[SPARK-9577][SQL] Surface concrete iterator types in various sort classes.

We often return abstract iterator types in various sort-related classes (e.g. UnsafeKVExternalSorter). It is actually better to return a more concrete type, so the callsite uses that type and JIT can inline the iterator calls.

Author: Reynold Xin <rxin@databricks.com>

Closes #7911 from rxin/surface-concrete-type and squashes the following commits:

0422add [Reynold Xin] [SPARK-9577][SQL] Surface concrete iterator types in various sort classes.

2 files changed, 4 insertions, 4 deletions

diff --git a/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeExternalSorter.java b/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeExternalSorter.java
index bf5f965a9d..dec7fcfa0d 100644
--- a/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeExternalSorter.java
+++ b/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeExternalSorter.java
@@ -428,7 +428,7 @@ public final class UnsafeExternalSorter {
 
   public UnsafeSorterIterator getSortedIterator() throws IOException {
     assert(inMemSorter != null);
-    final UnsafeSorterIterator inMemoryIterator = inMemSorter.getSortedIterator();
+    final UnsafeInMemorySorter.SortedIterator inMemoryIterator = inMemSorter.getSortedIterator();
     int numIteratorsToMerge = spillWriters.size() + (inMemoryIterator.hasNext() ? 1 : 0);
     if (spillWriters.isEmpty()) {
       return inMemoryIterator;
diff --git a/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeInMemorySorter.java b/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeInMemorySorter.java
index 3131465391..1e4b8a116e 100644
--- a/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeInMemorySorter.java
+++ b/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeInMemorySorter.java
@@ -133,7 +133,7 @@ public final class UnsafeInMemorySorter {
     pointerArrayInsertPosition++;
   }
 
-  private static final class SortedIterator extends UnsafeSorterIterator {
+  public static final class SortedIterator extends UnsafeSorterIterator {
 
     private final TaskMemoryManager memoryManager;
     private final int sortBufferInsertPosition;
@@ -144,7 +144,7 @@ public final class UnsafeInMemorySorter {
     private long keyPrefix;
     private int recordLength;
 
-    SortedIterator(
+    private SortedIterator(
         TaskMemoryManager memoryManager,
         int sortBufferInsertPosition,
         long[] sortBuffer) {
@@ -186,7 +186,7 @@ public final class UnsafeInMemorySorter {
    * Return an iterator over record pointers in sorted order. For efficiency, all calls to
    * {@code next()} will return the same mutable object.
    */
-  public UnsafeSorterIterator getSortedIterator() {
+  public SortedIterator getSortedIterator() {
     sorter.sort(pointerArray, 0, pointerArrayInsertPosition / 2, sortComparator);
     return new SortedIterator(memoryManager, pointerArrayInsertPosition, pointerArray);
   }