add buffering to the map

testint2intmaplike.py

@@ -16,6 +16,35 @@ class Int2IntMapLikeTest(unittest.TestCase):
         self.map.close()
         self.test_dir.cleanup()
 
+    def test_empty_map(self):
+        map = self.map
+        self.assertEqual(None, map.find(0))
+
+    def test_one_line_one_byte(self):
+        map = self.map
+        map.add(10, 1, 1)  # add only the key 10
+        self.assertEqual(None, map.find(9))  # directly before
+        self.assertEqual(1, map.find(10))
+        self.assertEqual(None, map.find(11))  # directly after
+
+    def test_one_line_two_bytes(self):
+        map = self.map
+        map.add(10, 2, 1)  # added keys 10 and 11
+        self.assertEqual(None, map.find(9))  # directly before
+        self.assertEqual(1, map.find(10))
+        self.assertEqual(1, map.find(11))
+        self.assertEqual(None, map.find(12))  # directly after
+
+    def test_two_lines(self):
+        map = self.map
+        map.add(10, 1, 1)  # added key 10
+        map.add(12, 1, 2)  # added key 12
+        self.assertEqual(None, map.find(9))  # directly before
+        self.assertEqual(1, map.find(10))
+        self.assertEqual(None, map.find(11))  # between
+        self.assertEqual(2, map.find(12))
+        self.assertEqual(None, map.find(13))  # directly after
+
     def test_fill_map(self):
         map = self.map
         map.blocksize = 64