ARROW-1558: [C++] Implement boolean filter (selection) kernel, rename comparison kernel-related functions

cpp/src/arrow/CMakeLists.txt

@@ -172,8 +172,8 @@ if(ARROW_COMPUTE)
       compute/kernels/cast.cc
       compute/kernels/compare.cc
       compute/kernels/count.cc
-      compute/kernels/filter.cc
       compute/kernels/hash.cc
+      compute/kernels/filter.cc
       compute/kernels/mean.cc
       compute/kernels/sum.cc
       compute/kernels/take.cc

cpp/src/arrow/array.cc

@@ -1369,6 +1369,175 @@ std::shared_ptr<Array> MakeArray(const std::shared_ptr<ArrayData>& data) {
 
 namespace internal {
 
+// get the maximum buffer length required, then allocate a single zeroed buffer
+// to use anywhere a buffer is required
+class NullArrayFactory {
+ public:
+  struct GetBufferLength {
+    GetBufferLength(const std::shared_ptr<DataType>& type, int64_t length)
+        : type_(*type), length_(length), buffer_length_(BitUtil::BytesForBits(length)) {}
+
+    operator int64_t() && {
+      DCHECK_OK(VisitTypeInline(type_, this));
+      return buffer_length_;
+    }
+
+    template <typename T, typename = decltype(TypeTraits<T>::bytes_required(0))>
+    Status Visit(const T&) {
+      return MaxOf(TypeTraits<T>::bytes_required(length_));
+    }
+
+    Status Visit(const ListType& type) {
+      // list's values array may be empty, but there must be at least one offset of 0
+      return MaxOf(sizeof(int32_t));
+    }
+
+    Status Visit(const FixedSizeListType& type) {
+      return MaxOf(GetBufferLength(type.value_type(), type.list_size() * length_));
+    }
+
+    Status Visit(const StructType& type) {
+      for (const auto& child : type.children()) {
+        DCHECK_OK(MaxOf(GetBufferLength(child->type(), length_)));
+      }
+      return Status::OK();
+    }
+
+    Status Visit(const UnionType& type) {
+      // type codes
+      DCHECK_OK(MaxOf(length_));
+      if (type.mode() == UnionMode::DENSE) {
+        // offsets
+        DCHECK_OK(MaxOf(sizeof(int32_t) * length_));
+      }
+      for (const auto& child : type.children()) {
+        DCHECK_OK(MaxOf(GetBufferLength(child->type(), length_)));
+      }
+      return Status::OK();
+    }
+
+    Status Visit(const DictionaryType& type) {
+      DCHECK_OK(MaxOf(GetBufferLength(type.value_type(), length_)));
+      return MaxOf(GetBufferLength(type.index_type(), length_));
+    }
+
+    Status Visit(const ExtensionType& type) {
+      // XXX is an extension array's length always == storage length
+      return MaxOf(GetBufferLength(type.storage_type(), length_));
+    }
+
+    Status Visit(const DataType& type) {
+      return Status::NotImplemented("construction of all-null ", type);
+    }
+
+   private:
+    Status MaxOf(int64_t buffer_length) {
+      if (buffer_length > buffer_length_) {
+        buffer_length_ = buffer_length;
+      }
+      return Status::OK();
+    }
+
+    const DataType& type_;
+    int64_t length_, buffer_length_;
+  };
+
+  NullArrayFactory(const std::shared_ptr<DataType>& type, int64_t length,
+                   std::shared_ptr<ArrayData>* out)
+      : type_(type), length_(length), out_(out) {}
+
+  Status CreateBuffer() {
+    int64_t buffer_length = GetBufferLength(type_, length_);
+    RETURN_NOT_OK(AllocateBuffer(buffer_length, &buffer_));
+    std::memset(buffer_->mutable_data(), 0, buffer_->size());
+    return Status::OK();
+  }
+
+  Status Create() {
+    if (buffer_ == nullptr) {
+      RETURN_NOT_OK(CreateBuffer());
+    }
+    std::vector<std::shared_ptr<ArrayData>> child_data(type_->num_children());
+    *out_ = ArrayData::Make(type_, length_, {buffer_}, child_data, length_, 0);
+    return VisitTypeInline(*type_, this);
+  }
+
+  Status Visit(const NullType&) { return Status::OK(); }
+
+  Status Visit(const FixedWidthType&) {
+    (*out_)->buffers.resize(2, buffer_);
+    return Status::OK();
+  }
+
+  Status Visit(const BinaryType&) {
+    (*out_)->buffers.resize(3, buffer_);
+    return Status::OK();
+  }
+
+  Status Visit(const ListType& type) {
+    (*out_)->buffers.resize(2, buffer_);
+    return CreateChild(0, length_, &(*out_)->child_data[0]);
+  }
+
+  Status Visit(const FixedSizeListType& type) {
+    return CreateChild(0, length_ * type.list_size(), &(*out_)->child_data[0]);
+  }
+
+  Status Visit(const StructType& type) {
+    for (int i = 0; i < type_->num_children(); ++i) {
+      DCHECK_OK(CreateChild(i, length_, &(*out_)->child_data[i]));
+    }
+    return Status::OK();
+  }
+
+  Status Visit(const UnionType& type) {
+    if (type.mode() == UnionMode::DENSE) {
+      (*out_)->buffers.resize(3, buffer_);
+    } else {
+      (*out_)->buffers.resize(2, buffer_);
+    }
+
+    for (int i = 0; i < type_->num_children(); ++i) {
+      DCHECK_OK(CreateChild(i, length_, &(*out_)->child_data[i]));
+    }
+    return Status::OK();
+  }
+
+  Status Visit(const DictionaryType& type) {
+    (*out_)->buffers.resize(2, buffer_);
+    std::shared_ptr<ArrayData> dictionary_data;
+    return MakeArrayOfNull(type.value_type(), 0, &(*out_)->dictionary);
+  }
+
+  Status Visit(const DataType& type) {
+    return Status::NotImplemented("construction of all-null ", type);
+  }
+
+  Status CreateChild(int i, int64_t length, std::shared_ptr<ArrayData>* out) {
+    NullArrayFactory child_factory(type_->child(i)->type(), length,
+                                   &(*out_)->child_data[i]);
+    child_factory.buffer_ = buffer_;
+    return child_factory.Create();
+  }
+
+  std::shared_ptr<DataType> type_;
+  int64_t length_;
+  std::shared_ptr<ArrayData>* out_;
+  std::shared_ptr<Buffer> buffer_;
+};
+
+}  // namespace internal
+
+Status MakeArrayOfNull(const std::shared_ptr<DataType>& type, int64_t length,
+                       std::shared_ptr<Array>* out) {
+  std::shared_ptr<ArrayData> out_data;
+  RETURN_NOT_OK(internal::NullArrayFactory(type, length, &out_data).Create());
+  *out = MakeArray(out_data);
+  return Status::OK();
+}
+
+namespace internal {
+
 std::vector<ArrayVector> RechunkArraysConsistently(
     const std::vector<ArrayVector>& groups) {
   if (groups.size() <= 1) {

cpp/src/arrow/array.h

@@ -220,6 +220,14 @@ struct ARROW_EXPORT ArrayData {
 ARROW_EXPORT
 std::shared_ptr<Array> MakeArray(const std::shared_ptr<ArrayData>& data);
 
+/// \brief Create a strongly-typed Array instance with all elements null
+/// \param[in] type the array type
+/// \param[in] length the array length
+/// \param[out] out resulting Array instance
+ARROW_EXPORT
+Status MakeArrayOfNull(const std::shared_ptr<DataType>& type, int64_t length,
+                       std::shared_ptr<Array>* out);
+
 // ----------------------------------------------------------------------
 // User array accessor types
 
@@ -521,12 +529,15 @@ class ARROW_EXPORT ListArray : public Array {
   /// Return pointer to raw value offsets accounting for any slice offset
   const int32_t* raw_value_offsets() const { return raw_value_offsets_ + data_->offset; }
 
-  // Neither of these functions will perform boundschecking
+  // The following functions will not perform boundschecking
   int32_t value_offset(int64_t i) const { return raw_value_offsets_[i + data_->offset]; }
   int32_t value_length(int64_t i) const {
     i += data_->offset;
     return raw_value_offsets_[i + 1] - raw_value_offsets_[i];
   }
+  std::shared_ptr<Array> value_slice(int64_t i) const {
+    return values_->Slice(value_offset(i), value_length(i));
+  }
 
  protected:
   // This constructor defers SetData to a derived array class
@@ -596,12 +607,15 @@ class ARROW_EXPORT FixedSizeListArray : public Array {
 
   std::shared_ptr<DataType> value_type() const;
 
-  // Neither of these functions will perform boundschecking
+  // The following functions will not perform boundschecking
   int32_t value_offset(int64_t i) const {
     i += data_->offset;
     return static_cast<int32_t>(list_size_ * i);
   }
   int32_t value_length(int64_t i = 0) const { return list_size_; }
+  std::shared_ptr<Array> value_slice(int64_t i) const {
+    return values_->Slice(value_offset(i), value_length(i));
+  }
 
  protected:
   void SetData(const std::shared_ptr<ArrayData>& data);

cpp/src/arrow/array/builder_primitive.cc

@@ -128,4 +128,11 @@ Status BooleanBuilder::AppendValues(const std::vector<bool>& values) {
   return Status::OK();
 }
 
+Status BooleanBuilder::AppendValues(int64_t length, bool value) {
+  RETURN_NOT_OK(Reserve(length));
+  data_builder_.UnsafeAppend(length, value);
+  ArrayBuilder::UnsafeSetNotNull(length);
+  return Status::OK();
+}
+
 }  // namespace arrow

cpp/src/arrow/array/builder_primitive.h

@@ -409,6 +409,8 @@ class ARROW_EXPORT BooleanBuilder : public ArrayBuilder {
     return Status::OK();
   }
 
+  Status AppendValues(int64_t length, bool value);
+
   Status FinishInternal(std::shared_ptr<ArrayData>* out) override;
 
   /// \cond FALSE

cpp/src/arrow/compute/benchmark-util.h

@@ -70,5 +70,28 @@ void RegressionSetArgs(benchmark::internal::Benchmark* bench) {
   BenchmarkSetArgsWithSizes(bench, {kL1Size});
 }
 
+// RAII struct to handle some of the boilerplate in regression benchmarks
+struct RegressionArgs {
+  // size of memory tested (per iteration) in bytes
+  const int64_t size;
+
+  // proportion of nulls in generated arrays
+  const double null_proportion;
+
+  explicit RegressionArgs(benchmark::State& state)
+      : size(state.range(0)),
+        null_proportion(static_cast<double>(state.range(1)) / 100.0),
+        state_(state) {}
+
+  ~RegressionArgs() {
+    state_.counters["size"] = static_cast<double>(size);
+    state_.counters["null_percent"] = static_cast<double>(state_.range(1));
+    state_.SetBytesProcessed(state_.iterations() * size);
+  }
+
+ private:
+  benchmark::State& state_;
+};
+
 }  // namespace compute
 }  // namespace arrow

cpp/src/arrow/compute/kernels/CMakeLists.txt

@@ -20,13 +20,17 @@ arrow_install_all_headers("arrow/compute/kernels")
 add_arrow_test(boolean-test PREFIX "arrow-compute")
 add_arrow_test(cast-test PREFIX "arrow-compute")
 add_arrow_test(hash-test PREFIX "arrow-compute")
-add_arrow_test(take-test PREFIX "arrow-compute")
 add_arrow_test(util-internal-test PREFIX "arrow-compute")
 
 # Aggregates
 add_arrow_test(aggregate-test PREFIX "arrow-compute")
 add_arrow_benchmark(aggregate-benchmark PREFIX "arrow-compute")
 
-# Filters
+# Comparison
+add_arrow_test(compare-test PREFIX "arrow-compute")
+add_arrow_benchmark(compare-benchmark PREFIX "arrow-compute")
+
+# Selection
+add_arrow_test(take-test PREFIX "arrow-compute")
 add_arrow_test(filter-test PREFIX "arrow-compute")
 add_arrow_benchmark(filter-benchmark PREFIX "arrow-compute")

cpp/src/arrow/compute/kernels/compare-benchmark.cc

@@ -0,0 +1,84 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+#include "benchmark/benchmark.h"
+
+#include <vector>
+
+#include "arrow/compute/benchmark-util.h"
+#include "arrow/compute/kernel.h"
+#include "arrow/compute/kernels/compare.h"
+#include "arrow/compute/test-util.h"
+#include "arrow/testing/gtest_util.h"
+#include "arrow/testing/random.h"
+
+namespace arrow {
+namespace compute {
+
+constexpr auto kSeed = 0x94378165;
+
+static void CompareArrayScalarKernel(benchmark::State& state) {
+  const int64_t memory_size = state.range(0);
+  const int64_t array_size = memory_size / sizeof(int64_t);
+  const double null_percent = static_cast<double>(state.range(1)) / 100.0;
+  auto rand = random::RandomArrayGenerator(kSeed);
+  auto array = std::static_pointer_cast<NumericArray<Int64Type>>(
+      rand.Int64(array_size, -100, 100, null_percent));
+
+  CompareOptions ge{GREATER_EQUAL};
+
+  FunctionContext ctx;
+  for (auto _ : state) {
+    Datum out;
+    ABORT_NOT_OK(Compare(&ctx, Datum(array), Datum(int64_t(0)), ge, &out));
+    benchmark::DoNotOptimize(out);
+  }
+
+  state.counters["size"] = static_cast<double>(memory_size);
+  state.counters["null_percent"] = static_cast<double>(state.range(1));
+  state.SetBytesProcessed(state.iterations() * array_size * sizeof(int64_t));
+}
+
+static void CompareArrayArrayKernel(benchmark::State& state) {
+  const int64_t memory_size = state.range(0);
+  const int64_t array_size = memory_size / sizeof(int64_t);
+  const double null_percent = static_cast<double>(state.range(1)) / 100.0;
+  auto rand = random::RandomArrayGenerator(kSeed);
+  auto lhs = std::static_pointer_cast<NumericArray<Int64Type>>(
+      rand.Int64(array_size, -100, 100, null_percent));
+  auto rhs = std::static_pointer_cast<NumericArray<Int64Type>>(
+      rand.Int64(array_size, -100, 100, null_percent));
+
+  CompareOptions ge(GREATER_EQUAL);
+
+  FunctionContext ctx;
+  for (auto _ : state) {
+    Datum out;
+    ABORT_NOT_OK(Compare(&ctx, Datum(lhs), Datum(rhs), ge, &out));
+    benchmark::DoNotOptimize(out);
+  }
+
+  state.counters["size"] = static_cast<double>(memory_size);
+  state.counters["null_percent"] = static_cast<double>(state.range(1));
+  state.SetBytesProcessed(state.iterations() * array_size * sizeof(int64_t) * 2);
+}
+
+BENCHMARK(CompareArrayScalarKernel)->Apply(RegressionSetArgs);
+BENCHMARK(CompareArrayArrayKernel)->Apply(RegressionSetArgs);
+
+}  // namespace compute
+}  // namespace arrow