fix(blockchain): handle block that I already have

mxmaxime · mxmaxime · commit 0c273e03ced7 · 2019-11-06T01:10:09.000+01:00
diff --git a/block.py b/block.py
@@ -72,6 +72,7 @@ def proof_of_work(last_block):
 
     @staticmethod
     def valid_block(block_to_validate, previous_block):
+        print('validating', block_to_validate.index, 'with prev_block', previous_block.index)
         previous_block_hash = Block.hash(previous_block)
 
         if block_to_validate.previous_hash != previous_block_hash:
@@ -84,6 +85,7 @@ def valid_block(block_to_validate, previous_block):
                   block_to_validate.nonce, ' prev_nonce=', previous_block.nonce)
             return False
 
+        print('Block valid')
         return True
 
     def check_sender_stock(self, tx, nb):
diff --git a/blockchain.py b/blockchain.py
@@ -156,6 +156,11 @@ def submit_block(self, block):
         if not isinstance(block, Block):
             raise ValueError('block should be an instance of Block')
 
+        # If I already have the block, I ignore the received one.
+        if block.index == self.last_block:
+            print("I received a block, but I already have it, so I ignore it.")
+            return False
+
         """
         Add a Block in the Blockchain if the Block signature is valid.
         """
