From 0b97e18e23dcce050247395f3c2538410e592cd2 Mon Sep 17 00:00:00 2001
From: Wes McKinney <wes.mckinney@twosigma.com>
Date: Thu, 5 Oct 2017 15:36:47 -0400
Subject: [PATCH] Add IsValid method to pair with IsNull

Change-Id: Ic0a3d187c3dcde067ea951437757a009faa866e1
---
 cpp/src/arrow/array-test.cc | 3 ++-
 cpp/src/arrow/array.h       | 9 ++++++++-
 cpp/src/arrow/compare.cc    | 2 +-
 3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/cpp/src/arrow/array-test.cc b/cpp/src/arrow/array-test.cc
index ef10257b59c..c1a51521c30 100644
--- a/cpp/src/arrow/array-test.cc
+++ b/cpp/src/arrow/array-test.cc
@@ -142,7 +142,7 @@ TEST_F(TestArray, SliceRecomputeNullCount) {
   ASSERT_EQ(6, null_arr_sliced->null_count());
 }
 
-TEST_F(TestArray, TestIsNull) {
+TEST_F(TestArray, TestIsNullIsValid) {
   // clang-format off
   vector<uint8_t> null_bitmap = {1, 0, 1, 1, 0, 1, 0, 0,
                                  1, 0, 1, 1, 0, 1, 0, 0,
@@ -170,6 +170,7 @@ TEST_F(TestArray, TestIsNull) {
 
   for (size_t i = 0; i < null_bitmap.size(); ++i) {
     EXPECT_EQ(null_bitmap[i] != 0, !arr->IsNull(i)) << i;
+    EXPECT_EQ(null_bitmap[i] != 0, arr->IsValid(i)) << i;
   }
 }
 
diff --git a/cpp/src/arrow/array.h b/cpp/src/arrow/array.h
index f668b6de929..1b14e242834 100644
--- a/cpp/src/arrow/array.h
+++ b/cpp/src/arrow/array.h
@@ -169,12 +169,19 @@ class ARROW_EXPORT Array {
  public:
   virtual ~Array() = default;
 
-  /// Determine if a slot is null. For inner loops. Does *not* boundscheck
+  /// \brief Return true if value at index is null. Does not boundscheck
   bool IsNull(int64_t i) const {
     return null_bitmap_data_ != nullptr &&
            BitUtil::BitNotSet(null_bitmap_data_, i + data_->offset);
   }
 
+  /// \brief Return true if value at index is valid (not null). Does not
+  /// boundscheck
+  bool IsValid(int64_t i) const {
+    return null_bitmap_data_ != nullptr &&
+      BitUtil::GetBit(null_bitmap_data_, i + data_->offset);
+  }
+
   /// Size in the number of elements this array contains.
   int64_t length() const { return data_->length; }
 
diff --git a/cpp/src/arrow/compare.cc b/cpp/src/arrow/compare.cc
index 984537fc94c..3d1f21cbc1b 100644
--- a/cpp/src/arrow/compare.cc
+++ b/cpp/src/arrow/compare.cc
@@ -351,7 +351,7 @@ class ArrayEqualsVisitor : public RangeEqualsVisitor {
       const uint8_t* right_data = right.values()->data();
 
       for (int64_t i = 0; i < left.length(); ++i) {
-        if (!left.IsNull(i) &&
+        if (left.IsValid(i) &&
             BitUtil::GetBit(left_data, i + left.offset()) !=
                 BitUtil::GetBit(right_data, i + right.offset())) {
           result_ = false;