From 177d26a25e389166ea6f67baf0aaa709fb849b53 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tomasz=20Drwi=C4=99ga?= <tomasz@ethcore.io>
Date: Thu, 17 Mar 2016 14:39:24 +0100
Subject: [PATCH] Stop adding transactions right after we know that no other
 will make it to block.

---
 ethcore/src/client/client.rs | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/ethcore/src/client/client.rs b/ethcore/src/client/client.rs
index 7818fcdc8..2c011047d 100644
--- a/ethcore/src/client/client.rs
+++ b/ethcore/src/client/client.rs
@@ -418,26 +418,33 @@ impl<V> BlockChainClient for Client<V> where V: Verifier {
 
 		// Add transactions
 		let block_number = b.block().header().number();
+		let min_tx_gas = U256::from(self.engine.schedule(&b.env_info()).tx_gas);
 		let gas_limit = *b.block().header().gas_limit();
 		let mut gas_left = gas_limit;
 		let mut invalid_transactions = HashSet::new();
 
 		for tx in transactions {
-			let hash = tx.hash();
-			let gas = tx.gas;
-			// TODO [todr] It seems that calculating gas_left here doesn't really look nice. After moving this function
+			// Stop early if we are sure that no other transaction will be included
+			if gas_left < min_tx_gas {
+				break;
+			}
+
+			// TODO [todr] It seems that calculating gas_left here doesn't look nice. After moving this function
 			// to miner crate we should consider rewriting this logic in some better way.
-			if gas > gas_left {
-				trace!(target: "miner", "Skipping adding transaction to block because of gas limit: {:?}", hash);
+			if tx.gas > gas_left {
+				trace!(target: "miner", "Skipping adding transaction to block because of gas limit: {:?}", tx.hash());
 				continue;
 			}
 
+			// Push transaction to block
+			let hash = tx.hash();
 			let import = b.push_transaction(tx, None);
 			match import {
 				Err(e) => {
-					trace!(target: "miner", "Error adding transaction to block: number={}. transaction_hash={:?}, Error: {:?}",
-						   block_number, hash, e);
 					invalid_transactions.insert(hash);
+					trace!(target: "miner",
+						   "Error adding transaction to block: number={}. transaction_hash={:?}, Error: {:?}",
+						   block_number, hash, e);
 				},
 				Ok(receipt) => {
 					gas_left = gas_limit - receipt.gas_used;