ClickHouse/dbms/src/Functions/URLHierarchy.cpp
alexey-milovidov 5b1eaba276
Every function in its own file, part 6 (#3661)
* 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

109 lines
3.1 KiB
C++

#include <Functions/FunctionFactory.h>
#include <Functions/FunctionsStringArray.h>
#include <Functions/FunctionsURL.h>
namespace DB
{
class URLPathHierarchyImpl
{
private:
Pos begin;
Pos pos;
Pos end;
Pos start;
public:
static constexpr auto name = "URLPathHierarchy";
static String getName() { return name; }
static size_t getNumberOfArguments() { return 1; }
static void checkArguments(const DataTypes & arguments)
{
if (!isString(arguments[0]))
throw Exception("Illegal type " + arguments[0]->getName() + " of first argument of function " + getName() + ". Must be String.",
ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
}
void init(Block & /*block*/, const ColumnNumbers & /*arguments*/) {}
/// Returns the position of the argument that is the column of rows
size_t getStringsArgumentPosition()
{
return 0;
}
/// Called for each next string.
void set(Pos pos_, Pos end_)
{
begin = pos = pos_;
start = begin;
end = end_;
}
/// Get the next token, if any, or return false.
bool get(Pos & token_begin, Pos & token_end)
{
/// Code from URLParser.
if (pos == end)
return false;
if (pos == begin)
{
/// Let's parse everything that goes before the path
/// Assume that the protocol has already been changed to lowercase.
while (pos < end && ((*pos > 'a' && *pos < 'z') || (*pos > '0' && *pos < '9')))
++pos;
/** We will calculate the hierarchy only for URLs in which there is a protocol, and after it there are two slashes.
* (http, file - fit, mailto, magnet - do not fit), and after two slashes still at least something is there.
* For the rest, just return an empty array.
*/
if (pos == begin || pos == end || !(*pos++ == ':' && pos < end && *pos++ == '/' && pos < end && *pos++ == '/' && pos < end))
{
pos = end;
return false;
}
/// The domain for simplicity is everything that after the protocol and the two slashes, until the next slash or `?` or `#`
while (pos < end && !(*pos == '/' || *pos == '?' || *pos == '#'))
++pos;
start = pos;
if (pos != end)
++pos;
}
/// We go to the next `/` or `?` or `#`, skipping all those at the beginning.
while (pos < end && (*pos == '/' || *pos == '?' || *pos == '#'))
++pos;
if (pos == end)
return false;
while (pos < end && !(*pos == '/' || *pos == '?' || *pos == '#'))
++pos;
if (pos != end)
++pos;
token_begin = start;
token_end = pos;
return true;
}
};
struct NameURLPathHierarchy { static constexpr auto name = "URLPathHierarchy"; };
using FunctionURLPathHierarchy = FunctionTokens<URLPathHierarchyImpl>;
void registerFunctionURLPathHierarchy(FunctionFactory & factory)
{
factory.registerFunction<FunctionURLPathHierarchy>();
}
}