Add chain stat, info cli

tests/test_stat.py

@@ -0,0 +1,49 @@
+# standard imports
+import unittest
+import datetime
+
+# external imports
+from chainlib.stat import Stat
+from chainlib.eth.block import Block
+
+
+class TestStat(unittest.TestCase):
+
+    def test_block(self):
+
+        s = ChainStat()
+ 
+        d = datetime.datetime.utcnow() - datetime.timedelta(seconds=30)
+        block_a = Block({
+            'timestamp': d.timestamp(),
+            'hash': None,
+            'transactions': [],
+            'number': 41,
+            })
+
+        d = datetime.datetime.utcnow()
+        block_b = Block({
+            'timestamp': d.timestamp(),
+            'hash': None,
+            'transactions': [],
+            'number': 42,
+            })
+
+        s.block_apply(block_a)
+        s.block_apply(block_b)
+        self.assertEqual(s.block_average(), 30.0)
+
+        d = datetime.datetime.utcnow() + datetime.timedelta(seconds=10)
+        block_c = Block({
+            'timestamp': d.timestamp(),
+            'hash': None,
+            'transactions': [],
+            'number': 43,
+            })
+
+        s.block_apply(block_c)
+        self.assertEqual(s.block_average(), 20.0)
+
+
+if __name__ == '__main__':
+    unittest.main()