Generalize engine trait (#6591)

* move common forks and parameters to common params

* port specs over to new format

* fix RPC tests

* parity-machine skeleton

* remove block type

* extract out ethereum-specific methods into EthereumMachine

* beginning to integrate Machine into engines. dealing with stale transitions in Ethash

* initial porting to machine

* move block reward back into engine

* abstract block reward logic

* move last hash and DAO HF logic into machine

* begin making engine function parameters generic

* abstract epoch verifier and ethash block reward logic

* instantiate special ethereummachine for ethash in spec

* optional full verification in verify_block_family

* re-instate tx_filter in a way that works for all engines

* fix warnings

* fix most tests, further generalize engine trait

* uncomment nullengine, get ethcore tests compiling

* fix warnings

* update a bunch of specs

* re-enable engine signer, validator set, and transition handler

* migrate basic_authority engine

* move last hashes into executedblock

* port tendermint

* make all ethcore tests pass

* json-tests compilation

* fix RPC tests: change in gas limit for new block changed PoW hash

* fix minor grumbles

* validate chainspecs

* fix broken import

* fix transaction verification for pre-homestead

ethcore/src/snapshot/consensus/authority.rs

@@ -25,7 +25,8 @@ use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::Arc;
 
 use blockchain::{BlockChain, BlockProvider};
-use engines::{Engine, EpochVerifier, EpochTransition};
+use engines::{EthEngine, EpochVerifier, EpochTransition};
+use machine::EthereumMachine;
 use ids::BlockId;
 use header::Header;
 use receipt::Receipt;
@@ -168,7 +169,7 @@ struct ChunkRebuilder {
 	// and epoch data from last blocks in chunks.
 	// verification for these will be done at the end.
 	unverified_firsts: Vec<(Header, Bytes, H256)>,
-	last_epochs: Vec<(Header, Box<EpochVerifier>)>,
+	last_epochs: Vec<(Header, Box<EpochVerifier<EthereumMachine>>)>,
 }
 
 // verified data.
@@ -180,9 +181,9 @@ struct Verified {
 impl ChunkRebuilder {
 	fn verify_transition(
 		&mut self,
-		last_verifier: &mut Option<Box<EpochVerifier>>,
+		last_verifier: &mut Option<Box<EpochVerifier<EthereumMachine>>>,
 		transition_rlp: UntrustedRlp,
-		engine: &Engine,
+		engine: &EthEngine,
 	) -> Result<Verified, ::error::Error> {
 		use engines::ConstructedVerifier;
 
@@ -238,7 +239,7 @@ impl Rebuilder for ChunkRebuilder {
 	fn feed(
 		&mut self,
 		chunk: &[u8],
-		engine: &Engine,
+		engine: &EthEngine,
 		abort_flag: &AtomicBool,
 	) -> Result<(), ::error::Error> {
 		let rlp = UntrustedRlp::new(chunk);
@@ -346,7 +347,7 @@ impl Rebuilder for ChunkRebuilder {
 		Ok(())
 	}
 
-	fn finalize(&mut self, _engine: &Engine) -> Result<(), ::error::Error> {
+	fn finalize(&mut self, _engine: &EthEngine) -> Result<(), ::error::Error> {
 		if !self.had_genesis {
 			return Err(Error::WrongChunkFormat("No genesis transition included.".into()).into());
 		}

ethcore/src/snapshot/consensus/mod.rs

@@ -21,7 +21,7 @@ use std::sync::atomic::AtomicBool;
 use std::sync::Arc;
 
 use blockchain::BlockChain;
-use engines::Engine;
+use engines::EthEngine;
 use snapshot::{Error, ManifestData};
 
 use bigint::hash::H256;
@@ -84,7 +84,7 @@ pub trait Rebuilder: Send {
 	fn feed(
 		&mut self,
 		chunk: &[u8],
-		engine: &Engine,
+		engine: &EthEngine,
 		abort_flag: &AtomicBool,
 	) -> Result<(), ::error::Error>;
 
@@ -93,5 +93,5 @@ pub trait Rebuilder: Send {
 	///
 	/// This should apply the necessary "glue" between chunks,
 	/// and verify against the restored state.
-	fn finalize(&mut self, engine: &Engine) -> Result<(), ::error::Error>;
+	fn finalize(&mut self, engine: &EthEngine) -> Result<(), ::error::Error>;
 }

ethcore/src/snapshot/consensus/work.rs

@@ -27,7 +27,7 @@ use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::Arc;
 
 use blockchain::{BlockChain, BlockProvider};
-use engines::Engine;
+use engines::EthEngine;
 use snapshot::{Error, ManifestData};
 use snapshot::block::AbridgedBlock;
 use bigint::hash::H256;
@@ -219,7 +219,7 @@ impl PowRebuilder {
 impl Rebuilder for PowRebuilder {
 	/// Feed the rebuilder an uncompressed block chunk.
 	/// Returns the number of blocks fed or any errors.
-	fn feed(&mut self, chunk: &[u8], engine: &Engine, abort_flag: &AtomicBool) -> Result<(), ::error::Error> {
+	fn feed(&mut self, chunk: &[u8], engine: &EthEngine, abort_flag: &AtomicBool) -> Result<(), ::error::Error> {
 		use basic_types::Seal::With;
 		use views::BlockView;
 		use snapshot::verify_old_block;
@@ -271,7 +271,6 @@ impl Rebuilder for PowRebuilder {
 				&block.header,
 				engine,
 				&self.chain,
-				Some(&block_bytes),
 				is_best
 			)?;
 
@@ -298,7 +297,7 @@ impl Rebuilder for PowRebuilder {
 	}
 
 	/// Glue together any disconnected chunks and check that the chain is complete.
-	fn finalize(&mut self, _: &Engine) -> Result<(), ::error::Error> {
+	fn finalize(&mut self, _: &EthEngine) -> Result<(), ::error::Error> {
 		let mut batch = self.db.transaction();
 
 		for (first_num, first_hash) in self.disconnected.drain(..) {