petern48 commented on code in PR #476: URL: https://github.com/apache/sedona-db/pull/476#discussion_r2656954524
########## c/sedona-geos/src/geos_to_wkb.rs: ########## @@ -0,0 +1,503 @@ +// 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::io::Write; + +use byteorder::{LittleEndian, WriteBytesExt}; +use datafusion_common::{error::Result, exec_err, DataFusionError}; +use geos::{Geom, Geometry, GeometryTypes}; + +// TODO: +const NATIVE_ENDIANNESS: u8 = 1; + +/// Write a GEOS geometry to WKB format. +/// +/// This is a fast, custom implementation that directly extracts coordinates +/// from GEOS geometries and writes them in WKB format into a buffer. +pub fn write_geos_geometry(geom: &Geometry, writer: &mut impl Write) -> Result<()> { + write_geometry(geom, writer) +} + +fn write_geometry(geom: &impl Geom, writer: &mut impl Write) -> Result<()> { + let geom_type = geom + .geometry_type() + .map_err(|e| DataFusionError::Execution(format!("Failed to get geometry type: {e}")))?; + + match geom_type { + GeometryTypes::Point => write_point(geom, writer), + GeometryTypes::LineString => write_line_string(geom, writer), + GeometryTypes::Polygon => write_polygon(geom, writer), + GeometryTypes::MultiPoint => write_multi_point(geom, writer), + GeometryTypes::MultiLineString => write_multi_line_string(geom, writer), + GeometryTypes::MultiPolygon => write_multi_polygon(geom, writer), + GeometryTypes::GeometryCollection => write_geometry_collection(geom, writer), + _ => Err(DataFusionError::Execution(format!( + "Unsupported geometry type: {geom_type:?}" + ))), + } +} + +fn write_point(geom: &impl Geom, writer: &mut impl Write) -> Result<()> { + // Write byte order + writer.write_u8(NATIVE_ENDIANNESS)?; + + let has_z = geom + .has_z() + .map_err(|e| DataFusionError::Execution(format!("Failed to check has_z: {e}")))?; + let has_m = geom + .has_m() + .map_err(|e| DataFusionError::Execution(format!("Failed to check has_m: {e}")))?; + + let wkb_type = match (has_z, has_m) { + (false, false) => 1, // Point + (true, false) => 1001, // Point Z + (false, true) => 2001, // Point M + (true, true) => 3001, // Point ZM + }; + + writer.write_u32::<LittleEndian>(wkb_type)?; + + let is_empty = geom + .is_empty() + .map_err(|e| DataFusionError::Execution(format!("Failed to check if empty: {e}")))?; + + if is_empty { + // Write NaN coordinates for empty point + writer.write_f64::<LittleEndian>(f64::NAN)?; // x + writer.write_f64::<LittleEndian>(f64::NAN)?; // y + if has_z { + writer.write_f64::<LittleEndian>(f64::NAN)?; // z + } + if has_m { + writer.write_f64::<LittleEndian>(f64::NAN)?; // m + } + } else { + let coord_seq = geom + .get_coord_seq() + .map_err(|e| DataFusionError::Execution(format!("Failed to get coord seq: {e}")))?; + + let num_coords = coord_seq.size().map_err(|e| { + DataFusionError::Execution(format!("Failed to get coord seq size: {e}")) + })?; + + if num_coords == 0 { + return exec_err!("Point has no coordinates"); + } + + write_coord_seq(&coord_seq, writer, has_z, has_m)?; + } + + Ok(()) +} + +fn write_line_string(geom: &impl Geom, writer: &mut impl Write) -> Result<()> { + writer.write_u8(NATIVE_ENDIANNESS)?; + + let has_z = geom + .has_z() + .map_err(|e| DataFusionError::Execution(format!("Failed to check has_z: {e}")))?; + + let has_m = geom + .has_m() + .map_err(|e| DataFusionError::Execution(format!("Failed to check has_m: {e}")))?; + + let wkb_type = match (has_z, has_m) { + (false, false) => 2, // LineString + (true, false) => 1002, // LineString Z + (false, true) => 2002, // LineString M + (true, true) => 3002, // LineString ZM + }; + + writer.write_u32::<LittleEndian>(wkb_type)?; + + let is_empty = geom + .is_empty() + .map_err(|e| DataFusionError::Execution(format!("Failed to check if empty: {e}")))?; + + if is_empty { + writer.write_u32::<LittleEndian>(0)?; // 0 points + } else { + let coord_seq = geom + .get_coord_seq() + .map_err(|e| DataFusionError::Execution(format!("Failed to get coord seq: {e}")))?; + + let num_points = coord_seq.size().map_err(|e| { + DataFusionError::Execution(format!("Failed to get coord seq size: {e}")) + })?; + + writer.write_u32::<LittleEndian>(num_points as u32)?; + + write_coord_seq(&coord_seq, writer, has_z, has_m)?; + } + + Ok(()) +} + +fn write_polygon(geom: &impl Geom, writer: &mut impl Write) -> Result<()> { + writer.write_u8(NATIVE_ENDIANNESS)?; + + let has_z = geom + .has_z() + .map_err(|e| DataFusionError::Execution(format!("Failed to check has_z: {e}")))?; + let has_m = geom + .has_m() + .map_err(|e| DataFusionError::Execution(format!("Failed to check has_m: {e}")))?; + + let wkb_type = match (has_z, has_m) { + (false, false) => 3, // Polygon + (true, false) => 1003, // Polygon Z + (false, true) => 2003, // Polygon M + (true, true) => 3003, // Polygon ZM + }; + + writer.write_u32::<LittleEndian>(wkb_type)?; + + let is_empty = geom + .is_empty() + .map_err(|e| DataFusionError::Execution(format!("Failed to check if empty: {e}")))?; + + if is_empty { + writer.write_u32::<LittleEndian>(0)?; // 0 rings + } else { + let exterior = geom + .get_exterior_ring() + .map_err(|e| DataFusionError::Execution(format!("Failed to get exterior ring: {e}")))?; + + let exterior_coord_seq = exterior.get_coord_seq().map_err(|e| { + DataFusionError::Execution(format!("Failed to get exterior coord seq: {e}")) + })?; + + let num_interior_rings = geom.get_num_interior_rings().map_err(|e| { + DataFusionError::Execution(format!("Failed to get num interior rings: {e}")) + })?; + + // Number of rings (interior rings + 1 exterior ring) + writer.write_u32::<LittleEndian>((num_interior_rings + 1) as u32)?; + + let exterior_size = exterior_coord_seq + .size() + .map_err(|e| DataFusionError::Execution(format!("Failed to get exterior size: {e}")))?; + + // Number of points in exterior ring + writer.write_u32::<LittleEndian>(exterior_size as u32)?; + write_coord_seq(&exterior_coord_seq, writer, has_z, has_m)?; + + // Write interior rings + for i in 0..num_interior_rings { + let interior = geom.get_interior_ring_n(i).map_err(|e| { + DataFusionError::Execution(format!("Failed to get interior ring {i}: {e}")) + })?; + + let interior_coord_seq = interior.get_coord_seq().map_err(|e| { + DataFusionError::Execution(format!("Failed to get interior coord seq: {e}")) + })?; + + let interior_size = interior_coord_seq.size().map_err(|e| { + DataFusionError::Execution(format!("Failed to get interior size: {e}")) + })?; + + writer.write_u32::<LittleEndian>(interior_size as u32)?; + write_coord_seq(&interior_coord_seq, writer, has_z, has_m)?; + } + } + + Ok(()) +} + +fn write_multi_point(geom: &impl Geom, writer: &mut impl Write) -> Result<()> { + writer.write_u8(NATIVE_ENDIANNESS)?; + + let has_z = geom + .has_z() + .map_err(|e| DataFusionError::Execution(format!("Failed to check has_z: {e}")))?; + let has_m = geom + .has_m() + .map_err(|e| DataFusionError::Execution(format!("Failed to check has_m: {e}")))?; + + let wkb_type = match (has_z, has_m) { + (false, false) => 4, // MultiPoint + (true, false) => 1004, // MultiPoint Z + (false, true) => 2004, // MultiPoint M + (true, true) => 3004, // MultiPoint ZM + }; + + writer.write_u32::<LittleEndian>(wkb_type)?; + + let is_empty = geom + .is_empty() + .map_err(|e| DataFusionError::Execution(format!("Failed to check if empty: {e}")))?; + + if is_empty { + writer.write_u32::<LittleEndian>(0)?; // 0 points + } else { + let num_points = geom.get_num_geometries().map_err(|e| { + DataFusionError::Execution(format!("Failed to get num geometries: {e}")) + })?; + + writer.write_u32::<LittleEndian>(num_points as u32)?; + + for i in 0..num_points { + let point = geom + .get_geometry_n(i) + .map_err(|e| DataFusionError::Execution(format!("Failed to get point {i}: {e}")))?; + + write_point(&point, writer)?; + } + } + + Ok(()) +} + +fn write_multi_line_string(geom: &impl Geom, writer: &mut impl Write) -> Result<()> { + writer.write_u8(NATIVE_ENDIANNESS)?; + + let has_z = geom + .has_z() + .map_err(|e| DataFusionError::Execution(format!("Failed to check has_z: {e}")))?; + let has_m = geom + .has_m() + .map_err(|e| DataFusionError::Execution(format!("Failed to check has_m: {e}")))?; + + let wkb_type = match (has_z, has_m) { + (false, false) => 5, // MultiLineString + (true, false) => 1005, // MultiLineString Z + (false, true) => 2005, // MultiLineString M + (true, true) => 3005, // MultiLineString ZM + }; + + writer.write_u32::<LittleEndian>(wkb_type)?; + + let is_empty = geom + .is_empty() + .map_err(|e| DataFusionError::Execution(format!("Failed to check if empty: {e}")))?; + + if is_empty { + writer.write_u32::<LittleEndian>(0)?; // 0 line strings + } else { + let num_line_strings = geom.get_num_geometries().map_err(|e| { + DataFusionError::Execution(format!("Failed to get num geometries: {e}")) + })?; + + writer.write_u32::<LittleEndian>(num_line_strings as u32)?; + + for i in 0..num_line_strings { + let ls = geom.get_geometry_n(i).map_err(|e| { + DataFusionError::Execution(format!("Failed to get line string {i}: {e}")) + })?; + + write_line_string(&ls, writer)?; + } + } + + Ok(()) +} + +fn write_multi_polygon(geom: &impl Geom, writer: &mut impl Write) -> Result<()> { + writer.write_u8(NATIVE_ENDIANNESS)?; + + let has_z = geom + .has_z() + .map_err(|e| DataFusionError::Execution(format!("Failed to check has_z: {e}")))?; + let has_m = geom + .has_m() + .map_err(|e| DataFusionError::Execution(format!("Failed to check has_m: {e}")))?; + + let wkb_type = match (has_z, has_m) { + (false, false) => 6, // MultiPolygon + (true, false) => 1006, // MultiPolygon Z + (false, true) => 2006, // MultiPolygon M + (true, true) => 3006, // MultiPolygon ZM + }; + + writer.write_u32::<LittleEndian>(wkb_type)?; + + let is_empty = geom + .is_empty() + .map_err(|e| DataFusionError::Execution(format!("Failed to check if empty: {e}")))?; + + if is_empty { + writer.write_u32::<LittleEndian>(0)?; // 0 polygons + } else { + let num_polygons = geom.get_num_geometries().map_err(|e| { + DataFusionError::Execution(format!("Failed to get num geometries: {e}")) + })?; + + writer.write_u32::<LittleEndian>(num_polygons as u32)?; + + for i in 0..num_polygons { + let poly = geom.get_geometry_n(i).map_err(|e| { + DataFusionError::Execution(format!("Failed to get polygon {i}: {e}")) + })?; + + write_polygon(&poly, writer)?; + } + } + Ok(()) +} + +fn write_geometry_collection(geom: &impl Geom, writer: &mut impl Write) -> Result<()> { + writer.write_u8(NATIVE_ENDIANNESS)?; + + // GeometryCollection's dimension might be specified on the child geometries only + let dimension = get_geomcol_dimension(geom)?; + writer.write_u32::<LittleEndian>(dimension)?; + + let num_geometries = geom + .get_num_geometries() + .map_err(|e| DataFusionError::Execution(format!("Failed to get num geometries: {e}")))?; + + writer.write_u32::<LittleEndian>(num_geometries as u32)?; + + for i in 0..num_geometries { + let sub_geom = geom + .get_geometry_n(i) + .map_err(|e| DataFusionError::Execution(format!("Failed to get geometry {i}: {e}")))?; + + write_geometry(&sub_geom, writer)?; + } + + Ok(()) +} + +// TBH. um not sure this is needed for geos +fn get_geomcol_dimension(geomcol: &impl Geom) -> Result<u32> { + let has_z = geomcol + .has_z() + .map_err(|e| DataFusionError::Execution(format!("Failed to check has_z: {e}")))?; + + let has_m = geomcol + .has_m() + .map_err(|e| DataFusionError::Execution(format!("Failed to check has_m: {e}")))?; + + let wkb_type = match (has_z, has_m) { + (true, false) => Some(1007), // GeometryCollection Z + (false, true) => Some(2007), // GeometryCollection M + (true, true) => Some(3007), // GeometryCollection ZM + (false, false) => None, // GeometryCollection + }; + + // If found non-xy dimension, use it + if let Some(wkb_type) = wkb_type { + return Ok(wkb_type); + } + + // Try inferring from first nested geom + let num_geometries = geomcol + .get_num_geometries() + .map_err(|e| DataFusionError::Execution(format!("Failed to get num geometries: {e}")))?; + + if num_geometries == 0 { + // Guaranteed to be XY only + return Ok(7); + } + + // Check the first geom's type + let sub_geom = geomcol.get_geometry_n(0).map_err(|e| { + DataFusionError::Execution(format!("Failed to get first nested geometry: {e}")) + })?; + let sub_geom_type = sub_geom + .geometry_type() + .map_err(|e| DataFusionError::Execution(format!("Failed to get geometry type: {e}")))?; + + // If it's a nested geom collection, recurse into that + if sub_geom_type == GeometryTypes::GeometryCollection { + return get_geomcol_dimension(&sub_geom); + } + + let has_z = sub_geom + .has_z() + .map_err(|e| DataFusionError::Execution(format!("Failed to check has_z: {e}")))?; + let has_m = sub_geom + .has_m() + .map_err(|e| DataFusionError::Execution(format!("Failed to check has_m: {e}")))?; + let wkb_type = match (has_z, has_m) { + (false, false) => 7, // GeometryCollection + (true, false) => 1007, // GeometryCollection Z + (false, true) => 2007, // GeometryCollection M + (true, true) => 3007, // GeometryCollection ZM + }; + Ok(wkb_type) +} + +fn write_coord_seq( + coord_seq: &geos::CoordSeq, + writer: &mut impl Write, + has_z: bool, + has_m: bool, +) -> Result<()> { + let dims = match (has_z, has_m) { + (true, true) => 4, + (true, false) | (false, true) => 3, + (false, false) => 2, + }; + + let coords = coord_seq + .as_buffer(Some(dims)) + .map_err(|e| DataFusionError::Execution(format!("Failed to get coord seq buffer: {e}")))?; + + // TODO: I guess we could compute the exact size buffer we expect here and check it. Should we do it or just assume geos correct? + // TODO: do we need to consider endianness?? + + // Cast Vec<f64> to &[u8] so we can write the bytes directly to the writer buffer + let byte_slice: &[u8] = bytemuck::cast_slice(&coords); Review Comment: I originally went with the approach of using the .get_x, get_y, etc methods to parse out the coords (code is still commented a few lines down atm), but I found we can just use this `as_buffer()` method and copy the buffer directly. 1. You think this is safe enough or would you prefer to go the getter route? (assuming tests pass) 2. WDYT about the questions in the TODO comments here? Should we check size? Do we need to support writing big endian? If I do, maybe geos handles that already? 3. `bytemuck` (a new external library) was the only way I could find to cast a `Vec<f64>` to a `&[u8]` so we can call `writer.write_all()` on the result of `as_buffer()`. Any better idea? -- This is an automated message from the Apache Git Service. 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