westonpace commented on a change in pull request #11542: URL: https://github.com/apache/arrow/pull/11542#discussion_r741573603
########## File path: cpp/src/arrow/compute/kernels/vector_buffer.cc ########## @@ -0,0 +1,345 @@ +// 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 <memory> +#include <type_traits> +#include <utility> +#include <vector> + +#include "arrow/array.h" +#include "arrow/array/builder_primitive.h" +#include "arrow/array/concatenate.h" +#include "arrow/buffer.h" +#include "arrow/chunked_array.h" +#include "arrow/compute/function.h" +#include "arrow/compute/kernel.h" +#include "arrow/compute/registry.h" +#include "arrow/record_batch.h" +#include "arrow/result.h" +#include "arrow/status.h" +#include "arrow/table.h" +#include "arrow/util/bit_util.h" +#include "arrow/util/logging.h" +#include "arrow/visitor_inline.h" + +namespace arrow { + +namespace compute { +namespace internal { + +namespace { + +struct GetByteRangesArray { + const std::shared_ptr<ArrayData>& input; + int64_t offset; + int64_t length; + UInt64Builder* range_starts; + UInt64Builder* range_offsets; + UInt64Builder* range_lengths; + + Status VisitBitmap(const std::shared_ptr<Buffer>& buffer) { + if (buffer) { + uint64_t data_start = reinterpret_cast<uint64_t>(buffer->data()); + RETURN_NOT_OK(range_starts->Append(data_start)); + RETURN_NOT_OK(range_offsets->Append(BitUtil::RoundDown(offset, 8) / 8)); + RETURN_NOT_OK(range_lengths->Append(BitUtil::CoveringBytes(offset, length))); + } + return Status::OK(); + } + + Status VisitFixedWidthArray(const Buffer& buffer, const FixedWidthType& type) { + uint64_t data_start = reinterpret_cast<uint64_t>(buffer.data()); + uint64_t offset_bits = offset * type.bit_width(); + uint64_t offset_bytes = BitUtil::RoundDown(offset_bits, 8) / 8; + uint64_t end_byte = + BitUtil::RoundUp(offset_bits + (length * type.bit_width()), 8) / 8; + uint64_t length_bytes = (end_byte - offset_bytes); + RETURN_NOT_OK(range_starts->Append(data_start)); + RETURN_NOT_OK(range_offsets->Append(offset_bytes)); + return range_lengths->Append(length_bytes); + } + + Status Visit(const FixedWidthType& type) { + static_assert(sizeof(uint8_t*) <= sizeof(uint64_t), + "Undefined behavior if pointer larger than uint64_t"); + RETURN_NOT_OK(VisitBitmap(input->buffers[0])); + RETURN_NOT_OK(VisitFixedWidthArray(*input->buffers[1], type)); + if (input->dictionary) { + // This is slightly imprecise because we always assume the entire dictionary is + // referenced. If this array has an offset it may only be referencing a portion of + // the dictionary + GetByteRangesArray dict_visitor{input->dictionary, + input->dictionary->offset, + input->dictionary->length, + range_starts, + range_offsets, + range_lengths}; + return VisitTypeInline(*input->dictionary->type, &dict_visitor); + } + return Status::OK(); + } + + Status Visit(const NullType& type) { return Status::OK(); } + + template <typename BaseBinaryType> + Status VisitBaseBinary(const BaseBinaryType& type) { + using offset_type = typename BaseBinaryType::offset_type; + RETURN_NOT_OK(VisitBitmap(input->buffers[0])); + + const Buffer& offsets_buffer = *input->buffers[1]; + RETURN_NOT_OK( + range_starts->Append(reinterpret_cast<uint64_t>(offsets_buffer.data()))); + RETURN_NOT_OK(range_offsets->Append(sizeof(offset_type) * offset)); + RETURN_NOT_OK(range_lengths->Append(sizeof(offset_type) * length)); + + const offset_type* offsets = input->GetValues<offset_type>(1, offset); + const Buffer& values = *input->buffers[2]; + offset_type start = offsets[0]; + offset_type end = offsets[length]; + RETURN_NOT_OK(range_starts->Append(reinterpret_cast<uint64_t>(values.data()))); + RETURN_NOT_OK(range_offsets->Append(static_cast<uint64_t>(start))); + return range_lengths->Append(static_cast<uint64_t>(end - start)); + } + + Status Visit(const BinaryType& type) { return VisitBaseBinary(type); } + + Status Visit(const LargeBinaryType& type) { return VisitBaseBinary(type); } + + template <typename BaseListType> + Status VisitBaseList(const BaseListType& type) { + using offset_type = typename BaseListType::offset_type; + RETURN_NOT_OK(VisitBitmap(input->buffers[0])); + + const Buffer& offsets_buffer = *input->buffers[1]; + RETURN_NOT_OK( + range_starts->Append(reinterpret_cast<uint64_t>(offsets_buffer.data()))); + RETURN_NOT_OK(range_offsets->Append(sizeof(offset_type) * offset)); + RETURN_NOT_OK(range_lengths->Append(sizeof(offset_type) * length)); + + const offset_type* offsets = input->GetValues<offset_type>(1, offset); + int64_t start = static_cast<int64_t>(offsets[0]); + int64_t end = static_cast<int64_t>(offsets[length]); + GetByteRangesArray child{input->child_data[0], start, end - start, + range_starts, range_offsets, range_lengths}; + return VisitTypeInline(*type.value_type(), &child); + } + + Status Visit(const ListType& type) { return VisitBaseList(type); } + + Status Visit(const LargeListType& type) { return VisitBaseList(type); } + + Status Visit(const FixedSizeListType& type) { + RETURN_NOT_OK(VisitBitmap(input->buffers[0])); + GetByteRangesArray child{input->child_data[0], + offset * type.list_size(), + length * type.list_size(), + range_starts, + range_offsets, + range_lengths}; + return VisitTypeInline(*type.value_type(), &child); + } + + Status Visit(const StructType& type) { + for (int i = 0; i < type.num_fields(); i++) { + GetByteRangesArray child{input->child_data[i], + offset + input->child_data[i]->offset, + length, + range_starts, + range_offsets, + range_lengths}; + RETURN_NOT_OK(VisitTypeInline(*type.field(i)->type(), &child)); + } + return Status::OK(); + } + + Status Visit(const DenseUnionType& type) { + // Skip validity map for DenseUnionType + // Types buffer is always int8 + RETURN_NOT_OK(VisitFixedWidthArray( + *input->buffers[1], *std::dynamic_pointer_cast<FixedWidthType>(int8()))); + // Offsets buffer is always int32 + RETURN_NOT_OK(VisitFixedWidthArray( + *input->buffers[2], *std::dynamic_pointer_cast<FixedWidthType>(int32()))); + + // We have to loop through the types buffer to figure out the correct + // offset / length being referenced in the child arrays + std::array<std::size_t, UnionType::kMaxTypeCode> type_code_index_lookup; + for (std::size_t i = 0; i < type.type_codes().size(); i++) { + type_code_index_lookup[static_cast<std::size_t>(type.type_codes()[i])] = i; + } + std::vector<int64_t> lengths_per_type(type.type_codes().size()); + std::vector<int64_t> offsets_per_type(type.type_codes().size()); + const int8_t* type_codes = input->GetValues<int8_t>(1, 0); + for (const int8_t* it = type_codes; it != type_codes + offset; it++) { + offsets_per_type[type_code_index_lookup[static_cast<std::size_t>(*it)]]++; + } + for (const int8_t* it = type_codes + offset; it != type_codes + offset + length; + it++) { + lengths_per_type[type_code_index_lookup[static_cast<std::size_t>(*it)]]++; + } + + for (int i = 0; i < type.num_fields(); i++) { + GetByteRangesArray child{ + input->child_data[i], offsets_per_type[i] + input->child_data[i]->offset, + lengths_per_type[i], range_starts, + range_offsets, range_lengths}; + RETURN_NOT_OK(VisitTypeInline(*type.field(i)->type(), &child)); + } + + return Status::OK(); + } + + Status Visit(const SparseUnionType& type) { + // Skip validity map for SparseUnionType + // Types buffer is always int8 + RETURN_NOT_OK(VisitFixedWidthArray( + *input->buffers[1], *std::dynamic_pointer_cast<FixedWidthType>(int8()))); + + for (int i = 0; i < type.num_fields(); i++) { + GetByteRangesArray child{input->child_data[i], + offset + input->child_data[i]->offset, + length, + range_starts, + range_offsets, + range_lengths}; + RETURN_NOT_OK(VisitTypeInline(*type.field(i)->type(), &child)); + } + + return Status::OK(); + } + + Status Visit(const ExtensionType& extension_type) { + GetByteRangesArray storage{input, offset, length, + range_starts, range_offsets, range_lengths}; + return VisitTypeInline(*extension_type.storage_type(), &storage); + } + + Status Visit(const DataType& type) { + return Status::TypeError("Extracting byte ranges not supported for type ", + type.ToString()); + } + + static std::shared_ptr<DataType> RangesType() { + return struct_( + {field("start", uint64()), field("offset", uint64()), field("length", uint64())}); + } + + Result<std::shared_ptr<Array>> MakeRanges() { + std::shared_ptr<Array> range_starts_arr, range_offsets_arr, range_lengths_arr; + RETURN_NOT_OK(range_starts->Finish(&range_starts_arr)); + RETURN_NOT_OK(range_offsets->Finish(&range_offsets_arr)); + RETURN_NOT_OK(range_lengths->Finish(&range_lengths_arr)); + return StructArray::Make( + {range_starts_arr, range_offsets_arr, range_lengths_arr}, + {field("start", uint64()), field("offset", uint64()), field("length", uint64())}); + } + + static Result<std::shared_ptr<Array>> Exec(const std::shared_ptr<ArrayData>& input) { + UInt64Builder range_starts, range_offsets, range_lengths; + GetByteRangesArray self{input, input->offset, input->length, + &range_starts, &range_offsets, &range_lengths}; + RETURN_NOT_OK(VisitTypeInline(*input->type, &self)); + return self.MakeRanges(); + } +}; + +const FunctionDoc byte_ranges_doc( + "Returns an array of byte ranges referenced by the input", + (R"(The output is a StructArray {"start": int64, "offset": int64, "length":)" + " int64} where each item represents a range of memory addressed by buffers in" + " the input. The ranges should have no overlap even if buffers are shared in the" + " input. If any of the arrays are sliced zero-copy views of the data this method" + " will return the sliced ranges that are referenced. There is a slight exception" + " in the case of dictionary arrays. If a dictionary array is sliced we will still" + " assume the entire dictionary is referenced by the sliced offsets array. This" + " will lead to overestimation if not all dictionary values are referenced. If" + " the first argument is a scalar this will return an empty array since there are no" + " buffers referenced by the scalar."), + {"input"}); + +class ByteRangesMetaFunction : public MetaFunction { + public: + ByteRangesMetaFunction() + : MetaFunction("byte_ranges", Arity::Unary(), &byte_ranges_doc) {} + + Result<Datum> ExecuteImpl(const std::vector<Datum>& args, + const FunctionOptions* options, + ExecContext* ctx) const override { + DCHECK_GT(args.size(), 0); + switch (args[0].kind()) { + case Datum::SCALAR: { + std::unique_ptr<ArrayBuilder> builder; + RETURN_NOT_OK( + MakeBuilder(ctx->memory_pool(), GetByteRangesArray::RangesType(), &builder)); + RETURN_NOT_OK(builder->Resize(0)); + return builder->Finish(); + } + case Datum::ARRAY: { + const std::shared_ptr<ArrayData>& array = args[0].array(); + DCHECK(array); + return GetByteRangesArray::Exec(array); + } + case Datum::CHUNKED_ARRAY: { + const std::shared_ptr<ChunkedArray>& chunked_array = args[0].chunked_array(); + DCHECK(chunked_array); + ArrayVector chunks; + for (const auto& chunk : chunked_array->chunks()) { + ARROW_ASSIGN_OR_RAISE(std::shared_ptr<Array> chunk_ranges, + GetByteRangesArray::Exec(chunk->data())); + chunks.push_back(chunk_ranges); + } + return Concatenate(chunks, ctx->memory_pool()); Review comment: I moved this out of the compute layer and changed the functions to return lengths instead of arrays. If someone needs all referenced ranges of a table they can cross that bridge when they come to it. -- 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]
