[android] geojson conversion optimisation

2 files changed, 401 insertions, 0 deletions

diff --git a/platform/android/src/geojson/conversion/feature.hpp b/platform/android/src/geojson/conversion/feature.hpp
new file mode 100644
index 0000000000..86aa5fc03c
--- /dev/null
+++ b/platform/android/src/geojson/conversion/feature.hpp
@@ -0,0 +1,217 @@
+#pragma once
+
+#include "../../conversion/constant.hpp"
+#include "../../conversion/conversion.hpp"
+#include "geometry.hpp"
+#include "../../gson/json_object.hpp"
+
+#include <mbgl/util/feature.hpp>
+#include <mapbox/variant.hpp>
+#include <mapbox/geometry.hpp>
+
+#include <jni/jni.hpp>
+#include "../../jni/local_object.hpp"
+#include "../feature.hpp"
+
+#include <string>
+#include <array>
+#include <vector>
+#include <sstream>
+
+#include <mbgl/util/logging.hpp>
+
+namespace mbgl {
+namespace android {
+namespace conversion {
+
+/**
+ * Turn feature identifier into std::string
+ */
+class FeatureIdVisitor {
+public:
+
+    template<class T>
+    std::string operator()(const T& i) const {
+        return std::to_string(i);
+    }
+
+    std::string operator()(const std::string& i) const {
+        return i;
+    }
+
+    std::string operator()(const std::nullptr_t&) const {
+        return "";
+    }
+
+};
+
+/**
+ * Turn properties into Java GSON JsonObject's
+ */
+class PropertyValueEvaluator {
+public:
+    jni::JNIEnv& env;
+
+    /**
+     * null
+     */
+    jni::jobject* operator()(const mapbox::geometry::null_value_t &) const {
+        return (jni::jobject*) nullptr;
+    }
+
+    /**
+     * Boolean primitive
+     */
+    jni::jobject* operator()(const bool& value) const {
+        static jni::jclass* javaClass = jni::NewGlobalRef(env, &jni::FindClass(env, "com/google/gson/JsonPrimitive")).release();
+        static jni::jmethodID* constructor = &jni::GetMethodID(env, *javaClass, "<init>", "(Ljava/lang/Boolean;)V");
+
+        // Create JsonPrimitive
+        jni::LocalObject<jni::jobject> converted = jni::NewLocalObject(env, *convert<jni::jobject*, bool>(env, value));
+        jni::jobject* object = &jni::NewObject(env, *javaClass, *constructor, *converted);
+
+        return object;
+    }
+
+    /**
+     * String primitive
+     */
+    jni::jobject* operator()(const std::string& value) const {
+        static jni::jclass* javaClass = jni::NewGlobalRef(env, &jni::FindClass(env, "com/google/gson/JsonPrimitive")).release();
+        static jni::jmethodID* constructor = &jni::GetMethodID(env, *javaClass, "<init>", "(Ljava/lang/String;)V");
+
+        // Create JsonPrimitive
+        jni::LocalObject<jni::jobject> converted = jni::NewLocalObject(env, *convert<jni::jobject*, std::string>(env, value));
+        jni::jobject* object = &jni::NewObject(env, *javaClass, *constructor, converted.get());
+
+        return object;
+    }
+
+    /**
+     * Number primitives
+     */
+    template <class Number>
+    jni::jobject* operator()(const Number& value) const {
+        static jni::jclass* javaClass = jni::NewGlobalRef(env, &jni::FindClass(env, "com/google/gson/JsonPrimitive")).release();
+        static jni::jmethodID* constructor = &jni::GetMethodID(env, *javaClass, "<init>", "(Ljava/lang/Number;)V");
+
+        // Create JsonPrimitive
+        jni::LocalObject<jni::jobject> converted = jni::NewLocalObject(env, *convert<jni::jobject*, Number>(env, value));
+        jni::jobject* object = &jni::NewObject(env, *javaClass, *constructor, converted.get());
+
+        return object;
+    }
+
+
+    /**
+     * Json Array
+     */
+    jni::jobject* operator()(const std::vector<mbgl::Value> &values) const {
+        static jni::jclass* javaClass = jni::NewGlobalRef(env, &jni::FindClass(env, "com/google/gson/JsonArray")).release();
+        static jni::jmethodID* constructor = &jni::GetMethodID(env, *javaClass, "<init>", "()V");;
+        static jni::jmethodID* add = &jni::GetMethodID(env, *javaClass, "add", "(Lcom/google/gson/JsonElement;)V");
+
+        // Create json array
+        jni::jobject* jarray = &jni::NewObject(env, *javaClass, *constructor);
+
+        // Add values
+        for (const auto &v : values) {
+            jni::LocalObject<jni::jobject> converted = jni::NewLocalObject(env, mbgl::Value::visit(v, *this));
+            jni::CallMethod<void>(env, jarray, *add, converted.get());
+        }
+
+        return jarray;
+    }
+
+    /**
+     * Json Object
+     */
+    jni::jobject* operator()(const std::unordered_map<std::string, mbgl::Value> &value) const {
+        // TODO: clean up duplication here
+        static jni::jclass* javaClass = jni::NewGlobalRef(env, &jni::FindClass(env, "com/google/gson/JsonObject")).release();
+        static jni::jmethodID* constructor = &jni::GetMethodID(env, *javaClass, "<init>", "()V");;
+        static jni::jmethodID* add = &jni::GetMethodID(env, *javaClass, "add", "(Ljava/lang/String;Lcom/google/gson/JsonElement;)V");
+
+        // Create json object
+        jni::jobject* jsonObject = &jni::NewObject(env, *javaClass, *constructor);
+
+        // Add items
+        for (auto &item : value) {
+            jni::LocalObject<jni::jobject> converted = jni::NewLocalObject(env, mbgl::Value::visit(item.second, *this));
+            jni::LocalObject<jni::jobject> key = jni::NewLocalObject(env, *convert<jni::jobject*, std::string>(env, item.first));
+            jni::CallMethod<void>(env, jsonObject, *add, key.get(), converted.get());
+        }
+
+        return jsonObject;
+    }
+};
+
+template <>
+struct Converter<jni::jobject*, std::unordered_map<std::string, mbgl::Value>> {
+    Result<jni::jobject*> operator()(jni::JNIEnv& env, const std::unordered_map<std::string, mbgl::Value>& value) const {
+        static jni::jclass* javaClass = jni::NewGlobalRef(env, &jni::FindClass(env, "com/google/gson/JsonObject")).release();
+        static jni::jmethodID* constructor = &jni::GetMethodID(env, *javaClass, "<init>", "()V");;
+        static jni::jmethodID* add = &jni::GetMethodID(env, *javaClass, "add", "(Ljava/lang/String;Lcom/google/gson/JsonElement;)V");
+
+        // Create json object
+        jni::jobject* jsonObject = &jni::NewObject(env, *javaClass, *constructor);
+
+        // Add items
+        PropertyValueEvaluator evaluator {env};
+        for (auto &item : value) {
+            jni::LocalObject<jni::jobject> converted = jni::NewLocalObject(env, mbgl::Value::visit(item.second, evaluator));
+            jni::LocalObject<jni::jobject> key = jni::NewLocalObject(env, *convert<jni::jobject*, std::string>(env, item.first));
+            jni::CallMethod<void>(env, jsonObject, *add, key.get(), converted.get());
+        }
+
+        return {jsonObject};
+    }
+};
+
+
+template <>
+struct Converter<jni::Object<android::geojson::Feature>, mbgl::Feature> {
+    Result<jni::Object<android::geojson::Feature>> operator()(jni::JNIEnv& env, const mbgl::Feature& value) const {
+
+        // Convert Id
+        FeatureIdVisitor idEvaluator;
+        std::string id = (value.id) ? mapbox::geometry::identifier::visit(value.id.value(), idEvaluator) : "";
+        auto jid = jni::Make<jni::String>(env, id);
+
+        // Convert properties
+        auto properties = jni::Object<gson::JsonObject>(*convert<jni::jobject*>(env, value.properties));
+
+        // Convert geometry
+        auto geometry = jni::Object<android::geojson::Geometry>(*convert<jni::jobject*>(env, value.geometry));
+
+        // Create feature
+        auto feature = android::geojson::Feature::fromGeometry(env, geometry, properties, jid);
+
+        //Cleanup
+        jni::DeleteLocalRef(env, jid);
+        jni::DeleteLocalRef(env, geometry);
+        jni::DeleteLocalRef(env, properties);
+
+        return feature;
+    }
+};
+
+template <>
+struct Converter<jni::Array<jni::Object<android::geojson::Feature>>, std::vector<mbgl::Feature>> {
+    Result<jni::Array<jni::Object<android::geojson::Feature>>> operator()(jni::JNIEnv& env, const std::vector<mbgl::Feature>& value) const {
+        using namespace mbgl::android::geojson;
+        auto features = jni::Array<jni::Object<Feature>>::New(env, value.size(), Feature::javaClass);
+
+        for(size_t i = 0; i < value.size(); i = i + 1) {
+            auto converted = *convert<jni::Object<android::geojson::Feature>, mbgl::Feature>(env, value.at(i));
+            features.Set(env, i, converted);
+            jni::DeleteLocalRef(env, converted);
+        }
+
+        return {features};
+    }
+};
+
+} // namespace conversion
+} // namespace android
+} // namespace mbgl
diff --git a/platform/android/src/geojson/conversion/geometry.hpp b/platform/android/src/geojson/conversion/geometry.hpp
new file mode 100644
index 0000000000..2ca63e2c11
--- /dev/null
+++ b/platform/android/src/geojson/conversion/geometry.hpp
@@ -0,0 +1,184 @@
+#pragma once
+
+#include "../../conversion/constant.hpp"
+#include "../../conversion/collection.hpp"
+
+#include <mapbox/geometry.hpp>
+#include <jni/jni.hpp>
+#include "../../jni/local_object.hpp"
+
+namespace mbgl {
+namespace android {
+namespace conversion {
+
+/**
+ * Turn mapbox::geometry type into Java GeoJson Geometries
+ */
+template <typename T>
+class GeometryEvaluator {
+public:
+
+    jni::JNIEnv& env;
+
+    /**
+     * Point (double[])
+     */
+    jni::jobject* operator()(const mapbox::geometry::point<T> &geometry) const {
+       static jni::jclass* javaClass = jni::NewGlobalRef(env, &jni::FindClass(env, "com/mapbox/services/commons/geojson/Point")).release();
+       static jni::jmethodID* fromCoordinates = &jni::GetStaticMethodID(env, *javaClass, "fromCoordinates", "([D)Lcom/mapbox/services/commons/geojson/Point;");
+
+       // Create Point
+       jni::LocalObject<jni::jarray<jni::jdouble>> position = jni::NewLocalObject(env, toGeoJsonPosition(env, geometry.x, geometry.y));
+       return reinterpret_cast<jni::jobject*>(jni::CallStaticMethod<jni::jobject*>(env, *javaClass, *fromCoordinates, position.get()));
+    }
+
+    /**
+     * LineString (double[][])
+     */
+    jni::jobject* operator()(const mapbox::geometry::line_string<T> &geometry) const {
+        static jni::jclass* javaClass = jni::NewGlobalRef(env, &jni::FindClass(env, "com/mapbox/services/commons/geojson/LineString")).release();
+        static jni::jmethodID* fromCoordinates = &jni::GetStaticMethodID(env, *javaClass, "fromCoordinates", "([[D)Lcom/mapbox/services/commons/geojson/LineString;");
+
+        // Create
+        jni::LocalObject<jni::jarray<jni::jobject>> coordinates = jni::NewLocalObject(env, toGeoJsonCoordinates(env, geometry));
+        return reinterpret_cast<jni::jobject*>(jni::CallStaticMethod<jni::jobject*>(env, *javaClass, *fromCoordinates, coordinates.get()));
+    }
+
+    /**
+     * MultiPoint (double[][])
+     */
+    jni::jobject* operator()(const mapbox::geometry::multi_point<T> &geometry) const {
+        static jni::jclass* javaClass = jni::NewGlobalRef(env, &jni::FindClass(env, "com/mapbox/services/commons/geojson/MultiPoint")).release();
+        static jni::jmethodID* fromCoordinates = &jni::GetStaticMethodID(env, *javaClass, "fromCoordinates", "([[D)Lcom/mapbox/services/commons/geojson/MultiPoint;");
+
+        // Create
+        jni::LocalObject<jni::jarray<jni::jobject>> coordinates = jni::NewLocalObject(env, toGeoJsonCoordinates(env, geometry));
+        return reinterpret_cast<jni::jobject*>(jni::CallStaticMethod<jni::jobject*>(env, *javaClass, *fromCoordinates, coordinates.get()));
+    }
+
+    /**
+     * Polygon (double[][][])
+     */
+    jni::jobject* operator()(const mapbox::geometry::polygon<T> &geometry) const {
+        static jni::jclass* javaClass = jni::NewGlobalRef(env, &jni::FindClass(env, "com/mapbox/services/commons/geojson/Polygon")).release();
+        static jni::jmethodID* fromCoordinates = &jni::GetStaticMethodID(env, *javaClass, "fromCoordinates", "([[[D)Lcom/mapbox/services/commons/geojson/Polygon;");
+
+        // Create
+        jni::LocalObject<jni::jarray<jni::jobject>> shape = jni::NewLocalObject(env, toShape<>(env, geometry));
+        return reinterpret_cast<jni::jobject*>(jni::CallStaticMethod<jni::jobject*>(env, *javaClass, *fromCoordinates, shape.get()));
+    }
+
+    /**
+     * MultiLineString (double[][][])
+     */
+    jni::jobject*  operator()(const mapbox::geometry::multi_line_string<T> &geometry) const {
+        static jni::jclass* javaClass = jni::NewGlobalRef(env, &jni::FindClass(env, "com/mapbox/services/commons/geojson/MultiLineString")).release();
+        static jni::jmethodID* fromCoordinates = &jni::GetStaticMethodID(env, *javaClass, "fromCoordinates", "([[[D)Lcom/mapbox/services/commons/geojson/MultiLineString;");
+
+        // Create
+        jni::LocalObject<jni::jarray<jni::jobject>> shape = jni::NewLocalObject(env, toShape<>(env, geometry));
+        return reinterpret_cast<jni::jobject*>(jni::CallStaticMethod<jni::jobject*>(env, *javaClass, *fromCoordinates, shape.get()));
+    }
+
+    /**
+     * MultiPolygon (double[][][][]) -> [[[D + Object array ==  [[[[D
+     */
+    jni::jobject*  operator()(const mapbox::geometry::multi_polygon<T> &geometry) const {
+        static jni::jclass* listClass = jni::NewGlobalRef(env, &jni::FindClass(env, "[[[D")).release();
+        jni::LocalObject<jni::jarray<jni::jobject>> jarray = jni::NewLocalObject(env, &jni::NewObjectArray(env, geometry.size(), *listClass));
+
+        for(size_t i = 0; i < geometry.size(); i = i + 1) {
+            jni::LocalObject<jni::jarray<jni::jobject>> shape = jni::NewLocalObject(env, toShape<>(env, geometry.at(i)));
+            jni::SetObjectArrayElement(env, *jarray, i, shape.get());
+        }
+
+        // Create the MultiPolygon
+        static jni::jclass* javaClass = jni::NewGlobalRef(env, &jni::FindClass(env, "com/mapbox/services/commons/geojson/MultiPolygon")).release();
+        static jni::jmethodID* fromGeometries = &jni::GetStaticMethodID(env, *javaClass, "fromCoordinates", "([[[[D)Lcom/mapbox/services/commons/geojson/MultiPolygon;");
+        return reinterpret_cast<jni::jobject*>(jni::CallStaticMethod<jni::jobject*>(env, *javaClass, *fromGeometries, jarray.get()));
+    }
+
+    /**
+     * GeometryCollection
+     */
+    jni::jobject*  operator()(const mapbox::geometry::geometry_collection<T> &collection) const {
+        static jni::jclass* geometryClass = jni::NewGlobalRef(env, &jni::FindClass(env, "com/mapbox/services/commons/geojson/Geometry")).release();
+        jni::LocalObject<jni::jarray<jni::jobject>> jarray = jni::NewLocalObject(env, &jni::NewObjectArray(env, collection.size(), *geometryClass));
+
+        for(size_t i = 0; i < collection.size(); i = i + 1) {
+            auto& geometry = collection.at(i);
+            jni::LocalObject<jni::jobject> converted = jni::NewLocalObject(env, mapbox::geometry::geometry<T>::visit(geometry, *this));
+            jni::SetObjectArrayElement(env, *jarray, i, converted.get());
+        }
+
+        // Turn into array list and create the GeometryCollection
+        static jni::jclass* javaClass = jni::NewGlobalRef(env, &jni::FindClass(env, "com/mapbox/services/commons/geojson/GeometryCollection")).release();
+        static jni::jmethodID* fromGeometries = &jni::GetStaticMethodID(env, *javaClass, "fromGeometries", "(Ljava/util/List;)Lcom/mapbox/services/commons/geojson/GeometryCollection;");
+
+        jni::LocalObject<jni::jobject> list = jni::NewLocalObject(env, toArrayList<>(env, *jarray));
+        return reinterpret_cast<jni::jobject*>(jni::CallStaticMethod<jni::jobject*>(env, *javaClass, *fromGeometries, list.get()));
+    }
+
+private:
+
+    /**
+     * x, y -> jarray<jdouble> ([x,y])
+     */
+    static jni::jarray<jni::jdouble>* toGeoJsonPosition(JNIEnv& env, double x, double y) {
+        jni::jarray<jni::jdouble>& jarray = jni::NewArray<jni::jdouble>(env, 2);
+        jni::jdouble array[] = {x, y};
+        jni::SetArrayRegion(env, jarray, 0, 2, array);
+        return &jarray;
+    }
+
+    /**
+     * vector<point<T>> -> jarray<jobject> (double[][]) -> [D + Object array ==  [[D
+     */
+    static jni::jarray<jni::jobject>* toGeoJsonCoordinates(JNIEnv& env, std::vector<mapbox::geometry::point<T>> points) {
+        static jni::jclass* javaClass = jni::NewGlobalRef(env, &jni::FindClass(env, "[D")).release();
+        jni::jarray<jni::jobject>& jarray = jni::NewObjectArray(env, points.size(), *javaClass);
+
+        for(size_t i = 0; i < points.size(); i = i + 1) {
+            mapbox::geometry::point<T> point = points.at(i);
+            jni::LocalObject<jni::jarray<jni::jdouble>> position = jni::NewLocalObject(env, toGeoJsonPosition(env, point.x, point.y));
+            jni::SetObjectArrayElement(env, jarray, i, position.get());
+        }
+
+        return &jarray;
+    }
+
+    /**
+     * polygon<T>
+     * multi_line_string<T>
+     *       -> jarray<jobject> (double[][][]) -> [[D + Object array ==  [[[D
+     */
+    template <class SHAPE>
+    static jni::jarray<jni::jobject>* toShape(JNIEnv& env, SHAPE value) {
+        static jni::jclass* javaClass = jni::NewGlobalRef(env, &jni::FindClass(env, "[[D")).release();
+        jni::jarray<jni::jobject>& jarray = jni::NewObjectArray(env, value.size(), *javaClass);
+
+        for(size_t i = 0; i < value.size(); i = i + 1) {
+            jni::LocalObject<jni::jarray<jni::jobject>> coordinates = jni::NewLocalObject(env, toGeoJsonCoordinates(env, value.at(i)));
+            jni::SetObjectArrayElement(env, jarray, i, coordinates.get());
+        }
+
+        return &jarray;
+    }
+};
+
+/**
+ * mapbox::geometry::geometry<T> -> Java GeoJson Geometry<>
+ */
+template <class T>
+struct Converter<jni::jobject*, mapbox::geometry::geometry<T>> {
+    Result<jni::jobject*> operator()(jni::JNIEnv& env, const mapbox::geometry::geometry<T>& value) const {
+       GeometryEvaluator<double> evaluator { env } ;
+       jni::jobject* converted = mapbox::geometry::geometry<double>::visit(value, evaluator);
+       return {converted};
+    }
+};
+
+
+}
+}
+}