aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/clickhouse/src/Functions/h3HexRing.cpp
blob: bdca7ca2fb7b0e90103b4c81a7d299ab56d220cd (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
#include "clickhouse_config.h"

#if USE_H3

#include <vector>
#include <Columns/ColumnArray.h>
#include <Columns/ColumnsNumber.h>
#include <DataTypes/DataTypeArray.h>
#include <DataTypes/DataTypesNumber.h>
#include <DataTypes/IDataType.h>
#include <Functions/FunctionFactory.h>
#include <Functions/IFunction.h>
#include <Common/typeid_cast.h>

#include <h3api.h>


namespace DB
{

namespace ErrorCodes
{
    extern const int ILLEGAL_TYPE_OF_ARGUMENT;
    extern const int PARAMETER_OUT_OF_BOUND;
    extern const int ILLEGAL_COLUMN;
    extern const int INCORRECT_DATA;
}

namespace
{

class FunctionH3HexRing : public IFunction
{
public:
    static constexpr auto name = "h3HexRing";

    static FunctionPtr create(ContextPtr) { return std::make_shared<FunctionH3HexRing>(); }

    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).isUInt16())
            throw Exception(
                ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT,
                "Illegal type {} of argument {} of function {}. Must be UInt16",
                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_hindex = checkAndGetColumn<ColumnUInt64>(non_const_arguments[0].column.get());
        if (!col_hindex)
            throw Exception(
                ErrorCodes::ILLEGAL_COLUMN,
                "Illegal type {} of argument {} of function {}. Must be UInt64.",
                arguments[0].type->getName(),
                1,
                getName());

        const auto & data_hindex = col_hindex->getData();

        /// ColumnUInt16 is sufficient as the max value of 2nd arg is checked (arg > 0 < 10000) in implementation below
        const auto * col_k = checkAndGetColumn<ColumnUInt16>(non_const_arguments[1].column.get());
        if (!col_k)
            throw Exception(
                ErrorCodes::ILLEGAL_COLUMN,
                "Illegal type {} of argument {} of function {}. Must be UInt16.",
                arguments[1].type->getName(),
                2,
                getName());

        const auto & data_k = col_k->getData();

        auto dst = ColumnArray::create(ColumnUInt64::create());
        auto & dst_data = typeid_cast<ColumnUInt64 &>(dst->getData());
        auto & dst_offsets = dst->getOffsets();
        dst_offsets.resize(input_rows_count);

        /// First calculate array sizes for all rows and save them in Offsets
        UInt64 current_offset = 0;
        for (size_t row = 0; row < input_rows_count; ++row)
        {
            const int k = data_k[row];

            /// The result size is 6*k. We should not allow to generate too large arrays nevertheless.
            constexpr auto max_k = 10000;
            if (k > max_k)
                throw Exception(ErrorCodes::PARAMETER_OUT_OF_BOUND, "Too large 'k' argument for {} function, maximum {}", getName(), max_k);
            /// Check is already made while fetching the argument for k (to determine if it's an unsigned integer). Nevertheless, it's checked again here.
            if (k < 0)
                throw Exception(ErrorCodes::PARAMETER_OUT_OF_BOUND, "Argument 'k' for {} function must be non negative", getName());

            const auto vec_size = (k == 0 ? 1 : 6 * k);  /// Required size according to comments in gridRingUnsafe() source code

            current_offset += vec_size;
            dst_offsets[row] = current_offset;
        }

        /// Allocate based on total size of arrays for all rows
        dst_data.getData().resize(current_offset);

        /// Fill the array for each row with known size
        auto* ptr = dst_data.getData().data();
        current_offset = 0;
        for (size_t row = 0; row < input_rows_count; ++row)
        {
            const H3Index origin_hindex = data_hindex[row];
            const int k = data_k[row];

            H3Error err = gridRingUnsafe(origin_hindex, k, ptr + current_offset);

            if (err)
                throw Exception(ErrorCodes::INCORRECT_DATA, "Incorrect arguments h3Index: {}, k: {}, error: {}", origin_hindex, k, err);

            const auto size = dst_offsets[row] - current_offset;
            current_offset += size;
        }

        return dst;
    }
};

}

REGISTER_FUNCTION(H3HexRing)
{
    factory.registerFunction<FunctionH3HexRing>();
}

}

#endif