paleolimbot commented on code in PR #45459: URL: https://github.com/apache/arrow/pull/45459#discussion_r1975826854
########## cpp/src/parquet/geometry_util_internal.h: ########## @@ -0,0 +1,184 @@ +// 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 <algorithm> +#include <limits> +#include <sstream> +#include <string> +#include <unordered_set> + +#include "parquet/platform.h" + +namespace parquet::geometry { + +/// \brief Infinity, used to define bounds of empty bounding boxes +constexpr double kInf = std::numeric_limits<double>::infinity(); + +/// \brief Valid combinations of dimensions allowed by ISO well-known binary +enum class Dimensions { XY = 0, XYZ = 1, XYM = 2, XYZM = 3, MIN = 0, MAX = 3 }; + +/// \brief The supported set of geometry types allowed by ISO well-known binary +enum class GeometryType { + POINT = 1, + LINESTRING = 2, + POLYGON = 3, + MULTIPOINT = 4, + MULTILINESTRING = 5, + MULTIPOLYGON = 6, + GEOMETRYCOLLECTION = 7, + MIN = 1, + MAX = 7 +}; + +/// \brief A collection of intervals representing the encountered ranges of values +/// in each dimension. +struct BoundingBox { + using XY = std::array<double, 2>; + using XYZ = std::array<double, 3>; + using XYM = std::array<double, 3>; + using XYZM = std::array<double, 4>; + + BoundingBox(const XYZM& mins, const XYZM& maxes) : min(mins), max(maxes) {} + BoundingBox() : min{kInf, kInf, kInf, kInf}, max{-kInf, -kInf, -kInf, -kInf} {} + + BoundingBox(const BoundingBox& other) = default; + BoundingBox& operator=(const BoundingBox&) = default; + + /// \brief Update the X and Y bounds to ensure these bounds contain coord + void UpdateXY(const XY& coord) { UpdateInternal(coord); } + + /// \brief Update the X, Y, and Z bounds to ensure these bounds contain coord + void UpdateXYZ(const XYZ& coord) { UpdateInternal(coord); } + + /// \brief Update the X, Y, and M bounds to ensure these bounds contain coord + void UpdateXYM(const XYM& coord) { + min[0] = std::min(min[0], coord[0]); + min[1] = std::min(min[1], coord[1]); + min[3] = std::min(min[3], coord[2]); + max[0] = std::max(max[0], coord[0]); + max[1] = std::max(max[1], coord[1]); + max[3] = std::max(max[3], coord[2]); + } + + /// \brief Update the X, Y, Z, and M bounds to ensure these bounds contain coord + void UpdateXYZM(const XYZM& coord) { UpdateInternal(coord); } + + /// \brief Reset these bounds to an empty state such that they contain no coordinates + void Reset() { + for (int i = 0; i < 4; i++) { + min[i] = kInf; + max[i] = -kInf; + } + } + + /// \brief Update these bounds such they also contain other + void Merge(const BoundingBox& other) { + for (int i = 0; i < 4; i++) { + min[i] = std::min(min[i], other.min[i]); + max[i] = std::max(max[i], other.max[i]); + } + } + + std::string ToString() const { + std::stringstream ss; + ss << "BoundingBox [" << min[0] << " => " << max[0]; + for (int i = 1; i < 4; i++) { + ss << ", " << min[i] << " => " << max[i]; + } + + ss << "]"; + + return ss.str(); + } + + XYZM min; + XYZM max; + + private: + // This works for XY, XYZ, and XYZM + template <typename Coord> + void UpdateInternal(Coord coord) { + static_assert(coord.size() <= 4); + + for (size_t i = 0; i < coord.size(); i++) { + min[i] = std::min(min[i], coord[i]); + max[i] = std::max(max[i], coord[i]); + } + } +}; + +inline bool operator==(const BoundingBox& lhs, const BoundingBox& rhs) { + return lhs.min == rhs.min && lhs.max == rhs.max; +} + +class WKBBuffer; + +/// \brief Accumulate a BoundingBox and geometry types based on zero or more well-known +/// binary blobs +class PARQUET_EXPORT WKBGeometryBounder { + public: + WKBGeometryBounder() = default; + WKBGeometryBounder(const WKBGeometryBounder&) = default; + + /// \brief Accumulate the bounds of a serialized well-known binary geometry + /// + /// Returns SerializationError for any parse errors encountered. Bounds for + /// any encountered coordinates are accumulated and the geometry type of + /// the geometry is added to the internal geometry type list. + /// + /// Note that this method is NOT appropriate for bounding a GEOGRAPHY, + /// whose bounds are not a function purely of the vertices. Geography bounding + /// is not yet implemented. + ::arrow::Status ReadGeometry(const uint8_t* data, int64_t size); + + /// \brief Accumulate the bounds of a previously-calculated BoundingBox + void ReadBox(const BoundingBox& box) { box_.Merge(box); } + + /// \brief Accumulate a previously-calculated list of geometry types + void ReadGeometryTypes(const std::vector<int32_t>& geospatial_types) { + geospatial_types_.insert(geospatial_types.begin(), geospatial_types.end()); + } + + /// \brief Retrieve the accumulated bounds + const BoundingBox& Bounds() const { return box_; } + + /// \brief Retrieve the accumulated geometry types + std::vector<int32_t> GeometryTypes() const { + std::vector<int32_t> out(geospatial_types_.begin(), geospatial_types_.end()); + std::sort(out.begin(), out.end()); + return out; + } + + /// \brief Reset the internal bounds and geometry types list to an empty state + void Reset() { + box_.Reset(); + geospatial_types_.clear(); + } + + private: + BoundingBox box_; + std::unordered_set<int32_t> geospatial_types_; + + ::arrow::Status ReadGeometryInternal(WKBBuffer* src, bool record_wkb_type); + + ::arrow::Status ReadSequence(WKBBuffer* src, Dimensions dimensions, uint32_t n_coords, + bool swap); Review Comment: Yes, these are called from `ReadGeometry()`. I briefly experimented with putting them in an anonymous namespace in the .cc file but I didn't like the look of it (required passing some of the private fields of the WKBBounder to the functions), but I'd be happy to try that again. -- 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]
