emkornfield commented on code in PR #48635: URL: https://github.com/apache/arrow/pull/48635#discussion_r3070300498
########## cpp/src/parquet/row_selection.h: ########## @@ -0,0 +1,78 @@ +// 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. + +#pragma once + +#include <cstdint> +#include <vector> + +#include "arrow/util/span.h" +#include "parquet/platform.h" + +namespace parquet { + +/// RowSelection is a collection of non-overlapping and ascendingly ordered row ranges. +class PARQUET_EXPORT RowSelection { + public: + /// \brief EXPERIMENTAL: A range of contiguous rows represented by an interval. + struct IntervalRange { + /// Start row of the range (inclusive). + int64_t start; + /// Number of rows in the range. + int64_t length; + }; + + /// \brief EXPERIMENTAL: An iterator for accessing row ranges in batches. + class Iterator { + public: + virtual ~Iterator() = default; + /// \brief Get the next batch of ranges. + /// Returns an empty span when exhausted. + virtual ::arrow::util::span<const IntervalRange> NextRange() = 0; + }; + + /// \brief EXPERIMENTAL: Create a new iterator for accessing row ranges in order. + std::unique_ptr<Iterator> NewIterator() const; + + /// \brief EXPERIMENTAL: Get the total number of rows in the row ranges. + int64_t row_count() const; + + /// \brief EXPERIMENTAL: Compute the intersection of two row ranges. + static RowSelection Intersect(const RowSelection& lhs, const RowSelection& rhs); + + /// \brief EXPERIMENTAL: Compute the union of two row ranges. + static RowSelection Union(const RowSelection& lhs, const RowSelection& rhs); + + /// \brief EXPERIMENTAL: Make a single row range of [start, end]. + static RowSelection MakeSingle(int64_t start, int64_t end); Review Comment: What is the use-case for this. It is a little big awkward that this uses a differnt convention then IntervalRange. Also, I assume inclusive here makes something easier (typically half-open ranges are more natural in APIs) -- 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]
