Repository: spark
Updated Branches:
  refs/heads/master 7f3c778fd -> 6a5a7254d


[SPARK-18667][PYSPARK][SQL] Change the way to group row in BatchEvalPythonExec 
so input_file_name function can work with UDF in pyspark

## What changes were proposed in this pull request?

`input_file_name` doesn't return filename when working with UDF in PySpark. An 
example shows the problem:

    from pyspark.sql.functions import *
    from pyspark.sql.types import *

    def filename(path):
        return path

    sourceFile = udf(filename, StringType())
    spark.read.json("tmp.json").select(sourceFile(input_file_name())).show()

    +---------------------------+
    |filename(input_file_name())|
    +---------------------------+
    |                           |
    +---------------------------+

The cause of this issue is, we group rows in `BatchEvalPythonExec` for batching 
processing of PythonUDF. Currently we group rows first and then evaluate 
expressions on the rows. If the data is less than the required number of rows 
for a group, the iterator will be consumed to the end before the evaluation. 
However, once the iterator reaches the end, we will unset input filename. So 
the input_file_name expression can't return correct filename.

This patch fixes the approach to group the batch of rows. We evaluate the 
expression first and then group evaluated results to batch.

## How was this patch tested?

Added unit test to PySpark.

Please review http://spark.apache.org/contributing.html before opening a pull 
request.

Author: Liang-Chi Hsieh <[email protected]>

Closes #16115 from viirya/fix-py-udf-input-filename.


Project: http://git-wip-us.apache.org/repos/asf/spark/repo
Commit: http://git-wip-us.apache.org/repos/asf/spark/commit/6a5a7254
Tree: http://git-wip-us.apache.org/repos/asf/spark/tree/6a5a7254
Diff: http://git-wip-us.apache.org/repos/asf/spark/diff/6a5a7254

Branch: refs/heads/master
Commit: 6a5a7254dc37952505989e9e580a14543adb730c
Parents: 7f3c778
Author: Liang-Chi Hsieh <[email protected]>
Authored: Thu Dec 8 23:22:18 2016 +0800
Committer: Wenchen Fan <[email protected]>
Committed: Thu Dec 8 23:22:18 2016 +0800

----------------------------------------------------------------------
 python/pyspark/sql/tests.py                     |  8 +++++
 .../execution/python/BatchEvalPythonExec.scala  | 35 +++++++++-----------
 2 files changed, 24 insertions(+), 19 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/spark/blob/6a5a7254/python/pyspark/sql/tests.py
----------------------------------------------------------------------
diff --git a/python/pyspark/sql/tests.py b/python/pyspark/sql/tests.py
index 50df68b..66320bd 100644
--- a/python/pyspark/sql/tests.py
+++ b/python/pyspark/sql/tests.py
@@ -412,6 +412,14 @@ class SQLTests(ReusedPySparkTestCase):
         res.explain(True)
         self.assertEqual(res.collect(), [Row(id=0, copy=0)])
 
+    def test_udf_with_input_file_name(self):
+        from pyspark.sql.functions import udf, input_file_name
+        from pyspark.sql.types import StringType
+        sourceFile = udf(lambda path: path, StringType())
+        filePath = "python/test_support/sql/people1.json"
+        row = 
self.spark.read.json(filePath).select(sourceFile(input_file_name())).first()
+        self.assertTrue(row[0].find("people1.json") != -1)
+
     def test_basic_functions(self):
         rdd = self.sc.parallelize(['{"foo":"bar"}', '{"foo":"baz"}'])
         df = self.spark.read.json(rdd)

http://git-wip-us.apache.org/repos/asf/spark/blob/6a5a7254/sql/core/src/main/scala/org/apache/spark/sql/execution/python/BatchEvalPythonExec.scala
----------------------------------------------------------------------
diff --git 
a/sql/core/src/main/scala/org/apache/spark/sql/execution/python/BatchEvalPythonExec.scala
 
b/sql/core/src/main/scala/org/apache/spark/sql/execution/python/BatchEvalPythonExec.scala
index dcaf2c7..7a5ac48 100644
--- 
a/sql/core/src/main/scala/org/apache/spark/sql/execution/python/BatchEvalPythonExec.scala
+++ 
b/sql/core/src/main/scala/org/apache/spark/sql/execution/python/BatchEvalPythonExec.scala
@@ -119,26 +119,23 @@ case class BatchEvalPythonExec(udfs: Seq[PythonUDF], 
output: Seq[Attribute], chi
       val pickle = new Pickler(needConversion)
       // Input iterator to Python: input rows are grouped so we send them in 
batches to Python.
       // For each row, add it to the queue.
-      val inputIterator = iter.grouped(100).map { inputRows =>
-        val toBePickled = inputRows.map { inputRow =>
-          queue.add(inputRow.asInstanceOf[UnsafeRow])
-          val row = projection(inputRow)
-          if (needConversion) {
-            EvaluatePython.toJava(row, schema)
-          } else {
-            // fast path for these types that does not need conversion in 
Python
-            val fields = new Array[Any](row.numFields)
-            var i = 0
-            while (i < row.numFields) {
-              val dt = dataTypes(i)
-              fields(i) = EvaluatePython.toJava(row.get(i, dt), dt)
-              i += 1
-            }
-            fields
+      val inputIterator = iter.map { inputRow =>
+        queue.add(inputRow.asInstanceOf[UnsafeRow])
+        val row = projection(inputRow)
+        if (needConversion) {
+          EvaluatePython.toJava(row, schema)
+        } else {
+          // fast path for these types that does not need conversion in Python
+          val fields = new Array[Any](row.numFields)
+          var i = 0
+          while (i < row.numFields) {
+            val dt = dataTypes(i)
+            fields(i) = EvaluatePython.toJava(row.get(i, dt), dt)
+            i += 1
           }
-        }.toArray
-        pickle.dumps(toBePickled)
-      }
+          fields
+        }
+      }.grouped(100).map(x => pickle.dumps(x.toArray))
 
       val context = TaskContext.get()
 


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