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.
19 #include <opensrf/utils.h>
20 #include <opensrf/osrf_list.h>
21 #include <opensrf/osrf_hash.h>
24 #define JSON_STATE_IN_OBJECT 0x1
25 #define JSON_STATE_IN_ARRAY 0x2
26 #define JSON_STATE_IN_STRING 0x4
27 #define JSON_STATE_IN_UTF 0x8
28 #define JSON_STATE_IN_ESCAPE 0x10
29 #define JSON_STATE_IN_KEY 0x20
30 #define JSON_STATE_IN_NULL 0x40
31 #define JSON_STATE_IN_TRUE 0x80
32 #define JSON_STATE_IN_FALSE 0x100
33 #define JSON_STATE_IN_NUMBER 0x200
34 #define JSON_STATE_IS_INVALID 0x400
35 #define JSON_STATE_IS_DONE 0x800
36 #define JSON_STATE_START_COMMEN 0x1000
37 #define JSON_STATE_IN_COMMENT 0x2000
38 #define JSON_STATE_END_COMMENT 0x4000
41 /* object and array (container) states are pushed onto a stack so we
42 * can keep track of the object nest. All other states are
43 * simply stored in the state field of the parser */
44 #define JSON_STATE_SET(ctx,s) ctx->state |= s; /* set a state */
45 #define JSON_STATE_REMOVE(ctx,s) ctx->state &= ~s; /* unset a state */
46 #define JSON_STATE_CHECK(ctx,s) (ctx->state & s) ? 1 : 0 /* check if a state is set */
47 #define JSON_STATE_POP(ctx) osrfListPop( ctx->stateStack ); /* remove a state from the stack */
48 #define JSON_STATE_PUSH(ctx, state) osrfListPush( ctx->stateStack,(void*) state );/* push a state on the stack */
49 #define JSON_STATE_PEEK(ctx) osrfListGetIndex(ctx->stateStack, ctx->stateStack->size -1) /* check which container type we're currently in */
50 #define JSON_STATE_CHECK_STACK(ctx, s) (JSON_STATE_PEEK(ctx) == (void*) s ) ? 1 : 0 /* compare stack values */
60 #define JSON_PARSE_LAST_CHUNK 0x1 /* this is the last part of the string we're parsing */
62 #define JSON_PARSE_FLAG_CHECK(ctx, f) (ctx->flags & f) ? 1 : 0 /* check if a parser state is set */
64 #ifndef JSON_CLASS_KEY
65 #define JSON_CLASS_KEY "__c"
68 #define JSON_DATA_KEY "__p"
72 struct jsonParserContextStruct {
73 int state; /* what are we currently parsing */
74 const char* chunk; /* the chunk we're currently parsing */
75 int index; /* where we are in parsing the current chunk */
76 int chunksize; /* the size of the current chunk */
77 int flags; /* parser flags */
78 osrfList* stateStack; /* represents the nest of object/array states */
79 growing_buffer* buffer; /* used to hold JSON strings, number, true, false, and null sequences */
80 growing_buffer* utfbuf; /* holds the current unicode characters */
81 void* userData; /* opaque user pointer. we ignore this */
82 const struct jsonParserHandlerStruct* handler; /* the event handler struct */
84 typedef struct jsonParserContextStruct jsonParserContext;
86 struct jsonParserHandlerStruct {
87 void (*handleStartObject) (void* userData);
88 void (*handleObjectKey) (void* userData, char* key);
89 void (*handleEndObject) (void* userData);
90 void (*handleStartArray) (void* userData);
91 void (*handleEndArray) (void* userData);
92 void (*handleNull) (void* userData);
93 void (*handleString) (void* userData, char* string);
94 void (*handleBool) (void* userData, int boolval);
95 void (*handleNumber) (void* userData, const char* numstr);
96 void (*handleError) (void* userData, char* err, ...);
98 typedef struct jsonParserHandlerStruct jsonParserHandler;
100 struct _jsonObjectStruct {
101 unsigned long size; /* number of sub-items */
102 char* classname; /* optional class hint (not part of the JSON spec) */
103 int type; /* JSON type */
104 struct _jsonObjectStruct* parent; /* who we're attached to */
105 union __jsonValue { /* cargo */
106 osrfHash* h; /* object container */
107 osrfList* l; /* array container */
108 char* s; /* string */
110 // double n; /* number */
111 double n; /* number */
114 typedef struct _jsonObjectStruct jsonObject;
116 struct _jsonIteratorStruct {
117 jsonObject* obj; /* the object we're traversing */
118 osrfHashIterator* hashItr; /* the iterator for this hash */
119 char* key; /* if this object is an object, the current key */
120 unsigned long index; /* if this object is an array, the index */
122 typedef struct _jsonIteratorStruct jsonIterator;
127 * Allocates a new parser context object
128 * @param handler The event handler struct
129 * @param userData Opaque user pointer which is available in callbacks
130 * and ignored by the parser
131 * @return An allocated parser context, NULL on error
133 jsonParserContext* jsonNewParser( const jsonParserHandler* handler, void* userData);
136 * Deallocates a parser context
137 * @param ctx The context object
139 void jsonParserFree( jsonParserContext* ctx );
142 * Parse a chunk of data.
143 * @param ctx The parser context
144 * @param data The data to parse
145 * @param datalen The size of the chunk to parser
146 * @param flags Reserved
148 int jsonParseChunk( jsonParserContext* ctx, const char* data, int datalen, int flags );
152 * Parses a JSON string;
153 * @param str The string to parser
154 * @return The resulting JSON object or NULL on error
156 jsonObject* jsonParseString( const char* str );
157 jsonObject* jsonParseStringRaw( const char* str );
159 jsonObject* jsonParseStringFmt( const char* str, ... );
162 * Parses a JSON string;
163 * @param str The string to parser
164 * @return The resulting JSON object or NULL on error
166 jsonObject* jsonParseStringHandleError( void (*errorHandler) (const char*), char* str, ... );
171 * Creates a new json object
172 * @param data The string data this object will hold if
173 * this object happens to be a JSON_STRING, NULL otherwise
174 * @return The allocated json object. Must be freed with
177 jsonObject* jsonNewObject(const char* data);
178 jsonObject* jsonNewObjectFmt(const char* data, ...);
181 * Creates a new object of the given type
183 jsonObject* jsonNewObjectType(int type);
186 * Creates a new number object from a double
188 jsonObject* jsonNewNumberObject( double num );
191 * Creates a new number object from a numeric string
193 jsonObject* jsonNewNumberStringObject( const char* numstr );
196 * Creates a new json bool
198 jsonObject* jsonNewBoolObject(int val);
201 * Deallocates an object
203 void jsonObjectFree( jsonObject* o );
206 * Returns all unused jsonObjects to the heap
208 void jsonObjectFreeUnused( void );
211 * Forces the given object to become an array (if it isn't already one)
212 * and pushes the new object into the array
214 unsigned long jsonObjectPush(jsonObject* o, jsonObject* newo);
217 * Forces the given object to become a hash (if it isn't already one)
218 * and assigns the new object to the key of the hash
220 unsigned long jsonObjectSetKey(
221 jsonObject* o, const char* key, jsonObject* newo);
225 * Turns the object into a JSON string. The string must be freed by the caller */
226 char* jsonObjectToJSON( const jsonObject* obj );
227 char* jsonObjectToJSONRaw( const jsonObject* obj );
231 * Retrieves the object at the given key
233 jsonObject* jsonObjectGetKey( jsonObject* obj, const char* key );
234 const jsonObject* jsonObjectGetKeyConst( const jsonObject* obj, const char* key );
240 /** Allocates a new iterator
241 @param obj The object over which to iterate.
243 jsonIterator* jsonNewIterator(const jsonObject* obj);
247 De-allocates an iterator
248 @param iter The iterator object to free
250 void jsonIteratorFree(jsonIterator* iter);
253 Returns the object_node currently pointed to by the iterator
254 and increments the pointer to the next node
255 @param iter The iterator in question.
257 jsonObject* jsonIteratorNext(jsonIterator* iter);
261 @param iter The iterator.
262 @return True if there is another node after the current node.
264 int jsonIteratorHasNext(const jsonIterator* iter);
268 Returns a pointer to the object at the given index. This call is
269 only valid if the object has a type of JSON_ARRAY.
270 @param obj The object
271 @param index The position within the object
272 @return The object at the given index.
274 jsonObject* jsonObjectGetIndex( const jsonObject* obj, unsigned long index );
277 /* removes (and deallocates) the object at the given index (if one exists) and inserts
278 * the new one. returns the size on success, -1 on error
279 * If obj is NULL, inserts a new object into the list with is_null set to true
281 unsigned long jsonObjectSetIndex(jsonObject* dest, unsigned long index, jsonObject* newObj);
283 /* removes the object at the given index and, if more items exist,
284 * re-indexes (shifts down by 1) the rest of the objects in the array
286 unsigned long jsonObjectRemoveIndex(jsonObject* dest, unsigned long index);
288 /* removes (and deallocates) the object with key 'key' if it exists */
289 unsigned long jsonObjectRemoveKey( jsonObject* dest, const char* key);
291 /* returns a pointer to the string data held by this object if this object
292 is a string. Otherwise returns NULL*/
293 char* jsonObjectGetString(const jsonObject*);
295 double jsonObjectGetNumber( const jsonObject* obj );
297 /* sets the string data */
298 void jsonObjectSetString(jsonObject* dest, const char* string);
300 /* sets the number value for the object */
301 void jsonObjectSetNumber(jsonObject* dest, double num);
302 int jsonObjectSetNumberString(jsonObject* dest, const char* string);
304 /* sets the class hint for this object */
305 void jsonObjectSetClass(jsonObject* dest, const char* classname );
306 const char* jsonObjectGetClass(const jsonObject* dest);
308 int jsonBoolIsTrue( const jsonObject* boolObj );
310 void jsonSetBool(jsonObject* bl, int val);
312 jsonObject* jsonObjectClone( const jsonObject* o );
315 /* tries to extract the string data from an object.
316 if object -> NULL (the C NULL)
320 if string/number the string version of either of those
321 The caller is responsible for freeing the returned string
323 char* jsonObjectToSimpleString( const jsonObject* o );
326 Allocate a buffer and format a specified numeric value into it,
327 with up to 30 decimal digits of precision. Caller is responsible
328 for freeing the buffer.
330 char* doubleToString( double num );
333 Return 1 if the string is numeric, otherwise return 0.
334 This validation follows the rules defined by the grammar at:
337 int jsonIsNumeric( const char* s );
340 Allocate and reformat a numeric string into one that is valid
341 by JSON rules. If the string is not numeric, return NULL.
342 Caller is responsible for freeing the buffer.
344 char* jsonScrubNumber( const char* s );
346 /* provides an XPATH style search interface (e.g. /some/node/here) and
347 return the object at that location if one exists. Naturally,
348 every element in the path must be a proper object ("hash" / {}).
349 Returns NULL if the specified node is not found
350 Note also that the object returned is a clone and
351 must be freed by the caller
353 jsonObject* jsonObjectFindPath( const jsonObject* obj, const char* path, ... );
356 /* formats a JSON string from printing. User must free returned string */
357 char* jsonFormatString( const char* jsonString );
359 /* sets the error handler for all parsers */
360 void jsonSetGlobalErrorHandler(void (*errorHandler) (const char*));
362 jsonObject* jsonParseFile( const char* filename );
364 /* ------------------------------------------------------------------------- */
366 * The following methods provide a facility for serializing and
367 * deserializing "classed" JSON objects. To give a JSON object a
368 * class, simply call jsonObjectSetClass().
369 * Then, calling jsonObjectEncodeClass() will convert the JSON
370 * object (and any sub-objects) to a JSON object with class
371 * wrapper objects like so:
372 * { _c : "classname", _d : <json_thing> }
373 * In this example _c is the class key and _d is the data (object)
374 * key. The keys are defined by the constants
375 * OSRF_JSON_CLASS_KEY and OSRF_JSON_DATA_KEY
376 * To revive a serialized object, simply call
377 * jsonObjectDecodeClass()
381 /** Converts a class-wrapped object into an object with the
383 * Caller must free the returned object
385 jsonObject* jsonObjectDecodeClass( const jsonObject* obj );
388 /** Converts an object with a classname into a
389 * class-wrapped (serialized) object
390 * Caller must free the returned object
392 jsonObject* jsonObjectEncodeClass( const jsonObject* obj );
394 /* ------------------------------------------------------------------------- */
398 * Generates an XML representation of a JSON object */
399 char* jsonObjectToXML(const jsonObject*);
403 * Builds a JSON object from the provided XML
405 jsonObject* jsonXMLToJSONObject(const char* xml);