petern48 commented on code in PR #233: URL: https://github.com/apache/sedona-db/pull/233#discussion_r2443543609
########## rust/sedona-geo/src/st_buffer.rs: ########## @@ -0,0 +1,224 @@ +// 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. + +use std::sync::Arc; + +use arrow_array::builder::BinaryBuilder; +use arrow_schema::DataType; +use datafusion_common::{error::Result, exec_err, DataFusionError}; +use datafusion_expr::ColumnarValue; +use geo::algorithm::buffer::{Buffer, BufferStyle}; +use sedona_expr::scalar_udf::{ScalarKernelRef, SedonaScalarKernel}; +use sedona_functions::executor::WkbExecutor; +use sedona_geometry::wkb_factory::WKB_MIN_PROBABLE_BYTES; +use sedona_schema::{ + datatypes::{SedonaType, WKB_GEOMETRY}, + matchers::ArgMatcher, +}; +use wkb::{ + writer::{write_geometry, WriteOptions}, + Endianness, +}; + +/// ST_Centroid() implementation using centroid extraction +pub fn st_buffer_impl() -> ScalarKernelRef { + Arc::new(STBuffer {}) +} + +#[derive(Debug)] +struct STBuffer {} + +impl SedonaScalarKernel for STBuffer { + fn return_type(&self, args: &[SedonaType]) -> Result<Option<SedonaType>> { + let matcher = ArgMatcher::new( + vec![ArgMatcher::is_geometry(), ArgMatcher::is_numeric()], + WKB_GEOMETRY, + ); + + matcher.match_args(args) + } + + fn invoke_batch( + &self, + arg_types: &[SedonaType], + args: &[ColumnarValue], + ) -> Result<ColumnarValue> { + // Extract the constant scalar value before looping over the input geometries + let params: Option<BufferStyle<f64>>; + let arg1 = args[1].cast_to(&DataType::Float64, None)?; + if let ColumnarValue::Scalar(scalar_arg) = &arg1 { + if scalar_arg.is_null() { + params = None; + } else { + let distance = f64::try_from(scalar_arg.clone())?; + params = Some(BufferStyle::new(distance)); + } + } else { + return exec_err!("Invalid distance: {:?}", args[1]); + } + + // let executor = GeoTypesExecutor::new(arg_types, args); + let executor = WkbExecutor::new(arg_types, args); + let mut builder = BinaryBuilder::with_capacity( + executor.num_iterations(), + WKB_MIN_PROBABLE_BYTES * executor.num_iterations(), + ); + executor.execute_wkb_void(|maybe_wkb| { + match (maybe_wkb, params.clone()) { + (Some(wkb), Some(params)) => { + invoke_scalar(&wkb, params, &mut builder)?; + builder.append_value([]); + } + _ => builder.append_null(), + } + + Ok(()) + })?; + + executor.finish(Arc::new(builder.finish())) + } +} + +use wkb::reader::Wkb; +fn invoke_scalar( + wkb: &Wkb, + params: BufferStyle<f64>, + writer: &mut impl std::io::Write, +) -> Result<()> { + use crate::to_geo::item_to_geometry; + use geo_types::Polygon; + use sedona_geometry::is_empty::is_geometry_empty; + + // PostGIS returns POLYGON EMPTY for all empty geometries + let is_empty = is_geometry_empty(wkb).map_err(|e| DataFusionError::External(Box::new(e)))?; + if is_empty { + let empty_polygon = Polygon::<f64>::empty(); + write_geometry( + writer, + &empty_polygon, + &WriteOptions { + endianness: Endianness::LittleEndian, + }, + ) + .map_err(|e| DataFusionError::External(Box::new(e)))?; + return Ok(()); + } + + let geom = item_to_geometry(wkb)?; + + let buffer = geom.buffer_with_style(params); + + // Convert type to geo::Geometry + let geometry = geo::Geometry::MultiPolygon(buffer); + + write_geometry( + writer, + &geometry, + &WriteOptions { + endianness: Endianness::LittleEndian, + }, + ) + .map_err(|e| DataFusionError::External(Box::new(e)))?; + Ok(()) +} + +#[cfg(test)] +mod tests { + use arrow_array::ArrayRef; + use datafusion_common::ScalarValue; + use rstest::rstest; + use sedona_expr::scalar_udf::SedonaScalarUDF; + use sedona_schema::datatypes::{WKB_GEOMETRY, WKB_VIEW_GEOMETRY}; + use sedona_testing::compare::assert_array_equal; + use sedona_testing::create::create_array; + use sedona_testing::testers::ScalarUdfTester; + + use super::*; + + #[rstest] + fn udf(#[values(WKB_GEOMETRY, WKB_VIEW_GEOMETRY)] sedona_type: SedonaType) { + let udf = SedonaScalarUDF::from_kernel("st_buffer", st_buffer_impl()); + let tester = ScalarUdfTester::new( + udf.into(), + vec![sedona_type.clone(), SedonaType::Arrow(DataType::Float64)], + ); + tester.assert_return_type(WKB_GEOMETRY); + + // Check the envelope of the buffers + let envelope_udf = sedona_functions::st_envelope::st_envelope_udf(); + let envelope_tester = ScalarUdfTester::new(envelope_udf.into(), vec![WKB_GEOMETRY]); + + let buffer_result = tester.invoke_scalar_scalar("POINT (1 2)", 2.0).unwrap(); + let envelope_result = envelope_tester.invoke_scalar(buffer_result).unwrap(); + let expected_envelope = "POLYGON((-1 0, -1 4, 3 4, 3 0, -1 0))"; + tester.assert_scalar_result_equals(envelope_result, expected_envelope); + + let result = tester + .invoke_scalar_scalar(ScalarValue::Null, ScalarValue::Null) + .unwrap(); + assert!(result.is_null()); + + let input_wkt = vec![None, Some("POINT (0 0)")]; + let input_dist = 1; + let expected_envelope: ArrayRef = create_array( + &[None, Some("POLYGON((-1 -1, -1 1, 1 1, 1 -1, -1 -1))")], + &WKB_GEOMETRY, + ); + let buffer_result = tester + .invoke_wkb_array_scalar(input_wkt, input_dist) + .unwrap(); + let envelope_result = envelope_tester.invoke_array(buffer_result).unwrap(); + assert_array_equal(&envelope_result, &expected_envelope); + } + + #[test] + fn test_empty_geometry() { Review Comment: The test suite here is the same as the `geos` buffer test suite plus this new function, which I also copied over to `geos` st_buffer to be sure it works the same. -- This is an automated message from the Apache Git Service. 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