initial commit for MemoryPool

.gitignore

@@ -6,3 +6,9 @@
 *.swo
 *.swn
 *.DS_Store
+
+# Visual Studio Code stuff
+/.vscode
+
+# GitEye stuff
+/.project

Cargo.lock

@@ -6,6 +6,7 @@ dependencies = [
  "clap 2.14.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "keys 0.1.0",
  "message 0.1.0",
+ "miner 0.1.0",
  "p2p 0.1.0",
  "script 0.1.0",
 ]
@@ -176,6 +177,15 @@ dependencies = [
  "serialization 0.1.0",
 ]
 
+[[package]]
+name = "miner"
+version = "0.1.0"
+dependencies = [
+ "chain 0.1.0",
+ "primitives 0.1.0",
+ "serialization 0.1.0",
+]
+
 [[package]]
 name = "mio"
 version = "0.6.0"

Cargo.toml

@@ -11,6 +11,7 @@ clap = { version = "2", features = ["yaml"] }
 bitcrypto = { path = "crypto" }
 keys = { path = "keys" }
 message = { path = "message" }
+miner = { path = "miner" }
 p2p = { path = "p2p" }
 script = { path = "script" }
 

miner/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "miner"
+version = "0.1.0"
+authors = ["Ethcore <admin@ethcore.io>"]
+
+[dependencies]
+chain = { path = "../chain" }
+primitives = { path = "../primitives" }
+serialization = { path = "../serialization" }

miner/src/lib.rs

@@ -0,0 +1,9 @@
+extern crate chain;
+extern crate primitives;
+extern crate serialization as ser;
+
+pub mod memory_pool;
+
+pub use primitives::{hash};
+
+pub use self::memory_pool::{MemoryPool, Information as MemoryPoolInformation};

miner/src/memory_pool.rs

@@ -0,0 +1,607 @@
+//! Transactions memory pool
+//!
+//! `MemoryPool` keeps track of all transactions seen by the node (received from other peers) and own transactions
+//! and orders them by given strategies. It works like multi-indexed priority queue, giving option to pop 'top'
+//! transactions.
+//! It also guarantees that ancestor-descendant relation won't break during removal (ancestors always removed
+//! before descendants).
+use std::rc::Rc; 
+use hash::H256;
+use chain::Transaction;
+use std::collections::HashMap;
+use std::collections::HashSet;
+use ser::stream::serialize;
+
+/// Transactions ordering strategy
+#[derive(Debug)]
+pub enum OrderingStrategy {
+	/// Order transactions by their timestamp
+	ByTimestamp,
+	/// Order transactions by miner score
+	ByMinerScore,
+}
+
+/// Information on current `MemoryPool` state
+#[derive(Debug)]
+pub struct Information {
+	/// The number of transactions currently in the `MemoryPool`
+	pub transactions_count: usize,
+	/// The total number of bytes in the transactions in the `MemoryPool` 
+	pub transactions_size_in_bytes: usize,
+}
+
+/// Transactions memory pool
+#[derive(Debug)]
+pub struct MemoryPool {
+	/// Transactions storage
+	storage: Storage,
+}
+
+/// Single entry
+#[derive(Debug)]
+pub struct Entry {
+	/// Transaction
+	transaction: Transaction,
+	/// Transaction ancestors hashes
+	ancestors: Rc<HashSet<H256>>,
+	/// Transaction hash (stored for effeciency)
+	hash: H256,
+	/// Transaction size (stored for effeciency)
+	size: usize,
+	/// 'Timestamp' when transaction has entered memory pool
+	timestamp: u64,
+	/// Transaction fee (stored for efficiency)
+	miner_fee: i64,
+	/// Virtual transaction fee (a way to prioritize/penalize transaction) 
+	miner_virtual_fee: i64,
+}
+
+/// Multi-index transactions storage
+#[derive(Debug)]
+struct Storage {
+	/// Transactions counter (for timestamp ordering)
+	counter: u64,
+	/// Total transactions size (when serialized) in bytes
+	transactions_size_in_bytes: usize,
+	/// By-input storage
+	by_input: HashMap<H256, HashSet<H256>>,
+	/// By-hash storage
+	by_hash: HashMap<H256, Entry>,
+	/// By-entry-time storage
+	by_timestamp: timestamp_strategy::Storage,
+	/// By-score storage
+	by_miner_score: miner_score_strategy::Storage,
+}
+
+macro_rules! ordering_strategy {
+	($strategy: ident; $($member: ident: $member_type: ty), *; $comparer: expr) => {
+		mod $strategy {
+			use std::rc::Rc;
+			use std::cmp::Ordering;
+			use hash::H256;
+			use std::collections::HashSet;
+			use std::collections::BTreeSet;
+			use super::Entry;
+
+			/// Lightweight struct maintain transactions ordering
+			#[derive(Debug, Eq, PartialEq)]
+			pub struct OrderedEntry {
+				/// Transaction hash
+				hash: H256,
+				/// Transaction ancestors
+				ancestors: Rc<HashSet<H256>>,
+				/// Transaction data
+				$($member: $member_type), *
+			}
+
+			impl OrderedEntry {
+				pub fn for_entry(entry: &Entry) -> OrderedEntry {
+					OrderedEntry {
+						hash: entry.hash.clone(),
+						ancestors: entry.ancestors.clone(),
+						$($member: entry.$member.clone()), *
+					}
+				}
+			}
+
+			impl PartialOrd for OrderedEntry {
+				fn partial_cmp(&self, other: &OrderedEntry) -> Option<Ordering> {
+					Some(self.cmp(other))
+				}
+			} 
+
+			impl Ord for OrderedEntry {
+				fn cmp(&self, other: &Self) -> Ordering {
+					if self.ancestors.contains(&other.hash) {
+						return Ordering::Greater
+					}
+					if other.ancestors.contains(&self.hash) {
+						return Ordering::Less
+					}
+
+					let order = $comparer(&self, other);
+					if order != Ordering::Equal {
+						return order
+					}
+
+					self.hash.cmp(&other.hash)
+				}
+			}
+
+			/// By-timestamp ordering storage
+			#[derive(Debug)]
+			pub struct Storage {
+				data: BTreeSet<OrderedEntry>,
+			}
+
+			impl Storage {
+				pub fn new() -> Self {
+					Storage {
+						data: BTreeSet::new()
+					}
+				}
+
+				/// Insert entry to storage
+				pub fn insert(&mut self, entry: &Entry) {
+					self.data.replace(OrderedEntry::for_entry(entry));
+				}
+
+				/// Remove entry from storage
+				pub fn remove(&mut self, entry: &Entry) {
+					self.data.remove(&OrderedEntry::for_entry(entry));
+				}
+
+				/// An iterator that takes first n entries using predicate
+				pub fn take(&self, n: usize) -> Vec<H256> {
+					self.data.iter()
+						.map(|ref entry| entry.hash.clone())
+						.take(n)
+						.collect()
+				}
+			}
+		}
+	}
+}
+
+ordering_strategy!(timestamp_strategy;
+	timestamp: u64;
+	|me: &Self, other: &Self|
+		me.timestamp.cmp(&other.timestamp));
+ordering_strategy!(miner_score_strategy;
+	size: usize, miner_fee: i64, miner_virtual_fee: i64;
+	|me: &Self, other: &Self| {
+		// lesser miner score means later removal
+		let left = (me.miner_fee + me.miner_virtual_fee) * (other.size as i64);
+		let right = (other.miner_fee + other.miner_virtual_fee) * (me.size as i64);
+		right.cmp(&left)
+	});
+
+macro_rules! insert_to_orderings {
+	($me: expr, $entry: expr) => (
+		$me.by_timestamp.insert(&$entry);
+		$me.by_miner_score.insert(&$entry);
+	)
+}
+
+macro_rules! remove_from_orderings {
+	($me: expr, $entry: expr) => (
+		$me.by_timestamp.remove(&$entry);
+		$me.by_miner_score.remove(&$entry);
+	)
+}
+
+impl Storage {
+	pub fn new() -> Self {
+		Storage {
+			counter: 0,
+			transactions_size_in_bytes: 0,
+			by_input: HashMap::new(),
+			by_hash: HashMap::new(),
+			by_timestamp: timestamp_strategy::Storage::new(),
+			by_miner_score: miner_score_strategy::Storage::new(),
+		}
+	}
+
+	pub fn insert(&mut self, entry: Entry) {
+		self.transactions_size_in_bytes += entry.size;
+
+		self.update_by_input_on_insert(&entry);
+		self.update_descendants_on_insert(&entry);
+
+		insert_to_orderings!(self, entry);
+		self.by_hash.insert(entry.hash.clone(), entry);
+	}
+
+	pub fn remove(&mut self, entry: &Entry) -> Option<Entry> {
+		self.transactions_size_in_bytes -= entry.size;
+
+		self.update_descendants_on_remove(&entry);
+		self.update_by_input_on_remove(&entry);
+
+		remove_from_orderings!(self, entry);
+		self.by_hash.remove(&entry.hash)
+	}
+
+	pub fn get_by_hash(&self, h: &H256) -> Option<&Entry> {
+		self.by_hash.get(h)
+	}
+
+	pub fn contains(&self, hash: &H256) -> bool {
+		self.by_hash.contains_key(hash)
+	}
+
+	pub fn remove_by_hash(&mut self, h: &H256) -> Option<Entry> {
+		self.by_hash.remove(h)
+			.map(|entry| {
+				self.remove(&entry);
+				entry
+			})
+	}
+
+	pub fn remove_n_with_strategy(&mut self, n: usize, strategy: OrderingStrategy) -> Vec<Transaction> {
+		let hashes = {
+			match strategy {
+				OrderingStrategy::ByTimestamp => self.by_timestamp.take(n),
+				OrderingStrategy::ByMinerScore => self.by_miner_score.take(n),
+			}
+		};
+		hashes
+			.iter()
+			.map(|ref hash| {
+				let entry = self.remove_by_hash(&hash)
+					.expect("`hash` is read from by_* index; all hashes from indexes are also stored in `by_hash`; remove returns entry from `by_hash`; qed");
+				entry.transaction
+			})
+			.collect()
+	}
+
+	pub fn set_virtual_fee(&mut self, h: &H256, virtual_fee: i64) {
+		if let Some(ref mut entry) = self.by_hash.get_mut(h) {
+			self.by_miner_score.remove(&entry);
+			entry.miner_virtual_fee = virtual_fee;
+			self.by_miner_score.insert(&entry);
+		}
+	}
+
+	pub fn get_transactions_ids(&self) -> Vec<H256> {
+		self.by_hash.keys().map(|h| h.clone()).collect()
+	}
+
+	fn update_by_input_on_insert(&mut self, entry: &Entry) {
+		// maintain map { ancestor: list<descendants> } to support inserting
+		// acendants & descendants in random order
+		for input_hash in entry.transaction.inputs.iter().map(|input| &input.previous_output.hash) {
+			self.by_input.entry(input_hash.clone()).or_insert_with(|| HashSet::new()).insert(entry.hash.clone());
+		}
+	}
+
+	fn update_descendants_on_insert(&mut self, entry: &Entry) {
+		// this code will run only when ancestor transaction is inserted
+		// in memory pool after its descendants
+		if let Some(descendants) = self.by_input.get(&entry.hash) {
+			for descendant in descendants.iter() {
+				if let Some(mut descendant_entry) = self.by_hash.remove(descendant) {
+					{
+						remove_from_orderings!(self, descendant_entry);
+
+						let ancestors = Rc::make_mut(&mut descendant_entry.ancestors);
+						ancestors.insert(entry.hash.clone());
+					}
+					insert_to_orderings!(self, descendant_entry);
+					self.by_hash.insert(descendant_entry.hash.clone(), descendant_entry);
+				};
+			}
+		}
+	}
+
+	fn update_by_input_on_remove(&mut self, entry: &Entry) {
+		for input_hash in entry.transaction.inputs.iter().map(|input| &input.previous_output.hash) {
+			let remove_entry = {
+				let by_input_item = self.by_input.get_mut(input_hash)
+					.expect("`entry.transaction` is immutable; on insert all transaction' inputs are stored in `by_input`; `by_input` only modified here; qed");
+				by_input_item.remove(&entry.hash);
+				by_input_item.is_empty()
+			};
+			if remove_entry {
+				self.by_input.remove(input_hash);
+			}
+		}
+	}
+
+	fn update_descendants_on_remove(&mut self, entry: &Entry) {
+		// this code will run when there still are dependent transactions in the pool
+		if let Some(descendants) = self.by_input.get(&entry.hash) {
+			for descendant in descendants.iter() {
+				if let Some(mut descendant_entry) = self.by_hash.remove(descendant) {
+					{
+						remove_from_orderings!(self, descendant_entry);
+
+						let ancestors = Rc::make_mut(&mut descendant_entry.ancestors);
+						ancestors.remove(&entry.hash);
+					}
+					insert_to_orderings!(self, descendant_entry);
+					self.by_hash.insert(descendant_entry.hash.clone(), descendant_entry);
+				};
+			}
+		}
+	}
+}
+
+impl MemoryPool {
+	/// Creates new memory pool
+	pub fn new() -> Self {
+		MemoryPool {
+			storage: Storage::new(),
+		}
+	}
+
+	/// Insert verified transaction to the `MemoryPool`
+	pub fn insert_verified(&mut self, t: Transaction) {
+		let entry = self.make_entry(t);
+		self.storage.insert(entry);
+	}
+
+	/// Removes transaction by its hash
+	pub fn remove_by_hash(&mut self, h: &H256) -> Option<Transaction> {
+		self.storage.remove_by_hash(h).map(|entry| entry.transaction)
+	}
+
+	/// Removes up to n transactions the `MemoryPool`, using selected strategy
+	pub fn remove_n_with_strategy(&mut self, n: usize, strategy: OrderingStrategy) -> Vec<Transaction> {
+		self.storage.remove_n_with_strategy(n, strategy)
+	}
+
+	/// Set miner virtual fee for transaction
+	pub fn set_virtual_fee(&mut self, h: &H256, virtual_fee: i64) {
+		self.storage.set_virtual_fee(h, virtual_fee)
+	}
+
+	/// Get transaction by hash
+	pub fn get(&self, hash: &H256) -> Option<&Transaction> {
+		self.storage.get_by_hash(hash).map(|ref entry| &entry.transaction)
+	}
+
+	/// Checks if transaction is in the mempool
+	pub fn contains(&self, hash: &H256) -> bool {
+		self.storage.contains(hash)
+	}
+
+	/// Returns information on `MemoryPool` (as in GetMemPoolInfo RPC)
+	/// https://bitcoin.org/en/developer-reference#getmempoolinfo
+	pub fn information(&self) -> Information {
+		Information {
+			transactions_count: self.storage.by_hash.len(),
+			transactions_size_in_bytes: self.storage.transactions_size_in_bytes
+		}
+	}
+
+	/// Returns TXIDs of all transactions in `MemoryPool` (as in GetRawMemPool RPC)
+	/// https://bitcoin.org/en/developer-reference#getrawmempool
+	pub fn get_transactions_ids(&self) -> Vec<H256> {
+		self.storage.get_transactions_ids()
+	}
+
+	fn make_entry(&mut self, t: Transaction) -> Entry {
+		let hash = t.hash();
+		let ancestors = Rc::new(self.get_ancestors(&t));
+		let size = self.get_transaction_size(&t);
+		let timestamp = self.get_timestamp();
+		let miner_fee = self.get_transaction_miner_fee(&t);
+		Entry {
+			transaction: t,
+			hash: hash,
+			ancestors: ancestors,
+			size: size,
+			timestamp: timestamp,
+			miner_fee: miner_fee,
+			miner_virtual_fee: 0,
+		}
+	}
+
+	fn get_ancestors(&self, t: &Transaction) -> HashSet<H256> {
+		let mut ancestors: HashSet<H256> = HashSet::new();
+		let ancestors_entries = t.inputs.iter()
+			.filter_map(|ref input| self.storage.get_by_hash(&input.previous_output.hash));
+		for ancestor_entry in ancestors_entries {
+			ancestors.insert(ancestor_entry.hash.clone());
+			for grand_ancestor in ancestor_entry.ancestors.iter() {
+				ancestors.insert(grand_ancestor.clone());
+			}
+		}
+		ancestors
+	}
+
+	fn get_transaction_size(&self, t: &Transaction) -> usize {
+		// TODO: the only correct way now?
+		serialize(t).len()
+	}
+
+	fn get_transaction_miner_fee(&self, t: &Transaction) -> i64 {
+		let input_value = 0; // TODO: sum all inputs of transaction
+		let output_value = t.outputs.iter().fold(0, |acc, ref output| acc + output.value);
+		(output_value - input_value) as i64
+	}
+
+	#[cfg(not(test))]
+	fn get_timestamp(&mut self) -> u64 {
+		self.storage.counter += 1;
+		self.storage.counter
+	}
+
+	#[cfg(test)]
+	fn get_timestamp(&self) -> u64 {
+		(self.storage.by_hash.len() % 3usize) as u64
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use std::cmp::Ordering;
+	use chain::Transaction;
+	use super::{MemoryPool, OrderingStrategy};
+
+	// output_value = 898126612, size = 225, miner_score ~ 3991673.83
+	const RAW_TRANSACTION1: &'static str = "01000000017e4e1bfa4cc16a46593390b9f627db9a3b7c3b1802daa826fc0c477c067ea4f1000000006a47304402203cca1b01b307d3dba3d4f819ef4e9ccf839fa7ef901fc39d2b1d6e33c159a0b0022009d135bd47b8465a69f4db7145af34e0f063e926d95d9c21fb4e8cbc2052838c0121039c01d413f0e296cb766b408c528d3526e75a0f63cfc44c1147160613a12e6cb7feffffff02c8f27535000000001976a914e54788b730b91eb9b29917fa10ddbc97996a987988ac4c601200000000001976a91421e8ed0ddc9a365c10fa3130c91c36237a45848888aca7a00600";
+	// output_value = 423675406, size = 225, miner_score ~ 1883001.80
+	const RAW_TRANSACTION2: &'static str = "0100000001efaf295b354d8063336a03652664e31b63666f6fbe51b377ad3bdd7b65678a43000000006a47304402206100084828cfc2b71881f1a99447658d5844043f69c1f9bd6c95cb0e11197d4002207c8e23b6233e7317fe0db3e12c8a4291efe671e02c4bbeeb3534e208bb9a3a75012103e091c9c970427a709646990ca16d4d418efc9e5c46ae794c3d09023a7e0e1c57feffffff0226662e19000000001976a914ffad82403bc2a1dd3789b7e653d352515ae86b7288ace85f1200000000001976a914c2f8a6513ebcf6f61edca10199442e33108d540988aca7a00600";
+	// output_value = 668388826, size = 225, miner_score ~ 2970617.00
+	const RAW_TRANSACTION3: &'static str = "01000000012eee0922c7385e6a11d4f92da65e16b205b2cdfe294c3140c3bc0427f6c11794000000006a47304402207aab34b1c9bb5464c3c1ddf9fee042d8755b81ed1e8c35b895ee2d7da17a23ac02205dfd9c8d14f44951c9e8c3a70f8820a6b113046db1ca25d52a31a4b68d62e07901210306a47c3c0ce5ad78616ad0695113ee4d7a848155fd9f4a1eb7aeed756e174211feffffff024c601200000000001976a914ae829d4d1a8945dc165a57f1149b4656e48c161988ac8e6dc427000000001976a9146c4f1f52adec5211f456acc12917fe902949b08088aca7a00600";
+	// output_value = 256505044, size = 226, miner_score ~ 1134978.07
+	const RAW_TRANSACTION4: &'static str = "01000000012969032b2a920c03fa71eeea5250d0f6259b130a15ed695f79d957e47b9b2d8b000000006b483045022100b34c8a714b295b84686211b37daaa65ef79cf0ce1dc7d7a4e133a5b08a308f6f02201abca9e08bddb56e205bd1c5e689419926031ec955d8c89671a16a7076dce0ec0121020db95d68c760d1e0a5090dbf0ed2cbfd1225c3bc46d4e31e272bcc14b42a9643feffffff021896370f000000001976a914552b2549642c22462dc0e82ea25500dea6bb5e2188acbc5e1200000000001976a914dca40d275f5eb00cefab813925a1b07b9b77159188aca7a00600";
+	const RAW_TRANSACTION1_HASH: &'static str = "af9d5d566b6c914fc0de758a5f18731f5570ac59d1f0c5d1516f0f2dda2c3f79";
+	const RAW_TRANSACTION2_HASH: &'static str = "e97719095d91821f691dcbebdf5fb82c4eff8dd33d0c3cc6690aae37ed82a01e";
+	const RAW_TRANSACTION3_HASH: &'static str = "2d3833b35efc8f2b9d1c2140505b207fd71155178ad604e03364448f7007fc04";
+	const RAW_TRANSACTION4_HASH: &'static str = "4a15e0b41b1a47381f2f2baa16087688d1cd9078416960deed1faae852a469ce";
+
+	fn construct_memory_pool() -> MemoryPool {
+		let transaction1: Transaction = RAW_TRANSACTION1.into();
+		let transaction2: Transaction = RAW_TRANSACTION2.into();
+		let transaction3: Transaction = RAW_TRANSACTION3.into();
+		let transaction4: Transaction = RAW_TRANSACTION4.into();
+		let transaction1_hash =  RAW_TRANSACTION1_HASH.into();
+		let transaction4_hash =  RAW_TRANSACTION4_HASH.into();
+		assert_eq!(transaction1.hash(), transaction1_hash);
+		assert_eq!(transaction2.hash(), RAW_TRANSACTION2_HASH.into());
+		assert_eq!(transaction3.hash(), RAW_TRANSACTION3_HASH.into());
+		assert_eq!(transaction4.hash(), transaction4_hash);
+
+		// hash of t4 must be lesser than hash of t4
+		assert_eq!(transaction4_hash.cmp(&transaction1_hash), Ordering::Less);
+
+		let mut pool = MemoryPool::new();
+		pool.insert_verified(RAW_TRANSACTION1.into());
+		pool.insert_verified(RAW_TRANSACTION2.into());
+		pool.insert_verified(RAW_TRANSACTION3.into());
+		pool.insert_verified(RAW_TRANSACTION4.into());
+
+		pool
+	}
+
+	#[test]
+	fn test_memory_pool_remove_by_hash() {
+		let mut pool = construct_memory_pool();
+
+		let pool_transactions = pool.get_transactions_ids();
+		assert_eq!(pool_transactions.len(), 4);
+
+		// check pool transactions
+		let ref hash_to_remove = pool_transactions[0]; 
+		assert!(*hash_to_remove == RAW_TRANSACTION1_HASH.into()
+			|| *hash_to_remove == RAW_TRANSACTION2_HASH.into()
+			|| *hash_to_remove == RAW_TRANSACTION3_HASH.into()
+			|| *hash_to_remove == RAW_TRANSACTION4_HASH.into());
+		assert_eq!(pool.get_transactions_ids().len(), 4);
+
+		// remove and check remaining transactions
+		let removed = pool.remove_by_hash(&hash_to_remove);
+		assert!(removed.is_some());
+		assert_eq!(removed.unwrap().hash(), *hash_to_remove);
+		assert_eq!(pool.get_transactions_ids().len(), 3);
+	}
+
+	#[test]
+	fn test_memory_pool_transaction_dependent_transactions_parent_after_child() {
+		let parent_transaction: Transaction = "00000000000164000000000000000000000000".into();
+		let child_transaction: Transaction = "0000000001545ac9cffeaa3ee074f08a5306e703cb30883192ed9b10ee9ddb76824e4985070000000000000000000000000000".into();
+		let parent_transaction_hash = parent_transaction.hash();
+		let child_transaction_hash = child_transaction.hash();
+
+		// insert child, then parent
+		let mut pool = MemoryPool::new();
+		pool.insert_verified(child_transaction); // timestamp 0
+		pool.insert_verified(parent_transaction); // timestamp 1
+
+		// check that parent transaction was removed before child trnasaction
+		let transactions = pool.remove_n_with_strategy(3, OrderingStrategy::ByTimestamp);
+		assert_eq!(transactions.len(), 2);
+		assert_eq!(transactions[0].hash(), parent_transaction_hash);
+		assert_eq!(transactions[1].hash(), child_transaction_hash);
+	}
+
+	#[test]
+	fn test_memory_pool_transaction_dependent_transactions_parent_before_child() {
+		let parent_transaction: Transaction = "00000000000164000000000000000000000000".into();
+		let child_transaction: Transaction = "0000000001545ac9cffeaa3ee074f08a5306e703cb30883192ed9b10ee9ddb76824e4985070000000000000000000000000000".into();
+		let parent_transaction_hash = parent_transaction.hash();
+		let child_transaction_hash = child_transaction.hash(); 
+
+		// insert child, then parent
+		let mut pool = MemoryPool::new();
+		pool.insert_verified(parent_transaction); // timestamp 0
+		pool.insert_verified(child_transaction); // timestamp 1
+
+		// check that parent transaction was removed before child trnasaction
+		let transactions = pool.remove_n_with_strategy(3, OrderingStrategy::ByTimestamp);
+		assert_eq!(transactions.len(), 2);
+		assert_eq!(transactions[0].hash(), parent_transaction_hash);
+		assert_eq!(transactions[1].hash(), child_transaction_hash);
+	}
+
+	#[test]
+	fn test_memory_pool_get_information() {
+		let mut pool = construct_memory_pool();
+		let pool_sizes = [901, 676, 451, 226, 0];
+		let removals = [RAW_TRANSACTION1_HASH, RAW_TRANSACTION2_HASH, RAW_TRANSACTION3_HASH, RAW_TRANSACTION4_HASH];
+		// check pool information after removing each transaction
+		for i in 0..pool_sizes.len() {
+			let expected_pool_count = 5 - i - 1;
+			let expected_pool_size = pool_sizes[i];
+			let info = pool.information();
+			assert_eq!(info.transactions_count, expected_pool_count);
+			assert_eq!(info.transactions_size_in_bytes, expected_pool_size);
+
+			if expected_pool_size != 0 {
+				pool.remove_by_hash(&removals[i].into());
+			} 
+		}
+	}
+
+	#[test]
+	fn test_memory_pool_timestamp_ordering_strategy() {
+		let mut pool = construct_memory_pool();
+
+		// remove transactions [4, 1, 2] (timestamps: [0, 0, 1])
+		let transactions = pool.remove_n_with_strategy(3, OrderingStrategy::ByTimestamp);
+		assert_eq!(transactions.len(), 3);
+		assert_eq!(transactions[0].hash(), RAW_TRANSACTION4_HASH.into());
+		assert_eq!(transactions[1].hash(), RAW_TRANSACTION1_HASH.into());
+		assert_eq!(transactions[2].hash(), RAW_TRANSACTION2_HASH.into());
+		assert_eq!(pool.get_transactions_ids().len(), 1);
+
+		// remove transactions [3] (timestamps: [2])
+		let transactions = pool.remove_n_with_strategy(3, OrderingStrategy::ByTimestamp);
+		assert_eq!(transactions.len(), 1);
+		assert_eq!(transactions[0].hash(), RAW_TRANSACTION3_HASH.into());
+	}
+
+	#[test]
+	fn test_memory_pool_miner_score_ordering_strategy() {
+		let mut pool = construct_memory_pool();
+
+		let transactions = pool.remove_n_with_strategy(4, OrderingStrategy::ByMinerScore);
+		assert_eq!(transactions.len(), 4);
+		assert_eq!(transactions[0].hash(), RAW_TRANSACTION1_HASH.into());
+		assert_eq!(transactions[1].hash(), RAW_TRANSACTION3_HASH.into());
+		assert_eq!(transactions[2].hash(), RAW_TRANSACTION2_HASH.into());
+		assert_eq!(transactions[3].hash(), RAW_TRANSACTION4_HASH.into());
+		assert_eq!(pool.get_transactions_ids().len(), 0);
+	}
+
+	#[test]
+	fn test_memory_pool_miner_score_ordering_strategy_with_virtual_fee() {
+		let mut pool = construct_memory_pool();
+
+		// increase miner score of transaction 4 to move it to position #1
+		pool.set_virtual_fee(&RAW_TRANSACTION4_HASH.into(), 1000000000);
+		// decrease miner score of transaction 3 to move it to position #4
+		pool.set_virtual_fee(&RAW_TRANSACTION3_HASH.into(), -500000000);
+
+		let transactions = pool.remove_n_with_strategy(4, OrderingStrategy::ByMinerScore);
+		assert_eq!(transactions.len(), 4);
+		assert_eq!(transactions[0].hash(), RAW_TRANSACTION4_HASH.into());
+		assert_eq!(transactions[1].hash(), RAW_TRANSACTION1_HASH.into());
+		assert_eq!(transactions[2].hash(), RAW_TRANSACTION2_HASH.into());
+		assert_eq!(transactions[3].hash(), RAW_TRANSACTION3_HASH.into());
+		assert_eq!(pool.remove_n_with_strategy(1, OrderingStrategy::ByMinerScore).len(), 0);
+	}
+}

primitives/src/hash.rs

@@ -1,4 +1,5 @@
 use std::{fmt, ops, cmp, str};
+use std::hash::{Hash, Hasher};
 use hex::{ToHex, FromHex, FromHexError};
 
 macro_rules! impl_hash {
@@ -88,6 +89,8 @@ macro_rules! impl_hash {
 			}
 		}
 
+		impl Eq for $name {}
+
 		impl cmp::PartialEq for $name {
 			fn eq(&self, other: &Self) -> bool {
 				let self_ref: &[u8] = &self.0;
@@ -96,6 +99,13 @@ macro_rules! impl_hash {
 			}
 		}
 
+		impl Hash for $name {
+			fn hash<H>(&self, state: &mut H) where H: Hasher {
+				state.write(&self.0);
+				state.finish();
+			}
+		}
+
 		impl $name {
 			pub fn reversed(&self) -> Self {
 				let mut result = self.clone();

tools/test.sh

@@ -5,6 +5,7 @@ cargo test\
 	-p bitcrypto\
 	-p keys\
 	-p message\
+	-p miner\
 	-p p2p\
 	-p primitives\
 	-p script\