Limit the number of transactions in pending set (#8777)

* Unordered iterator.

* Use unordered and limited set if full not required.

* Split timeout work into smaller timers.

* Avoid collecting all pending transactions when mining

* Remove println.

* Use priority ordering in eth-filter.

* Fix ethcore-miner tests and tx propagation.

* Review grumbles addressed.

* Add test for unordered not populating the cache.

* Fix ethcore tests.

* Fix light tests.

* Fix ethcore-sync tests.

* Fix RPC tests.

ethcore/src/client/client.rs

@@ -1956,8 +1956,8 @@ impl BlockChainClient for Client {
 		(*self.build_last_hashes(&self.chain.read().best_block_hash())).clone()
 	}
 
-	fn ready_transactions(&self) -> Vec<Arc<VerifiedTransaction>> {
-		self.importer.miner.ready_transactions(self)
+	fn ready_transactions(&self, max_len: usize) -> Vec<Arc<VerifiedTransaction>> {
+		self.importer.miner.ready_transactions(self, max_len, ::miner::PendingOrdering::Priority)
 	}
 
 	fn signing_chain_id(&self) -> Option<u64> {

ethcore/src/client/test_client.rs

@@ -48,7 +48,7 @@ use log_entry::LocalizedLogEntry;
 use receipt::{Receipt, LocalizedReceipt, TransactionOutcome};
 use error::ImportResult;
 use vm::Schedule;
-use miner::{Miner, MinerService};
+use miner::{self, Miner, MinerService};
 use spec::Spec;
 use types::basic_account::BasicAccount;
 use types::pruning_info::PruningInfo;
@@ -806,8 +806,8 @@ impl BlockChainClient for TestBlockChainClient {
 		self.traces.read().clone()
 	}
 
-	fn ready_transactions(&self) -> Vec<Arc<VerifiedTransaction>> {
-		self.miner.ready_transactions(self)
+	fn ready_transactions(&self, max_len: usize) -> Vec<Arc<VerifiedTransaction>> {
+		self.miner.ready_transactions(self, max_len, miner::PendingOrdering::Priority)
 	}
 
 	fn signing_chain_id(&self) -> Option<u64> { None }

ethcore/src/client/traits.rs

@@ -321,7 +321,7 @@ pub trait BlockChainClient : Sync + Send + AccountData + BlockChain + CallContra
 	fn last_hashes(&self) -> LastHashes;
 
 	/// List all transactions that are allowed into the next block.
-	fn ready_transactions(&self) -> Vec<Arc<VerifiedTransaction>>;
+	fn ready_transactions(&self, max_len: usize) -> Vec<Arc<VerifiedTransaction>>;
 
 	/// Sorted list of transaction gas prices from at least last sample_size blocks.
 	fn gas_price_corpus(&self, sample_size: usize) -> ::stats::Corpus<U256> {

ethcore/src/miner/miner.rs

@@ -364,18 +364,28 @@ impl Miner {
 
 		let client = self.pool_client(chain);
 		let engine_params = self.engine.params();
-		let min_tx_gas = self.engine.schedule(chain_info.best_block_number).tx_gas.into();
+		let min_tx_gas: U256 = self.engine.schedule(chain_info.best_block_number).tx_gas.into();
 		let nonce_cap: Option<U256> = if chain_info.best_block_number + 1 >= engine_params.dust_protection_transition {
 			Some((engine_params.nonce_cap_increment * (chain_info.best_block_number + 1)).into())
 		} else {
 			None
 		};
+		// we will never need more transactions than limit divided by min gas
+		let max_transactions = if min_tx_gas.is_zero() {
+			usize::max_value()
+		} else {
+			(*open_block.block().header().gas_limit() / min_tx_gas).as_u64() as usize
+		};
 
 		let pending: Vec<Arc<_>> = self.transaction_queue.pending(
 			client.clone(),
-			chain_info.best_block_number,
-			chain_info.best_block_timestamp,
-			nonce_cap,
+			pool::PendingSettings {
+				block_number: chain_info.best_block_number,
+				current_timestamp: chain_info.best_block_timestamp,
+				nonce_cap,
+				max_len: max_transactions,
+				ordering: miner::PendingOrdering::Priority,
+			}
 		);
 
 		let took_ms = |elapsed: &Duration| {
@@ -807,20 +817,28 @@ impl miner::MinerService for Miner {
 		self.transaction_queue.all_transactions()
 	}
 
-	fn ready_transactions<C>(&self, chain: &C) -> Vec<Arc<VerifiedTransaction>> where
+	fn ready_transactions<C>(&self, chain: &C, max_len: usize, ordering: miner::PendingOrdering)
+		-> Vec<Arc<VerifiedTransaction>>
+	where
 		C: ChainInfo + Nonce + Sync,
 	{
 		let chain_info = chain.chain_info();
 
 		let from_queue = || {
+			// We propagate transactions over the nonce cap.
+			// The mechanism is only to limit number of transactions in pending block
+			// those transactions are valid and will just be ready to be included in next block.
+			let nonce_cap = None;
+
 			self.transaction_queue.pending(
 				CachedNonceClient::new(chain, &self.nonce_cache),
-				chain_info.best_block_number,
-				chain_info.best_block_timestamp,
-				// We propagate transactions over the nonce cap.
-				// The mechanism is only to limit number of transactions in pending block
-				// those transactions are valid and will just be ready to be included in next block.
-				None,
+				pool::PendingSettings {
+					block_number: chain_info.best_block_number,
+					current_timestamp: chain_info.best_block_timestamp,
+					nonce_cap,
+					max_len,
+					ordering,
+				},
 			)
 		};
 
@@ -830,6 +848,7 @@ impl miner::MinerService for Miner {
 					.iter()
 					.map(|signed| pool::VerifiedTransaction::from_pending_block_transaction(signed.clone()))
 					.map(Arc::new)
+					.take(max_len)
 					.collect()
 			}, chain_info.best_block_number)
 		};
@@ -1083,7 +1102,7 @@ mod tests {
 	use rustc_hex::FromHex;
 
 	use client::{TestBlockChainClient, EachBlockWith, ChainInfo, ImportSealedBlock};
-	use miner::MinerService;
+	use miner::{MinerService, PendingOrdering};
 	use test_helpers::{generate_dummy_client, generate_dummy_client_with_spec_and_accounts};
 	use transaction::{Transaction};
 
@@ -1179,7 +1198,7 @@ mod tests {
 		assert_eq!(res.unwrap(), ());
 		assert_eq!(miner.pending_transactions(best_block).unwrap().len(), 1);
 		assert_eq!(miner.pending_receipts(best_block).unwrap().len(), 1);
-		assert_eq!(miner.ready_transactions(&client).len(), 1);
+		assert_eq!(miner.ready_transactions(&client, 10, PendingOrdering::Priority).len(), 1);
 		// This method will let us know if pending block was created (before calling that method)
 		assert!(!miner.prepare_pending_block(&client));
 	}
@@ -1198,7 +1217,7 @@ mod tests {
 		assert_eq!(res.unwrap(), ());
 		assert_eq!(miner.pending_transactions(best_block), None);
 		assert_eq!(miner.pending_receipts(best_block), None);
-		assert_eq!(miner.ready_transactions(&client).len(), 1);
+		assert_eq!(miner.ready_transactions(&client, 10, PendingOrdering::Priority).len(), 1);
 	}
 
 	#[test]
@@ -1217,11 +1236,11 @@ mod tests {
 		assert_eq!(miner.pending_transactions(best_block), None);
 		assert_eq!(miner.pending_receipts(best_block), None);
 		// By default we use PendingSet::AlwaysSealing, so no transactions yet.
-		assert_eq!(miner.ready_transactions(&client).len(), 0);
+		assert_eq!(miner.ready_transactions(&client, 10, PendingOrdering::Priority).len(), 0);
 		// This method will let us know if pending block was created (before calling that method)
 		assert!(miner.prepare_pending_block(&client));
 		// After pending block is created we should see a transaction.
-		assert_eq!(miner.ready_transactions(&client).len(), 1);
+		assert_eq!(miner.ready_transactions(&client, 10, PendingOrdering::Priority).len(), 1);
 	}
 
 	#[test]

ethcore/src/miner/mod.rs

@@ -26,6 +26,7 @@ pub mod pool_client;
 pub mod stratum;
 
 pub use self::miner::{Miner, MinerOptions, Penalization, PendingSet, AuthoringParams};
+pub use ethcore_miner::pool::PendingOrdering;
 
 use std::sync::Arc;
 use std::collections::BTreeMap;
@@ -156,10 +157,12 @@ pub trait MinerService : Send + Sync {
 	fn next_nonce<C>(&self, chain: &C, address: &Address) -> U256
 		where C: Nonce + Sync;
 
-	/// Get a list of all ready transactions.
+	/// Get a list of all ready transactions either ordered by priority or unordered (cheaper).
 	///
 	/// Depending on the settings may look in transaction pool or only in pending block.
-	fn ready_transactions<C>(&self, chain: &C) -> Vec<Arc<VerifiedTransaction>>
+	/// If you don't need a full set of transactions, you can add `max_len` and create only a limited set of
+	/// transactions.
+	fn ready_transactions<C>(&self, chain: &C, max_len: usize, ordering: PendingOrdering) -> Vec<Arc<VerifiedTransaction>>
 		where C: ChainInfo + Nonce + Sync;
 
 	/// Get a list of all transactions in the pool (some of them might not be ready for inclusion yet).

ethcore/src/tests/client.rs

@@ -30,7 +30,7 @@ use test_helpers::{
 use types::filter::Filter;
 use ethereum_types::{U256, Address};
 use kvdb_rocksdb::{Database, DatabaseConfig};
-use miner::Miner;
+use miner::{Miner, PendingOrdering};
 use spec::Spec;
 use views::BlockView;
 use ethkey::KeyPair;
@@ -343,12 +343,12 @@ fn does_not_propagate_delayed_transactions() {
 
 	client.miner().import_own_transaction(&*client, tx0).unwrap();
 	client.miner().import_own_transaction(&*client, tx1).unwrap();
-	assert_eq!(0, client.ready_transactions().len());
-	assert_eq!(0, client.miner().ready_transactions(&*client).len());
+	assert_eq!(0, client.ready_transactions(10).len());
+	assert_eq!(0, client.miner().ready_transactions(&*client, 10, PendingOrdering::Priority).len());
 	push_blocks_to_client(&client, 53, 2, 2);
 	client.flush_queue();
-	assert_eq!(2, client.ready_transactions().len());
-	assert_eq!(2, client.miner().ready_transactions(&*client).len());
+	assert_eq!(2, client.ready_transactions(10).len());
+	assert_eq!(2, client.miner().ready_transactions(&*client, 10, PendingOrdering::Priority).len());
 }
 
 #[test]