zanmato1984 commented on code in PR #44394: URL: https://github.com/apache/arrow/pull/44394#discussion_r1879808996
########## cpp/src/arrow/compute/kernels/vector_swizzle.cc: ########## @@ -0,0 +1,415 @@ +// 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 "arrow/compute/api_vector.h" + +#include "arrow/compute/api_vector.h" +#include "arrow/compute/function.h" +#include "arrow/compute/kernels/codegen_internal.h" +#include "arrow/compute/registry.h" +#include "arrow/util/checked_cast.h" +#include "arrow/util/logging.h" + +namespace arrow::compute::internal { + +namespace { + +// ---------------------------------------------------------------------- +// InversePermutation + +const FunctionDoc inverse_permutation_doc( + "Return the inverse permutation of the given indices", + "For the `i`-th `index` in `indices`, the `index`-th output is `i`", {"indices"}); + +const InversePermutationOptions* GetDefaultInversePermutationOptions() { + static const auto kDefaultInversePermutationOptions = + InversePermutationOptions::Defaults(); + return &kDefaultInversePermutationOptions; +} + +using InversePermutationState = OptionsWrapper<InversePermutationOptions>; + +/// Resolve the output type of inverse_permutation. The output type is specified in the +/// options, and if null, set it to the input type. The output type must be integer. +Result<TypeHolder> ResolveInversePermutationOutputType( + KernelContext* ctx, const std::vector<TypeHolder>& input_types) { + DCHECK_EQ(input_types.size(), 1); + DCHECK_NE(input_types[0], nullptr); + + std::shared_ptr<DataType> output_type = InversePermutationState::Get(ctx).output_type; + if (!output_type) { + output_type = input_types[0].owned_type; + } + if (!is_integer(output_type->id())) { + return Status::Invalid("Output type of inverse_permutation must be integer, got " + + output_type->ToString()); + } + + return TypeHolder(std::move(output_type)); +} + +template <typename ExecType> +struct InversePermutationImpl { + using ThisType = InversePermutationImpl<ExecType>; + using IndexType = typename ExecType::IndexType; + using IndexCType = typename IndexType::c_type; + using ShapeType = typename ExecType::ShapeType; + + static Result<std::shared_ptr<ArrayData>> Exec( + KernelContext* ctx, const ShapeType& indices, int64_t input_length, + const std::shared_ptr<DataType>& input_type) { + const auto& options = InversePermutationState::Get(ctx); + + // Apply default options semantics. + int64_t output_length = options.max_index < 0 ? input_length : options.max_index + 1; + std::shared_ptr<DataType> output_type = options.output_type; + if (!output_type) { + output_type = input_type; + } + + ThisType impl(ctx, indices, input_length, output_length); + RETURN_NOT_OK(VisitTypeInline(*output_type, &impl)); + + return ArrayData::Make(std::move(output_type), output_length, + {std::move(impl.validity_buf), std::move(impl.data_buf)}); + } + + private: + KernelContext* ctx; + const ShapeType& indices; + const int64_t input_length; + const int64_t output_length; + + std::shared_ptr<Buffer> validity_buf = nullptr; + std::shared_ptr<Buffer> data_buf = nullptr; + + private: + InversePermutationImpl(KernelContext* ctx, const ShapeType& indices, + int64_t input_length, int64_t output_length) + : ctx(ctx), + indices(indices), + input_length(input_length), + output_length(output_length) {} + + Status Visit(const DataType& output_type) { + DCHECK(false) << "Shouldn't reach here"; + return Status::Invalid("Shouldn't reach here"); + } + + template <typename Type> + enable_if_t<is_integer_type<Type>::value, Status> Visit(const Type& output_type) { + using OutputCType = typename Type::c_type; + + RETURN_NOT_OK(CheckInput(output_type)); + + // Dispatch the execution based on whether there are likely many nulls in the output. + // - If many nulls (i.e. the output is "sparse"), preallocate an all-false validity + // buffer and an uninitialized data buffer. The subsequent processing will fill the + // valid values only. + // - Otherwise (i.e. the output is "dense"), the validity buffer is lazily allocated + // and initialized all-true in the subsequent processing only when needed. The data + // buffer is preallocated and filled with all "impossible" values (that is, + // input_length - note that the range of inverse_permutation is [0, input_length)) for + // the subsequent processing to detect validity. + if (LikelyManyNulls()) { + RETURN_NOT_OK(AllocateValidityBufAndFill(false)); + RETURN_NOT_OK(AllocateDataBuf(output_type)); + return Execute<Type, true>(); + } else { + RETURN_NOT_OK( + AllocateDataBufAndFill(output_type, static_cast<OutputCType>(input_length))); + return Execute<Type, false>(); + } + } + + template <typename Type> + Status CheckInput(const Type& output_type) { + using OutputCType = typename Type::c_type; + + if constexpr (!std::is_same_v<OutputCType, uint64_t>) { + if (static_cast<int64_t>(std::numeric_limits<OutputCType>::max()) < input_length) { + return Status::Invalid( + "Output type " + output_type.ToString() + + " of inverse_permutation is insufficient to store indices of length " + + std::to_string(input_length)); + } + } + + return Status::OK(); + } + + bool LikelyManyNulls() { return output_length > 2 * input_length; } + + Status AllocateValidityBufAndFill(bool valid) { + DCHECK_EQ(validity_buf, nullptr); + + ARROW_ASSIGN_OR_RAISE(validity_buf, ctx->AllocateBitmap(output_length)); + auto validity = validity_buf->mutable_data_as<uint8_t>(); + std::memset(validity, valid ? 0xff : 0, validity_buf->size()); + + return Status::OK(); + } + + Status AllocateDataBuf(const DataType& output_type) { + DCHECK_EQ(data_buf, nullptr); + + ARROW_ASSIGN_OR_RAISE(data_buf, + ctx->Allocate(output_length * output_type.byte_width())); + + return Status::OK(); + } + + template <typename Type, typename OutputCType = typename Type::c_type> + Status AllocateDataBufAndFill(const Type& output_type, OutputCType value) { + RETURN_NOT_OK(AllocateDataBuf(output_type)); + + OutputCType* data = data_buf->mutable_data_as<OutputCType>(); + for (int64_t i = 0; i < output_length; ++i) { + data[i] = value; + } + + return Status::OK(); + } + + template <typename Type, bool likely_many_nulls> + Status Execute() { + using OutputCType = typename Type::c_type; + + uint8_t* validity = nullptr; + if constexpr (likely_many_nulls) { + DCHECK_NE(validity_buf, nullptr); + validity = validity_buf->mutable_data_as<uint8_t>(); + } else { + DCHECK_EQ(validity_buf, nullptr); + } + DCHECK_NE(data_buf, nullptr); + OutputCType* data = data_buf->mutable_data_as<OutputCType>(); + int64_t inverse = 0; + RETURN_NOT_OK(ExecType::template VisitIndices( + indices, + [&](IndexCType index) { + if (ARROW_PREDICT_TRUE(index >= 0 && + static_cast<int64_t>(index) < output_length)) { + data[index] = static_cast<OutputCType>(inverse); + // If many nulls, set validity to true for valid values. + if constexpr (likely_many_nulls) { + bit_util::SetBitTo(validity, index, true); + } + } + ++inverse; + return Status::OK(); + }, + [&]() { + ++inverse; + return Status::OK(); + })); + + // If not many nulls, run another pass iterating over the data to set the validity + // to false if the value is "impossible". The validity buffer is on demand allocated + // and initialized all-true when the first "impossible" value is seen. + if constexpr (!likely_many_nulls) { + for (int64_t i = 0; i < output_length; ++i) { + if (ARROW_PREDICT_FALSE(data[i] == static_cast<OutputCType>(input_length))) { + if (ARROW_PREDICT_FALSE(!validity_buf)) { + RETURN_NOT_OK(AllocateValidityBufAndFill(true)); + validity = validity_buf->mutable_data_as<uint8_t>(); + } + bit_util::SetBitTo(validity, i, false); + } + } + } + + return Status::OK(); + } + + template <typename VISITOR, typename... ARGS> + friend Status arrow::VisitTypeInline(const DataType&, VISITOR*, ARGS&&... args); +}; + +template <typename Ignored, typename Type> +struct InversePermutation { + using ThisType = InversePermutation<Ignored, Type>; + using IndexType = Type; + using ShapeType = ArraySpan; + + template <typename ValidFunc, typename NullFunc> + static Status VisitIndices(const ArraySpan& span, ValidFunc&& valid_func, + NullFunc&& null_func) { + return VisitArraySpanInline<IndexType>(span, std::forward<ValidFunc>(valid_func), + std::forward<NullFunc>(null_func)); + } + + static Status Exec(KernelContext* ctx, const ExecSpan& span, ExecResult* result) { + DCHECK_EQ(span.num_values(), 1); + DCHECK(span[0].is_array()); + const auto& indices = span[0].array; + ARROW_ASSIGN_OR_RAISE( + result->value, InversePermutationImpl<ThisType>::Exec( + ctx, indices, indices.length, indices.type->GetSharedPtr())); + return Status::OK(); + } +}; + +template <typename Ignored, typename Type> +struct InversePermutationChunked { + using ThisType = InversePermutationChunked<Ignored, Type>; + using IndexType = Type; + using ShapeType = std::shared_ptr<ChunkedArray>; + + template <typename ValidFunc, typename NullFunc> + static Status VisitIndices(const std::shared_ptr<ChunkedArray>& chunked_array, + ValidFunc&& valid_func, NullFunc&& null_func) { + for (const auto& chunk : chunked_array->chunks()) { + ArraySpan span(*chunk->data()); + RETURN_NOT_OK(VisitArraySpanInline<IndexType>( + span, std::forward<ValidFunc>(valid_func), std::forward<NullFunc>(null_func))); + } + return Status::OK(); + } + + static Status Exec(KernelContext* ctx, const ExecBatch& batch, Datum* result) { + DCHECK_EQ(batch.num_values(), 1); + DCHECK(batch[0].is_chunked_array()); + const auto& indices = batch[0].chunked_array(); + ARROW_ASSIGN_OR_RAISE(auto inverse_permutation, + InversePermutationImpl<ThisType>::Exec( + ctx, indices, indices->length(), indices->type())); + *result = + Datum(std::make_shared<ChunkedArray>(MakeArray(std::move(inverse_permutation)))); + return Status::OK(); + } +}; + +void RegisterVectorInversePermutation(FunctionRegistry* registry) { + auto function = std::make_shared<VectorFunction>("inverse_permutation", Arity::Unary(), + inverse_permutation_doc, + GetDefaultInversePermutationOptions()); + + auto add_kernel = [&function](Type::type type_id) { + VectorKernel kernel; + kernel.signature = + KernelSignature::Make({InputType(match::SameTypeId(type_id))}, + OutputType(ResolveInversePermutationOutputType)); + kernel.init = InversePermutationState::Init; + kernel.exec = GenerateInteger<InversePermutation, void, ArrayKernelExec>(type_id); + kernel.exec_chunked = + GenerateInteger<InversePermutationChunked, void, VectorKernel::ChunkedExec>( + type_id); + kernel.can_execute_chunkwise = false; + kernel.output_chunked = false; + DCHECK_OK(function->AddKernel(std::move(kernel))); + }; + for (const auto& t : IntTypes()) { Review Comment: I think signed integers should suffice. I've reduced the input/output types to signed only. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
