[SPARK-5946] [STREAMING] Add Python API for direct Kafka stream

Currently only added `createDirectStream` API, I'm not sure if `createRDD` is also needed, since some Java object needs to be wrapped in Python. Please help to review, thanks a lot.

Author: jerryshao <saisai.shao@intel.com>
Author: Saisai Shao <saisai.shao@intel.com>

Closes #4723 from jerryshao/direct-kafka-python-api and squashes the following commits:

a1fe97c [jerryshao] Fix rebase issue
eebf333 [jerryshao] Address the comments
da40f4e [jerryshao] Fix Python 2.6 Syntax error issue
5c0ee85 [jerryshao] Style fix
4aeac18 [jerryshao] Fix bug in example code
7146d86 [jerryshao] Add unit test
bf3bdd6 [jerryshao] Add more APIs and address the comments
f5b3801 [jerryshao] Small style fix
8641835 [Saisai Shao] Rebase and update the code
589c05b [Saisai Shao] Fix the style
d6fcb6a [Saisai Shao] Address the comments
dfda902 [Saisai Shao] Style fix
0f7d168 [Saisai Shao] Add the doc and fix some style issues
67e6880 [Saisai Shao] Fix test bug
917b0db [Saisai Shao] Add Python createRDD API for Kakfa direct stream
c3fc11d [jerryshao] Modify the docs
2c00936 [Saisai Shao] address the comments
3360f44 [jerryshao] Fix code style
e0e0f0d [jerryshao] Code clean and bug fix
338c41f [Saisai Shao] Add python API and example for direct kafka stream

1 files changed, 77 insertions, 7 deletions

diff --git a/python/pyspark/streaming/tests.py b/python/pyspark/streaming/tests.py
index 5fa1e5ef08..7c06c20345 100644
--- a/python/pyspark/streaming/tests.py
+++ b/python/pyspark/streaming/tests.py
@@ -21,6 +21,7 @@ from itertools import chain
 import time
 import operator
 import tempfile
+import random
 import struct
 from functools import reduce
 
@@ -35,7 +36,7 @@ else:
 
 from pyspark.context import SparkConf, SparkContext, RDD
 from pyspark.streaming.context import StreamingContext
-from pyspark.streaming.kafka import KafkaUtils
+from pyspark.streaming.kafka import Broker, KafkaUtils, OffsetRange, TopicAndPartition
 
 
 class PySparkStreamingTestCase(unittest.TestCase):
@@ -590,9 +591,27 @@ class KafkaStreamTests(PySparkStreamingTestCase):
 
         super(KafkaStreamTests, self).tearDown()
 
+    def _randomTopic(self):
+        return "topic-%d" % random.randint(0, 10000)
+
+    def _validateStreamResult(self, sendData, stream):
+        result = {}
+        for i in chain.from_iterable(self._collect(stream.map(lambda x: x[1]),
+                                                   sum(sendData.values()))):
+            result[i] = result.get(i, 0) + 1
+
+        self.assertEqual(sendData, result)
+
+    def _validateRddResult(self, sendData, rdd):
+        result = {}
+        for i in rdd.map(lambda x: x[1]).collect():
+            result[i] = result.get(i, 0) + 1
+
+        self.assertEqual(sendData, result)
+
     def test_kafka_stream(self):
         """Test the Python Kafka stream API."""
-        topic = "topic1"
+        topic = self._randomTopic()
         sendData = {"a": 3, "b": 5, "c": 10}
 
         self._kafkaTestUtils.createTopic(topic)
@@ -601,13 +620,64 @@ class KafkaStreamTests(PySparkStreamingTestCase):
         stream = KafkaUtils.createStream(self.ssc, self._kafkaTestUtils.zkAddress(),
                                          "test-streaming-consumer", {topic: 1},
                                          {"auto.offset.reset": "smallest"})
+        self._validateStreamResult(sendData, stream)
 
-        result = {}
-        for i in chain.from_iterable(self._collect(stream.map(lambda x: x[1]),
-                                                   sum(sendData.values()))):
-            result[i] = result.get(i, 0) + 1
+    def test_kafka_direct_stream(self):
+        """Test the Python direct Kafka stream API."""
+        topic = self._randomTopic()
+        sendData = {"a": 1, "b": 2, "c": 3}
+        kafkaParams = {"metadata.broker.list": self._kafkaTestUtils.brokerAddress(),
+                       "auto.offset.reset": "smallest"}
 
-        self.assertEqual(sendData, result)
+        self._kafkaTestUtils.createTopic(topic)
+        self._kafkaTestUtils.sendMessages(topic, sendData)
+
+        stream = KafkaUtils.createDirectStream(self.ssc, [topic], kafkaParams)
+        self._validateStreamResult(sendData, stream)
+
+    @unittest.skipIf(sys.version >= "3", "long type not support")
+    def test_kafka_direct_stream_from_offset(self):
+        """Test the Python direct Kafka stream API with start offset specified."""
+        topic = self._randomTopic()
+        sendData = {"a": 1, "b": 2, "c": 3}
+        fromOffsets = {TopicAndPartition(topic, 0): long(0)}
+        kafkaParams = {"metadata.broker.list": self._kafkaTestUtils.brokerAddress()}
+
+        self._kafkaTestUtils.createTopic(topic)
+        self._kafkaTestUtils.sendMessages(topic, sendData)
+
+        stream = KafkaUtils.createDirectStream(self.ssc, [topic], kafkaParams, fromOffsets)
+        self._validateStreamResult(sendData, stream)
+
+    @unittest.skipIf(sys.version >= "3", "long type not support")
+    def test_kafka_rdd(self):
+        """Test the Python direct Kafka RDD API."""
+        topic = self._randomTopic()
+        sendData = {"a": 1, "b": 2}
+        offsetRanges = [OffsetRange(topic, 0, long(0), long(sum(sendData.values())))]
+        kafkaParams = {"metadata.broker.list": self._kafkaTestUtils.brokerAddress()}
+
+        self._kafkaTestUtils.createTopic(topic)
+        self._kafkaTestUtils.sendMessages(topic, sendData)
+
+        rdd = KafkaUtils.createRDD(self.sc, kafkaParams, offsetRanges)
+        self._validateRddResult(sendData, rdd)
+
+    @unittest.skipIf(sys.version >= "3", "long type not support")
+    def test_kafka_rdd_with_leaders(self):
+        """Test the Python direct Kafka RDD API with leaders."""
+        topic = self._randomTopic()
+        sendData = {"a": 1, "b": 2, "c": 3}
+        offsetRanges = [OffsetRange(topic, 0, long(0), long(sum(sendData.values())))]
+        kafkaParams = {"metadata.broker.list": self._kafkaTestUtils.brokerAddress()}
+        address = self._kafkaTestUtils.brokerAddress().split(":")
+        leaders = {TopicAndPartition(topic, 0): Broker(address[0], int(address[1]))}
+
+        self._kafkaTestUtils.createTopic(topic)
+        self._kafkaTestUtils.sendMessages(topic, sendData)
+
+        rdd = KafkaUtils.createRDD(self.sc, kafkaParams, offsetRanges, leaders)
+        self._validateRddResult(sendData, rdd)
 
 if __name__ == "__main__":
     unittest.main()