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Diffstat (limited to 'include/jsoncons_ext/jsonpath/json_location.hpp')
| -rw-r--r-- | include/jsoncons_ext/jsonpath/json_location.hpp | 445 |
1 files changed, 445 insertions, 0 deletions
diff --git a/include/jsoncons_ext/jsonpath/json_location.hpp b/include/jsoncons_ext/jsonpath/json_location.hpp new file mode 100644 index 0000000..9105608 --- /dev/null +++ b/include/jsoncons_ext/jsonpath/json_location.hpp @@ -0,0 +1,445 @@ +// Copyright 2021 Daniel Parker +// Distributed under the Boost license, Version 1.0. +// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) + +// See https://github.com/danielaparker/jsoncons for latest version + +#ifndef JSONCONS_JSONPATH_JSON_LOCATION_HPP +#define JSONCONS_JSONPATH_JSON_LOCATION_HPP + +#include <string> +#include <vector> +#include <functional> +#include <algorithm> // std::reverse +#include <jsoncons/config/jsoncons_config.hpp> +#include <jsoncons/detail/write_number.hpp> +#include <jsoncons_ext/jsonpath/jsonpath_error.hpp> +#include <jsoncons/json_type.hpp> + +namespace jsoncons { +namespace jsonpath { + + template <class CharT> + class json_location; + + enum class json_location_node_kind { root, index, name }; + + template <class CharT> + class json_location_node + { + friend class json_location<CharT>; + public: + using char_type = CharT; + using string_type = std::basic_string<CharT>; + private: + + const json_location_node* parent_; + json_location_node_kind node_kind_; + string_type name_; + std::size_t index_; + public: + json_location_node(char_type c) + : parent_(nullptr), node_kind_(json_location_node_kind::root), index_(0) + { + name_.push_back(c); + } + + json_location_node(const json_location_node* parent, const string_type& name) + : parent_(parent), node_kind_(json_location_node_kind::name), name_(name), index_(0) + { + } + + json_location_node(const json_location_node* parent, std::size_t index) + : parent_(parent), node_kind_(json_location_node_kind::index), index_(index) + { + } + + const json_location_node* parent() const { return parent_;} + + json_location_node_kind node_kind() const + { + return node_kind_; + } + + const string_type& name() const + { + return name_; + } + + std::size_t index() const + { + return index_; + } + + void swap(json_location_node& node) + { + std::swap(parent_, node.parent_); + std::swap(node_kind_, node.node_kind_); + std::swap(name_, node.name_); + std::swap(index_, node.index_); + } + + private: + + std::size_t node_hash() const + { + std::size_t h = node_kind_ == json_location_node_kind::index ? std::hash<std::size_t>{}(index_) : std::hash<string_type>{}(name_); + + return h; + } + + int compare_node(const json_location_node& other) const + { + int diff = 0; + if (node_kind_ != other.node_kind_) + { + diff = static_cast<int>(node_kind_) - static_cast<int>(other.node_kind_); + } + else + { + switch (node_kind_) + { + case json_location_node_kind::root: + diff = name_.compare(other.name_); + break; + case json_location_node_kind::index: + diff = index_ < other.index_ ? -1 : index_ > other.index_ ? 1 : 0; + break; + case json_location_node_kind::name: + diff = name_.compare(other.name_); + break; + } + } + return diff; + } + }; + + namespace detail { + + template <class Iterator> + class json_location_iterator + { + Iterator it_; + + public: + using iterator_category = std::random_access_iterator_tag; + + using value_type = typename std::remove_pointer<typename std::iterator_traits<Iterator>::value_type>::type; + using difference_type = typename std::iterator_traits<Iterator>::difference_type; + using pointer = const value_type*; + using reference = const value_type&; + + json_location_iterator() : it_() + { + } + + explicit json_location_iterator(Iterator ptr) : it_(ptr) + { + } + + json_location_iterator(const json_location_iterator&) = default; + json_location_iterator(json_location_iterator&&) = default; + json_location_iterator& operator=(const json_location_iterator&) = default; + json_location_iterator& operator=(json_location_iterator&&) = default; + + template <class Iter, + class=typename std::enable_if<!std::is_same<Iter,Iterator>::value && std::is_convertible<Iter,Iterator>::value>::type> + json_location_iterator(const json_location_iterator<Iter>& other) + : it_(other.it_) + { + } + + operator Iterator() const + { + return it_; + } + + reference operator*() const + { + return *(*it_); + } + + pointer operator->() const + { + return (*it_); + } + + json_location_iterator& operator++() + { + ++it_; + return *this; + } + + json_location_iterator operator++(int) + { + json_location_iterator temp = *this; + ++*this; + return temp; + } + + json_location_iterator& operator--() + { + --it_; + return *this; + } + + json_location_iterator operator--(int) + { + json_location_iterator temp = *this; + --*this; + return temp; + } + + json_location_iterator& operator+=(const difference_type offset) + { + it_ += offset; + return *this; + } + + json_location_iterator operator+(const difference_type offset) const + { + json_location_iterator temp = *this; + return temp += offset; + } + + json_location_iterator& operator-=(const difference_type offset) + { + return *this += -offset; + } + + json_location_iterator operator-(const difference_type offset) const + { + json_location_iterator temp = *this; + return temp -= offset; + } + + difference_type operator-(const json_location_iterator& rhs) const noexcept + { + return it_ - rhs.it_; + } + + reference operator[](const difference_type offset) const noexcept + { + return *(*(*this + offset)); + } + + bool operator==(const json_location_iterator& rhs) const noexcept + { + return it_ == rhs.it_; + } + + bool operator!=(const json_location_iterator& rhs) const noexcept + { + return !(*this == rhs); + } + + bool operator<(const json_location_iterator& rhs) const noexcept + { + return it_ < rhs.it_; + } + + bool operator>(const json_location_iterator& rhs) const noexcept + { + return rhs < *this; + } + + bool operator<=(const json_location_iterator& rhs) const noexcept + { + return !(rhs < *this); + } + + bool operator>=(const json_location_iterator& rhs) const noexcept + { + return !(*this < rhs); + } + + inline + friend json_location_iterator<Iterator> operator+( + difference_type offset, json_location_iterator<Iterator> next) + { + return next += offset; + } + }; + + } // namespace detail + + template <class CharT> + class json_location + { + public: + using char_type = CharT; + using string_type = std::basic_string<CharT>; + using json_location_node_type = json_location_node<CharT>; + private: + std::vector<const json_location_node_type*> nodes_; + public: + using iterator = typename detail::json_location_iterator<typename std::vector<const json_location_node_type*>::iterator>; + using const_iterator = typename detail::json_location_iterator<typename std::vector<const json_location_node_type*>::const_iterator>; + + json_location(const json_location_node_type& node) + { + const json_location_node_type* p = std::addressof(node); + do + { + nodes_.push_back(p); + p = p->parent_; + } + while (p != nullptr); + + std::reverse(nodes_.begin(), nodes_.end()); + } + + iterator begin() + { + return iterator(nodes_.begin()); + } + + iterator end() + { + return iterator(nodes_.end()); + } + + const_iterator begin() const + { + return const_iterator(nodes_.begin()); + } + + const_iterator end() const + { + return const_iterator(nodes_.end()); + } + + const json_location_node_type& last() const + { + return *nodes_.back(); + } + + string_type to_string() const + { + string_type buffer; + + for (const auto& node : nodes_) + { + switch (node->node_kind()) + { + case json_location_node_kind::root: + buffer.append(node->name()); + break; + case json_location_node_kind::name: + buffer.push_back('['); + buffer.push_back('\''); + for (auto c : node->name()) + { + if (c == '\'') + { + buffer.push_back('\\'); + buffer.push_back('\''); + } + else + { + buffer.push_back(c); + } + } + buffer.push_back('\''); + buffer.push_back(']'); + break; + case json_location_node_kind::index: + buffer.push_back('['); + jsoncons::detail::from_integer(node->index(), buffer); + buffer.push_back(']'); + break; + } + } + + return buffer; + } + + int compare(const json_location& other) const + { + if (this == &other) + { + return 0; + } + + auto it1 = nodes_.begin(); + auto it2 = other.nodes_.begin(); + while (it1 != nodes_.end() && it2 != other.nodes_.end()) + { + int diff = (*it1)->compare_node(*(*it2)); + if (diff != 0) + { + return diff; + } + ++it1; + ++it2; + } + return (nodes_.size() < other.nodes_.size()) ? -1 : (nodes_.size() == other.nodes_.size()) ? 0 : 1; + } + + std::size_t hash() const + { + + auto it = nodes_.begin(); + std::size_t hash = (*it).hash(); + ++it; + + while (it != nodes_.end()) + { + hash += 17*(*it)->node_hash(); + ++it; + } + + return hash; + } + + friend bool operator==(const json_location& lhs, const json_location& rhs) + { + return lhs.compare(rhs) == 0; + } + + friend bool operator!=(const json_location& lhs, const json_location& rhs) + { + return !(lhs == rhs); + } + + friend bool operator<(const json_location& lhs, const json_location& rhs) + { + return lhs.compare(rhs) < 0; + } + }; + + template <class Json> + Json* select(Json& root, const json_location<typename Json::char_type>& path) + { + Json* current = std::addressof(root); + for (const auto& json_location_node : path) + { + if (json_location_node.node_kind() == json_location_node_kind::index) + { + if (current->type() != json_type::array_value || json_location_node.index() >= current->size()) + { + return nullptr; + } + current = std::addressof(current->at(json_location_node.index())); + } + else if (json_location_node.node_kind() == json_location_node_kind::name) + { + if (current->type() != json_type::object_value) + { + return nullptr; + } + auto it = current->find(json_location_node.name()); + if (it == current->object_range().end()) + { + return nullptr; + } + current = std::addressof(it->value()); + } + } + return current; + } + +} // namespace jsonpath +} // namespace jsoncons + +#endif |