WIP: added PythonTestInputStream

Author: giwa

examples/src/main/python/streaming/test_oprations.py

@@ -6,20 +6,14 @@
 from pyspark.streaming.duration import *
 
 if __name__ == "__main__":
-    if len(sys.argv) != 3:
-        print >> sys.stderr, "Usage: wordcount <hostname> <port>"
-        exit(-1)
     conf = SparkConf()
     conf.setAppName("PythonStreamingNetworkWordCount")
     ssc = StreamingContext(conf=conf, duration=Seconds(1))
 
-    lines = ssc.socketTextStream(sys.argv[1], int(sys.argv[2]))
-    words = lines.flatMap(lambda line: line.split(" "))
-#    ssc.checkpoint("checkpoint")
-    mapped_words = words.map(lambda word: (word, 1))
-    count = mapped_words.reduceByKey(add)
+    test_input = ssc._testInputStream([1,1,1,1])
+    mapped = test_input.map(lambda x: (x, 1))
+    mapped.pyprint()
 
-    count.pyprint()
     ssc.start()
-    ssc.awaitTermination()
+#    ssc.awaitTermination()
 #    ssc.stop()

python/pyspark/streaming/context.py

@@ -17,6 +17,7 @@
 
 import sys
 from signal import signal, SIGTERM, SIGINT
+from tempfile import NamedTemporaryFile
 
 from pyspark.conf import SparkConf
 from pyspark.files import SparkFiles
@@ -138,3 +139,27 @@ def checkpoint(self, directory):
         """
         """
         self._jssc.checkpoint(directory)
+
+    def _testInputStream(self, test_input, numSlices=None):
+
+        numSlices = numSlices or self._sc.defaultParallelism
+        # Calling the Java parallelize() method with an ArrayList is too slow,
+        # because it sends O(n) Py4J commands.  As an alternative, serialized
+        # objects are written to a file and loaded through textFile().
+        tempFile = NamedTemporaryFile(delete=False, dir=self._sc._temp_dir)
+        # Make sure we distribute data evenly if it's smaller than self.batchSize
+        if "__len__" not in dir(test_input):
+            c = list(test_input)    # Make it a list so we can compute its length
+        batchSize = min(len(test_input) // numSlices, self._sc._batchSize)
+        if batchSize > 1:
+            serializer = BatchedSerializer(self._sc._unbatched_serializer,
+                                           batchSize)
+        else:
+            serializer = self._sc._unbatched_serializer
+        serializer.dump_stream(test_input, tempFile)
+        tempFile.close()
+        print tempFile.name
+        jinput_stream = self._jvm.PythonTestInputStream(self._jssc,
+                                                        tempFile.name,
+                                                        numSlices).asJavaDStream()
+        return DStream(jinput_stream, self, UTF8Deserializer())

python/pyspark/streaming/dstream.py

@@ -141,6 +141,7 @@ def _mergeCombiners(iterator):
                     combiners[k] = v
                 else:
                     combiners[k] = mergeCombiners(combiners[k], v)
+            return combiners.iteritems()
 
         return shuffled._mapPartitions(_mergeCombiners)
 

streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaStreamingContext.scala

@@ -549,6 +549,9 @@ class JavaStreamingContext(val ssc: StreamingContext) extends Closeable {
  * JavaStreamingContext object contains a number of utility functions.
  */
 object JavaStreamingContext {
+  implicit def fromStreamingContext(ssc: StreamingContext): JavaStreamingContext = new JavaStreamingContext(ssc)
+
+  implicit def toStreamingContext(jssc: JavaStreamingContext): StreamingContext = jssc.ssc
 
   /**
    * Either recreate a StreamingContext from checkpoint data or create a new StreamingContext.

streaming/src/main/scala/org/apache/spark/streaming/api/python/PythonDStream.scala

@@ -23,6 +23,7 @@ import scala.reflect.ClassTag
 
 import org.apache.spark._
 import org.apache.spark.rdd.RDD
+import org.apache.spark.api.java._
 import org.apache.spark.api.python._
 import org.apache.spark.broadcast.Broadcast
 import org.apache.spark.streaming.{StreamingContext, Duration, Time}