[beam] 06/24: Conform to spark ExpressionEncoders: pass classTags, implement scala Product, pass children from within the ExpressionEncoder

[ec...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

echauchot pushed a commit to branch spark-runner_structured-streaming
in repository https://gitbox.apache.org/repos/asf/beam.git

commit 23735e4bc4cc6fe7a0e56a5370499d0ce95d381d
Author: Etienne Chauchot <ec...@apache.org>
AuthorDate: Thu Aug 29 15:10:40 2019 +0200

    Conform to spark ExpressionEncoders: pass classTags, implement scala Product, pass children from within the ExpressionEncoder
---
 .../translation/helpers/EncoderHelpers.java        | 60 +++++++++++++---------
 1 file changed, 36 insertions(+), 24 deletions(-)

diff --git a/runners/spark/src/main/java/org/apache/beam/runners/spark/structuredstreaming/translation/helpers/EncoderHelpers.java b/runners/spark/src/main/java/org/apache/beam/runners/spark/structuredstreaming/translation/helpers/EncoderHelpers.java
index 8a4f1de..002545e 100644
--- a/runners/spark/src/main/java/org/apache/beam/runners/spark/structuredstreaming/translation/helpers/EncoderHelpers.java
+++ b/runners/spark/src/main/java/org/apache/beam/runners/spark/structuredstreaming/translation/helpers/EncoderHelpers.java
@@ -100,13 +100,13 @@ public class EncoderHelpers {
 
     List<Expression> serialiserList = new ArrayList<>();
     Class<T> claz = (Class<T>) Object.class;
-    serialiserList.add(new EncodeUsingBeamCoder<>(claz, coder));
+    serialiserList.add(new EncodeUsingBeamCoder<>(new BoundReference(0, new ObjectType(claz), true), coder));
     ClassTag<T> classTag = ClassTag$.MODULE$.apply(claz);
     return new ExpressionEncoder<>(
         SchemaHelpers.binarySchema(),
         false,
         JavaConversions.collectionAsScalaIterable(serialiserList).toSeq(),
-        new DecodeUsingBeamCoder<>(claz, coder),
+        new DecodeUsingBeamCoder<>(new Cast(new GetColumnByOrdinal(0, BinaryType), BinaryType), classTag, coder),
         classTag);
 
 /*
@@ -128,14 +128,12 @@ public class EncoderHelpers {
 
   private static class EncodeUsingBeamCoder<T> extends UnaryExpression implements NonSQLExpression {
 
-    private Class<T> claz;
-    private Coder<T> beamCoder;
     private Expression child;
+    private Coder<T> beamCoder;
 
-    private EncodeUsingBeamCoder( Class<T> claz, Coder<T> beamCoder) {
-      this.claz = claz;
+    private EncodeUsingBeamCoder(Expression child, Coder<T> beamCoder) {
+      this.child = child;
       this.beamCoder = beamCoder;
-      this.child = new BoundReference(0, new ObjectType(claz), true);
     }
 
     @Override public Expression child() {
@@ -175,11 +173,18 @@ public class EncoderHelpers {
     }
 
     @Override public Object productElement(int n) {
-      return null;
+      switch (n) {
+        case 0:
+          return child;
+        case 1:
+          return beamCoder;
+        default:
+          throw new ArrayIndexOutOfBoundsException("productElement out of bounds");
+      }
     }
 
     @Override public int productArity() {
-      return 0;
+      return 2;
     }
 
     @Override public boolean canEqual(Object that) {
@@ -194,11 +199,11 @@ public class EncoderHelpers {
         return false;
       }
       EncodeUsingBeamCoder<?> that = (EncodeUsingBeamCoder<?>) o;
-      return claz.equals(that.claz) && beamCoder.equals(that.beamCoder);
+      return beamCoder.equals(that.beamCoder);
     }
 
     @Override public int hashCode() {
-      return Objects.hash(super.hashCode(), claz, beamCoder);
+      return Objects.hash(super.hashCode(), beamCoder);
     }
   }
 
@@ -228,14 +233,14 @@ public class EncoderHelpers {
 
   private static class DecodeUsingBeamCoder<T> extends UnaryExpression implements  NonSQLExpression{
 
-    private Class<T> claz;
-    private Coder<T> beamCoder;
     private Expression child;
+    private ClassTag<T> classTag;
+    private Coder<T> beamCoder;
 
-    private DecodeUsingBeamCoder(Class<T> claz, Coder<T> beamCoder) {
-      this.claz = claz;
+    private DecodeUsingBeamCoder(Expression child, ClassTag<T> classTag, Coder<T> beamCoder) {
+      this.child = child;
+      this.classTag = classTag;
       this.beamCoder = beamCoder;
-      this.child = new Cast(new GetColumnByOrdinal(0, BinaryType), BinaryType);
     }
 
     @Override public Expression child() {
@@ -267,7 +272,7 @@ public class EncoderHelpers {
       args.add(new VariableValue("deserialize", String.class));
       Block code = blockHelper.code(JavaConversions.collectionAsScalaIterable(args).toSeq());
 
-      return ev.copy(input.code().$plus(code), input.isNull(), new VariableValue("output", claz));
+      return ev.copy(input.code().$plus(code), input.isNull(), new VariableValue("output", classTag.runtimeClass()));
 
     }
 
@@ -280,17 +285,24 @@ public class EncoderHelpers {
     }
 
     @Override public DataType dataType() {
-//      return new ObjectType(classTag.runtimeClass());
-      //TODO does type erasure impose to use classTag.runtimeClass() ?
-      return new ObjectType(claz);
+      return new ObjectType(classTag.runtimeClass());
     }
 
     @Override public Object productElement(int n) {
-      return null;
+      switch (n) {
+        case 0:
+          return child;
+        case 1:
+          return classTag;
+        case 2:
+          return beamCoder;
+        default:
+          throw new ArrayIndexOutOfBoundsException("productElement out of bounds");
+      }
     }
 
     @Override public int productArity() {
-      return 0;
+      return 3;
     }
 
     @Override public boolean canEqual(Object that) {
@@ -305,11 +317,11 @@ public class EncoderHelpers {
         return false;
       }
       DecodeUsingBeamCoder<?> that = (DecodeUsingBeamCoder<?>) o;
-      return claz.equals(that.claz) && beamCoder.equals(that.beamCoder);
+      return classTag.equals(that.classTag) && beamCoder.equals(that.beamCoder);
     }
 
     @Override public int hashCode() {
-      return Objects.hash(super.hashCode(), claz, beamCoder);
+      return Objects.hash(super.hashCode(), classTag, beamCoder);
     }
   }
 /*