From 6c1b00307fa7f2b3babf68006190120ac640c06c Mon Sep 17 00:00:00 2001
From: Nick Rabinowitz <nrabinowitz@foursquare.com>
Date: Thu, 2 Nov 2023 17:00:24 -0700
Subject: [PATCH] Generate polygonToCells benchmark with Natural Earth country
 geometry (#795)

Adds a script and CMake targets to download relatively simple geometry for all countries and create a benchmark file. The benchmark currently runs both old and new algos for comparison.
---
 .github/workflows/test-bench.yml              |   2 +-
 .gitignore                                    |   2 +
 CMakeLists.txt                                |  11 ++
 scripts/make_countries.js                     | 178 ++++++++++++++++++
 .../docs/core-library/compilation-options.md  |   6 +
 5 files changed, 198 insertions(+), 1 deletion(-)
 create mode 100644 scripts/make_countries.js

diff --git a/.github/workflows/test-bench.yml b/.github/workflows/test-bench.yml
index 33ca6930d..5e59bb9d9 100644
--- a/.github/workflows/test-bench.yml
+++ b/.github/workflows/test-bench.yml
@@ -24,7 +24,7 @@ jobs:
         run: |
           mkdir build
           cd build
-          cmake -DCMAKE_BUILD_TYPE=Release ..
+          cmake -DCMAKE_BUILD_TYPE=Release -DENABLE_COUNTRY_BENCHMARKS=ON ..
 
       - name: Build
         run: |
diff --git a/.gitignore b/.gitignore
index c6c22e644..5ecab9725 100644
--- a/.gitignore
+++ b/.gitignore
@@ -83,6 +83,7 @@ RunCoverage.cmake
 # Generated coverage runner
 scripts/coverage.sh
 
+
 # CTest / coverage
 CTestTestfile.cmake
 Testing/
@@ -105,3 +106,4 @@ KML/res*centers.kml
 
 # Generated files
 src/h3lib/include/h3api.h
+src/apps/benchmarks/benchmarkCountries.c
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 11198211d..4c90917a1 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -47,6 +47,7 @@ endif()
 
 option(ENABLE_COVERAGE "Enable compiling tests with coverage." OFF)
 option(BUILD_BENCHMARKS "Build benchmarking applications." ON)
+option(ENABLE_COUNTRY_BENCHMARKS "Build benchmarking applications with Natural Earth geometries." OFF)
 option(BUILD_FUZZERS "Build fuzzer applications (for use with afl)." ON)
 option(BUILD_FILTERS "Build filter applications." ON)
 option(BUILD_GENERATORS "Build code generation applications." ON)
@@ -577,6 +578,16 @@ if(BUILD_BENCHMARKS)
     if(ENABLE_REQUIRES_ALL_SYMBOLS)
         add_h3_benchmark(benchmarkPolygon src/apps/benchmarks/benchmarkPolygon.c)
     endif()
+
+    if(ENABLE_COUNTRY_BENCHMARKS)
+        # Country benchmark: Downloads country geometry and generates the benchmark file
+        add_custom_command(OUTPUT src/apps/benchmarks/benchmarkCountries.c
+            COMMAND node ${CMAKE_CURRENT_SOURCE_DIR}/scripts/make_countries.js ${CMAKE_CURRENT_BINARY_DIR}/src/apps/benchmarks/benchmarkCountries.c
+            )
+
+        add_h3_benchmark(benchmarkCountries ${CMAKE_CURRENT_BINARY_DIR}/src/apps/benchmarks/benchmarkCountries.c)
+        # add_dependencies(bench_benchmarkCountries )
+    endif()
 endif()
 
 # Installation (https://github.com/forexample/package-example)
diff --git a/scripts/make_countries.js b/scripts/make_countries.js
new file mode 100644
index 000000000..4e8a495d4
--- /dev/null
+++ b/scripts/make_countries.js
@@ -0,0 +1,178 @@
+#!/usr/bin/env node
+/*
+ * Copyright 2023 Uber Technologies, Inc.
+ *
+ * Licensed 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.
+ */
+
+/** @file make_countries.js
+ * @brief Script to make country test fixtures based on Natural Earth data.
+ *        This makes the fixture with polygonToCells benchmarks.
+ */
+
+const fs = require('fs');
+const path = require('path');
+const https = require('https');
+
+// Using GeoJSON version as it is easy to convert
+const SOURCE_URL = 'https://raw.githubusercontent.com/nvkelso/natural-earth-vector/master/geojson/ne_50m_admin_0_countries.geojson';
+const TARGET = process.argv[2];
+
+// Use Node HTTPS module for download, to avoid dependencies
+function getSource(url) {
+  return new Promise((resolve, reject) => {
+    https.get(url, (resp) => {
+      let data = '';
+      resp.on('data', (chunk) => {
+        data += chunk;
+      });
+      resp.on('end', () => {
+        resolve(data);
+      });
+    }).on('error', reject);
+  });
+}
+
+function degsToRads(deg) {
+    return (deg * Math.PI) / 180;
+}
+
+function formatCoord([lng, lat]) {
+  return `{${degsToRads(lat)}, ${degsToRads(lng)}}`;
+}
+
+function formatGeoLoop(loop) {
+  return `{
+    .numVerts = ${loop.length},
+    .verts = (LatLng[]) {
+      ${loop.map(formatCoord).join(',\n')}
+    }
+  }`
+}
+
+function formatGeoPolygon(poly, {i, name, verts}) {
+  const holes = poly.slice(1);
+
+  return `
+  // ${i}. ${name} (${verts} verts)
+  {
+    .geoloop = ${formatGeoLoop(poly[0])},
+    .numHoles = ${holes.length}${holes.length ? `,
+    .holes = (GeoLoop[]) {
+      ${holes.map(formatGeoLoop).join(',\n')}
+    }` : ''}
+  }`
+}
+
+async function makeCountries(sourceUrl, targetPath) {
+  console.log(`Downloading from ${sourceUrl}...`)
+  const countriesJson = await getSource(sourceUrl);
+  const countries = JSON.parse(countriesJson);
+
+  console.log(`Download completed, found ${countries.features.length} countries`);
+
+  const polygons = [];
+  const names = [];
+
+  let i = 0;
+
+  for (const {geometry, properties: {ADMIN: name}} of countries.features) {
+    if (geometry.type === 'Polygon') {
+      polygons.push(geometry.coordinates);
+      names.push({i: String(i++), name, verts: geometry.coordinates[0].length});
+    } else if (geometry.type === 'MultiPolygon') {
+      for (const poly of geometry.coordinates) {
+        polygons.push(poly);
+        names.push({i: String(i++), name, verts: poly[0].length});
+      }
+    }
+  }
+
+  console.log(`Found ${polygons.length} polygons`);
+
+  // In order to only allocate memory once, we take the biggest size
+  // at res 7, pad it, and size up based on powers of 7. This number was
+  // empirically determined.
+  const MAX_SIZE_RES_7 = 17544338;
+
+  const out = `/*
+ * Copyright 2023 Uber Technologies, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * This file is generated by scripts/make_countries.js.
+ * Made with Natural Earth. Contains data from nvkelso/natural-earth-vector.
+ * https://github.com/nvkelso/natural-earth-vector/blob/ca96624a56bd078437bca8184e78163e5039ad19/LICENSE.md
+ */
+
+#include "benchmark.h"
+#include "h3api.h"
+#include "mathExtensions.h"
+#include "polyfill.h"
+
+const GeoPolygon COUNTRIES[${polygons.length}] = {${
+  polygons.map((poly, i) => formatGeoPolygon(poly, names[i])).join(',')
+}};
+
+BEGIN_BENCHMARKS();
+
+int MAX_RES = 5;
+// Max size of largest polygon at res 5, rounded up with padding
+int64_t numHexagons = 400000;
+H3Index *hexagons = calloc(numHexagons, sizeof(H3Index));
+
+for (int res = 0; res < MAX_RES + 1; res++) {
+
+  printf("Res %d", res);
+
+  BENCHMARK(polygonToCells_AllCountries1, 5, {
+    for (int index = 0; index < ${polygons.length}; index++) {
+      H3_EXPORT(polygonToCells)(&COUNTRIES[index], res, 0, hexagons);
+    }
+  });
+
+  BENCHMARK(polygonToCells_AllCountries2, 5, {
+    for (int index = 0; index < ${polygons.length}; index++) {
+      H3_EXPORT(polygonToCellsExperimental)(&COUNTRIES[index], res, 0, hexagons);
+    }
+  });
+
+}
+
+free(hexagons);
+
+END_BENCHMARKS();
+  `
+
+  fs.mkdirSync(path.dirname(targetPath), { recursive:true });
+  fs.writeFileSync(targetPath, out, 'utf-8');
+
+  console.log(`Wrote fixture to ${targetPath}`);
+}
+
+makeCountries(SOURCE_URL, TARGET);
+
+
+
diff --git a/website/docs/core-library/compilation-options.md b/website/docs/core-library/compilation-options.md
index b74223cb5..dcc55f12c 100644
--- a/website/docs/core-library/compilation-options.md
+++ b/website/docs/core-library/compilation-options.md
@@ -35,6 +35,12 @@ Whether to build the parts of the [test suite](./testing) that exercise the [H3_
 
 Whether to build the [benchmark suite](./testing#benchmarks).
 
+## BUILD_COUNTRY_BENCHMARKS
+
+Whether to build benchmarks that use [Natural Earth](https://github.com/nvkelso/natural-earth-vector/) geometries.
+
+The geometries will be downloaded at build time using Node.
+
 ## BUILD_FILTERS
 
 Whether to build the [H3 command line filter](./filters) executables.