[ARROW-6355][Java] Make range equal visitor reusable

apache · Aug 26, 2019 · 9e04bc2 · 9e04bc2
1 parent c9bd6d7
commit 9e04bc2
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Showing 3 changed files with 40 additions and 19 deletions.
diff --git a/java/vector/src/main/java/org/apache/arrow/vector/compare/ApproxEqualsVisitor.java b/java/vector/src/main/java/org/apache/arrow/vector/compare/ApproxEqualsVisitor.java
@@ -49,6 +49,11 @@ public class ApproxEqualsVisitor extends RangeEqualsVisitor {
   private DiffFunction<Double> doubleDiffFunction =
       (Double value1, Double value2) -> Math.abs(value1 - value2);
 
+  public ApproxEqualsVisitor(float floatEpsilon, double doubleEpsilon) {
+    this.floatEpsilon = floatEpsilon;
+    this.doubleEpsilon = doubleEpsilon;
+  }
+
   public ApproxEqualsVisitor(ValueVector right, float epsilon) {
     this (right, epsilon, epsilon, true);
   }
@@ -66,9 +71,9 @@ public ApproxEqualsVisitor(ValueVector right, float floatEpsilon, double doubleE
    */
   public ApproxEqualsVisitor(ValueVector right, float floatEpsilon, double doubleEpsilon, boolean typeCheckNeeded,
       int leftStart, int rightStart, int length) {
-    super(right, rightStart, leftStart, length, typeCheckNeeded);
     this.floatEpsilon = floatEpsilon;
     this.doubleEpsilon = doubleEpsilon;
+    set(right, rightStart, leftStart, length, typeCheckNeeded);
   }
 
   public void setFloatDiffFunction(DiffFunction<Float> floatDiffFunction) {
@@ -102,9 +107,9 @@ protected boolean compareUnionVectors(UnionVector left) {
       return false;
     }
 
+    ApproxEqualsVisitor visitor = new ApproxEqualsVisitor(floatEpsilon, doubleEpsilon);
     for (int k = 0; k < leftChildren.size(); k++) {
-      ApproxEqualsVisitor visitor = new ApproxEqualsVisitor(rightChildren.get(k),
-          floatEpsilon, doubleEpsilon);
+      visitor.set(rightChildren.get(k), 0, 0, rightChildren.get(k).getValueCount(), true);
       if (!leftChildren.get(k).accept(visitor, null)) {
         return false;
       }
@@ -121,9 +126,9 @@ protected boolean compareStructVectors(NonNullableStructVector left) {
       return false;
     }
 
+    ApproxEqualsVisitor visitor = new ApproxEqualsVisitor(floatEpsilon, doubleEpsilon);
     for (String name : left.getChildFieldNames()) {
-      ApproxEqualsVisitor visitor = new ApproxEqualsVisitor(rightVector.getChild(name),
-          floatEpsilon, doubleEpsilon);
+      visitor.set(rightVector.getChild(name), 0, 0, rightVector.getChild(name).getValueCount(), true);
       if (!left.getChild(name).accept(visitor, null)) {
         return false;
       }

diff --git a/java/vector/src/main/java/org/apache/arrow/vector/compare/RangeEqualsVisitor.java b/java/vector/src/main/java/org/apache/arrow/vector/compare/RangeEqualsVisitor.java
@@ -37,23 +37,24 @@
  */
 public class RangeEqualsVisitor implements VectorVisitor<Boolean, Void> {
 
-  protected final ValueVector right;
+  protected ValueVector right;
   protected int leftStart;
   protected int rightStart;
   protected int length;
 
   protected boolean typeCheckNeeded = true;
 
+  /**
+   * The default constructor.
+   */
+  public RangeEqualsVisitor() {
+  }
+
   /**
    * Constructs a new instance.
    */
   public RangeEqualsVisitor(ValueVector right, int rightStart,  int leftStart, int length, boolean typeCheckNeeded) {
-    this.leftStart = leftStart;
-    this.rightStart = rightStart;
-    this.right = right;
-    this.length = length;
-    this.typeCheckNeeded = typeCheckNeeded;
-    Preconditions.checkArgument(length >= 0, "length must be non negative");
+    set(right, rightStart, leftStart, length, typeCheckNeeded);
   }
 
   /**
@@ -63,6 +64,18 @@ public RangeEqualsVisitor(ValueVector right, int leftStart, int rightStart, int
     this(right, rightStart, leftStart, length, true);
   }
 
+  /**
+   * Sets the parameters for comparison.
+   */
+  public void set(ValueVector right, int rightStart,  int leftStart, int length, boolean typeCheckNeeded) {
+    this.right = right;
+    this.leftStart = leftStart;
+    this.rightStart = rightStart;
+    this.length = length;
+    this.typeCheckNeeded = typeCheckNeeded;
+    Preconditions.checkArgument(length >= 0, "length must be non negative");
+  }
+
   /**
    * Do some validation work, like type check and indices check.
    */
@@ -144,9 +157,10 @@ protected boolean compareUnionVectors(UnionVector left) {
       return false;
     }
 
+    RangeEqualsVisitor visitor = new RangeEqualsVisitor();
     for (int k = 0; k < leftChildren.size(); k++) {
-      RangeEqualsVisitor visitor = new RangeEqualsVisitor(rightChildren.get(k),
-          leftStart, rightStart, length);
+      visitor.set(rightChildren.get(k),
+          rightStart, leftStart, length, true);
       if (!leftChildren.get(k).accept(visitor, null)) {
         return false;
       }
@@ -162,9 +176,10 @@ protected boolean compareStructVectors(NonNullableStructVector left) {
       return false;
     }
 
+    RangeEqualsVisitor visitor = new RangeEqualsVisitor();
     for (String name : left.getChildFieldNames()) {
-      RangeEqualsVisitor visitor = new RangeEqualsVisitor(rightVector.getChild(name),
-          leftStart, rightStart, length);
+      visitor.set(rightVector.getChild(name),
+          rightStart, leftStart, length, true);
       if (!left.getChild(name).accept(visitor, null)) {
         return false;
       }

diff --git a/java/vector/src/main/java/org/apache/arrow/vector/dictionary/DictionaryHashTable.java b/java/vector/src/main/java/org/apache/arrow/vector/dictionary/DictionaryHashTable.java
@@ -136,12 +136,13 @@ static final int roundUpToPowerOf2(int size) {
   public int getIndex(int indexInArray, ValueVector toEncode) {
     int hash = toEncode.hashCode(indexInArray);
     int index = indexFor(hash, table.length);
+
+    RangeEqualsVisitor equalVisitor = new RangeEqualsVisitor();
     for (DictionaryHashTable.Entry e = table[index]; e != null ; e = e.next) {
       if (e.hash == hash) {
         int dictIndex = e.index;
-
-        if (new RangeEqualsVisitor(dictionary, dictIndex, indexInArray, 1, false)
-            .equals(toEncode)) {
+        equalVisitor.set(dictionary, dictIndex, indexInArray, 1, false);
+        if (equalVisitor.equals(toEncode)) {
           return dictIndex;
         }
       }