revert [SPARK-22785][SQL] remove ColumnVector.anyNullsSet

## What changes were proposed in this pull request?

In #19980 , we thought `anyNullsSet` can be simply implemented by `numNulls() > 0`. This is logically true, but may have performance problems.

`OrcColumnVector` is an example. It doesn't have the `numNulls` property, only has a `noNulls` property. We will lose a lot of performance if we use `numNulls() > 0` to check null.

This PR simply revert #19980, with a renaming to call it `hasNull`. Better name suggestions are welcome, e.g. `nullable`?

## How was this patch tested?

existing test

Author: Wenchen Fan <[email protected]>

Closes #20452 from cloud-fan/null.

Author: cloud-fan

sql/core/src/main/java/org/apache/spark/sql/execution/datasources/orc/OrcColumnVector.java

@@ -77,6 +77,11 @@ public void close() {
 
   }
 
+  @Override
+  public boolean hasNull() {
+    return !baseData.noNulls;
+  }
+
   @Override
   public int numNulls() {
     if (baseData.isRepeating) {

sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/OffHeapColumnVector.java

@@ -123,7 +123,7 @@ public void putNulls(int rowId, int count) {
 
   @Override
   public void putNotNulls(int rowId, int count) {
-    if (numNulls == 0) return;
+    if (!hasNull()) return;
     long offset = nulls + rowId;
     for (int i = 0; i < count; ++i, ++offset) {
       Platform.putByte(null, offset, (byte) 0);

sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/OnHeapColumnVector.java

@@ -119,7 +119,7 @@ public void putNulls(int rowId, int count) {
 
   @Override
   public void putNotNulls(int rowId, int count) {
-    if (numNulls == 0) return;
+    if (!hasNull()) return;
     for (int i = 0; i < count; ++i) {
       nulls[rowId + i] = (byte)0;
     }

sql/core/src/main/java/org/apache/spark/sql/execution/vectorized/WritableColumnVector.java

@@ -59,8 +59,8 @@ public void reset() {
     elementsAppended = 0;
     if (numNulls > 0) {
       putNotNulls(0, capacity);
+      numNulls = 0;
     }
-    numNulls = 0;
   }
 
   @Override
@@ -102,6 +102,11 @@ private void throwUnsupportedException(int requiredCapacity, Throwable cause) {
     throw new RuntimeException(message, cause);
   }
 
+  @Override
+  public boolean hasNull() {
+    return numNulls > 0;
+  }
+
   @Override
   public int numNulls() { return numNulls; }
 

sql/core/src/main/java/org/apache/spark/sql/vectorized/ArrowColumnVector.java

@@ -37,6 +37,11 @@ public final class ArrowColumnVector extends ColumnVector {
   private final ArrowVectorAccessor accessor;
   private ArrowColumnVector[] childColumns;
 
+  @Override
+  public boolean hasNull() {
+    return accessor.getNullCount() > 0;
+  }
+
   @Override
   public int numNulls() {
     return accessor.getNullCount();

sql/core/src/main/java/org/apache/spark/sql/vectorized/ColumnVector.java

@@ -65,6 +65,11 @@ public abstract class ColumnVector implements AutoCloseable {
   @Override
   public abstract void close();
 
+  /**
+   * Returns true if this column vector contains any null values.
+   */
+  public abstract boolean hasNull();
+
   /**
    * Returns the number of nulls in this column vector.
    */

sql/core/src/test/scala/org/apache/spark/sql/execution/vectorized/ArrowColumnVectorSuite.scala

@@ -42,6 +42,7 @@ class ArrowColumnVectorSuite extends SparkFunSuite {
 
     val columnVector = new ArrowColumnVector(vector)
     assert(columnVector.dataType === BooleanType)
+    assert(columnVector.hasNull)
     assert(columnVector.numNulls === 1)
 
     (0 until 10).foreach { i =>
@@ -69,6 +70,7 @@ class ArrowColumnVectorSuite extends SparkFunSuite {
 
     val columnVector = new ArrowColumnVector(vector)
     assert(columnVector.dataType === ByteType)
+    assert(columnVector.hasNull)
     assert(columnVector.numNulls === 1)
 
     (0 until 10).foreach { i =>
@@ -96,6 +98,7 @@ class ArrowColumnVectorSuite extends SparkFunSuite {
 
     val columnVector = new ArrowColumnVector(vector)
     assert(columnVector.dataType === ShortType)
+    assert(columnVector.hasNull)
     assert(columnVector.numNulls === 1)
 
     (0 until 10).foreach { i =>
@@ -123,6 +126,7 @@ class ArrowColumnVectorSuite extends SparkFunSuite {
 
     val columnVector = new ArrowColumnVector(vector)
     assert(columnVector.dataType === IntegerType)
+    assert(columnVector.hasNull)
     assert(columnVector.numNulls === 1)
 
     (0 until 10).foreach { i =>
@@ -150,6 +154,7 @@ class ArrowColumnVectorSuite extends SparkFunSuite {
 
     val columnVector = new ArrowColumnVector(vector)
     assert(columnVector.dataType === LongType)
+    assert(columnVector.hasNull)
     assert(columnVector.numNulls === 1)
 
     (0 until 10).foreach { i =>
@@ -177,6 +182,7 @@ class ArrowColumnVectorSuite extends SparkFunSuite {
 
     val columnVector = new ArrowColumnVector(vector)
     assert(columnVector.dataType === FloatType)
+    assert(columnVector.hasNull)
     assert(columnVector.numNulls === 1)
 
     (0 until 10).foreach { i =>
@@ -204,6 +210,7 @@ class ArrowColumnVectorSuite extends SparkFunSuite {
 
     val columnVector = new ArrowColumnVector(vector)
     assert(columnVector.dataType === DoubleType)
+    assert(columnVector.hasNull)
     assert(columnVector.numNulls === 1)
 
     (0 until 10).foreach { i =>
@@ -232,6 +239,7 @@ class ArrowColumnVectorSuite extends SparkFunSuite {
 
     val columnVector = new ArrowColumnVector(vector)
     assert(columnVector.dataType === StringType)
+    assert(columnVector.hasNull)
     assert(columnVector.numNulls === 1)
 
     (0 until 10).foreach { i =>
@@ -258,6 +266,7 @@ class ArrowColumnVectorSuite extends SparkFunSuite {
 
     val columnVector = new ArrowColumnVector(vector)
     assert(columnVector.dataType === BinaryType)
+    assert(columnVector.hasNull)
     assert(columnVector.numNulls === 1)
 
     (0 until 10).foreach { i =>
@@ -300,6 +309,7 @@ class ArrowColumnVectorSuite extends SparkFunSuite {
 
     val columnVector = new ArrowColumnVector(vector)
     assert(columnVector.dataType === ArrayType(IntegerType))
+    assert(columnVector.hasNull)
     assert(columnVector.numNulls === 1)
 
     val array0 = columnVector.getArray(0)
@@ -344,6 +354,7 @@ class ArrowColumnVectorSuite extends SparkFunSuite {
 
     val columnVector = new ArrowColumnVector(vector)
     assert(columnVector.dataType === schema)
+    assert(!columnVector.hasNull)
     assert(columnVector.numNulls === 0)
 
     val row0 = columnVector.getStruct(0)
@@ -396,6 +407,7 @@ class ArrowColumnVectorSuite extends SparkFunSuite {
 
     val columnVector = new ArrowColumnVector(vector)
     assert(columnVector.dataType === schema)
+    assert(columnVector.hasNull)
     assert(columnVector.numNulls === 1)
 
     val row0 = columnVector.getStruct(0)

sql/core/src/test/scala/org/apache/spark/sql/execution/vectorized/ColumnarBatchSuite.scala

@@ -66,41 +66,49 @@ class ColumnarBatchSuite extends SparkFunSuite {
     column =>
       val reference = mutable.ArrayBuffer.empty[Boolean]
       var idx = 0
+      assert(!column.hasNull)
       assert(column.numNulls() == 0)
 
       column.appendNotNull()
       reference += false
+      assert(!column.hasNull)
       assert(column.numNulls() == 0)
 
       column.appendNotNulls(3)
       (1 to 3).foreach(_ => reference += false)
+      assert(!column.hasNull)
       assert(column.numNulls() == 0)
 
       column.appendNull()
       reference += true
+      assert(column.hasNull)
       assert(column.numNulls() == 1)
 
       column.appendNulls(3)
       (1 to 3).foreach(_ => reference += true)
+      assert(column.hasNull)
       assert(column.numNulls() == 4)
 
       idx = column.elementsAppended
 
       column.putNotNull(idx)
       reference += false
       idx += 1
+      assert(column.hasNull)
       assert(column.numNulls() == 4)
 
       column.putNull(idx)
       reference += true
       idx += 1
+      assert(column.hasNull)
       assert(column.numNulls() == 5)
 
       column.putNulls(idx, 3)
       reference += true
       reference += true
       reference += true
       idx += 3
+      assert(column.hasNull)
       assert(column.numNulls() == 8)
 
       column.putNotNulls(idx, 4)
@@ -109,6 +117,7 @@ class ColumnarBatchSuite extends SparkFunSuite {
       reference += false
       reference += false
       idx += 4
+      assert(column.hasNull)
       assert(column.numNulls() == 8)
 
       reference.zipWithIndex.foreach { v =>