Resolve #245

processor/src/coins/bitcoin.rs

@@ -197,6 +197,13 @@ impl BlockTrait<Bitcoin> for Block {
     hash.reverse();
     hash
   }
+
+  fn parent(&self) -> Self::Id {
+    let mut hash = *self.header.prev_blockhash.as_raw_hash().as_byte_array();
+    hash.reverse();
+    hash
+  }
+
   fn median_fee(&self) -> Fee {
     // TODO
     Fee(20)

processor/src/coins/mod.rs

@@ -175,6 +175,7 @@ pub trait Block<C: Coin>: Send + Sync + Sized + Clone + Debug {
   // This is currently bounded to being 32-bytes.
   type Id: 'static + Id;
   fn id(&self) -> Self::Id;
+  fn parent(&self) -> Self::Id;
   fn median_fee(&self) -> C::Fee;
 }
 

processor/src/coins/monero.rs

@@ -142,6 +142,10 @@ impl BlockTrait<Monero> for Block {
     self.0
   }
 
+  fn parent(&self) -> Self::Id {
+    self.1.header.previous
+  }
+
   fn median_fee(&self) -> Fee {
     // TODO
     Fee { per_weight: 80000, mask: 10000 }