Add LogDog Python client library.

client/libs/logdog/tests/varint_test.py

Index: client/libs/logdog/tests/varint_test.py
diff --git a/client/libs/logdog/tests/varint_test.py b/client/libs/logdog/tests/varint_test.py
new file mode 100755
index 0000000000000000000000000000000000000000..0e80dddc48e31d60b17405277fdd02a8fea39c5d
--- /dev/null
+++ b/client/libs/logdog/tests/varint_test.py
@@ -0,0 +1,66 @@
+#!/usr/bin/env python
+# Copyright 2016 The LUCI Authors. All rights reserved.
+# Use of this source code is governed by the Apache v2.0 license that can be
+# found in the LICENSE file.
+
+import itertools
+import os
+import sys
+import unittest
+import StringIO
+
+ROOT_DIR = os.path.dirname(os.path.abspath(os.path.join(
+    __file__, os.pardir, os.pardir, os.pardir)))
+sys.path.insert(0, ROOT_DIR)
+
+from libs.logdog import varint
+
+
+class VarintTestCase(unittest.TestCase):
+
+  def testVarintEncodingRaw(self):
+    for base, exp in (
+        (0, b'\x00'),
+        (1, b'\x01'),
+        (0x7F, b'\x7f'),
+        (0x80, b'\x80\x01'),
+        (0x81, b'\x81\x01'),
+        (0x18080, b'\x80\x81\x06'),
+    ):
+      sio = StringIO.StringIO()
+      count = varint.write_uvarint(sio, base)
+      act = sio.getvalue()
+
+      self.assertEqual(act, exp,
+          "Encoding for %d (%r) doesn't match expected (%r)" % (base, act, exp))
+      self.assertEqual(count, len(act),
+          "Length of %d (%d) doesn't match encoded length (%d)" % (
+              base, len(act), count))
+
+  def testVarintEncodeDecode(self):
+    seed = (b'\x00', b'\x01', b'\x55', b'\x7F', b'\x80', b'\x81', b'\xff')
+    for perm in itertools.permutations(seed):
+      perm = ''.join(perm).encode('hex')
+
+      while len(perm) > 0:
+        exp = int(perm.encode('hex'), 16)
+
+        sio = StringIO.StringIO()
+        count = varint.write_uvarint(sio, exp)
+        sio.seek(0)
+        act, count = varint.read_uvarint(sio)
+
+        self.assertEqual(act, exp,
+            "Decoded %r (%d) doesn't match expected (%d)" % (
+                sio.getvalue().encode('hex'), act, exp))
+        self.assertEqual(count, len(sio.getvalue()),
+            "Decoded length (%d) doesn't match expected (%d)" % (
+                count, len(sio.getvalue())))
+
+        if perm == 0:
+          break
+        perm = perm[1:]
+
+
+if __name__ == '__main__':
+  unittest.main()