Allow configuration of target gas limit.

ethcore/src/block.rs

@@ -171,7 +171,7 @@ pub struct SealedBlock {
 
 impl<'x> OpenBlock<'x> {
 	/// Create a new OpenBlock ready for transaction pushing.
-	pub fn new(engine: &'x Engine, db: Box<JournalDB>, parent: &Header, last_hashes: LastHashes, author: Address, extra_data: Bytes) -> Self {
+	pub fn new(engine: &'x Engine, db: Box<JournalDB>, parent: &Header, last_hashes: LastHashes, author: Address, gas_floor_target: U256, extra_data: Bytes) -> Self {
 		let mut r = OpenBlock {
 			block: ExecutedBlock::new(State::from_existing(db, parent.state_root().clone(), engine.account_start_nonce())),
 			engine: engine,
@@ -185,7 +185,7 @@ impl<'x> OpenBlock<'x> {
 		r.block.base.header.extra_data = extra_data;
 		r.block.base.header.note_dirty();
 
-		engine.populate_from_parent(&mut r.block.base.header, parent);
+		engine.populate_from_parent(&mut r.block.base.header, parent, gas_floor_target);
 		engine.on_new_block(&mut r.block);
 		r
 	}
@@ -347,7 +347,7 @@ pub fn enact(header: &Header, transactions: &[SignedTransaction], uncles: &[Head
 		}
 	}
 
-	let mut b = OpenBlock::new(engine, db, parent, last_hashes, header.author().clone(), header.extra_data().clone());
+	let mut b = OpenBlock::new(engine, db, parent, last_hashes, header.author().clone(), x!(3141562), header.extra_data().clone());
 	b.set_difficulty(*header.difficulty());
 	b.set_gas_limit(*header.gas_limit());
 	b.set_timestamp(header.timestamp());
@@ -391,7 +391,7 @@ mod tests {
 		let mut db = db_result.take();
 		engine.spec().ensure_db_good(db.as_hashdb_mut());
 		let last_hashes = vec![genesis_header.hash()];
-		let b = OpenBlock::new(engine.deref(), db, &genesis_header, last_hashes, Address::zero(), vec![]);
+		let b = OpenBlock::new(engine.deref(), db, &genesis_header, last_hashes, Address::zero(), x!(3141562), vec![]);
 		let b = b.close();
 		let _ = b.seal(engine.deref(), vec![]);
 	}
@@ -405,7 +405,7 @@ mod tests {
 		let mut db_result = get_temp_journal_db();
 		let mut db = db_result.take();
 		engine.spec().ensure_db_good(db.as_hashdb_mut());
-		let b = OpenBlock::new(engine.deref(), db, &genesis_header, vec![genesis_header.hash()], Address::zero(), vec![]).close().seal(engine.deref(), vec![]).unwrap();
+		let b = OpenBlock::new(engine.deref(), db, &genesis_header, vec![genesis_header.hash()], Address::zero(), x!(3141562), vec![]).close().seal(engine.deref(), vec![]).unwrap();
 		let orig_bytes = b.rlp_bytes();
 		let orig_db = b.drain();
 

ethcore/src/client/client.rs

@@ -380,15 +380,13 @@ impl<V> Client<V> where V: Verifier {
 }
 
 impl<V> BlockChainClient for Client<V> where V: Verifier {
-
-
 	// TODO [todr] Should be moved to miner crate eventually.
 	fn try_seal(&self, block: ClosedBlock, seal: Vec<Bytes>) -> Result<SealedBlock, ClosedBlock> {
 		block.try_seal(self.engine.deref().deref(), seal)
 	}
 
 	// TODO [todr] Should be moved to miner crate eventually.
-	fn prepare_sealing(&self, author: Address, extra_data: Bytes, transactions: Vec<SignedTransaction>) -> Option<ClosedBlock> {
+	fn prepare_sealing(&self, author: Address, gas_floor_target: U256, extra_data: Bytes, transactions: Vec<SignedTransaction>) -> Option<ClosedBlock> {
 		let engine = self.engine.deref().deref();
 		let h = self.chain.best_block_hash();
 
@@ -398,6 +396,7 @@ impl<V> BlockChainClient for Client<V> where V: Verifier {
 			match self.chain.block_header(&h) { Some(ref x) => x, None => {return None} },
 			self.build_last_hashes(h.clone()),
 			author,
+			gas_floor_target,
 			extra_data,
 		);
 

ethcore/src/client/mod.rs

@@ -110,7 +110,7 @@ pub trait BlockChainClient : Sync + Send {
 
 	// TODO [todr] Should be moved to miner crate eventually.
 	/// Returns ClosedBlock prepared for sealing.
-	fn prepare_sealing(&self, author: Address, extra_data: Bytes, transactions: Vec<SignedTransaction>) -> Option<ClosedBlock>;
+	fn prepare_sealing(&self, author: Address, gas_floor_target: U256, extra_data: Bytes, transactions: Vec<SignedTransaction>) -> Option<ClosedBlock>;
 
 	// TODO [todr] Should be moved to miner crate eventually.
 	/// Attempts to seal given block. Returns `SealedBlock` on success and the same block in case of error.

ethcore/src/client/test_client.rs

@@ -215,7 +215,7 @@ impl BlockChainClient for TestBlockChainClient {
 		unimplemented!();
 	}
 
-	fn prepare_sealing(&self, _author: Address, _extra_data: Bytes, _transactions: Vec<SignedTransaction>) -> Option<ClosedBlock> {
+	fn prepare_sealing(&self, _author: Address, _gas_floor_target: U256, _extra_data: Bytes, _transactions: Vec<SignedTransaction>) -> Option<ClosedBlock> {
 		unimplemented!()
 	}
 

ethcore/src/engine.rs

@@ -85,7 +85,7 @@ pub trait Engine : Sync + Send {
 
 	/// Don't forget to call Super::populate_from_parent when subclassing & overriding.
 	// TODO: consider including State in the params.
-	fn populate_from_parent(&self, header: &mut Header, parent: &Header) {
+	fn populate_from_parent(&self, header: &mut Header, parent: &Header, _gas_floor_target: U256) {
 		header.difficulty = parent.difficulty;
 		header.gas_limit = parent.gas_limit;
 		header.note_dirty();

ethcore/src/ethereum/ethash.rs

@@ -92,10 +92,9 @@ impl Engine for Ethash {
 		}
 	}
 
-	fn populate_from_parent(&self, header: &mut Header, parent: &Header) {
+	fn populate_from_parent(&self, header: &mut Header, parent: &Header, gas_floor_target: U256) {
 		header.difficulty = self.calculate_difficuty(header, parent);
 		header.gas_limit = {
-			let gas_floor_target: U256 = x!(3141562);
 			let gas_limit = parent.gas_limit;
 			let bound_divisor = self.u256_param("gasLimitBoundDivisor");
 			if gas_limit < gas_floor_target {
@@ -300,7 +299,7 @@ mod tests {
 		let mut db = db_result.take();
 		engine.spec().ensure_db_good(db.as_hashdb_mut());
 		let last_hashes = vec![genesis_header.hash()];
-		let b = OpenBlock::new(engine.deref(), db, &genesis_header, last_hashes, Address::zero(), vec![]);
+		let b = OpenBlock::new(engine.deref(), db, &genesis_header, last_hashes, Address::zero(), x!(3141562), vec![]);
 		let b = b.close();
 		assert_eq!(b.state().balance(&Address::zero()), U256::from_str("4563918244f40000").unwrap());
 	}
@@ -313,7 +312,7 @@ mod tests {
 		let mut db = db_result.take();
 		engine.spec().ensure_db_good(db.as_hashdb_mut());
 		let last_hashes = vec![genesis_header.hash()];
-		let mut b = OpenBlock::new(engine.deref(), db, &genesis_header, last_hashes, Address::zero(), vec![]);
+		let mut b = OpenBlock::new(engine.deref(), db, &genesis_header, last_hashes, Address::zero(), x!(3141562), vec![]);
 		let mut uncle = Header::new();
 		let uncle_author = address_from_hex("ef2d6d194084c2de36e0dabfce45d046b37d1106");
 		uncle.author = uncle_author.clone();

miner/src/miner.rs

@@ -19,7 +19,7 @@ use std::sync::{Mutex, RwLock, Arc};
 use std::sync::atomic;
 use std::sync::atomic::AtomicBool;
 
-use util::{H256, U256, Address, Bytes};
+use util::{H256, U256, Address, Bytes, Uint};
 use ethcore::views::{BlockView};
 use ethcore::client::{BlockChainClient, BlockId};
 use ethcore::block::{ClosedBlock};
@@ -34,8 +34,10 @@ pub struct Miner {
 	// for sealing...
 	sealing_enabled: AtomicBool,
 	sealing_block: Mutex<Option<ClosedBlock>>,
+	gas_floor_target: RwLock<U256>,
 	author: RwLock<Address>,
 	extra_data: RwLock<Bytes>,
+
 }
 
 impl Default for Miner {
@@ -44,6 +46,7 @@ impl Default for Miner {
 			transaction_queue: Mutex::new(TransactionQueue::new()),
 			sealing_enabled: AtomicBool::new(false),
 			sealing_block: Mutex::new(None),
+			gas_floor_target: RwLock::new(U256::zero()),
 			author: RwLock::new(Address::default()),
 			extra_data: RwLock::new(Vec::new()),
 		}
@@ -66,6 +69,11 @@ impl Miner {
 		self.extra_data.read().unwrap().clone()
 	}
 
+	/// Get the extra_data that we will seal blocks wuth.
+	fn gas_floor_target(&self) -> U256 {
+		self.gas_floor_target.read().unwrap().clone()
+	}
+
 	/// Set the author that we will seal blocks as.
 	pub fn set_author(&self, author: Address) {
 		*self.author.write().unwrap() = author;
@@ -76,6 +84,11 @@ impl Miner {
 		*self.extra_data.write().unwrap() = extra_data;
 	}
 
+	/// Set the gas limit we wish to target when sealing a new block.
+	pub fn set_gas_floor_target(&self, target: U256) {
+		*self.gas_floor_target.write().unwrap() = target;
+	}
+
 	/// 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);
@@ -110,12 +123,14 @@ impl MinerService for Miner {
 
 	fn prepare_sealing(&self, chain: &BlockChainClient) {
 		let no_of_transactions = 128;
+		// TODO: should select transactions orm queue according to gas limit of block.
 		let transactions = self.transaction_queue.lock().unwrap().top_transactions(no_of_transactions);
 
 		let b = chain.prepare_sealing(
 			self.author(),
+			self.gas_floor_target(),
 			self.extra_data(),
-			transactions,
+			transactions
 		);
 		*self.sealing_block.lock().unwrap() = b;
 	}

parity/main.rs

@@ -115,6 +115,7 @@ API and Console Options:
 
 Sealing/Mining Options:
   --gas-price WEI          Minimum amount of Wei to be paid for a transaction to be accepted for mining [default: 20000000000].
+  --gas-floor-target GAS   Amount of gas per block to target when sealing a new block [default: 4712388].
   --author ADDRESS         Specify the block author (aka "coinbase") address for sending block rewards
                            from sealed blocks [default: 0037a6b811ffeb6e072da21179d11b1406371c63].
   --extra-data STRING      Specify a custom extra-data for authored blocks, no more than 32 characters.
@@ -178,6 +179,7 @@ struct Args {
 	flag_jsonrpc_apis: String,
 	flag_author: String,
 	flag_gas_price: String,
+	flag_gas_floor_target: String,
 	flag_extra_data: Option<String>,
 	flag_logging: Option<String>,
 	flag_version: bool,
@@ -303,6 +305,13 @@ impl Configuration {
 		})
 	}
 
+	fn gas_floor_target(&self) -> U256 {
+		let d = &self.args.flag_gas_floor_target;
+		U256::from_dec_str(d).unwrap_or_else(|_| {
+			die!("{}: Invalid target gas floor given. Must be a decimal unsigned 256-bit number.", d)
+		})
+	}
+
 	fn gas_price(&self) -> U256 {
 		let d = self.args.flag_gasprice.as_ref().unwrap_or(&self.args.flag_gas_price);
 		U256::from_dec_str(d).unwrap_or_else(|_| {
@@ -485,6 +494,7 @@ impl Configuration {
 		// Miner
 		let miner = Miner::new();
 		miner.set_author(self.author());
+		miner.set_gas_floor_target(self.gas_floor_target());
 		miner.set_extra_data(self.extra_data());
 		miner.set_minimal_gas_price(self.gas_price());