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#pragma once
#include "clickhouse_config.h"
#if USE_SIMDJSON
# include <base/types.h>
# include <Common/Exception.h>
# include <base/defines.h>
# error #include <simdjson.h>
# include "ElementTypes.h"
namespace DB
{
namespace ErrorCodes
{
extern const int CANNOT_ALLOCATE_MEMORY;
}
/// This class can be used as an argument for the template class FunctionJSON.
/// It provides ability to parse JSONs using simdjson library.
struct SimdJSONParser
{
class Array;
class Object;
/// References an element in a JSON document, representing a JSON null, boolean, string, number,
/// array or object.
class Element
{
public:
ALWAYS_INLINE Element() {} /// NOLINT
ALWAYS_INLINE Element(const simdjson::dom::element & element_) : element(element_) {} /// NOLINT
ALWAYS_INLINE ElementType type() const
{
switch (element.type())
{
case simdjson::dom::element_type::INT64: return ElementType::INT64;
case simdjson::dom::element_type::UINT64: return ElementType::UINT64;
case simdjson::dom::element_type::DOUBLE: return ElementType::DOUBLE;
case simdjson::dom::element_type::STRING: return ElementType::STRING;
case simdjson::dom::element_type::ARRAY: return ElementType::ARRAY;
case simdjson::dom::element_type::OBJECT: return ElementType::OBJECT;
case simdjson::dom::element_type::BOOL: return ElementType::BOOL;
case simdjson::dom::element_type::NULL_VALUE: return ElementType::NULL_VALUE;
}
}
ALWAYS_INLINE bool isInt64() const { return element.type() == simdjson::dom::element_type::INT64; }
ALWAYS_INLINE bool isUInt64() const { return element.type() == simdjson::dom::element_type::UINT64; }
ALWAYS_INLINE bool isDouble() const { return element.type() == simdjson::dom::element_type::DOUBLE; }
ALWAYS_INLINE bool isString() const { return element.type() == simdjson::dom::element_type::STRING; }
ALWAYS_INLINE bool isArray() const { return element.type() == simdjson::dom::element_type::ARRAY; }
ALWAYS_INLINE bool isObject() const { return element.type() == simdjson::dom::element_type::OBJECT; }
ALWAYS_INLINE bool isBool() const { return element.type() == simdjson::dom::element_type::BOOL; }
ALWAYS_INLINE bool isNull() const { return element.type() == simdjson::dom::element_type::NULL_VALUE; }
ALWAYS_INLINE Int64 getInt64() const { return element.get_int64().value_unsafe(); }
ALWAYS_INLINE UInt64 getUInt64() const { return element.get_uint64().value_unsafe(); }
ALWAYS_INLINE double getDouble() const { return element.get_double().value_unsafe(); }
ALWAYS_INLINE bool getBool() const { return element.get_bool().value_unsafe(); }
ALWAYS_INLINE std::string_view getString() const { return element.get_string().value_unsafe(); }
ALWAYS_INLINE Array getArray() const;
ALWAYS_INLINE Object getObject() const;
ALWAYS_INLINE simdjson::dom::element getElement() const { return element; }
private:
simdjson::dom::element element;
};
/// References an array in a JSON document.
class Array
{
public:
class Iterator
{
public:
ALWAYS_INLINE Iterator(const simdjson::dom::array::iterator & it_) : it(it_) {} /// NOLINT
ALWAYS_INLINE Element operator*() const { return *it; }
ALWAYS_INLINE Iterator & operator++() { ++it; return *this; }
ALWAYS_INLINE Iterator operator++(int) { auto res = *this; ++it; return res; } /// NOLINT
ALWAYS_INLINE friend bool operator!=(const Iterator & left, const Iterator & right) { return left.it != right.it; }
ALWAYS_INLINE friend bool operator==(const Iterator & left, const Iterator & right) { return !(left != right); }
private:
simdjson::dom::array::iterator it;
};
ALWAYS_INLINE Array(const simdjson::dom::array & array_) : array(array_) {} /// NOLINT
ALWAYS_INLINE Iterator begin() const { return array.begin(); }
ALWAYS_INLINE Iterator end() const { return array.end(); }
ALWAYS_INLINE size_t size() const { return array.size(); }
ALWAYS_INLINE Element operator[](size_t index) const { assert(index < size()); return array.at(index).value_unsafe(); }
private:
simdjson::dom::array array;
};
using KeyValuePair = std::pair<std::string_view, Element>;
/// References an object in a JSON document.
class Object
{
public:
class Iterator
{
public:
ALWAYS_INLINE Iterator(const simdjson::dom::object::iterator & it_) : it(it_) {} /// NOLINT
ALWAYS_INLINE KeyValuePair operator*() const { const auto & res = *it; return {res.key, res.value}; }
ALWAYS_INLINE Iterator & operator++() { ++it; return *this; }
ALWAYS_INLINE Iterator operator++(int) { auto res = *this; ++it; return res; } /// NOLINT
ALWAYS_INLINE friend bool operator!=(const Iterator & left, const Iterator & right) { return left.it != right.it; }
ALWAYS_INLINE friend bool operator==(const Iterator & left, const Iterator & right) { return !(left != right); }
private:
simdjson::dom::object::iterator it;
};
ALWAYS_INLINE Object(const simdjson::dom::object & object_) : object(object_) {} /// NOLINT
ALWAYS_INLINE Iterator begin() const { return object.begin(); }
ALWAYS_INLINE Iterator end() const { return object.end(); }
ALWAYS_INLINE size_t size() const { return object.size(); }
bool find(std::string_view key, Element & result) const
{
auto x = object.at_key(key);
if (x.error())
return false;
result = x.value_unsafe();
return true;
}
/// Optional: Provides access to an object's element by index.
KeyValuePair operator[](size_t index) const
{
assert(index < size());
auto it = object.begin();
while (index--)
++it;
const auto & res = *it;
return {res.key, res.value};
}
private:
simdjson::dom::object object;
};
/// Parses a JSON document, returns the reference to its root element if succeeded.
bool parse(std::string_view json, Element & result)
{
auto document = parser.parse(json.data(), json.size());
if (document.error())
return false;
result = document.value_unsafe();
return true;
}
/// Optional: Allocates memory to parse JSON documents faster.
void reserve(size_t max_size)
{
if (parser.allocate(max_size) != simdjson::error_code::SUCCESS)
throw Exception(ErrorCodes::CANNOT_ALLOCATE_MEMORY, "Couldn't allocate {} bytes when parsing JSON", max_size);
}
private:
simdjson::dom::parser parser;
};
inline ALWAYS_INLINE SimdJSONParser::Array SimdJSONParser::Element::getArray() const
{
return element.get_array().value_unsafe();
}
inline ALWAYS_INLINE SimdJSONParser::Object SimdJSONParser::Element::getObject() const
{
return element.get_object().value_unsafe();
}
}
#endif
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