1 /** 2 * Copyright (c) 2021-2022 Huawei Device Co., Ltd. 3 * Licensed under the Apache License, Version 2.0 (the "License"); 4 * you may not use this file except in compliance with the License. 5 * You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software 10 * distributed under the License is distributed on an "AS IS" BASIS, 11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 * See the License for the specific language governing permissions and 13 * limitations under the License. 14 */ 15 16 #ifndef LIBPANDABASE_UTILS_JSON_PARSER_H 17 #define LIBPANDABASE_UTILS_JSON_PARSER_H 18 19 #include <string> 20 #include <vector> 21 #include <unordered_map> 22 #include <variant> 23 #include <memory> 24 #include <algorithm> 25 26 #include "macros.h" 27 28 WEAK_FOR_LTO_START 29 30 namespace panda { 31 32 class JsonObject { 33 public: 34 class Value; 35 using StringT = std::string; 36 using NumT = double; 37 using BoolT = bool; 38 using ArrayT = std::vector<Value>; 39 using Key = StringT; 40 using JsonObjPointer = std::unique_ptr<JsonObject>; 41 42 class Value { 43 public: 44 Value() = default; 45 ~Value() = default; 46 NO_COPY_SEMANTIC(Value); Value(Value && rhs)47 Value(Value &&rhs) noexcept 48 { 49 value_ = std::move(rhs.value_); 50 rhs.value_ = std::monostate {}; 51 } 52 Value &operator=(Value &&rhs) noexcept 53 { 54 value_ = std::move(rhs.value_); 55 rhs.value_ = std::monostate {}; 56 return *this; 57 } 58 59 template <typename T> SetValue(T && rhs)60 void SetValue(T &&rhs) noexcept 61 { 62 value_ = std::forward<T>(rhs); 63 } 64 65 template <typename T> Get()66 T *Get() 67 { 68 return std::get_if<T>(&value_); 69 } 70 template <typename T> Get()71 const T *Get() const 72 { 73 return std::get_if<T>(&value_); 74 } 75 76 private: 77 std::variant<std::monostate, StringT, NumT, BoolT, ArrayT, JsonObjPointer> value_; 78 }; 79 80 // Recursive descent parser: 81 class Parser { 82 public: Parser(JsonObject * target)83 explicit Parser(JsonObject *target) : current_obj_(target) {} 84 bool Parse(const std::string &text); 85 bool Parse(std::streambuf *stream_buf); 86 87 virtual ~Parser() = default; 88 89 NO_COPY_SEMANTIC(Parser); 90 NO_MOVE_SEMANTIC(Parser); 91 92 private: 93 bool Parse(); 94 95 bool GetJsonObject(JsonObject *empty_obj); 96 bool GetValue(); 97 bool GetString(char delim); 98 bool GetJsonString(); 99 bool GetNum(); 100 bool GetBool(); 101 bool GetArray(); 102 bool InsertKeyValuePairIn(JsonObject *obj); 103 104 char GetSymbol(); 105 char PeekSymbol(); 106 bool TryGetSymbol(int symbol); 107 108 static bool IsWhitespace(int symbol); 109 110 private: 111 std::istream istream_ {nullptr}; 112 JsonObject *current_obj_ {nullptr}; 113 Value parsed_temp_; 114 StringT string_temp_; 115 116 size_t log_recursion_level_ {0}; 117 }; 118 119 public: 120 JsonObject() = default; 121 ~JsonObject() = default; 122 NO_COPY_SEMANTIC(JsonObject); 123 NO_MOVE_SEMANTIC(JsonObject); JsonObject(const std::string & text)124 explicit JsonObject(const std::string &text) 125 { 126 Parser(this).Parse(text); 127 } JsonObject(std::streambuf * stream_buf)128 explicit JsonObject(std::streambuf *stream_buf) 129 { 130 Parser(this).Parse(stream_buf); 131 } 132 GetSize()133 size_t GetSize() const 134 { 135 ASSERT(values_map_.size() == keys_.size()); 136 ASSERT(values_map_.size() == string_map_.size()); 137 return values_map_.size(); 138 } 139 GetIndexByKey(const Key & key)140 size_t GetIndexByKey(const Key &key) const 141 { 142 auto it = std::find(keys_.begin(), keys_.end(), key); 143 if (it != keys_.end()) { 144 return it - keys_.begin(); 145 } 146 return static_cast<size_t>(-1); 147 } GetKeyByIndex(size_t idx)148 const auto &GetKeyByIndex(size_t idx) const 149 { 150 ASSERT(idx < GetSize()); 151 return keys_[idx]; 152 } 153 154 template <typename T> GetValue(const Key & key)155 const T *GetValue(const Key &key) const 156 { 157 auto iter = values_map_.find(key); 158 return (iter == values_map_.end()) ? nullptr : iter->second.Get<T>(); 159 } GetValueSourceString(const Key & key)160 const StringT *GetValueSourceString(const Key &key) const 161 { 162 auto iter = string_map_.find(key); 163 return (iter == string_map_.end()) ? nullptr : &iter->second; 164 } 165 template <typename T> GetValue(size_t idx)166 const T *GetValue(size_t idx) const 167 { 168 auto iter = values_map_.find(GetKeyByIndex(idx)); 169 return (iter == values_map_.end()) ? nullptr : iter->second.Get<T>(); 170 } 171 GetUnorderedMap()172 const auto &GetUnorderedMap() const 173 { 174 return values_map_; 175 } 176 IsValid()177 bool IsValid() const 178 { 179 return is_valid_; 180 } 181 182 private: 183 bool is_valid_ {false}; 184 std::unordered_map<Key, Value> values_map_; 185 // String representation is stored additionally as a "source" of scalar values: 186 std::unordered_map<Key, StringT> string_map_; 187 188 // Stores the order in which keys were added (allows to access elements by index): 189 std::vector<Key> keys_; 190 }; 191 192 } // namespace panda 193 194 WEAK_FOR_LTO_END 195 196 #endif // LIBPANDABASE_UTILS_JSON_PARSER_H 197