Make batched writing support all iterables (#746)

* Make batched writing support all iterables

* Also test batching generator against real server

* Fix PEP257 error

* Import itertools functions directly

Author: JayH5

influxdb/client.py

@@ -15,11 +15,11 @@
 import socket
 import struct
 import time
+from itertools import chain, islice
 
 import msgpack
 import requests
 import requests.exceptions
-from six.moves import xrange
 from six.moves.urllib.parse import urlparse
 
 from influxdb.line_protocol import make_lines, quote_ident, quote_literal
@@ -597,8 +597,17 @@ def ping(self):
 
     @staticmethod
     def _batches(iterable, size):
-        for i in xrange(0, len(iterable), size):
-            yield iterable[i:i + size]
+        # Iterate over an iterable producing iterables of batches. Based on:
+        # http://code.activestate.com/recipes/303279-getting-items-in-batches/
+        iterator = iter(iterable)
+        while True:
+            try:        # Try get the first element in the iterator...
+                head = (next(iterator),)
+            except StopIteration:
+                return  # ...so that we can stop if there isn't one
+            # Otherwise, lazily slice the rest of the batch
+            rest = islice(iterator, size - 1)
+            yield chain(head, rest)
 
     def _write_points(self,
                       points,

influxdb/tests/client_test.py

@@ -332,6 +332,36 @@ def test_write_points_batch(self):
         self.assertEqual(expected_last_body,
                          m.last_request.body.decode('utf-8'))
 
+    def test_write_points_batch_generator(self):
+        """Test write points batch from a generator for TestInfluxDBClient."""
+        dummy_points = [
+            {"measurement": "cpu_usage", "tags": {"unit": "percent"},
+             "time": "2009-11-10T23:00:00Z", "fields": {"value": 12.34}},
+            {"measurement": "network", "tags": {"direction": "in"},
+             "time": "2009-11-10T23:00:00Z", "fields": {"value": 123.00}},
+            {"measurement": "network", "tags": {"direction": "out"},
+             "time": "2009-11-10T23:00:00Z", "fields": {"value": 12.00}}
+        ]
+        dummy_points_generator = (point for point in dummy_points)
+        expected_last_body = (
+            "network,direction=out,host=server01,region=us-west "
+            "value=12.0 1257894000000000000\n"
+        )
+
+        with requests_mock.Mocker() as m:
+            m.register_uri(requests_mock.POST,
+                           "http://localhost:8086/write",
+                           status_code=204)
+            cli = InfluxDBClient(database='db')
+            cli.write_points(points=dummy_points_generator,
+                             database='db',
+                             tags={"host": "server01",
+                                   "region": "us-west"},
+                             batch_size=2)
+        self.assertEqual(m.call_count, 2)
+        self.assertEqual(expected_last_body,
+                         m.last_request.body.decode('utf-8'))
+
     def test_write_points_udp(self):
         """Test write points UDP for TestInfluxDBClient object."""
         s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

influxdb/tests/server_tests/client_test_with_server.py

@@ -452,6 +452,33 @@ def test_write_points_batch(self):
         self.assertIn(12, net_out['series'][0]['values'][0])
         self.assertIn(12.34, cpu['series'][0]['values'][0])
 
+    def test_write_points_batch_generator(self):
+        """Test writing points in a batch from a generator."""
+        dummy_points = [
+            {"measurement": "cpu_usage", "tags": {"unit": "percent"},
+                "time": "2009-11-10T23:00:00Z", "fields": {"value": 12.34}},
+            {"measurement": "network", "tags": {"direction": "in"},
+                "time": "2009-11-10T23:00:00Z", "fields": {"value": 123.00}},
+            {"measurement": "network", "tags": {"direction": "out"},
+                "time": "2009-11-10T23:00:00Z", "fields": {"value": 12.00}}
+        ]
+        dummy_points_generator = (point for point in dummy_points)
+        self.cli.write_points(points=dummy_points_generator,
+                              tags={"host": "server01",
+                                    "region": "us-west"},
+                              batch_size=2)
+        time.sleep(5)
+        net_in = self.cli.query("SELECT value FROM network "
+                                "WHERE direction=$dir",
+                                bind_params={'dir': 'in'}
+                                ).raw
+        net_out = self.cli.query("SELECT value FROM network "
+                                 "WHERE direction='out'").raw
+        cpu = self.cli.query("SELECT value FROM cpu_usage").raw
+        self.assertIn(123, net_in['series'][0]['values'][0])
+        self.assertIn(12, net_out['series'][0]['values'][0])
+        self.assertIn(12.34, cpu['series'][0]['values'][0])
+
     def test_query(self):
         """Test querying data back from server."""
         self.assertIs(True, self.cli.write_points(dummy_point))