Remove transaction RPC (#4949)

ethcore/src/miner/miner.rs

@@ -1018,6 +1018,16 @@ impl MinerService for Miner {
 		}
 	}
 
+	fn remove_pending_transaction(&self, chain: &MiningBlockChainClient, hash: &H256) -> Option<PendingTransaction> {
+		let mut queue = self.transaction_queue.lock();
+		let tx = queue.find(hash);
+		if tx.is_some() {
+			let fetch_nonce = |a: &Address| chain.latest_nonce(a);
+			queue.remove_invalid(hash, &fetch_nonce);
+		}
+		tx
+	}
+
 	fn pending_receipt(&self, best_block: BlockNumber, hash: &H256) -> Option<RichReceipt> {
 		self.from_pending_block(
 			best_block,

ethcore/src/miner/mod.rs

@@ -150,6 +150,10 @@ pub trait MinerService : Send + Sync {
 	/// Query pending transactions for hash.
 	fn transaction(&self, best_block: BlockNumber, hash: &H256) -> Option<PendingTransaction>;
 
+	/// Removes transaction from the queue.
+	/// NOTE: The transaction is not removed from pending block if mining.
+	fn remove_pending_transaction(&self, chain: &MiningBlockChainClient, hash: &H256) -> Option<PendingTransaction>;
+
 	/// Get a list of all pending transactions in the queue.
 	fn pending_transactions(&self) -> Vec<PendingTransaction>;