set| set.contains(bh, address))
 	}

ethcore/src/miner/miner.rs

@@ -1133,7 +1133,7 @@ impl MinerService for Miner {
 				|b| &b.hash() == &block_hash
 			) {
 				trace!(target: "miner", "Submitted block {}={}={} with seal {:?}", block_hash, b.hash(), b.header().bare_hash(), seal);
-				b.lock().try_seal(&*self.engine, seal, None).or_else(|(e, _)| {
+				b.lock().try_seal(&*self.engine, seal).or_else(|(e, _)| {
 					warn!(target: "miner", "Mined solution rejected: {}", e);
 					Err(Error::PowInvalid)
 				})

ethcore/src/snapshot/mod.rs

@@ -567,7 +567,7 @@ pub fn verify_old_block(rng: &mut OsRng, header: &Header, engine: &Engine, chain
 	if always || rng.gen::<f32>() <= POW_VERIFY_RATE {
 		match chain.block_header(header.parent_hash()) {
 			Some(parent) => engine.verify_block_family(header, &parent, body),
-			None => engine.verify_block_seal(header, None), // TODO: fetch validation proof as necessary.
+			None => engine.verify_block_seal(header), // TODO: fetch validation proof as necessary.
 		}
 	} else {
 		engine.verify_block_basic(header, body)