Beginnings of Ethash engine.

src/ethash.rs

@@ -0,0 +1,22 @@
+use engine::Engine;
+use spec::Spec;
+use evm_schedule::EvmSchedule;
+use env_info::EnvInfo;
+
+/// Engine using Ethash proof-of-work consensus algorithm, suitable for Ethereum
+/// mainnet chains in the Olympic, Frontier and Homestead eras.
+pub struct Ethash {
+	spec: Spec,
+}
+
+impl Ethash {
+	pub fn new_boxed(spec: Spec) -> Box<Engine> {
+		Box::new(NullEngine{spec: spec})
+	}
+}
+
+impl Engine for NullEngine {
+	fn name(&self) -> &str { "Ethash" }
+	fn spec(&self) -> &Spec { &self.spec }
+	fn evm_schedule(&self, _env_info: &EnvInfo) -> EvmSchedule { EvmSchedule::new_frontier() }
+}

src/spec.rs

@@ -93,6 +93,7 @@ impl Spec {
 	pub fn to_engine(self) -> Result<Box<Engine>, EthcoreError> {
 		match self.engine_name.as_ref() {
 			"NullEngine" => Ok(NullEngine::new_boxed(self)),
+			"Ethash" => Ok(Ethash::new_boxed(self)),
 			_ => Err(EthcoreError::UnknownName)
 		}
 	}