petern48 commented on code in PR #233: URL: https://github.com/apache/sedona-db/pull/233#discussion_r2621885400
########## rust/sedona-geo/src/st_buffer.rs: ########## @@ -0,0 +1,223 @@ +// 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 geo_types::Polygon; +use sedona_expr::scalar_udf::{ScalarKernelRef, SedonaScalarKernel}; +use sedona_functions::executor::WkbExecutor; +use sedona_geometry::is_empty::is_geometry_empty; +use sedona_geometry::wkb_factory::WKB_MIN_PROBABLE_BYTES; +use sedona_schema::{ + datatypes::{SedonaType, WKB_GEOMETRY}, + matchers::ArgMatcher, +}; +use wkb::{ + reader::Wkb, + writer::{write_geometry, WriteOptions}, + Endianness, +}; + +use crate::to_geo::item_to_geometry; + +/// ST_Buffer() implementation using buffer calculation +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 = 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())) + } +} + +fn invoke_scalar( + wkb: &Wkb, + params: BufferStyle<f64>, + writer: &mut impl std::io::Write, +) -> Result<()> { + // 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 { Review Comment: still not the cleanest solution, but i do like the idea. though, i prefer to keep it simple for now. we can revisit this as we get a better idea of what we need to handle as we encounter this issue more for other functions. -- 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]
