Wallet recovery return unspent only (#340)

* beginning to add wallet restore... api endpoints and basic restore

* basic restore working, still missing features

* rustfmt

* large speed up to output search, should be more or less working

* properly mark coinbase status

* ensure only unspent utxos are returned from sumtree

api/src/handlers.rs

@@ -118,7 +118,8 @@ impl UtxoHandler {
 		let outputs = block
 			.outputs
 			.iter()
-			.map(|k| OutputSwitch::from_output(k, &header))
+			.filter(|c|self.chain.is_unspent(&c.commit).unwrap())
+			.map(|k|OutputSwitch::from_output(k, &header))
 			.collect();
 		BlockOutputs {
 			header: BlockHeaderInfo::from_header(&header),

chain/src/chain.rs

@@ -239,6 +239,12 @@ impl Chain {
 		}
 	}
 
+	/// Checks whether an output is unspent
+	pub fn is_unspent(&self, output_ref: &Commitment) -> Result<bool, Error> {
+		let sumtrees = self.sumtrees.read().unwrap();
+		sumtrees.is_unspent(output_ref)
+	}
+
 	/// Sets the sumtree roots on a brand new block by applying the block on the
 	/// current sumtree state.
 	pub fn set_sumtree_roots(&self, b: &mut Block) -> Result<(), Error> {