add h3Line func

src/Functions/h3Line.cpp

@@ -0,0 +1,131 @@
+#include "config_functions.h"
+
+#if USE_H3
+
+#include <Columns/ColumnArray.h>
+#include <Columns/ColumnsNumber.h>
+#include <DataTypes/DataTypeArray.h>
+#include <DataTypes/DataTypesNumber.h>
+#include <Functions/FunctionFactory.h>
+#include <Functions/IFunction.h>
+#include <Common/typeid_cast.h>
+#include <IO/WriteHelpers.h>
+#include <base/range.h>
+
+#include <constants.h>
+#include <h3api.h>
+
+
+namespace DB
+{
+namespace ErrorCodes
+{
+    extern const int ILLEGAL_TYPE_OF_ARGUMENT;
+    extern const int ILLEGAL_COLUMN;
+}
+
+namespace
+{
+
+class FunctionH3Line : public IFunction
+{
+public:
+    static constexpr auto name = "h3Line";
+
+    static FunctionPtr create(ContextPtr) { return std::make_shared<FunctionH3Line>(); }
+
+    std::string getName() const override { return name; }
+
+    size_t getNumberOfArguments() const override { return 2; }
+    bool useDefaultImplementationForConstants() const override { return true; }
+    bool isSuitableForShortCircuitArgumentsExecution(const DataTypesWithConstInfo & /*arguments*/) const override { return true; }
+
+    DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
+    {
+        const auto * arg = arguments[0].get();
+        if (!WhichDataType(arg).isUInt64())
+            throw Exception(
+                ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT,
+                "Illegal type {} of argument {} of function {}. Must be UInt64",
+                arg->getName(), 1, getName());
+
+        arg = arguments[1].get();
+        if (!WhichDataType(arg).isUInt64())
+            throw Exception(
+                ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT,
+                "Illegal type {} of argument {} of function {}. Must be UInt64",
+                arg->getName(), 2, getName());
+
+        return std::make_shared<DataTypeArray>(std::make_shared<DataTypeUInt64>());
+    }
+
+    ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr &, size_t input_rows_count) const override
+    {
+        auto non_const_arguments = arguments;
+        for (auto & argument : non_const_arguments)
+            argument.column = argument.column->convertToFullColumnIfConst();
+
+        const auto * col_start_index = checkAndGetColumn<ColumnUInt64>(non_const_arguments[0].column.get());
+        if (!col_start_index)
+            throw Exception(
+                ErrorCodes::ILLEGAL_COLUMN,
+                "Illegal type {} of argument {} of function {}. Must be UInt64.",
+                arguments[0].type->getName(),
+                1,
+                getName());
+
+        const auto & data_start_index = col_start_index->getData();
+
+        const auto * col_end_index = checkAndGetColumn<ColumnUInt64>(non_const_arguments[1].column.get());
+        if (!col_end_index)
+            throw Exception(
+                ErrorCodes::ILLEGAL_COLUMN,
+                "Illegal type {} of argument {} of function {}. Must be UInt64.",
+                arguments[1].type->getName(),
+                2,
+                getName());
+
+        const auto & data_end_index = col_end_index->getData();
+
+
+        auto dst = ColumnArray::create(ColumnUInt64::create());
+        auto & dst_data = dst->getData();
+        auto & dst_offsets = dst->getOffsets();
+        dst_offsets.resize(input_rows_count);
+        auto current_offset = 0;
+
+        for (size_t row = 0; row < input_rows_count; ++row)
+        {
+            const UInt64 start = data_start_index[row];
+            const UInt64 end = data_end_index[row];
+
+            // calculate the max number of indexes possible
+            // to allocate the result vector size.
+            auto size = gridPathCellsSize(start, end);
+            std::vector<H3Index> results;
+            results.resize(size);
+            gridPathCells(start, end, results.data());
+
+            dst_data.reserve(dst_data.size() + size);
+            for (auto hindex : results)
+            {
+                ++current_offset;
+                dst_data.insert(hindex);
+            }
+            dst_offsets[row] = current_offset;
+        }
+
+        return dst;
+    }
+};
+
+}
+
+void registerFunctionH3Line(FunctionFactory & factory)
+{
+    factory.registerFunction<FunctionH3Line>();
+}
+
+}
+
+#endif

src/Functions/registerFunctionsGeo.cpp

@@ -57,6 +57,7 @@ void registerFunctionH3PointDistKm(FunctionFactory &);
 void registerFunctionH3PointDistRads(FunctionFactory &);
 void registerFunctionH3GetRes0Indexes(FunctionFactory &);
 void registerFunctionH3GetPentagonIndexes(FunctionFactory &);
+void registerFunctionH3Line(FunctionFactory &);
 
 #endif
 
@@ -128,6 +129,7 @@ void registerFunctionsGeo(FunctionFactory & factory)
     registerFunctionH3PointDistRads(factory);
     registerFunctionH3GetRes0Indexes(factory);
     registerFunctionH3GetPentagonIndexes(factory);
+    registerFunctionH3Line(factory);
 #endif
 
 #if USE_S2_GEOMETRY