Setting limit from CLI

miner/src/lib.rs

@@ -100,6 +100,12 @@ pub trait MinerService : Send + Sync {
 	/// Set the gas limit we wish to target when sealing a new block.
 	fn set_gas_floor_target(&self, target: U256);
 
+	/// Get current transactions limit in queue.
+	fn transactions_limit(&self) -> usize;
+
+	/// Set maximal number of transactions kept in the queue (both current and future).
+	fn set_transactions_limit(&self, limit: usize);
+
 	/// Imports transactions to transaction queue.
 	fn import_transactions<T>(&self, transactions: Vec<SignedTransaction>, fetch_account: T) ->
 		Vec<Result<TransactionImportResult, Error>>

miner/src/miner.rs

@@ -205,6 +205,14 @@ impl MinerService for Miner {
 		*self.gas_floor_target.read().unwrap() / x!(5)
 	}
 
+	fn transactions_limit(&self) -> usize {
+		self.transaction_queue.lock().unwrap().limit()
+	}
+
+	fn set_transactions_limit(&self, limit: usize) {
+		self.transaction_queue.lock().unwrap().set_limit(limit)
+	}
+
 	/// Get the author that we will seal blocks as.
 	fn author(&self) -> Address {
 		*self.author.read().unwrap()

miner/src/transaction_queue.rs

@@ -242,6 +242,12 @@ impl TransactionSet {
 		self.by_priority.clear();
 		self.by_address.clear();
 	}
+
+	/// Sets new limit for number of transactions in this `TransactionSet`.
+	/// Note the limit is not applied (no transactions are removed) by calling this method.
+	fn set_limit(&mut self, limit: usize) {
+		self.limit = limit;
+	}
 }
 
 #[derive(Debug)]
@@ -290,20 +296,21 @@ impl Default for TransactionQueue {
 impl TransactionQueue {
 	/// Creates new instance of this Queue
 	pub fn new() -> Self {
-		Self::with_limits(1024, 1024)
+		Self::with_limit(1024)
 	}
 
 	/// Create new instance of this Queue with specified limits
-	pub fn with_limits(current_limit: usize, future_limit: usize) -> Self {
+	pub fn with_limit(limit: usize) -> Self {
 		let current = TransactionSet {
 			by_priority: BTreeSet::new(),
 			by_address: Table::new(),
-			limit: current_limit,
+			limit: limit,
 		};
+
 		let future = TransactionSet {
 			by_priority: BTreeSet::new(),
 			by_address: Table::new(),
-			limit: future_limit,
+			limit: limit,
 		};
 
 		TransactionQueue {
@@ -316,6 +323,20 @@ impl TransactionQueue {
 		}
 	}
 
+	/// Set the new limit for `current` and `future` queue.
+	pub fn set_limit(&mut self, limit: usize) {
+		self.current.set_limit(limit);
+		self.future.set_limit(limit);
+		// And ensure the limits
+		self.current.enforce_limit(&mut self.by_hash);
+		self.future.enforce_limit(&mut self.by_hash);
+	}
+
+	/// Returns current limit of transactions in the queue.
+	pub fn limit(&self) -> usize {
+		self.current.limit
+	}
+
 	/// Get the minimal gas price.
 	pub fn minimal_gas_price(&self) -> &U256 {
 		&self.minimal_gas_price
@@ -1085,7 +1106,7 @@ mod test {
 	#[test]
 	fn should_drop_old_transactions_when_hitting_the_limit() {
 		// given
-		let mut txq = TransactionQueue::with_limits(1, 1);
+		let mut txq = TransactionQueue::with_limit(1);
 		let (tx, tx2) = new_txs(U256::one());
 		txq.add(tx.clone(), &default_nonce).unwrap();
 		assert_eq!(txq.status().pending, 1);
@@ -1102,7 +1123,8 @@ mod test {
 
 	#[test]
 	fn should_limit_future_transactions() {
-		let mut txq = TransactionQueue::with_limits(10, 1);
+		let mut txq = TransactionQueue::with_limit(1);
+		txq.current.set_limit(10);
 		let (tx1, tx2) = new_txs(U256::from(4));
 		let (tx3, tx4) = new_txs(U256::from(4));
 		txq.add(tx1.clone(), &default_nonce).unwrap();

parity/main.rs

@@ -172,6 +172,8 @@ Sealing/Mining Options:
                            [default: 0037a6b811ffeb6e072da21179d11b1406371c63].
   --extra-data STRING      Specify a custom extra-data for authored blocks, no
                            more than 32 characters.
+  --tx-limit LIMIT         Limit of transactions kept in the queue (waiting to
+                           be included in next block) [default: 1024].
 
 Footprint Options:
   --pruning METHOD         Configure pruning of the state/storage trie. METHOD
@@ -259,6 +261,7 @@ struct Args {
 	flag_usd_per_eth: String,
 	flag_gas_floor_target: String,
 	flag_extra_data: Option<String>,
+	flag_tx_limit: usize,
 	flag_logging: Option<String>,
 	flag_version: bool,
 	// geth-compatibility...
@@ -713,6 +716,7 @@ impl Configuration {
 		miner.set_gas_floor_target(self.gas_floor_target());
 		miner.set_extra_data(self.extra_data());
 		miner.set_minimal_gas_price(self.gas_price());
+		miner.set_transactions_limit(self.args.flag_tx_limit);
 
 		// Sync
 		let sync = EthSync::register(service.network(), sync_config, client.clone(), miner.clone());