allow optional casting of engine client to full client

ethcore/light/src/client/mod.rs

@@ -19,9 +19,9 @@
 use std::sync::{Weak, Arc};
 
 use ethcore::block_status::BlockStatus;
-use ethcore::client::{TransactionImportResult, ClientReport, EnvInfo};
+use ethcore::client::{ClientReport, EnvInfo};
 use ethcore::engines::{epoch, Engine, EpochChange, EpochTransition, Proof, Unsure};
-use ethcore::error::{TransactionError, BlockImportError, Error as EthcoreError};
+use ethcore::error::BlockImportError;
 use ethcore::ids::BlockId;
 use ethcore::header::{BlockNumber, Header};
 use ethcore::verification::queue::{self, HeaderQueue};
@@ -35,7 +35,6 @@ use bigint::prelude::U256;
 use bigint::hash::H256;
 use futures::{IntoFuture, Future};
 
-use util::Address;
 use util::kvdb::{KeyValueDB, CompactionProfile};
 
 use self::fetch::ChainDataFetcher;
@@ -619,17 +618,8 @@ impl<T: ChainDataFetcher> ::ethcore::client::EngineClient for Client<T> {
 		Client::chain_info(self)
 	}
 
-	fn call_contract(&self, _id: BlockId, _address: Address, _data: Vec<u8>) -> Result<Vec<u8>, String> {
-		Err("Contract calling not supported by light client".into())
-	}
-
-	fn transact_contract(&self, _address: Address, _data: Vec<u8>)
-		-> Result<TransactionImportResult, EthcoreError>
-	{
-		// TODO: these are only really used for misbehavior reporting.
-		// no relevant clients will be running light clients, but maybe
-		// they could be at some point?
-		Err(TransactionError::LimitReached.into())
+	fn as_full_client(&self) -> Option<&::ethcore::client::BlockChainClient> {
+		None
 	}
 
 	fn block_number(&self, id: BlockId) -> Option<BlockNumber> {

ethcore/src/client/client.rs

@@ -1960,13 +1960,7 @@ impl super::traits::EngineClient for Client {
 		BlockChainClient::chain_info(self)
 	}
 
-	fn call_contract(&self, id: BlockId, address: Address, data: Bytes) -> Result<Bytes, String> {
-		BlockChainClient::call_contract(self, id, address, data)
-	}
-
-	fn transact_contract(&self, address: Address, data: Bytes) -> Result<TransactionImportResult, EthcoreError> {
-		BlockChainClient::transact_contract(self, address, data)
-	}
+	fn as_full_client(&self) -> Option<&BlockChainClient> { Some(self) }
 
 	fn block_number(&self, id: BlockId) -> Option<BlockNumber> {
 		BlockChainClient::block_number(self, id)

ethcore/src/client/test_client.rs

@@ -828,13 +828,7 @@ impl super::traits::EngineClient for TestBlockChainClient {
 		BlockChainClient::chain_info(self)
 	}
 
-	fn call_contract(&self, id: BlockId, address: Address, data: Bytes) -> Result<Bytes, String> {
-		BlockChainClient::call_contract(self, id, address, data)
-	}
-
-	fn transact_contract(&self, address: Address, data: Bytes) -> Result<TransactionImportResult, EthcoreError> {
-		BlockChainClient::transact_contract(self, address, data)
-	}
+	fn as_full_client(&self) -> Option<&BlockChainClient> { Some(self) }
 
 	fn block_number(&self, id: BlockId) -> Option<BlockNumber> {
 		BlockChainClient::block_number(self, id)

ethcore/src/client/traits.rs

@@ -337,12 +337,10 @@ pub trait EngineClient: Sync + Send {
 	/// Get block chain info.
 	fn chain_info(&self) -> BlockChainInfo;
 
-	/// Like `call`, but with various defaults. Designed to be used for calling contracts.
-	fn call_contract(&self, id: BlockId, address: Address, data: Bytes) -> Result<Bytes, String>;
-
-	/// Import a transaction: used for misbehaviour reporting.
-	fn transact_contract(&self, address: Address, data: Bytes) -> Result<TransactionImportResult, EthcoreError>;
+	/// Attempt to cast the engine client to a full client.
+	fn as_full_client(&self) -> Option<&BlockChainClient>;
 
+	/// Get a block number by ID.
 	fn block_number(&self, id: BlockId) -> Option<BlockNumber>;
 }
 

ethcore/src/engines/tendermint/mod.rs

@@ -35,7 +35,7 @@ use bigint::hash::{H256, H520};
 use parking_lot::RwLock;
 use util::*;
 use unexpected::{OutOfBounds, Mismatch};
-use client::{Client, EngineClient};
+use client::EngineClient;
 use error::{Error, BlockError};
 use header::{Header, BlockNumber};
 use builtin::Builtin;

ethcore/src/engines/validator_set/contract.rs

@@ -58,7 +58,13 @@ impl ValidatorContract {
 		Box::new(move |a, d| client.as_ref()
 			.and_then(Weak::upgrade)
 			.ok_or("No client!".into())
-			.and_then(|c| c.transact_contract(a, d).map_err(|e| format!("Transaction import error: {}", e)))
+			.and_then(|c| {
+				match c.as_full_client() {
+					Some(c) => c.transact_contract(a, d)
+						.map_err(|e| format!("Transaction import error: {}", e)),
+					None => Err("No full client!".into()),
+				}
+			})
 			.map(|_| Default::default()))
 	}
 }

ethcore/src/engines/validator_set/safe_contract.rs

@@ -311,7 +311,12 @@ impl ValidatorSet for ValidatorSafeContract {
 		Box::new(move |addr, data| client.as_ref()
 			.and_then(Weak::upgrade)
 			.ok_or("No client!".into())
-			.and_then(|c| c.call_contract(id, addr, data))
+			.and_then(|c| {
+				match c.as_full_client() {
+					Some(c) => c.call_contract(id, addr, data),
+					None => Err("No full client!".into()),
+				}
+			})
 			.map(|out| (out, Vec::new()))) // generate no proofs in general
 	}
 

ethcore/src/ethereum/ethash.rs

@@ -40,7 +40,7 @@ use rlp::{self, UntrustedRlp};
 use vm::LastHashes;
 use semantic_version::SemanticVersion;
 use tx_filter::{TransactionFilter};
-use client::{Client, BlockChainClient};
+use client::EngineClient;
 
 /// Parity tries to round block.gas_limit to multiple of this constant
 pub const PARITY_GAS_LIMIT_DETERMINANT: U256 = U256([37, 0, 0, 0]);
@@ -460,9 +460,9 @@ impl Engine for Arc<Ethash> {
 		Some(Box::new(::snapshot::PowSnapshot::new(SNAPSHOT_BLOCKS, MAX_SNAPSHOT_BLOCKS)))
 	}
 
-	fn register_client(&self, client: Weak<Client>) {
+	fn register_client(&self, client: Weak<EngineClient>) {
 		if let Some(ref filter) = self.tx_filter {
-			filter.register_client(client as Weak<BlockChainClient>);
+			filter.register_client(client);
 		}
 	}
 

ethcore/src/tx_filter.rs

@@ -19,9 +19,10 @@
 use std::sync::Weak;
 use std::collections::HashMap;
 use std::collections::hash_map::Entry;
+use bigint::hash::H256;
 use native_contracts::TransactAcl as Contract;
-use client::{BlockChainClient, BlockId, ChainNotify};
-use util::{Address, H256, Bytes};
+use client::{EngineClient, BlockId, ChainNotify};
+use util::{Address, Bytes};
 use parking_lot::{Mutex, RwLock};
 use futures::{self, Future};
 use spec::CommonParams;
@@ -42,7 +43,7 @@ mod tx_permissions {
 /// Connection filter that uses a contract to manage permissions.
 pub struct TransactionFilter {
 	contract: Mutex<Option<Contract>>,
-	client: RwLock<Option<Weak<BlockChainClient>>>,
+	client: RwLock<Option<Weak<EngineClient>>>,
 	contract_address: Address,
 	permission_cache: Mutex<HashMap<(H256, Address), u32>>,
 }
@@ -66,7 +67,7 @@ impl TransactionFilter {
 	}
 
 	/// Set client reference to be used for contract call.
-	pub fn register_client(&self, client: Weak<BlockChainClient>) {
+	pub fn register_client(&self, client: Weak<EngineClient>) {
 		*self.client.write() = Some(client);
 	}
 
@@ -78,6 +79,12 @@ impl TransactionFilter {
 				Some(client) => client,
 				_ => return false,
 			};
+
+			let client = match client.as_full_client() {
+				Some(client) => client,
+				_ => return false, // TODO: how to handle verification for light clients?
+			};
+
 			let tx_type = match transaction.action {
 				Action::Create => tx_permissions::CREATE,
 				Action::Call(address) => if client.code_hash(&address, BlockId::Hash(*parent_hash)).map_or(false, |c| c != KECCAK_EMPTY) {