ClickHouse/dbms/src/Functions/cutURLParameter.cpp
alexey-milovidov 5b1eaba276
Every function in its own file, part 6 ()
* Every function in its own file, part 6 [#CLICKHOUSE-2]

* Every function in its own file, part 6 [#CLICKHOUSE-2]

* Every function in its own file, part 6 [#CLICKHOUSE-2]
2018-11-26 02:24:26 +03:00

87 lines
2.9 KiB
C++

#include <Functions/FunctionFactory.h>
#include <Functions/FunctionsStringSearch.h>
#include <Functions/FunctionsURL.h>
#include <common/find_symbols.h>
namespace DB
{
struct CutURLParameterImpl
{
static void vector(const ColumnString::Chars & data,
const ColumnString::Offsets & offsets,
std::string pattern,
ColumnString::Chars & res_data, ColumnString::Offsets & res_offsets)
{
res_data.reserve(data.size());
res_offsets.resize(offsets.size());
pattern += '=';
const char * param_str = pattern.c_str();
size_t param_len = pattern.size();
size_t prev_offset = 0;
size_t res_offset = 0;
for (size_t i = 0; i < offsets.size(); ++i)
{
size_t cur_offset = offsets[i];
const char * url_begin = reinterpret_cast<const char *>(&data[prev_offset]);
const char * url_end = reinterpret_cast<const char *>(&data[cur_offset]) - 1;
const char * begin_pos = url_begin;
const char * end_pos = begin_pos;
do
{
const char * query_string_begin = find_first_symbols<'?', '#'>(url_begin, url_end);
if (query_string_begin + 1 >= url_end)
break;
const char * pos = static_cast<const char *>(memmem(query_string_begin + 1, url_end - query_string_begin - 1, param_str, param_len));
if (pos == nullptr)
break;
if (pos[-1] != '?' && pos[-1] != '#' && pos[-1] != '&')
{
pos = nullptr;
break;
}
begin_pos = pos;
end_pos = begin_pos + param_len;
/// Skip the value.
while (*end_pos && *end_pos != '&' && *end_pos != '#')
++end_pos;
/// Capture '&' before or after the parameter.
if (*end_pos == '&')
++end_pos;
else if (begin_pos[-1] == '&')
--begin_pos;
} while (false);
size_t cut_length = (url_end - url_begin) - (end_pos - begin_pos);
res_data.resize(res_offset + cut_length + 1);
memcpySmallAllowReadWriteOverflow15(&res_data[res_offset], url_begin, begin_pos - url_begin);
memcpySmallAllowReadWriteOverflow15(&res_data[res_offset] + (begin_pos - url_begin), end_pos, url_end - end_pos);
res_offset += cut_length + 1;
res_data[res_offset - 1] = 0;
res_offsets[i] = res_offset;
prev_offset = cur_offset;
}
}
};
struct NameCutURLParameter { static constexpr auto name = "cutURLParameter"; };
using FunctionCutURLParameter = FunctionsStringSearchToString<CutURLParameterImpl, NameCutURLParameter>;
void registerFunctionCutURLParameter(FunctionFactory & factory)
{
factory.registerFunction<FunctionCutURLParameter>();
}
}