Replace SimpleVector metadata with strongly typed SimpleVectorStats (#…

…1347)

Summary:
Pull Request resolved: #1347

SimpleVector uses a string-ly typed map to store metadata.  This seems to be used primarily for storing min/max stats as well as the bias for BiasVectors.

This is inefficient because we end up de/serializing back and forth from strings, and doesn't work for all types (e.g. opaque types).  This causes issues in VectorMaker as it tries to initialize stats when creating vectors, so we can't create vectors of Opaque types.

Since SimpleVector is templated on the underlying type, I add a SimpleVectorStats object, also templated on this type, and pass this to the vector's constructor instead of the map of strings.  This way min/max don't need to be serialized/deserialized, and it works for any type.

Reviewed By: laithsakka

Differential Revision: D35363043

fbshipit-source-id: 853c979184aef8e420154f73ba5738c98cfc5334

velox/dwio/dwrf/reader/SelectiveColumnReaderInternal.h

@@ -129,7 +129,7 @@ void SelectiveColumnReader::getFlatValues(
         true,
         type,
         T(),
-        cdvi::EMPTY_METADATA,
+        SimpleVectorStats<TVector>{},
         sizeof(TVector) * rows.size());
     return;
   }

velox/expression/EvalCtx.cpp

@@ -141,7 +141,7 @@ void EvalCtx::addError(
         AlignedBuffer::allocate<ErrorVector::value_type>(
             size, pool(), ErrorVector::value_type()),
         std::vector<BufferPtr>(0),
-        cdvi::EMPTY_METADATA,
+        SimpleVectorStats<std::shared_ptr<void>>{},
         1 /*distinctValueCount*/,
         size /*nullCount*/,
         false /*isSorted*/,

velox/type/Type.h

@@ -1564,40 +1564,39 @@ static inline int32_t sizeOfTypeKind(TypeKind kind) {
   return VELOX_DYNAMIC_SCALAR_TYPE_DISPATCH(sizeOfTypeKindHelper, kind);
 }
 
-// Helper for using folly::to with StringView.
 template <typename T, typename U>
-static inline T to(U value) {
+static inline T to(const U& value) {
   return folly::to<T>(value);
 }
 
 template <>
-inline Timestamp to(std::string value) {
+inline Timestamp to(const std::string& value) {
   return Timestamp(0, 0);
 }
 
 template <>
-inline UnknownValue to(std::string /* value */) {
+inline UnknownValue to(const std::string& /* value */) {
   return UnknownValue();
 }
 
 template <>
-inline std::string to(Timestamp value) {
+inline std::string to(const Timestamp& value) {
   return value.toString();
 }
 
 template <>
-inline std::string to(velox::StringView value) {
+inline std::string to(const velox::StringView& value) {
   return std::string(value.data(), value.size());
 }
 
 template <>
-inline std::string to(ComplexType value) {
+inline std::string to(const ComplexType& value) {
   return std::string("ComplexType");
 }
 
 template <>
-inline ComplexType to(std::string value) {
-  return ComplexType();
+inline velox::StringView to(const std::string& value) {
+  return velox::StringView(value);
 }
 
 namespace exec {

velox/vector/BaseVector.cpp

@@ -111,7 +111,7 @@ static VectorPtr addDictionary(
       std::move(vector),
       TypeKind::INTEGER,
       std::move(indices),
-      cdvi::EMPTY_METADATA,
+      SimpleVectorStats<typename KindToFlatVector<kind>::WrapperType>{},
       indicesBuffer->size() / sizeof(vector_size_t) /*distinctValueCount*/,
       base->getNullCount(),
       false /*isSorted*/,
@@ -144,7 +144,7 @@ addSequence(BufferPtr lengths, vector_size_t size, VectorPtr vector) {
       size,
       std::move(vector),
       std::move(lengths),
-      cdvi::EMPTY_METADATA,
+      SimpleVectorStats<typename KindToFlatVector<kind>::WrapperType>{},
       std::nullopt /*distinctCount*/,
       std::nullopt,
       false /*sorted*/,
@@ -177,7 +177,7 @@ addConstant(vector_size_t size, vector_size_t index, VectorPtr vector) {
       auto singleNull = BaseVector::create(vector->type(), 1, pool);
       singleNull->setNull(0, true);
       return std::make_shared<ConstantVector<T>>(
-          pool, size, 0, singleNull, cdvi::EMPTY_METADATA);
+          pool, size, 0, singleNull, SimpleVectorStats<T>{});
     } else {
       return std::make_shared<ConstantVector<T>>(
           pool, size, true, vector->type(), T());
@@ -207,7 +207,7 @@ addConstant(vector_size_t size, vector_size_t index, VectorPtr vector) {
   }
 
   return std::make_shared<ConstantVector<T>>(
-      pool, size, index, std::move(vector), cdvi::EMPTY_METADATA);
+      pool, size, index, std::move(vector), SimpleVectorStats<T>{});
 }
 
 // static
@@ -234,7 +234,7 @@ static VectorPtr createEmpty(
       size,
       std::move(values),
       std::vector<BufferPtr>(),
-      cdvi::EMPTY_METADATA,
+      SimpleVectorStats<T>{},
       0 /*distinctValueCount*/,
       0 /*nullCount*/,
       false /*isSorted*/,
@@ -332,7 +332,7 @@ VectorPtr BaseVector::create(
           size,
           BufferPtr(nullptr),
           std::vector<BufferPtr>(),
-          cdvi::EMPTY_METADATA,
+          SimpleVectorStats<UnknownValue>{},
           1 /*distinctValueCount*/,
           size /*nullCount*/,
           true /*isSorted*/,
@@ -539,7 +539,7 @@ VectorPtr newConstant(
       value.isNull(),
       Type::create<kind>(),
       std::move(copy),
-      cdvi::EMPTY_METADATA,
+      SimpleVectorStats<T>{},
       sizeof(T) /*representedByteCount*/);
 }
 
@@ -557,7 +557,7 @@ VectorPtr newConstant<TypeKind::OPAQUE>(
       value.isNull(),
       capsule.type,
       std::shared_ptr<void>(capsule.obj),
-      cdvi::EMPTY_METADATA,
+      SimpleVectorStats<std::shared_ptr<void>>{},
       sizeof(std::shared_ptr<void>) /*representedByteCount*/);
 }
 

velox/vector/BaseVector.h

@@ -43,10 +43,6 @@
 namespace facebook {
 namespace velox {
 
-namespace cdvi {
-const folly::F14FastMap<std::string, std::string> EMPTY_METADATA;
-} // namespace cdvi
-
 template <typename T>
 class SimpleVector;
 

velox/vector/BiasVector-inl.h

@@ -46,8 +46,6 @@ static inline __m256i simdAdd(const __m256i& left, const __m256i& right) {
  * 2 buffers.
  *
  * Buffer order: [nullData, valueData]
- *
- * The bias value is stored in the metaData block via the BIAS_VALUE key.
  */
 template <typename T>
 BiasVector<T>::BiasVector(
@@ -56,7 +54,8 @@ BiasVector<T>::BiasVector(
     size_t length,
     TypeKind valueType,
     BufferPtr values,
-    const folly::F14FastMap<std::string, std::string>& metaData,
+    T bias,
+    const SimpleVectorStats<T>& stats,
     std::optional<vector_size_t> distinctCount,
     std::optional<vector_size_t> nullCount,
     std::optional<bool> sorted,
@@ -66,23 +65,20 @@ BiasVector<T>::BiasVector(
           pool,
           nulls,
           length,
-          metaData,
+          stats,
           distinctCount,
           nullCount,
           sorted,
           representedBytes,
           storageByteCount),
       valueType_(valueType),
-      values_(std::move(values)) {
+      values_(std::move(values)),
+      bias_(bias) {
   VELOX_CHECK(
       valueType_ == TypeKind::INTEGER || valueType_ == TypeKind::SMALLINT ||
           valueType_ == TypeKind::TINYINT,
       "Invalid array type for biased values");
 
-  auto bias =
-      SimpleVector<T>::template getMetaDataValue<T>(metaData, BIAS_VALUE);
-  VELOX_CHECK(bias.has_value(), "Bias value is required");
-  bias_ = bias.value();
   biasBuffer_ = simd::setAll256i(bias_);
 
   switch (valueType_) {
@@ -122,7 +118,7 @@ std::unique_ptr<SimpleVector<uint64_t>> BiasVector<T>::hashAll() const {
       BaseVector::length_,
       hashes,
       std::vector<BufferPtr>(0) /*stringBuffers*/,
-      cdvi::EMPTY_METADATA,
+      SimpleVectorStats<uint64_t>{},
       std::nullopt /*distinctValueCount*/,
       0 /* nullCount */,
       false /*isSorted*/,

velox/vector/BiasVector.h

@@ -92,7 +92,6 @@ class BiasVector : public SimpleVector<T> {
   //    bias");
 
  public:
-  static const std::string BIAS_VALUE;
   static constexpr bool can_simd =
       (std::is_same<T, int64_t>::value || std::is_same<T, int32_t>::value ||
        std::is_same<T, int16_t>::value);
@@ -103,8 +102,8 @@ class BiasVector : public SimpleVector<T> {
       size_t length,
       TypeKind valueType,
       BufferPtr values,
-      const folly::F14FastMap<std::string, std::string>& metaData =
-          cdvi::EMPTY_METADATA,
+      T bias,
+      const SimpleVectorStats<T>& stats = {},
       std::optional<int32_t> distinctCount = std::nullopt,
       std::optional<vector_size_t> nullCount = std::nullopt,
       std::optional<bool> sorted = std::nullopt,
@@ -256,9 +255,6 @@ class BiasVector : public SimpleVector<T> {
   __m256i biasBuffer_;
 };
 
-template <typename T>
-const std::string BiasVector<T>::BIAS_VALUE = "CDV1";
-
 template <typename T>
 using BiasVectorPtr = std::shared_ptr<BiasVector<T>>;
 

velox/vector/CMakeLists.txt

@@ -21,7 +21,6 @@ add_library(
   LazyVector.cpp
   SelectivityVector.cpp
   SequenceVector.cpp
-  SimpleVector.cpp
   VectorEncoding.cpp
   VectorStream.cpp)
 

velox/vector/ConstantVector-inl.h

@@ -24,7 +24,7 @@ std::unique_ptr<SimpleVector<uint64_t>> ConstantVector<T>::hashAll() const {
       BaseVector::length_,
       false /* isNull */,
       this->hashValueAt(0),
-      folly::F14FastMap<std::string, std::string>(),
+      SimpleVectorStats<uint64_t>{}, /* stats */
       sizeof(uint64_t) * BaseVector::length_ /* representedBytes */);
 }
 

velox/vector/ConstantVector.cpp

@@ -36,5 +36,11 @@ void ConstantVector<std::shared_ptr<void>>::setValue(
   VELOX_NYI();
 }
 
+template <>
+void ConstantVector<ComplexType>::setValue(const std::string& /*string*/) {
+  VELOX_UNSUPPORTED(
+      "ConstantVectors of ComplexType cannot be initialized from string values.");
+}
+
 } // namespace velox
 } // namespace facebook

velox/vector/ConstantVector.h

@@ -45,8 +45,7 @@ class ConstantVector final : public SimpleVector<T> {
       size_t length,
       bool isNull,
       T&& val,
-      const folly::F14FastMap<std::string, std::string>& metaData =
-          cdvi::EMPTY_METADATA,
+      const SimpleVectorStats<T>& stats = {},
       std::optional<ByteCount> representedBytes = std::nullopt,
       std::optional<ByteCount> storageByteCount = std::nullopt)
       : ConstantVector(
@@ -55,7 +54,7 @@ class ConstantVector final : public SimpleVector<T> {
             isNull,
             CppToType<T>::create(),
             std::move(val),
-            metaData,
+            stats,
             representedBytes,
             storageByteCount) {}
 
@@ -65,16 +64,15 @@ class ConstantVector final : public SimpleVector<T> {
       bool isNull,
       std::shared_ptr<const Type> type,
       T&& val,
-      const folly::F14FastMap<std::string, std::string>& metaData =
-          cdvi::EMPTY_METADATA,
+      const SimpleVectorStats<T>& stats = {},
       std::optional<ByteCount> representedBytes = std::nullopt,
       std::optional<ByteCount> storageByteCount = std::nullopt)
       : SimpleVector<T>(
             pool,
             type,
             BufferPtr(nullptr),
             length,
-            metaData,
+            stats,
             isNull ? 0 : 1 /* distinctValueCount */,
             isNull ? length : 0 /* nullCount */,
             true /*isSorted*/,
@@ -114,14 +112,13 @@ class ConstantVector final : public SimpleVector<T> {
       vector_size_t length,
       vector_size_t index,
       VectorPtr base,
-      const folly::F14FastMap<std::string, std::string>& metaData =
-          cdvi::EMPTY_METADATA)
+      const SimpleVectorStats<T>& stats = {})
       : SimpleVector<T>(
             pool,
             base->type(),
             BufferPtr(nullptr),
             length,
-            metaData,
+            stats,
             std::nullopt,
             std::nullopt,
             true /*isSorted*/,
@@ -413,6 +410,9 @@ void ConstantVector<StringView>::setValue(const std::string& string);
 template <>
 void ConstantVector<std::shared_ptr<void>>::setValue(const std::string& string);
 
+template <>
+void ConstantVector<ComplexType>::setValue(const std::string& string);
+
 template <typename T>
 using ConstantVectorPtr = std::shared_ptr<ConstantVector<T>>;
 

velox/vector/DictionaryVector-inl.h

@@ -55,7 +55,7 @@ DictionaryVector<T>::DictionaryVector(
     std::shared_ptr<BaseVector> dictionaryValues,
     TypeKind indexType,
     BufferPtr dictionaryIndices,
-    const folly::F14FastMap<std::string, std::string>& metaData,
+    const SimpleVectorStats<T>& stats,
     std::optional<vector_size_t> distinctValueCount,
     std::optional<vector_size_t> nullCount,
     std::optional<bool> isSorted,
@@ -66,13 +66,13 @@ DictionaryVector<T>::DictionaryVector(
           dictionaryValues->type(),
           nulls,
           length,
-          metaData,
+          stats,
           distinctValueCount,
           nullCount,
           isSorted,
           representedBytes,
           storageByteCount),
-      dictionaryMetaData_(metaData) {
+      dictionaryStats_(stats) {
   VELOX_CHECK(dictionaryValues != nullptr, "dictionaryValues must not be null");
   VELOX_CHECK(
       dictionaryIndices != nullptr, "dictionaryIndices must not be null");
@@ -139,7 +139,7 @@ std::unique_ptr<SimpleVector<uint64_t>> DictionaryVector<T>::hashAll() const {
       BaseVector::length_,
       hashes,
       std::vector<BufferPtr>(0) /* stringBuffers */,
-      folly::F14FastMap<std::string, std::string>(),
+      SimpleVectorStats<uint64_t>{},
       BaseVector::distinctValueCount_.value() +
           (BaseVector::nullCount_.value_or(0) > 0 ? 1 : 0),
       0 /* nullCount */,

velox/vector/DictionaryVector.h

@@ -55,8 +55,7 @@ class DictionaryVector : public SimpleVector<T> {
       VectorPtr dictionaryValues,
       TypeKind indexTypeKind,
       BufferPtr dictionaryIndexArray,
-      const folly::F14FastMap<std::string, std::string>& metaData =
-          cdvi::EMPTY_METADATA,
+      const SimpleVectorStats<T>& stats = {},
       std::optional<vector_size_t> distinctValueCount = std::nullopt,
       std::optional<vector_size_t> nullCount = std::nullopt,
       std::optional<bool> isSorted = std::nullopt,
@@ -114,13 +113,12 @@ class DictionaryVector : public SimpleVector<T> {
   }
 
   /**
-   * @return metadata for the internal dictionary value vector. They
+   * @return stats for the internal dictionary value vector. They
    * hold the min and max value in the dictionary.
    */
   // TODO (T61713241): Remove this later.
-  inline const folly::F14FastMap<std::string, std::string>&
-  getDictionaryMetaData() const {
-    return dictionaryMetaData_;
+  inline const SimpleVectorStats<T>& getDictionaryStats() const {
+    return dictionaryStats_;
   }
 
   inline const BufferPtr& indices() const {
@@ -238,8 +236,8 @@ class DictionaryVector : public SimpleVector<T> {
 
   void setInternalState();
 
-  // metadata over the contained vector data
-  folly::F14FastMap<std::string, std::string> dictionaryMetaData_;
+  // stats over the contained vector data
+  SimpleVectorStats<T> dictionaryStats_;
 
   // the dictionary indices of the vector can be variable types depending on the
   // size of the dictionary - kept as original and typed