Minimal gas price threshold. Closes: #636

miner/src/miner.rs

@@ -24,7 +24,7 @@ use ethcore::error::*;
 use ethcore::transaction::SignedTransaction;
 use transaction_queue::{TransactionQueue};
 
-/// Miner external API
+/// Miner client API
 pub trait MinerService {
 
 	/// Returns miner's status.
@@ -34,12 +34,6 @@ pub trait MinerService {
 	fn import_transactions<T>(&self, transactions: Vec<SignedTransaction>, fetch_nonce: T)
 		where T: Fn(&Address) -> U256;
 
-	/// Set the author that we will seal blocks as.
-	fn set_author(&self, author: Address);
-
-	/// Set the extra_data that we will seal blocks with.
-	fn set_extra_data(&self, extra_data: Bytes);
-
 	/// Removes all transactions from the queue and restart mining operation.
 	fn clear_and_reset(&self, chain: &BlockChainClient);
 
@@ -103,6 +97,21 @@ impl Miner {
 	fn extra_data(&self) -> Bytes {
 		self.extra_data.read().unwrap().clone()
 	}
+
+	/// Set the author that we will seal blocks as.
+	pub fn set_author(&self, author: Address) {
+		*self.author.write().unwrap() = author;
+	}
+
+	/// Set the extra_data that we will seal blocks with.
+	pub fn set_extra_data(&self, extra_data: Bytes) {
+		*self.extra_data.write().unwrap() = extra_data;
+	}
+
+	/// Set minimal gas price of transaction to be accepted for mining.
+	pub fn set_minimal_gas_price(&self, min_gas_price: U256) {
+		self.transaction_queue.lock().unwrap().set_minimal_gas_price(min_gas_price);
+	}
 }
 
 impl MinerService for Miner {
@@ -126,15 +135,6 @@ impl MinerService for Miner {
 		transaction_queue.add_all(transactions, fetch_nonce);
 	}
 
-	fn set_author(&self, author: Address) {
-		*self.author.write().unwrap() = author;
-	}
-
-
-	fn set_extra_data(&self, extra_data: Bytes) {
-		*self.extra_data.write().unwrap() = extra_data;
-	}
-
 	fn prepare_sealing(&self, chain: &BlockChainClient) {
 		let no_of_transactions = 128;
 		let transactions = self.transaction_queue.lock().unwrap().top_transactions(no_of_transactions);

miner/src/transaction_queue.rs

@@ -159,6 +159,8 @@ pub struct TransactionQueueStatus {
 
 /// TransactionQueue implementation
 pub struct TransactionQueue {
+	/// Gas Price threshold for transactions that can be imported to this queue (defaults to 0)
+	minimal_gas_price: U256,
 	/// Priority queue for transactions that can go to block
 	current: TransactionSet,
 	/// Priority queue for transactions that has been received but are not yet valid to go to block
@@ -189,6 +191,7 @@ impl TransactionQueue {
 		};
 
 		TransactionQueue {
+			minimal_gas_price: U256::zero(),
 			current: current,
 			future: future,
 			by_hash: HashMap::new(),
@@ -196,6 +199,12 @@ impl TransactionQueue {
 		}
 	}
 
+	/// Sets new gas price threshold for incoming transactions.
+	/// Any transactions already imported to the queue are not affected.
+	pub fn set_minimal_gas_price(&mut self, min_gas_price: U256) {
+		self.minimal_gas_price = min_gas_price;
+	}
+
 	/// Returns current status for this queue
 	pub fn status(&self) -> TransactionQueueStatus {
 		TransactionQueueStatus {
@@ -215,6 +224,15 @@ impl TransactionQueue {
 	/// Add signed transaction to queue to be verified and imported
 	pub fn add<T>(&mut self, tx: SignedTransaction, fetch_nonce: &T)
 		where T: Fn(&Address) -> U256 {
+
+		if tx.gas_price < self.minimal_gas_price {
+			trace!(target: "sync",
+				"Dropping transaction below minimal gas price threshold: {:?} (gp: {} < {})",
+				tx.hash(), tx.gas_price, self.minimal_gas_price
+			);
+			return;
+		}
+		// Everything ok - import transaction
 		self.import_tx(VerifiedTransaction::new(tx), fetch_nonce);
 	}
 
@@ -503,6 +521,22 @@ mod test {
 		assert_eq!(stats.pending, 1);
 	}
 
+	#[test]
+	fn should_not_import_transaction_below_min_gas_price_threshold() {
+		// given
+		let mut txq = TransactionQueue::new();
+		let tx = new_tx();
+		txq.set_minimal_gas_price(tx.gas_price + U256::one());
+
+		// when
+		txq.add(tx, &default_nonce);
+
+		// then
+		let stats = txq.status();
+		assert_eq!(stats.pending, 0);
+		assert_eq!(stats.future, 0);
+	}
+
 	#[test]
 	fn should_import_txs_from_same_sender() {
 		// given

parity/main.rs

@@ -108,6 +108,7 @@ API and Console Options:
   --rpccorsdomain URL      Equivalent to --jsonrpc-cors URL (geth-compatible).
 
 Sealing/Mining Options:
+  --gasprice GAS		   Minimal gas price a transaction must have to be accepted for mining [default: 50000000000].
   --author ADDRESS         Specify the block author (aka "coinbase") address for sending block rewards
                            from sealed blocks [default: 0037a6b811ffeb6e072da21179d11b1406371c63].
   --extradata STRING       Specify a custom extra-data for authored blocks, no more than 32 characters.
@@ -161,6 +162,7 @@ struct Args {
 	flag_rpcapi: Option<String>,
 	flag_logging: Option<String>,
 	flag_version: bool,
+	flag_gasprice: String,
 	flag_author: String,
 	flag_extra_data: Option<String>,
 }
@@ -248,6 +250,11 @@ impl Configuration {
 		Address::from_str(&self.args.flag_author).unwrap_or_else(|_| die!("{}: Invalid address for --author. Must be 40 hex characters, without the 0x at the beginning.", self.args.flag_author))
 	}
 
+	fn gasprice(&self) -> U256 {
+		U256::from_dec_str(self.args.flag_gasprice).unwrap_or_else(|_| die("{}: Invalid gasprice given. Must be a
+																		   decimal unsigned 256-bit number."))
+	}
+
 	fn extra_data(&self) -> Bytes {
 		match self.args.flag_extra_data {
 			Some(ref x) if x.len() <= 32 => x.as_bytes().to_owned(),
@@ -385,6 +392,7 @@ impl Configuration {
 		let miner = Miner::new();
 		miner.set_author(self.author());
 		miner.set_extra_data(self.extra_data());
+		miner.set_minimal_gas_price(self.gasprice());
 
 		// Sync
 		let sync = EthSync::register(service.network(), sync_config, client.clone(), miner.clone());