ClickHouse/src/Functions/formatQuery.cpp
2023-11-05 20:13:49 +00:00

158 lines
5.6 KiB
C++

#include <Columns/ColumnString.h>
#include <Functions/FunctionFactory.h>
#include <Functions/FunctionHelpers.h>
#include <IO/WriteBufferFromString.h>
#include <Interpreters/Context.h>
#include <Parsers/ParserQuery.h>
#include <Parsers/formatAST.h>
#include <Parsers/parseQuery.h>
namespace DB
{
namespace ErrorCodes
{
extern const int ILLEGAL_COLUMN;
}
enum class OutputFormatting
{
SingleLine,
MultiLine
};
template <OutputFormatting output_formatting, typename Name>
class FunctionFormatQuery : public IFunction
{
public:
static constexpr auto name = Name::name;
static FunctionPtr create(ContextPtr context)
{
const auto & settings = context->getSettings();
return std::make_shared<FunctionFormatQuery>(settings.max_query_size, settings.max_parser_depth);
}
FunctionFormatQuery(size_t max_query_size_, size_t max_parser_depth_)
: max_query_size(max_query_size_)
, max_parser_depth(max_parser_depth_)
{
}
String getName() const override { return name; }
size_t getNumberOfArguments() const override { return 1; }
bool isSuitableForShortCircuitArgumentsExecution(const DataTypesWithConstInfo & /*arguments*/) const override { return true; }
bool useDefaultImplementationForConstants() const override { return true; }
DataTypePtr getReturnTypeImpl(const ColumnsWithTypeAndName & arguments) const override
{
FunctionArgumentDescriptors args{
{"query", &isString<IDataType>, nullptr, "String"}
};
validateFunctionArgumentTypes(*this, arguments, args);
return arguments[0].type;
}
ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr &, size_t /*input_rows_count*/) const override
{
const ColumnPtr col_query = arguments[0].column;
if (const ColumnString * col_query_string = checkAndGetColumn<ColumnString>(col_query.get()))
{
auto col_res = ColumnString::create();
formatVector(col_query_string->getChars(), col_query_string->getOffsets(), col_res->getChars(), col_res->getOffsets());
return col_res;
}
else
throw Exception(ErrorCodes::ILLEGAL_COLUMN, "Illegal column {} of argument of function {}", col_query->getName(), getName());
}
private:
void formatVector(
const ColumnString::Chars & data,
const ColumnString::Offsets & offsets,
ColumnString::Chars & res_data,
ColumnString::Offsets & res_offsets) const
{
const size_t size = offsets.size();
res_offsets.resize(size);
res_data.resize(data.size());
size_t prev_offset = 0;
size_t res_data_size = 0;
for (size_t i = 0; i < size; ++i)
{
const char * begin = reinterpret_cast<const char *>(&data[prev_offset]);
const char * end = begin + offsets[i] - prev_offset - 1;
ParserQuery parser(end);
auto ast = parseQuery(parser, begin, end, /*query_description*/ {}, max_query_size, max_parser_depth);
WriteBufferFromOwnString buf;
formatAST(*ast, buf, /*hilite*/ false, /*single_line*/ output_formatting == OutputFormatting::SingleLine);
auto formatted = buf.stringView();
const size_t res_data_new_size = res_data_size + formatted.size() + 1;
if (res_data_new_size > res_data.size())
res_data.resize(2 * res_data_new_size);
memcpy(&res_data[res_data_size], formatted.begin(), formatted.size());
res_data_size += formatted.size();
res_data[res_data_size] = '\0';
res_data_size += 1;
res_offsets[i] = res_data_size;
prev_offset = offsets[i];
}
res_data.resize(res_data_size);
}
const size_t max_query_size;
const size_t max_parser_depth;
};
struct NameFormatQuery
{
static constexpr auto name = "formatQuery";
};
struct NameFormatQuerySingleLine
{
static constexpr auto name = "formatQuerySingleLine";
};
REGISTER_FUNCTION(formatQuery)
{
factory.registerFunction<FunctionFormatQuery<OutputFormatting::MultiLine, NameFormatQuery>>(FunctionDocumentation{
.description = "Returns a formatted, possibly multi-line, version of the given SQL query.\n[example:multiline]",
.syntax = "formatQuery(query)",
.arguments = {{"query", "The SQL query to be formatted. [String](../../sql-reference/data-types/string.md)"}},
.returned_value = "The formatted query. [String](../../sql-reference/data-types/string.md).",
.examples{
{"multiline",
"SELECT formatQuery('select a, b FRom tab WHERE a > 3 and b < 3');",
"SELECT\n"
" a,\n"
" b\n"
"FROM tab\n"
"WHERE (a > 3) AND (b < 3)"}},
.categories{"Other"}});
}
REGISTER_FUNCTION(formatQuerySingleLine)
{
factory.registerFunction<FunctionFormatQuery<OutputFormatting::SingleLine, NameFormatQuerySingleLine>>(FunctionDocumentation{
.description = "Like formatQuery() but the returned formatted string contains no line breaks.\n[example:multiline]",
.syntax = "formatQuerySingleLine(query)",
.arguments = {{"query", "The SQL query to be formatted. [String](../../sql-reference/data-types/string.md)"}},
.returned_value = "The formatted query. [String](../../sql-reference/data-types/string.md).",
.examples{
{"multiline",
"SELECT formatQuerySingleLine('select a, b FRom tab WHERE a > 3 and b < 3');",
"SELECT a, b FROM tab WHERE (a > 3) AND (b < 3)"}},
.categories{"Other"}});
}
}