1#include <Functions/FunctionFactory.h>
2#include <Functions/FunctionsStringSearch.h>
3#include <common/find_symbols.h>
4
5namespace DB
6{
7
8struct CutURLParameterImpl
9{
10 static void vector(const ColumnString::Chars & data,
11 const ColumnString::Offsets & offsets,
12 std::string pattern,
13 ColumnString::Chars & res_data, ColumnString::Offsets & res_offsets)
14 {
15 res_data.reserve(data.size());
16 res_offsets.resize(offsets.size());
17
18 pattern += '=';
19 const char * param_str = pattern.c_str();
20 size_t param_len = pattern.size();
21
22 size_t prev_offset = 0;
23 size_t res_offset = 0;
24
25 for (size_t i = 0; i < offsets.size(); ++i)
26 {
27 size_t cur_offset = offsets[i];
28
29 const char * url_begin = reinterpret_cast<const char *>(&data[prev_offset]);
30 const char * url_end = reinterpret_cast<const char *>(&data[cur_offset]) - 1;
31 const char * begin_pos = url_begin;
32 const char * end_pos = begin_pos;
33
34 do
35 {
36 const char * query_string_begin = find_first_symbols<'?', '#'>(url_begin, url_end);
37 if (query_string_begin + 1 >= url_end)
38 break;
39
40 const char * pos = static_cast<const char *>(memmem(query_string_begin + 1, url_end - query_string_begin - 1, param_str, param_len));
41 if (pos == nullptr)
42 break;
43
44 if (pos[-1] != '?' && pos[-1] != '#' && pos[-1] != '&')
45 {
46 pos = nullptr;
47 break;
48 }
49
50 begin_pos = pos;
51 end_pos = begin_pos + param_len;
52
53 /// Skip the value.
54 while (*end_pos && *end_pos != '&' && *end_pos != '#')
55 ++end_pos;
56
57 /// Capture '&' before or after the parameter.
58 if (*end_pos == '&')
59 ++end_pos;
60 else if (begin_pos[-1] == '&')
61 --begin_pos;
62 } while (false);
63
64 size_t cut_length = (url_end - url_begin) - (end_pos - begin_pos);
65 res_data.resize(res_offset + cut_length + 1);
66 memcpySmallAllowReadWriteOverflow15(&res_data[res_offset], url_begin, begin_pos - url_begin);
67 memcpySmallAllowReadWriteOverflow15(&res_data[res_offset] + (begin_pos - url_begin), end_pos, url_end - end_pos);
68 res_offset += cut_length + 1;
69 res_data[res_offset - 1] = 0;
70 res_offsets[i] = res_offset;
71
72 prev_offset = cur_offset;
73 }
74 }
75};
76
77struct NameCutURLParameter { static constexpr auto name = "cutURLParameter"; };
78using FunctionCutURLParameter = FunctionsStringSearchToString<CutURLParameterImpl, NameCutURLParameter>;
79
80void registerFunctionCutURLParameter(FunctionFactory & factory)
81{
82 factory.registerFunction<FunctionCutURLParameter>();
83}
84
85}
86