few functions are more idiomatic, initial support for bip30

db/src/storage.rs

@@ -175,7 +175,7 @@ impl Storage {
 		if let Some(accepted_tx) = accepted_txs.iter().next() {
 			context.meta.insert(
 				accepted_tx.hash(),
-				TransactionMeta::new(number, accepted_tx.outputs.len()).coinbase()
+				TransactionMeta::new_coinbase(number, accepted_tx.outputs.len())
 			);
 		}
 
@@ -186,29 +186,27 @@ impl Storage {
 			);
 
 			for input in &accepted_tx.inputs {
-				if !match context.meta.get_mut(&input.previous_output.hash) {
-					Some(ref mut meta) => {
+				use std::collections::hash_map::Entry;
+
+				match context.meta.entry(input.previous_output.hash.clone()) {
+					Entry::Occupied(mut entry) => {
+						let meta = entry.get_mut();
+						if meta.is_spent(input.previous_output.index as usize) {
+							return Err(Error::double_spend(&input.previous_output.hash));
+						}
+						meta.denote_used(input.previous_output.index as usize);
+					},
+					Entry::Vacant(entry) => {
+						let mut meta = self.transaction_meta(&input.previous_output.hash)
+							.ok_or(Error::unknown_spending(&input.previous_output.hash))?;
+
 						if meta.is_spent(input.previous_output.index as usize) {
 							return Err(Error::double_spend(&input.previous_output.hash));
 						}
 
 						meta.denote_used(input.previous_output.index as usize);
-						true
+						entry.insert(meta);
 					},
-					None => false,
-				} {
-					let mut meta = self.transaction_meta(&input.previous_output.hash)
-						.ok_or(Error::unknown_spending(&input.previous_output.hash))?;
-
-					if meta.is_spent(input.previous_output.index as usize) {
-						return Err(Error::double_spend(&input.previous_output.hash));
-					}
-
-					meta.denote_used(input.previous_output.index as usize);
-
-					context.meta.insert(
-						input.previous_output.hash.clone(),
-						meta);
 				}
 			}
 		}
@@ -238,30 +236,24 @@ impl Storage {
 			// remove meta
 			context.db_transaction.delete(Some(COL_TRANSACTIONS_META), &**tx_hash);
 
-			// denote outputs used
-			if tx_hash_num == 0 { continue; } // coinbase transaction does not have inputs
+			// coinbase transaction does not have inputs
+			if tx_hash_num == 0 {
+				continue;
+			}
+
+			// denote outputs as unused
 			for input in &tx.inputs {
-				if !match context.meta.get_mut(&input.previous_output.hash) {
-					Some(ref mut meta) => {
-						meta.denote_unused(input.previous_output.index as usize);
-						true
+				use std::collections::hash_map::Entry;
+				match context.meta.entry(input.previous_output.hash.clone()) {
+					Entry::Occupied(mut entry) => {
+						entry.get_mut().denote_unused(input.previous_output.index as usize);
+					},
+					Entry::Vacant(entry) => {
+						let mut meta = self.transaction_meta(&input.previous_output.hash)
+							.expect("No transaction metadata! Possible db corruption");
+						meta.denote_unused(input.previous_output.index as usize);
+						entry.insert(meta);
 					},
-					None => false,
-				} {
-					let mut meta =
-						self.transaction_meta(&input.previous_output.hash)
-							.unwrap_or_else(|| panic!(
-								// decanonization should always have meta
-								// because block could not have made canonical without writing meta
-								"No transaction metadata for {}! Corrupted DB? Reindex?",
-								&input.previous_output.hash
-							));
-
-					meta.denote_unused(input.previous_output.index as usize);
-
-					context.meta.insert(
-						input.previous_output.hash.clone(),
-						meta);
 				}
 			}
 		}

db/src/transaction_meta.rs

@@ -7,7 +7,8 @@ use byteorder::{LittleEndian, ByteOrder};
 #[derive(Debug, Clone)]
 pub struct TransactionMeta {
 	block_height: u32,
-	// first bit is coinbase flag, others - one per output listed
+	/// first bit indicate if transaction is a coinbase transaction
+	/// next bits indicate if transaction has spend outputs
 	bits: BitVec,
 }
 
@@ -17,7 +18,7 @@ pub enum Error {
 }
 
 impl TransactionMeta {
-	/// new transaction description for indexing
+	/// New transaction description for indexing
 	pub fn new(block_height: u32, outputs: usize) -> Self {
 		TransactionMeta {
 			block_height: block_height,
@@ -25,22 +26,25 @@ impl TransactionMeta {
 		}
 	}
 
-	pub fn coinbase(mut self) -> Self {
-		self.bits.set(0, true);
-		self
+	/// New coinbase transaction
+	pub fn new_coinbase(block_height: u32, outputs: usize) -> Self {
+		let mut result = Self::new(block_height, outputs);
+		result.bits.set(0, true);
+		result
 	}
 
+	/// Returns true if it is a coinbase transaction
 	pub fn is_coinbase(&self) -> bool {
 		self.bits.get(0)
-			.expect("One bit should always exists, since it is created as usize + 1; minimum value of usize is 0; 0 + 1 = 1;  qed")
+			.expect("One bit should always exists, since it is created as usize + 1; minimum value of usize is 0; 0 + 1 = 1; qed")
 	}
 
-	/// denote particular output as used
+	/// Denote particular output as used
 	pub fn denote_used(&mut self, index: usize) {
 		self.bits.set(index + 1 , true);
 	}
 
-	/// denote particular output as not used
+	/// Denote particular output as not used
 	pub fn denote_unused(&mut self, index: usize) {
 		self.bits.set(index + 1, false);
 	}
@@ -61,8 +65,34 @@ impl TransactionMeta {
 		})
 	}
 
-	pub fn height(&self) -> u32 { self.block_height }
+	pub fn height(&self) -> u32 {
+		self.block_height
+	}
 
-	pub fn is_spent(&self, idx: usize) -> bool { self.bits.get(idx + 1).expect("Index should be verified by the caller") }
+	pub fn is_spent(&self, idx: usize) -> bool {
+		self.bits.get(idx + 1).expect("Index should be verified by the caller")
+	}
 
+	pub fn is_fully_spent(&self) -> bool {
+		// skip coinbase bit, the rest needs to true
+		self.bits.iter().skip(1).all(|x| x)
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use super::TransactionMeta;
+
+	#[test]
+	fn test_is_fully_spent() {
+		let t = TransactionMeta::new(0, 0);
+		assert!(t.is_fully_spent());
+
+		let mut t = TransactionMeta::new(0, 1);
+		assert!(!t.is_fully_spent());
+		t.denote_used(0);
+		assert!(t.is_fully_spent());
+		t.denote_unused(0);
+		assert!(!t.is_fully_spent());
+	}
 }

verification/src/chain_verifier.rs

@@ -68,6 +68,16 @@ impl ChainVerifier {
 
 		let coinbase_spends = block.transactions()[0].total_spends();
 
+		// bip30
+		// TODO: add exceptions
+		for (tx_index, tx) in block.transactions.iter().enumerate() {
+			if let Some(meta) = self.store.transaction_meta(&tx.hash()) {
+				if !meta.is_fully_spent() {
+					return Err(Error::Transaction(tx_index, TransactionError::BIP30));
+				}
+			}
+		}
+
 		let mut total_unspent = 0u64;
 		for (tx_index, tx) in block.transactions().iter().enumerate().skip(1) {
 

verification/src/lib.rs

@@ -84,6 +84,8 @@ pub enum TransactionError {
 	SigopsP2SH(usize),
 	/// Coinbase transaction is found at position that is not 0
 	MisplacedCoinbase(usize),
+	/// Not fully spent transaction with the same hash already exists.
+	BIP30,
 }
 
 #[derive(PartialEq, Debug)]