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Diffstat (limited to 'include/lib/modernjson/detail/input/json_sax.hpp')
| -rw-r--r-- | include/lib/modernjson/detail/input/json_sax.hpp | 701 |
1 files changed, 0 insertions, 701 deletions
diff --git a/include/lib/modernjson/detail/input/json_sax.hpp b/include/lib/modernjson/detail/input/json_sax.hpp deleted file mode 100644 index e1d48a2..0000000 --- a/include/lib/modernjson/detail/input/json_sax.hpp +++ /dev/null @@ -1,701 +0,0 @@ -#pragma once - -#include <cstddef> -#include <string> -#include <vector> - -#include <lib/modernjson/detail/input/parser.hpp> -#include <lib/modernjson/detail/exceptions.hpp> - -namespace nlohmann -{ - -/*! -@brief SAX interface - -This class describes the SAX interface used by @ref nlohmann::json::sax_parse. -Each function is called in different situations while the input is parsed. The -boolean return value informs the parser whether to continue processing the -input. -*/ -template<typename BasicJsonType> -struct json_sax -{ - /// type for (signed) integers - using number_integer_t = typename BasicJsonType::number_integer_t; - /// type for unsigned integers - using number_unsigned_t = typename BasicJsonType::number_unsigned_t; - /// type for floating-point numbers - using number_float_t = typename BasicJsonType::number_float_t; - /// type for strings - using string_t = typename BasicJsonType::string_t; - - /*! - @brief a null value was read - @return whether parsing should proceed - */ - virtual bool null() = 0; - - /*! - @brief a boolean value was read - @param[in] val boolean value - @return whether parsing should proceed - */ - virtual bool boolean(bool val) = 0; - - /*! - @brief an integer number was read - @param[in] val integer value - @return whether parsing should proceed - */ - virtual bool number_integer(number_integer_t val) = 0; - - /*! - @brief an unsigned integer number was read - @param[in] val unsigned integer value - @return whether parsing should proceed - */ - virtual bool number_unsigned(number_unsigned_t val) = 0; - - /*! - @brief an floating-point number was read - @param[in] val floating-point value - @param[in] s raw token value - @return whether parsing should proceed - */ - virtual bool number_float(number_float_t val, const string_t& s) = 0; - - /*! - @brief a string was read - @param[in] val string value - @return whether parsing should proceed - @note It is safe to move the passed string. - */ - virtual bool string(string_t& val) = 0; - - /*! - @brief the beginning of an object was read - @param[in] elements number of object elements or -1 if unknown - @return whether parsing should proceed - @note binary formats may report the number of elements - */ - virtual bool start_object(std::size_t elements) = 0; - - /*! - @brief an object key was read - @param[in] val object key - @return whether parsing should proceed - @note It is safe to move the passed string. - */ - virtual bool key(string_t& val) = 0; - - /*! - @brief the end of an object was read - @return whether parsing should proceed - */ - virtual bool end_object() = 0; - - /*! - @brief the beginning of an array was read - @param[in] elements number of array elements or -1 if unknown - @return whether parsing should proceed - @note binary formats may report the number of elements - */ - virtual bool start_array(std::size_t elements) = 0; - - /*! - @brief the end of an array was read - @return whether parsing should proceed - */ - virtual bool end_array() = 0; - - /*! - @brief a parse error occurred - @param[in] position the position in the input where the error occurs - @param[in] last_token the last read token - @param[in] ex an exception object describing the error - @return whether parsing should proceed (must return false) - */ - virtual bool parse_error(std::size_t position, - const std::string& last_token, - const detail::exception& ex) = 0; - - virtual ~json_sax() = default; -}; - - -namespace detail -{ -/*! -@brief SAX implementation to create a JSON value from SAX events - -This class implements the @ref json_sax interface and processes the SAX events -to create a JSON value which makes it basically a DOM parser. The structure or -hierarchy of the JSON value is managed by the stack `ref_stack` which contains -a pointer to the respective array or object for each recursion depth. - -After successful parsing, the value that is passed by reference to the -constructor contains the parsed value. - -@tparam BasicJsonType the JSON type -*/ -template<typename BasicJsonType> -class json_sax_dom_parser -{ - public: - using number_integer_t = typename BasicJsonType::number_integer_t; - using number_unsigned_t = typename BasicJsonType::number_unsigned_t; - using number_float_t = typename BasicJsonType::number_float_t; - using string_t = typename BasicJsonType::string_t; - - /*! - @param[in, out] r reference to a JSON value that is manipulated while - parsing - @param[in] allow_exceptions_ whether parse errors yield exceptions - */ - explicit json_sax_dom_parser(BasicJsonType& r, const bool allow_exceptions_ = true) - : root(r), allow_exceptions(allow_exceptions_) - {} - - bool null() - { - handle_value(nullptr); - return true; - } - - bool boolean(bool val) - { - handle_value(val); - return true; - } - - bool number_integer(number_integer_t val) - { - handle_value(val); - return true; - } - - bool number_unsigned(number_unsigned_t val) - { - handle_value(val); - return true; - } - - bool number_float(number_float_t val, const string_t& /*unused*/) - { - handle_value(val); - return true; - } - - bool string(string_t& val) - { - handle_value(val); - return true; - } - - bool start_object(std::size_t len) - { - ref_stack.push_back(handle_value(BasicJsonType::value_t::object)); - - if (JSON_UNLIKELY(len != std::size_t(-1) and len > ref_stack.back()->max_size())) - { - JSON_THROW(out_of_range::create(408, - "excessive object size: " + std::to_string(len))); - } - - return true; - } - - bool key(string_t& val) - { - // add null at given key and store the reference for later - object_element = &(ref_stack.back()->m_value.object->operator[](val)); - return true; - } - - bool end_object() - { - ref_stack.pop_back(); - return true; - } - - bool start_array(std::size_t len) - { - ref_stack.push_back(handle_value(BasicJsonType::value_t::array)); - - if (JSON_UNLIKELY(len != std::size_t(-1) and len > ref_stack.back()->max_size())) - { - JSON_THROW(out_of_range::create(408, - "excessive array size: " + std::to_string(len))); - } - - return true; - } - - bool end_array() - { - ref_stack.pop_back(); - return true; - } - - bool parse_error(std::size_t /*unused*/, const std::string& /*unused*/, - const detail::exception& ex) - { - errored = true; - if (allow_exceptions) - { - // determine the proper exception type from the id - switch ((ex.id / 100) % 100) - { - case 1: - JSON_THROW(*reinterpret_cast<const detail::parse_error*>(&ex)); - case 4: - JSON_THROW(*reinterpret_cast<const detail::out_of_range*>(&ex)); - // LCOV_EXCL_START - case 2: - JSON_THROW(*reinterpret_cast<const detail::invalid_iterator*>(&ex)); - case 3: - JSON_THROW(*reinterpret_cast<const detail::type_error*>(&ex)); - case 5: - JSON_THROW(*reinterpret_cast<const detail::other_error*>(&ex)); - default: - assert(false); - // LCOV_EXCL_STOP - } - } - return false; - } - - constexpr bool is_errored() const - { - return errored; - } - - private: - /*! - @invariant If the ref stack is empty, then the passed value will be the new - root. - @invariant If the ref stack contains a value, then it is an array or an - object to which we can add elements - */ - template<typename Value> - BasicJsonType* handle_value(Value&& v) - { - if (ref_stack.empty()) - { - root = BasicJsonType(std::forward<Value>(v)); - return &root; - } - - assert(ref_stack.back()->is_array() or ref_stack.back()->is_object()); - - if (ref_stack.back()->is_array()) - { - ref_stack.back()->m_value.array->emplace_back(std::forward<Value>(v)); - return &(ref_stack.back()->m_value.array->back()); - } - else - { - assert(object_element); - *object_element = BasicJsonType(std::forward<Value>(v)); - return object_element; - } - } - - /// the parsed JSON value - BasicJsonType& root; - /// stack to model hierarchy of values - std::vector<BasicJsonType*> ref_stack; - /// helper to hold the reference for the next object element - BasicJsonType* object_element = nullptr; - /// whether a syntax error occurred - bool errored = false; - /// whether to throw exceptions in case of errors - const bool allow_exceptions = true; -}; - -template<typename BasicJsonType> -class json_sax_dom_callback_parser -{ - public: - using number_integer_t = typename BasicJsonType::number_integer_t; - using number_unsigned_t = typename BasicJsonType::number_unsigned_t; - using number_float_t = typename BasicJsonType::number_float_t; - using string_t = typename BasicJsonType::string_t; - using parser_callback_t = typename BasicJsonType::parser_callback_t; - using parse_event_t = typename BasicJsonType::parse_event_t; - - json_sax_dom_callback_parser(BasicJsonType& r, - const parser_callback_t cb, - const bool allow_exceptions_ = true) - : root(r), callback(cb), allow_exceptions(allow_exceptions_) - { - keep_stack.push_back(true); - } - - bool null() - { - handle_value(nullptr); - return true; - } - - bool boolean(bool val) - { - handle_value(val); - return true; - } - - bool number_integer(number_integer_t val) - { - handle_value(val); - return true; - } - - bool number_unsigned(number_unsigned_t val) - { - handle_value(val); - return true; - } - - bool number_float(number_float_t val, const string_t& /*unused*/) - { - handle_value(val); - return true; - } - - bool string(string_t& val) - { - handle_value(val); - return true; - } - - bool start_object(std::size_t len) - { - // check callback for object start - const bool keep = callback(static_cast<int>(ref_stack.size()), parse_event_t::object_start, discarded); - keep_stack.push_back(keep); - - auto val = handle_value(BasicJsonType::value_t::object, true); - ref_stack.push_back(val.second); - - // check object limit - if (ref_stack.back()) - { - if (JSON_UNLIKELY(len != std::size_t(-1) and len > ref_stack.back()->max_size())) - { - JSON_THROW(out_of_range::create(408, - "excessive object size: " + std::to_string(len))); - } - } - - return true; - } - - bool key(string_t& val) - { - BasicJsonType k = BasicJsonType(val); - - // check callback for key - const bool keep = callback(static_cast<int>(ref_stack.size()), parse_event_t::key, k); - key_keep_stack.push_back(keep); - - // add discarded value at given key and store the reference for later - if (keep and ref_stack.back()) - { - object_element = &(ref_stack.back()->m_value.object->operator[](val) = discarded); - } - - return true; - } - - bool end_object() - { - if (ref_stack.back()) - { - if (not callback(static_cast<int>(ref_stack.size()) - 1, parse_event_t::object_end, *ref_stack.back())) - { - // discard object - *ref_stack.back() = discarded; - } - } - - assert(not ref_stack.empty()); - assert(not keep_stack.empty()); - ref_stack.pop_back(); - keep_stack.pop_back(); - - if (not ref_stack.empty() and ref_stack.back()) - { - // remove discarded value - if (ref_stack.back()->is_object()) - { - for (auto it = ref_stack.back()->begin(); it != ref_stack.back()->end(); ++it) - { - if (it->is_discarded()) - { - ref_stack.back()->erase(it); - break; - } - } - } - } - - return true; - } - - bool start_array(std::size_t len) - { - const bool keep = callback(static_cast<int>(ref_stack.size()), parse_event_t::array_start, discarded); - keep_stack.push_back(keep); - - auto val = handle_value(BasicJsonType::value_t::array, true); - ref_stack.push_back(val.second); - - // check array limit - if (ref_stack.back()) - { - if (JSON_UNLIKELY(len != std::size_t(-1) and len > ref_stack.back()->max_size())) - { - JSON_THROW(out_of_range::create(408, - "excessive array size: " + std::to_string(len))); - } - } - - return true; - } - - bool end_array() - { - bool keep = true; - - if (ref_stack.back()) - { - keep = callback(static_cast<int>(ref_stack.size()) - 1, parse_event_t::array_end, *ref_stack.back()); - if (not keep) - { - // discard array - *ref_stack.back() = discarded; - } - } - - assert(not ref_stack.empty()); - assert(not keep_stack.empty()); - ref_stack.pop_back(); - keep_stack.pop_back(); - - // remove discarded value - if (not keep and not ref_stack.empty()) - { - if (ref_stack.back()->is_array()) - { - ref_stack.back()->m_value.array->pop_back(); - } - } - - return true; - } - - bool parse_error(std::size_t /*unused*/, const std::string& /*unused*/, - const detail::exception& ex) - { - errored = true; - if (allow_exceptions) - { - // determine the proper exception type from the id - switch ((ex.id / 100) % 100) - { - case 1: - JSON_THROW(*reinterpret_cast<const detail::parse_error*>(&ex)); - case 4: - JSON_THROW(*reinterpret_cast<const detail::out_of_range*>(&ex)); - // LCOV_EXCL_START - case 2: - JSON_THROW(*reinterpret_cast<const detail::invalid_iterator*>(&ex)); - case 3: - JSON_THROW(*reinterpret_cast<const detail::type_error*>(&ex)); - case 5: - JSON_THROW(*reinterpret_cast<const detail::other_error*>(&ex)); - default: - assert(false); - // LCOV_EXCL_STOP - } - } - return false; - } - - constexpr bool is_errored() const - { - return errored; - } - - private: - /*! - @param[in] v value to add to the JSON value we build during parsing - @param[in] skip_callback whether we should skip calling the callback - function; this is required after start_array() and - start_object() SAX events, because otherwise we would call the - callback function with an empty array or object, respectively. - - @invariant If the ref stack is empty, then the passed value will be the new - root. - @invariant If the ref stack contains a value, then it is an array or an - object to which we can add elements - - @return pair of boolean (whether value should be kept) and pointer (to the - passed value in the ref_stack hierarchy; nullptr if not kept) - */ - template<typename Value> - std::pair<bool, BasicJsonType*> handle_value(Value&& v, const bool skip_callback = false) - { - assert(not keep_stack.empty()); - - // do not handle this value if we know it would be added to a discarded - // container - if (not keep_stack.back()) - { - return {false, nullptr}; - } - - // create value - auto value = BasicJsonType(std::forward<Value>(v)); - - // check callback - const bool keep = skip_callback or callback(static_cast<int>(ref_stack.size()), parse_event_t::value, value); - - // do not handle this value if we just learnt it shall be discarded - if (not keep) - { - return {false, nullptr}; - } - - if (ref_stack.empty()) - { - root = std::move(value); - return {true, &root}; - } - - // skip this value if we already decided to skip the parent - // (https://github.com/nlohmann/json/issues/971#issuecomment-413678360) - if (not ref_stack.back()) - { - return {false, nullptr}; - } - - // we now only expect arrays and objects - assert(ref_stack.back()->is_array() or ref_stack.back()->is_object()); - - if (ref_stack.back()->is_array()) - { - ref_stack.back()->m_value.array->push_back(std::move(value)); - return {true, &(ref_stack.back()->m_value.array->back())}; - } - else - { - // check if we should store an element for the current key - assert(not key_keep_stack.empty()); - const bool store_element = key_keep_stack.back(); - key_keep_stack.pop_back(); - - if (not store_element) - { - return {false, nullptr}; - } - - assert(object_element); - *object_element = std::move(value); - return {true, object_element}; - } - } - - /// the parsed JSON value - BasicJsonType& root; - /// stack to model hierarchy of values - std::vector<BasicJsonType*> ref_stack; - /// stack to manage which values to keep - std::vector<bool> keep_stack; - /// stack to manage which object keys to keep - std::vector<bool> key_keep_stack; - /// helper to hold the reference for the next object element - BasicJsonType* object_element = nullptr; - /// whether a syntax error occurred - bool errored = false; - /// callback function - const parser_callback_t callback = nullptr; - /// whether to throw exceptions in case of errors - const bool allow_exceptions = true; - /// a discarded value for the callback - BasicJsonType discarded = BasicJsonType::value_t::discarded; -}; - -template<typename BasicJsonType> -class json_sax_acceptor -{ - public: - using number_integer_t = typename BasicJsonType::number_integer_t; - using number_unsigned_t = typename BasicJsonType::number_unsigned_t; - using number_float_t = typename BasicJsonType::number_float_t; - using string_t = typename BasicJsonType::string_t; - - bool null() - { - return true; - } - - bool boolean(bool /*unused*/) - { - return true; - } - - bool number_integer(number_integer_t /*unused*/) - { - return true; - } - - bool number_unsigned(number_unsigned_t /*unused*/) - { - return true; - } - - bool number_float(number_float_t /*unused*/, const string_t& /*unused*/) - { - return true; - } - - bool string(string_t& /*unused*/) - { - return true; - } - - bool start_object(std::size_t /*unused*/ = std::size_t(-1)) - { - return true; - } - - bool key(string_t& /*unused*/) - { - return true; - } - - bool end_object() - { - return true; - } - - bool start_array(std::size_t /*unused*/ = std::size_t(-1)) - { - return true; - } - - bool end_array() - { - return true; - } - - bool parse_error(std::size_t /*unused*/, const std::string& /*unused*/, const detail::exception& /*unused*/) - { - return false; - } -}; -} // namespace detail - -} // namespace nlohmann |