Add check for overlapping ranges of ARRAY and MAP vectors (#10960)

Summary:
Pull Request resolved: #10960

We don't allow overlapping ranges in ARRAY and MAP vectors.  However this is not clear in the code, so we add a method for user to check that, and also add the check to `BaseVector::validate()` method to make it clear it is not valid.  Later we will also add the check to `ArrayVectorBase` constructor.

Differential Revision: D62212238

velox/connectors/hive/tests/HivePartitionFunctionTest.cpp

@@ -319,23 +319,17 @@ TEST_F(HivePartitionFunctionTest, arrayElementsEncoded) {
   auto rawSizes = sizesBuffer->asMutable<vector_size_t>();
   auto rawNulls = nullsBuffer->asMutable<uint64_t>();
 
-  // Make the elements overlap and have gaps.
+  // Make the elements have gaps.
   // Set the values in position 2 to be invalid since that Array should be null.
   std::vector<vector_size_t> offsets{
-      0, 2, std::numeric_limits<int32_t>().max(), 1, 8};
+      0, 2, std::numeric_limits<int32_t>().max(), 4, 8};
   std::vector<vector_size_t> sizes{
-      4, 3, std::numeric_limits<int32_t>().max(), 5, 2};
+      2, 1, std::numeric_limits<int32_t>().max(), 3, 2};
   memcpy(rawOffsets, offsets.data(), size * sizeof(vector_size_t));
   memcpy(rawSizes, sizes.data(), size * sizeof(vector_size_t));
 
   bits::setNull(rawNulls, 2);
 
-  // Produces arrays that look like:
-  // [9, NULL, 7, 6]
-  // [7, 6, 5]
-  // NULL
-  // [NULL, 7, 6, 5, NULL]
-  // [1, NULL]
   auto values = std::make_shared<ArrayVector>(
       pool_.get(),
       ARRAY(elements->type()),
@@ -346,9 +340,9 @@ TEST_F(HivePartitionFunctionTest, arrayElementsEncoded) {
       encodedElements);
 
   assertPartitions(values, 1, {0, 0, 0, 0, 0});
-  assertPartitions(values, 2, {0, 0, 0, 0, 1});
-  assertPartitions(values, 500, {342, 418, 0, 458, 31});
-  assertPartitions(values, 997, {149, 936, 0, 103, 31});
+  assertPartitions(values, 2, {1, 1, 0, 0, 1});
+  assertPartitions(values, 500, {279, 7, 0, 308, 31});
+  assertPartitions(values, 997, {279, 7, 0, 820, 31});
 
   assertPartitionsWithConstChannel(values, 1);
   assertPartitionsWithConstChannel(values, 2);
@@ -428,23 +422,17 @@ TEST_F(HivePartitionFunctionTest, mapEntriesEncoded) {
   auto rawSizes = sizesBuffer->asMutable<vector_size_t>();
   auto rawNulls = nullsBuffer->asMutable<uint64_t>();
 
-  // Make the elements overlap and have gaps.
+  // Make the elements have gaps.
   // Set the values in position 2 to be invalid since that Map should be null.
   std::vector<vector_size_t> offsets{
-      0, 2, std::numeric_limits<int32_t>().max(), 1, 8};
+      0, 2, std::numeric_limits<int32_t>().max(), 4, 8};
   std::vector<vector_size_t> sizes{
-      4, 3, std::numeric_limits<int32_t>().max(), 5, 2};
+      2, 1, std::numeric_limits<int32_t>().max(), 3, 2};
   memcpy(rawOffsets, offsets.data(), size * sizeof(vector_size_t));
   memcpy(rawSizes, sizes.data(), size * sizeof(vector_size_t));
 
   bits::setNull(rawNulls, 2);
 
-  // Produces maps that look like:
-  // {key_0: 9, key_3: NULL, key_6: 7, key_9: 6}
-  // {key_6: 7, key_9: 6, key_2: 5}
-  // NULL
-  // {key_3: NULL, key_6: 7, key_9: 6, key_2: 5, key_5: NULL}
-  // {key_4: 1, key_7: NULL}
   auto values = std::make_shared<MapVector>(
       pool_.get(),
       MAP(mapKeys->type(), mapValues->type()),
@@ -457,8 +445,8 @@ TEST_F(HivePartitionFunctionTest, mapEntriesEncoded) {
 
   assertPartitions(values, 1, {0, 0, 0, 0, 0});
   assertPartitions(values, 2, {0, 1, 0, 1, 0});
-  assertPartitions(values, 500, {176, 259, 0, 91, 336});
-  assertPartitions(values, 997, {694, 24, 0, 365, 345});
+  assertPartitions(values, 500, {336, 413, 0, 259, 336});
+  assertPartitions(values, 997, {345, 666, 0, 24, 345});
 
   assertPartitionsWithConstChannel(values, 1);
   assertPartitionsWithConstChannel(values, 2);

velox/docs/develop/vectors.rst

@@ -386,8 +386,9 @@ ArrayVector
 ~~~~~~~~~~~
 
 ArrayVector stores values of type ARRAY. In addition to nulls buffer, it
-contains offsets and sizes buffers and an elements vector. Offsets and sizes
-are 32-bit integers.
+contains offsets and sizes buffers and an elements vector. Offsets and sizes are
+32-bit integers. The non-null non-empty ranges formed by offsets and sizes in a
+vector is not allowed to overlap with each other.
 
 .. code-block:: c++
 
@@ -443,8 +444,9 @@ MapVector
 ~~~~~~~~~
 
 MapVector stores values of type MAP. In addition to nulls buffer, it contains
-offsets and sizes buffers, keys and values vectors. Offsets and sizes are
-32-bit integers.
+offsets and sizes buffers, keys and values vectors. Offsets and sizes are 32-bit
+integers. The non-null non-empty ranges formed by offsets and sizes in a vector
+is not allowed to overlap with each other.
 
 .. code-block:: c++
 

velox/expression/tests/CastExprTest.cpp

@@ -1279,7 +1279,8 @@ TEST_F(CastExprTest, mapCast) {
 
     SelectivityVector rows(5);
     rows.setValid(2, false);
-    mapVector->setOffsetAndSize(2, 100, 100);
+    mapVector->setOffsetAndSize(2, 100, 1);
+    mapVector->setOffsetAndSize(51, 2, 1);
     std::vector<VectorPtr> results(1);
 
     auto rowVector = makeRowVector({mapVector});
@@ -1369,7 +1370,8 @@ TEST_F(CastExprTest, arrayCast) {
 
     SelectivityVector rows(5);
     rows.setValid(2, false);
-    arrayVector->setOffsetAndSize(2, 100, 10);
+    arrayVector->setOffsetAndSize(2, 100, 5);
+    arrayVector->setOffsetAndSize(20, 10, 5);
     std::vector<VectorPtr> results(1);
 
     auto rowVector = makeRowVector({arrayVector});

velox/expression/tests/ExprTest.cpp

@@ -3568,10 +3568,10 @@ TEST_P(ParameterizedExprTest, mapKeysAndValues) {
       MAP(BIGINT(), BIGINT()),
       makeNulls(vectorSize, nullEvery(3)),
       vectorSize,
-      makeIndices(vectorSize, [](auto /* row */) { return 0; }),
+      makeIndices(vectorSize, folly::identity),
       makeIndices(vectorSize, [](auto /* row */) { return 1; }),
-      makeFlatVector<int64_t>({1, 2, 3}),
-      makeFlatVector<int64_t>({10, 20, 30}));
+      makeFlatVector<int64_t>(vectorSize, folly::identity),
+      makeFlatVector<int64_t>(vectorSize, [](auto i) { return 10 * i; }));
   auto input = makeRowVector({mapVector});
   auto exprSet = compileMultiple(
       {"map_keys(c0)", "map_values(c0)"}, asRowType(input->type()));
@@ -4805,7 +4805,7 @@ TEST_F(ExprTest, disablePeeling) {
   // Verify that peeling is disabled when the config is set by checking whether
   // the number of rows processed is equal to the alphabet size (when enabled)
   // or the dictionary size (when disabled).
-  // Also, ensure that single arg function recieves a flat vector even when
+  // Also, ensure that single arg function receives a flat vector even when
   // peeling is disabled.
 
   // This throws if input is not flat or constant.
@@ -4847,7 +4847,7 @@ TEST_F(ExprTest, disablePeeling) {
   ASSERT_TRUE(stats.find("plus") != stats.end());
   ASSERT_EQ(stats["plus"].numProcessedRows, dictSize);
 
-  // Ensure single arg function recieves a flat vector.
+  // Ensure single arg function receives a flat vector.
   // When top level column is dictionary wrapped.
   ASSERT_NO_THROW(evaluateMultiple(
       {"testing_single_arg_deterministic((c0))"},

velox/functions/lib/tests/SliceTestBase.h

@@ -35,7 +35,7 @@ class SliceTestBase : public FunctionBaseTest {
       const ArrayVectorPtr& expectedArrayVector) {
     auto result = evaluate<ArrayVector>(expression, makeRowVector(parameters));
     ::facebook::velox::test::assertEqualVectors(expectedArrayVector, result);
-    EXPECT_NO_THROW(expectedArrayVector->checkRanges());
+    EXPECT_FALSE(expectedArrayVector->hasOverlappingRanges());
   }
 
   void basicTestCases() {

velox/functions/prestosql/tests/MapEntriesTest.cpp

@@ -168,14 +168,14 @@ TEST_F(MapEntriesTest, differentSizedValueKeyVectors) {
       makeNullableFlatVector<int64_t>({1, 2, 3, 4, std::nullopt, std::nullopt});
   auto valueVector = makeFlatVector<int64_t>({1, 2, 3, 4});
 
-  auto offsetBuffer = makeIndices({3, 2, 1, 0, 0, 0});
-  auto sizeBuffer = makeIndices({1, 1, 1, 1, 1, 1});
+  auto offsetBuffer = makeIndices({3, 2, 1, 0});
+  auto sizeBuffer = makeIndices({1, 1, 1, 1});
 
   auto mapVector = std::make_shared<MapVector>(
       pool(),
       MAP(BIGINT(), BIGINT()),
       nullptr,
-      6,
+      4,
       offsetBuffer,
       sizeBuffer,
       keyVector,
@@ -188,9 +188,9 @@ TEST_F(MapEntriesTest, differentSizedValueKeyVectors) {
 
   EXPECT_NE(result, nullptr);
   auto elementVector = makeRowVector(
-      {makeFlatVector<int64_t>({4, 3, 2, 1, 1, 1}),
-       makeFlatVector<int64_t>({4, 3, 2, 1, 1, 1})});
-  auto arrayVector = makeArrayVector({0, 1, 2, 3, 4, 5}, elementVector);
+      {makeFlatVector<int64_t>({4, 3, 2, 1}),
+       makeFlatVector<int64_t>({4, 3, 2, 1})});
+  auto arrayVector = makeArrayVector({0, 1, 2, 3}, elementVector);
 
   test::assertEqualVectors(arrayVector, result);
 }

velox/functions/prestosql/tests/ZipTest.cpp

@@ -326,7 +326,7 @@ TEST_F(ZipTest, flatArraysWithDifferentOffsets) {
 
 /// Test if we can zip two flat vectors of arrays with overlapping ranges of
 /// elements.
-TEST_F(ZipTest, flatArraysWithOverlappingRanges) {
+TEST_F(ZipTest, DISABLED_flatArraysWithOverlappingRanges) {
   const auto size = 3;
   BufferPtr offsetsBuffer = allocateOffsets(size, pool_.get());
   BufferPtr sizesBuffer = allocateSizes(size, pool_.get());

velox/vector/ComplexVector.cpp

@@ -809,31 +809,59 @@ VectorPtr RowVector::pushDictionaryToRowVectorLeaves(const VectorPtr& input) {
       wrappers, input->size(), input, input->pool());
 }
 
-void ArrayVectorBase::checkRanges() const {
-  std::unordered_map<vector_size_t, vector_size_t> seenElements;
-  seenElements.reserve(size());
+template <bool kHasNulls>
+vector_size_t ArrayVectorBase::nextNonEmpty(vector_size_t i) const {
+  while (i < size() &&
+         ((kHasNulls && bits::isBitNull(rawNulls(), i)) || rawSizes_[i] <= 0)) {
+    ++i;
+  }
+  return i;
+}
+
+template <bool kHasNulls>
+bool ArrayVectorBase::maybeHaveOverlappingRanges() const {
+  vector_size_t curr = 0;
+  curr = nextNonEmpty<kHasNulls>(curr);
+  if (curr >= size()) {
+    return false;
+  }
+  for (;;) {
+    auto next = nextNonEmpty<kHasNulls>(curr + 1);
+    if (next >= size()) {
+      return false;
+    }
+    // This also implicitly ensures rawOffsets_[curr] <= rawOffsets_[next].
+    if (rawOffsets_[curr] + rawSizes_[curr] > rawOffsets_[next]) {
+      return true;
+    }
+    curr = next;
+  }
+}
 
+bool ArrayVectorBase::hasOverlappingRanges() const {
+  if (!(rawNulls() ? maybeHaveOverlappingRanges<true>()
+                   : maybeHaveOverlappingRanges<false>())) {
+    return false;
+  }
+  std::vector<vector_size_t> indices;
+  indices.reserve(size());
   for (vector_size_t i = 0; i < size(); ++i) {
-    auto size = sizeAt(i);
-    auto offset = offsetAt(i);
-
-    for (vector_size_t j = 0; j < size; ++j) {
-      auto it = seenElements.find(offset + j);
-      if (it != seenElements.end()) {
-        VELOX_FAIL(
-            "checkRanges() found overlap at idx {}: element {} has offset {} "
-            "and size {}, and element {} has offset {} and size {}.",
-            offset + j,
-            it->second,
-            offsetAt(it->second),
-            sizeAt(it->second),
-            i,
-            offset,
-            size);
-      }
-      seenElements.emplace(offset + j, i);
+    const bool isNull = rawNulls() && bits::isBitNull(rawNulls(), i);
+    if (!isNull && rawSizes_[i] > 0) {
+      indices.push_back(i);
+    }
+  }
+  std::sort(indices.begin(), indices.end(), [&](auto i, auto j) {
+    return rawOffsets_[i] < rawOffsets_[j];
+  });
+  for (vector_size_t i = 1; i < indices.size(); ++i) {
+    auto j = indices[i - 1];
+    auto k = indices[i];
+    if (rawOffsets_[j] + rawSizes_[j] > rawOffsets_[k]) {
+      return true;
     }
   }
+  return false;
 }
 
 void ArrayVectorBase::validateArrayVectorBase(
@@ -868,6 +896,9 @@ void ArrayVectorBase::validateArrayVectorBase(
         "vector's size. Index: {}.",
         i);
   }
+  VELOX_CHECK(
+      !hasOverlappingRanges(),
+      "No overlapping ranges of offsets and sizes are allowed in ARRAY or MAP vectors");
 }
 
 namespace {

velox/vector/ComplexVector.h

@@ -364,9 +364,8 @@ struct ArrayVectorBase : BaseVector {
     sizes_->asMutable<vector_size_t>()[i] = size;
   }
 
-  /// Verify that an ArrayVector/MapVector does not contain overlapping [offset,
-  /// size] ranges. Throws in case overlaps are found.
-  void checkRanges() const;
+  /// Check if there is any overlapping [offset, size] ranges.
+  bool hasOverlappingRanges() const;
 
  protected:
   ArrayVectorBase(
@@ -411,6 +410,14 @@ struct ArrayVectorBase : BaseVector {
   const vector_size_t* rawOffsets_;
   BufferPtr sizes_;
   const vector_size_t* rawSizes_;
+
+ private:
+  template <bool kHasNulls>
+  bool maybeHaveOverlappingRanges() const;
+
+  // Return the next non-null non-empty array/map after `index'.
+  template <bool kHasNulls>
+  vector_size_t nextNonEmpty(vector_size_t index) const;
 };
 
 class ArrayVector : public ArrayVectorBase {

velox/vector/tests/VectorTest.cpp

@@ -2882,7 +2882,7 @@ TEST_F(VectorTest, resizeArrayAndMapResetOffsets) {
 
   // Test array.
   {
-    auto offsets = makeIndices({1, 1, 1, 1});
+    auto offsets = makeIndices({0, 1, 2, 3});
     auto sizes = makeIndices({1, 1, 1, 1});
 
     auto* rawSizes = sizes->as<vector_size_t>();
@@ -2907,7 +2907,7 @@ TEST_F(VectorTest, resizeArrayAndMapResetOffsets) {
 
   // Test map.
   {
-    auto offsets = makeIndices({1, 1, 1, 1});
+    auto offsets = makeIndices({0, 1, 2, 3});
     auto sizes = makeIndices({1, 1, 1, 1});
 
     auto* rawSizes = sizes->as<vector_size_t>();
@@ -3899,5 +3899,39 @@ TEST_F(VectorTest, testOverSizedArray) {
   EXPECT_THROW(BaseVector::flattenVector(constArray), VeloxUserError);
 }
 
+TEST_F(VectorTest, hasOverlappingRanges) {
+  auto test = [this](
+                  vector_size_t length,
+                  const std::vector<bool>& nulls,
+                  const std::vector<vector_size_t>& offsets,
+                  const std::vector<vector_size_t>& sizes,
+                  bool overlap) {
+    auto makeArray = [&] {
+      return std::make_shared<ArrayVector>(
+          pool(),
+          ARRAY(BIGINT()),
+          makeNulls(nulls),
+          length,
+          makeIndices(length, [&](auto i) { return offsets[i]; }),
+          makeIndices(length, [&](auto i) { return sizes[i]; }),
+          makeNullConstant(
+              TypeKind::BIGINT, std::numeric_limits<vector_size_t>::max()));
+    };
+    if (!overlap) {
+      ASSERT_FALSE(makeArray()->hasOverlappingRanges());
+    } else {
+      ASSERT_TRUE(makeArray()->hasOverlappingRanges());
+    }
+  };
+  test(3, {false, false, false}, {0, 1, 2}, {1, 1, 1}, false);
+  test(3, {false, true, false}, {0, 0, 2}, {1, 1, 1}, false);
+  test(3, {false, false, false}, {0, 0, 2}, {1, 0, 1}, false);
+  test(3, {false, false, false}, {0, 0, 2}, {1, 1, 1}, true);
+  test(3, {false, false, false}, {2, 1, 0}, {1, 1, 1}, false);
+  test(3, {false, false, false}, {2, 1, 0}, {1, 2, 1}, true);
+  test(2, {false, false}, {0, 1}, {3, 1}, true);
+  test(2, {false, false}, {1, 0}, {1, 3}, true);
+}
+
 } // namespace
 } // namespace facebook::velox