2 Copyright (C) 2006 Georgia Public Library Service
3 Bill Erickson <billserickson@gmail.com>
5 This program is free software; you can redistribute it and/or
6 modify it under the terms of the GNU General Public License
7 as published by the Free Software Foundation; either version 2
8 of the License, or (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
17 #include <opensrf/utils.h>
18 #include <opensrf/osrf_list.h>
19 #include <opensrf/osrf_hash.h>
26 #define JSON_STATE_IN_OBJECT 0x1
27 #define JSON_STATE_IN_ARRAY 0x2
28 #define JSON_STATE_IN_STRING 0x4
29 #define JSON_STATE_IN_UTF 0x8
30 #define JSON_STATE_IN_ESCAPE 0x10
31 #define JSON_STATE_IN_KEY 0x20
32 #define JSON_STATE_IN_NULL 0x40
33 #define JSON_STATE_IN_TRUE 0x80
34 #define JSON_STATE_IN_FALSE 0x100
35 #define JSON_STATE_IN_NUMBER 0x200
36 #define JSON_STATE_IS_INVALID 0x400
37 #define JSON_STATE_IS_DONE 0x800
38 #define JSON_STATE_START_COMMEN 0x1000
39 #define JSON_STATE_IN_COMMENT 0x2000
40 #define JSON_STATE_END_COMMENT 0x4000
43 /* object and array (container) states are pushed onto a stack so we
44 * can keep track of the object nest. All other states are
45 * simply stored in the state field of the parser */
46 #define JSON_STATE_SET(ctx,s) ctx->state |= s; /* set a state */
47 #define JSON_STATE_REMOVE(ctx,s) ctx->state &= ~s; /* unset a state */
48 #define JSON_STATE_CHECK(ctx,s) (ctx->state & s) ? 1 : 0 /* check if a state is set */
49 #define JSON_STATE_POP(ctx) osrfListPop( ctx->stateStack ); /* remove a state from the stack */
50 #define JSON_STATE_PUSH(ctx, state) osrfListPush( ctx->stateStack,(void*) state );/* push a state on the stack */
51 #define JSON_STATE_PEEK(ctx) osrfListGetIndex(ctx->stateStack, ctx->stateStack->size -1) /* check which container type we're currently in */
52 #define JSON_STATE_CHECK_STACK(ctx, s) (JSON_STATE_PEEK(ctx) == (void*) s ) ? 1 : 0 /* compare stack values */
62 #define JSON_PARSE_LAST_CHUNK 0x1 /* this is the last part of the string we're parsing */
64 #define JSON_PARSE_FLAG_CHECK(ctx, f) (ctx->flags & f) ? 1 : 0 /* check if a parser state is set */
66 #ifndef JSON_CLASS_KEY
67 #define JSON_CLASS_KEY "__c"
70 #define JSON_DATA_KEY "__p"
74 struct jsonParserContextStruct {
75 int state; /* what are we currently parsing */
76 const char* chunk; /* the chunk we're currently parsing */
77 int index; /* where we are in parsing the current chunk */
78 int chunksize; /* the size of the current chunk */
79 int flags; /* parser flags */
80 osrfList* stateStack; /* represents the nest of object/array states */
81 growing_buffer* buffer; /* used to hold JSON strings, number, true, false, and null sequences */
82 growing_buffer* utfbuf; /* holds the current unicode characters */
83 void* userData; /* opaque user pointer. we ignore this */
84 struct jsonParserHandlerStruct* handler; /* the event handler struct */
86 typedef struct jsonParserContextStruct jsonParserContext;
88 struct jsonParserHandlerStruct {
89 void (*handleStartObject) (void* userData);
90 void (*handleObjectKey) (void* userData, char* key);
91 void (*handleEndObject) (void* userData);
92 void (*handleStartArray) (void* userData);
93 void (*handleEndArray) (void* userData);
94 void (*handleNull) (void* userData);
95 void (*handleString) (void* userData, char* string);
96 void (*handleBool) (void* userData, int boolval);
97 void (*handleNumber) (void* userData, double num);
98 void (*handleError) (void* userData, char* err, ...);
100 typedef struct jsonParserHandlerStruct jsonParserHandler;
102 struct _jsonObjectStruct {
103 unsigned long size; /* number of sub-items */
104 char* classname; /* optional class hint (not part of the JSON spec) */
105 int type; /* JSON type */
106 struct _jsonObjectStruct* parent; /* who we're attached to */
107 union __jsonValue { /* cargo */
108 osrfHash* h; /* object container */
109 osrfList* l; /* array container */
110 char* s; /* string */
112 // double n; /* number */
113 double n; /* number */
116 typedef struct _jsonObjectStruct jsonObject;
118 struct _jsonIteratorStruct {
119 jsonObject* obj; /* the object we're traversing */
120 osrfHashIterator* hashItr; /* the iterator for this hash */
121 char* key; /* if this object is an object, the current key */
122 unsigned long index; /* if this object is an array, the index */
124 typedef struct _jsonIteratorStruct jsonIterator;
129 * Allocates a new parser context object
130 * @param handler The event handler struct
131 * @param userData Opaque user pointer which is available in callbacks
132 * and ignored by the parser
133 * @return An allocated parser context, NULL on error
135 jsonParserContext* jsonNewParser( jsonParserHandler* handler, void* userData);
138 * Deallocates a parser context
139 * @param ctx The context object
141 void jsonParserFree( jsonParserContext* ctx );
144 * Parse a chunk of data.
145 * @param ctx The parser context
146 * @param data The data to parse
147 * @param datalen The size of the chunk to parser
148 * @param flags Reserved
150 int jsonParseChunk( jsonParserContext* ctx, const char* data, int datalen, int flags );
154 * Parses a JSON string;
155 * @param str The string to parser
156 * @return The resulting JSON object or NULL on error
158 jsonObject* jsonParseString( const char* str );
159 jsonObject* jsonParseStringRaw( const char* str );
161 jsonObject* jsonParseStringFmt( const char* str, ... );
164 * Parses a JSON string;
165 * @param str The string to parser
166 * @return The resulting JSON object or NULL on error
168 jsonObject* jsonParseStringHandleError( void (*errorHandler) (const char*), char* str, ... );
173 * Creates a new json object
174 * @param data The string data this object will hold if
175 * this object happens to be a JSON_STRING, NULL otherwise
176 * @return The allocated json object. Must be freed with
179 jsonObject* jsonNewObject(const char* data);
180 jsonObject* jsonNewObjectFmt(const char* data, ...);
183 * Creates a new object of the given type
185 jsonObject* jsonNewObjectType(int type);
188 * Creates a new number object
190 jsonObject* jsonNewNumberObject( double num );
194 * Creates a new json bool
196 jsonObject* jsonNewBoolObject(int val);
199 * Deallocates an object
201 void jsonObjectFree( jsonObject* o );
204 * Returns all unused jsonObjects to the heap
206 void jsonObjectFreeUnused( void );
209 * Forces the given object to become an array (if it isn't already one)
210 * and pushes the new object into the array
212 unsigned long jsonObjectPush(jsonObject* o, jsonObject* newo);
215 * Forces the given object to become a hash (if it isn't already one)
216 * and assigns the new object to the key of the hash
218 unsigned long jsonObjectSetKey(
219 jsonObject* o, const char* key, jsonObject* newo);
223 * Turns the object into a JSON string. The string must be freed by the caller */
224 char* jsonObjectToJSON( const jsonObject* obj );
225 char* jsonObjectToJSONRaw( const jsonObject* obj );
229 * Retrieves the object at the given key
231 jsonObject* jsonObjectGetKey( jsonObject* obj, const char* key );
232 const jsonObject* jsonObjectGetKeyConst( const jsonObject* obj, const char* key );
238 /** Allocates a new iterator
239 @param obj The object over which to iterate.
241 jsonIterator* jsonNewIterator(const jsonObject* obj);
245 De-allocates an iterator
246 @param iter The iterator object to free
248 void jsonIteratorFree(jsonIterator* iter);
251 Returns the object_node currently pointed to by the iterator
252 and increments the pointer to the next node
253 @param iter The iterator in question.
255 jsonObject* jsonIteratorNext(jsonIterator* iter);
259 @param iter The iterator.
260 @return True if there is another node after the current node.
262 int jsonIteratorHasNext(const jsonIterator* iter);
266 Returns a pointer to the object at the given index. This call is
267 only valid if the object has a type of JSON_ARRAY.
268 @param obj The object
269 @param index The position within the object
270 @return The object at the given index.
272 jsonObject* jsonObjectGetIndex( const jsonObject* obj, unsigned long index );
275 /* removes (and deallocates) the object at the given index (if one exists) and inserts
276 * the new one. returns the size on success, -1 on error
277 * If obj is NULL, inserts a new object into the list with is_null set to true
279 unsigned long jsonObjectSetIndex(jsonObject* dest, unsigned long index, jsonObject* newObj);
281 /* removes the object at the given index and, if more items exist,
282 * re-indexes (shifts down by 1) the rest of the objects in the array
284 unsigned long jsonObjectRemoveIndex(jsonObject* dest, unsigned long index);
286 /* removes (and deallocates) the object with key 'key' if it exists */
287 unsigned long jsonObjectRemoveKey( jsonObject* dest, const char* key);
289 /* returns a pointer to the string data held by this object if this object
290 is a string. Otherwise returns NULL*/
291 char* jsonObjectGetString(const jsonObject*);
293 double jsonObjectGetNumber( const jsonObject* obj );
295 /* sets the string data */
296 void jsonObjectSetString(jsonObject* dest, const char* string);
298 /* sets the number value for the object */
299 void jsonObjectSetNumber(jsonObject* dest, double num);
301 /* sets the class hint for this object */
302 void jsonObjectSetClass(jsonObject* dest, const char* classname );
303 const char* jsonObjectGetClass(const jsonObject* dest);
305 int jsonBoolIsTrue( const jsonObject* boolObj );
307 void jsonSetBool(jsonObject* bl, int val);
309 jsonObject* jsonObjectClone( const jsonObject* o );
312 /* tries to extract the string data from an object.
313 if object -> NULL (the C NULL)
317 if string/number the string version of either of those
318 The caller is responsible for freeing the returned string
320 char* jsonObjectToSimpleString( const jsonObject* o );
324 /* provides an XPATH style search interface (e.g. /some/node/here) and
325 return the object at that location if one exists. Naturally,
326 every element in the path must be a proper object ("hash" / {}).
327 Returns NULL if the specified node is not found
328 Note also that the object returned is a clone and
329 must be freed by the caller
331 jsonObject* jsonObjectFindPath( const jsonObject* obj, char* path, ... );
334 /* formats a JSON string from printing. User must free returned string */
335 char* jsonFormatString( const char* jsonString );
337 /* sets the error handler for all parsers */
338 void jsonSetGlobalErrorHandler(void (*errorHandler) (const char*));
340 jsonObject* jsonParseFile( char* filename );
342 /* ------------------------------------------------------------------------- */
344 * The following methods provide a facility for serializing and
345 * deserializing "classed" JSON objects. To give a JSON object a
346 * class, simply call jsonObjectSetClass().
347 * Then, calling jsonObjectEncodeClass() will convert the JSON
348 * object (and any sub-objects) to a JSON object with class
349 * wrapper objects like so:
350 * { _c : "classname", _d : <json_thing> }
351 * In this example _c is the class key and _d is the data (object)
352 * key. The keys are defined by the constants
353 * OSRF_JSON_CLASS_KEY and OSRF_JSON_DATA_KEY
354 * To revive a serialized object, simply call
355 * jsonObjectDecodeClass()
359 /** Converts a class-wrapped object into an object with the
361 * Caller must free the returned object
363 jsonObject* jsonObjectDecodeClass( const jsonObject* obj );
366 /** Converts an object with a classname into a
367 * class-wrapped (serialized) object
368 * Caller must free the returned object
370 jsonObject* jsonObjectEncodeClass( const jsonObject* obj );
372 /* ------------------------------------------------------------------------- */
376 * Generates an XML representation of a JSON object */
377 char* jsonObjectToXML(const jsonObject*);
381 * Builds a JSON object from the provided XML
383 jsonObject* jsonXMLToJSONObject(const char* xml);