1 | // Copyright 2007-2010 Baptiste Lepilleur and The JsonCpp Authors |
2 | // Distributed under MIT license, or public domain if desired and |
3 | // recognized in your jurisdiction. |
4 | // See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE |
5 | |
6 | #ifndef JSON_READER_H_INCLUDED |
7 | #define JSON_READER_H_INCLUDED |
8 | |
9 | #if !defined(JSON_IS_AMALGAMATION) |
10 | #include "json_features.h" |
11 | #include "value.h" |
12 | #endif // if !defined(JSON_IS_AMALGAMATION) |
13 | #include <deque> |
14 | #include <iosfwd> |
15 | #include <istream> |
16 | #include <stack> |
17 | #include <string> |
18 | |
19 | // Disable warning C4251: <data member>: <type> needs to have dll-interface to |
20 | // be used by... |
21 | #if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING) |
22 | #pragma warning(push) |
23 | #pragma warning(disable : 4251) |
24 | #endif // if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING) |
25 | |
26 | #pragma pack(push, 8) |
27 | |
28 | namespace Json { |
29 | |
30 | /** \brief Unserialize a <a HREF="http://www.json.org">JSON</a> document into a |
31 | * Value. |
32 | * |
33 | * \deprecated Use CharReader and CharReaderBuilder. |
34 | */ |
35 | |
36 | class JSONCPP_DEPRECATED( |
37 | "Use CharReader and CharReaderBuilder instead." ) JSON_API Reader { |
38 | public: |
39 | using Char = char; |
40 | using Location = const Char*; |
41 | |
42 | /** \brief An error tagged with where in the JSON text it was encountered. |
43 | * |
44 | * The offsets give the [start, limit) range of bytes within the text. Note |
45 | * that this is bytes, not codepoints. |
46 | */ |
47 | struct StructuredError { |
48 | ptrdiff_t offset_start; |
49 | ptrdiff_t offset_limit; |
50 | String message; |
51 | }; |
52 | |
53 | /** \brief Constructs a Reader allowing all features for parsing. |
54 | */ |
55 | JSONCPP_DEPRECATED("Use CharReader and CharReaderBuilder instead" ) |
56 | Reader(); |
57 | |
58 | /** \brief Constructs a Reader allowing the specified feature set for parsing. |
59 | */ |
60 | JSONCPP_DEPRECATED("Use CharReader and CharReaderBuilder instead" ) |
61 | Reader(const Features& features); |
62 | |
63 | /** \brief Read a Value from a <a HREF="http://www.json.org">JSON</a> |
64 | * document. |
65 | * |
66 | * \param document UTF-8 encoded string containing the document |
67 | * to read. |
68 | * \param[out] root Contains the root value of the document if it |
69 | * was successfully parsed. |
70 | * \param collectComments \c true to collect comment and allow writing |
71 | * them back during serialization, \c false to |
72 | * discard comments. This parameter is ignored |
73 | * if Features::allowComments_ is \c false. |
74 | * \return \c true if the document was successfully parsed, \c false if an |
75 | * error occurred. |
76 | */ |
77 | bool parse(const std::string& document, Value& root, |
78 | bool = true); |
79 | |
80 | /** \brief Read a Value from a <a HREF="http://www.json.org">JSON</a> |
81 | * document. |
82 | * |
83 | * \param beginDoc Pointer on the beginning of the UTF-8 encoded |
84 | * string of the document to read. |
85 | * \param endDoc Pointer on the end of the UTF-8 encoded string |
86 | * of the document to read. Must be >= beginDoc. |
87 | * \param[out] root Contains the root value of the document if it |
88 | * was successfully parsed. |
89 | * \param collectComments \c true to collect comment and allow writing |
90 | * them back during serialization, \c false to |
91 | * discard comments. This parameter is ignored |
92 | * if Features::allowComments_ is \c false. |
93 | * \return \c true if the document was successfully parsed, \c false if an |
94 | * error occurred. |
95 | */ |
96 | bool parse(const char* beginDoc, const char* endDoc, Value& root, |
97 | bool = true); |
98 | |
99 | /// \brief Parse from input stream. |
100 | /// \see Json::operator>>(std::istream&, Json::Value&). |
101 | bool parse(IStream& is, Value& root, bool = true); |
102 | |
103 | /** \brief Returns a user friendly string that list errors in the parsed |
104 | * document. |
105 | * |
106 | * \return Formatted error message with the list of errors with their |
107 | * location in the parsed document. An empty string is returned if no error |
108 | * occurred during parsing. |
109 | * \deprecated Use getFormattedErrorMessages() instead (typo fix). |
110 | */ |
111 | JSONCPP_DEPRECATED("Use getFormattedErrorMessages() instead." ) |
112 | String getFormatedErrorMessages() const; |
113 | |
114 | /** \brief Returns a user friendly string that list errors in the parsed |
115 | * document. |
116 | * |
117 | * \return Formatted error message with the list of errors with their |
118 | * location in the parsed document. An empty string is returned if no error |
119 | * occurred during parsing. |
120 | */ |
121 | String getFormattedErrorMessages() const; |
122 | |
123 | /** \brief Returns a vector of structured errors encountered while parsing. |
124 | * |
125 | * \return A (possibly empty) vector of StructuredError objects. Currently |
126 | * only one error can be returned, but the caller should tolerate multiple |
127 | * errors. This can occur if the parser recovers from a non-fatal parse |
128 | * error and then encounters additional errors. |
129 | */ |
130 | std::vector<StructuredError> getStructuredErrors() const; |
131 | |
132 | /** \brief Add a semantic error message. |
133 | * |
134 | * \param value JSON Value location associated with the error |
135 | * \param message The error message. |
136 | * \return \c true if the error was successfully added, \c false if the Value |
137 | * offset exceeds the document size. |
138 | */ |
139 | bool pushError(const Value& value, const String& message); |
140 | |
141 | /** \brief Add a semantic error message with extra context. |
142 | * |
143 | * \param value JSON Value location associated with the error |
144 | * \param message The error message. |
145 | * \param extra Additional JSON Value location to contextualize the error |
146 | * \return \c true if the error was successfully added, \c false if either |
147 | * Value offset exceeds the document size. |
148 | */ |
149 | bool pushError(const Value& value, const String& message, const Value& ); |
150 | |
151 | /** \brief Return whether there are any errors. |
152 | * |
153 | * \return \c true if there are no errors to report \c false if errors have |
154 | * occurred. |
155 | */ |
156 | bool good() const; |
157 | |
158 | private: |
159 | enum TokenType { |
160 | tokenEndOfStream = 0, |
161 | tokenObjectBegin, |
162 | tokenObjectEnd, |
163 | tokenArrayBegin, |
164 | tokenArrayEnd, |
165 | tokenString, |
166 | tokenNumber, |
167 | tokenTrue, |
168 | tokenFalse, |
169 | tokenNull, |
170 | tokenArraySeparator, |
171 | tokenMemberSeparator, |
172 | , |
173 | tokenError |
174 | }; |
175 | |
176 | class Token { |
177 | public: |
178 | TokenType type_; |
179 | Location start_; |
180 | Location end_; |
181 | }; |
182 | |
183 | class ErrorInfo { |
184 | public: |
185 | Token token_; |
186 | String message_; |
187 | Location ; |
188 | }; |
189 | |
190 | using Errors = std::deque<ErrorInfo>; |
191 | |
192 | bool readToken(Token& token); |
193 | void skipSpaces(); |
194 | bool match(const Char* pattern, int patternLength); |
195 | bool (); |
196 | bool (); |
197 | bool (); |
198 | bool readString(); |
199 | void readNumber(); |
200 | bool readValue(); |
201 | bool readObject(Token& token); |
202 | bool readArray(Token& token); |
203 | bool decodeNumber(Token& token); |
204 | bool decodeNumber(Token& token, Value& decoded); |
205 | bool decodeString(Token& token); |
206 | bool decodeString(Token& token, String& decoded); |
207 | bool decodeDouble(Token& token); |
208 | bool decodeDouble(Token& token, Value& decoded); |
209 | bool decodeUnicodeCodePoint(Token& token, Location& current, Location end, |
210 | unsigned int& unicode); |
211 | bool decodeUnicodeEscapeSequence(Token& token, Location& current, |
212 | Location end, unsigned int& unicode); |
213 | bool addError(const String& message, Token& token, Location = nullptr); |
214 | bool recoverFromError(TokenType skipUntilToken); |
215 | bool addErrorAndRecover(const String& message, Token& token, |
216 | TokenType skipUntilToken); |
217 | void skipUntilSpace(); |
218 | Value& currentValue(); |
219 | Char getNextChar(); |
220 | void getLocationLineAndColumn(Location location, int& line, |
221 | int& column) const; |
222 | String getLocationLineAndColumn(Location location) const; |
223 | void (Location begin, Location end, CommentPlacement placement); |
224 | void (Token& token); |
225 | |
226 | static bool containsNewLine(Location begin, Location end); |
227 | static String normalizeEOL(Location begin, Location end); |
228 | |
229 | using Nodes = std::stack<Value*>; |
230 | Nodes nodes_; |
231 | Errors errors_; |
232 | String document_; |
233 | Location begin_{}; |
234 | Location end_{}; |
235 | Location current_{}; |
236 | Location lastValueEnd_{}; |
237 | Value* lastValue_{}; |
238 | String ; |
239 | Features features_; |
240 | bool {}; |
241 | }; // Reader |
242 | |
243 | /** Interface for reading JSON from a char array. |
244 | */ |
245 | class JSON_API CharReader { |
246 | public: |
247 | virtual ~CharReader() = default; |
248 | /** \brief Read a Value from a <a HREF="http://www.json.org">JSON</a> |
249 | * document. The document must be a UTF-8 encoded string containing the |
250 | * document to read. |
251 | * |
252 | * \param beginDoc Pointer on the beginning of the UTF-8 encoded string |
253 | * of the document to read. |
254 | * \param endDoc Pointer on the end of the UTF-8 encoded string of the |
255 | * document to read. Must be >= beginDoc. |
256 | * \param[out] root Contains the root value of the document if it was |
257 | * successfully parsed. |
258 | * \param[out] errs Formatted error messages (if not NULL) a user |
259 | * friendly string that lists errors in the parsed |
260 | * document. |
261 | * \return \c true if the document was successfully parsed, \c false if an |
262 | * error occurred. |
263 | */ |
264 | virtual bool parse(char const* beginDoc, char const* endDoc, Value* root, |
265 | String* errs) = 0; |
266 | |
267 | class JSON_API Factory { |
268 | public: |
269 | virtual ~Factory() = default; |
270 | /** \brief Allocate a CharReader via operator new(). |
271 | * \throw std::exception if something goes wrong (e.g. invalid settings) |
272 | */ |
273 | virtual CharReader* newCharReader() const = 0; |
274 | }; // Factory |
275 | }; // CharReader |
276 | |
277 | /** \brief Build a CharReader implementation. |
278 | * |
279 | * Usage: |
280 | * \code |
281 | * using namespace Json; |
282 | * CharReaderBuilder builder; |
283 | * builder["collectComments"] = false; |
284 | * Value value; |
285 | * String errs; |
286 | * bool ok = parseFromStream(builder, std::cin, &value, &errs); |
287 | * \endcode |
288 | */ |
289 | class JSON_API CharReaderBuilder : public CharReader::Factory { |
290 | public: |
291 | // Note: We use a Json::Value so that we can add data-members to this class |
292 | // without a major version bump. |
293 | /** Configuration of this builder. |
294 | * These are case-sensitive. |
295 | * Available settings (case-sensitive): |
296 | * - `"collectComments": false or true` |
297 | * - true to collect comment and allow writing them back during |
298 | * serialization, false to discard comments. This parameter is ignored |
299 | * if allowComments is false. |
300 | * - `"allowComments": false or true` |
301 | * - true if comments are allowed. |
302 | * - `"allowTrailingCommas": false or true` |
303 | * - true if trailing commas in objects and arrays are allowed. |
304 | * - `"strictRoot": false or true` |
305 | * - true if root must be either an array or an object value |
306 | * - `"allowDroppedNullPlaceholders": false or true` |
307 | * - true if dropped null placeholders are allowed. (See |
308 | * StreamWriterBuilder.) |
309 | * - `"allowNumericKeys": false or true` |
310 | * - true if numeric object keys are allowed. |
311 | * - `"allowSingleQuotes": false or true` |
312 | * - true if '' are allowed for strings (both keys and values) |
313 | * - `"stackLimit": integer` |
314 | * - Exceeding stackLimit (recursive depth of `readValue()`) will cause an |
315 | * exception. |
316 | * - This is a security issue (seg-faults caused by deeply nested JSON), so |
317 | * the default is low. |
318 | * - `"failIfExtra": false or true` |
319 | * - If true, `parse()` returns false when extra non-whitespace trails the |
320 | * JSON value in the input string. |
321 | * - `"rejectDupKeys": false or true` |
322 | * - If true, `parse()` returns false when a key is duplicated within an |
323 | * object. |
324 | * - `"allowSpecialFloats": false or true` |
325 | * - If true, special float values (NaNs and infinities) are allowed and |
326 | * their values are lossfree restorable. |
327 | * |
328 | * You can examine 'settings_` yourself to see the defaults. You can also |
329 | * write and read them just like any JSON Value. |
330 | * \sa setDefaults() |
331 | */ |
332 | Json::Value settings_; |
333 | |
334 | CharReaderBuilder(); |
335 | ~CharReaderBuilder() override; |
336 | |
337 | CharReader* newCharReader() const override; |
338 | |
339 | /** \return true if 'settings' are legal and consistent; |
340 | * otherwise, indicate bad settings via 'invalid'. |
341 | */ |
342 | bool validate(Json::Value* invalid) const; |
343 | |
344 | /** A simple way to update a specific setting. |
345 | */ |
346 | Value& operator[](const String& key); |
347 | |
348 | /** Called by ctor, but you can use this to reset settings_. |
349 | * \pre 'settings' != NULL (but Json::null is fine) |
350 | * \remark Defaults: |
351 | * \snippet src/lib_json/json_reader.cpp CharReaderBuilderDefaults |
352 | */ |
353 | static void setDefaults(Json::Value* settings); |
354 | /** Same as old Features::strictMode(). |
355 | * \pre 'settings' != NULL (but Json::null is fine) |
356 | * \remark Defaults: |
357 | * \snippet src/lib_json/json_reader.cpp CharReaderBuilderStrictMode |
358 | */ |
359 | static void strictMode(Json::Value* settings); |
360 | }; |
361 | |
362 | /** Consume entire stream and use its begin/end. |
363 | * Someday we might have a real StreamReader, but for now this |
364 | * is convenient. |
365 | */ |
366 | bool JSON_API parseFromStream(CharReader::Factory const&, IStream&, Value* root, |
367 | String* errs); |
368 | |
369 | /** \brief Read from 'sin' into 'root'. |
370 | * |
371 | * Always keep comments from the input JSON. |
372 | * |
373 | * This can be used to read a file into a particular sub-object. |
374 | * For example: |
375 | * \code |
376 | * Json::Value root; |
377 | * cin >> root["dir"]["file"]; |
378 | * cout << root; |
379 | * \endcode |
380 | * Result: |
381 | * \verbatim |
382 | * { |
383 | * "dir": { |
384 | * "file": { |
385 | * // The input stream JSON would be nested here. |
386 | * } |
387 | * } |
388 | * } |
389 | * \endverbatim |
390 | * \throw std::exception on parse error. |
391 | * \see Json::operator<<() |
392 | */ |
393 | JSON_API IStream& operator>>(IStream&, Value&); |
394 | |
395 | } // namespace Json |
396 | |
397 | #pragma pack(pop) |
398 | |
399 | #if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING) |
400 | #pragma warning(pop) |
401 | #endif // if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING) |
402 | |
403 | #endif // JSON_READER_H_INCLUDED |
404 | |