src/dump.c

   1 /*
   2  * Copyright (c) 2009-2011 Petri Lehtinen <petri@digip.org>
   3  *
   4  * Jansson is free software; you can redistribute it and/or modify
   5  * it under the terms of the MIT license. See LICENSE for details.
   6  */
   7
   8 #define _GNU_SOURCE
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <assert.h>
  13
  14 #include <jansson.h>
  15 #include "jansson_private.h"
  16 #include "strbuffer.h"
  17 #include "utf.h"
  18
  19 #define MAX_INTEGER_STR_LENGTH  100
  20 #define MAX_REAL_STR_LENGTH     100
  21
  22 struct object_key {
  23     size_t serial;
  24     const char *key;
  25 };
  26
  27 static int dump_to_strbuffer(const char *buffer, size_t size, void *data)
  28 {
  29     return strbuffer_append_bytes((strbuffer_t *)data, buffer, size);
  30 }
  31
  32 static int dump_to_file(const char *buffer, size_t size, void *data)
  33 {
  34     FILE *dest = (FILE *)data;
  35     if(fwrite(buffer, size, 1, dest) != 1)
  36         return -1;
  37     return 0;
  38 }
  39
  40 /* 32 spaces (the maximum indentation size) */
  41 static char whitespace[] = "                                ";
  42
  43 static int dump_indent(size_t flags, int depth, int space, json_dump_callback_t dump, void *data)
  44 {
  45     if(JSON_INDENT(flags) > 0)
  46     {
  47         int i, ws_count = JSON_INDENT(flags);
  48
  49         if(dump("\n", 1, data))
  50             return -1;
  51
  52         for(i = 0; i < depth; i++)
  53         {
  54             if(dump(whitespace, ws_count, data))
  55                 return -1;
  56         }
  57     }
  58     else if(space && !(flags & JSON_COMPACT))
  59     {
  60         return dump(" ", 1, data);
  61     }
  62     return 0;
  63 }
  64
  65 static int dump_string(const char *str, int ascii, json_dump_callback_t dump, void *data)
  66 {
  67     const char *pos, *end;
  68     int32_t codepoint;
  69
  70     if(dump("\"", 1, data))
  71         return -1;
  72
  73     end = pos = str;
  74     while(1)
  75     {
  76         const char *text;
  77         char seq[13];
  78         int length;
  79
  80         while(*end)
  81         {
  82             end = utf8_iterate(pos, &codepoint);
  83             if(!end)
  84                 return -1;
  85
  86             /* mandatory escape or control char */
  87             if(codepoint == '\\' || codepoint == '"' || codepoint < 0x20)
  88                 break;
  89
  90             /* non-ASCII */
  91             if(ascii && codepoint > 0x7F)
  92                 break;
  93
  94             pos = end;
  95         }
  96
  97         if(pos != str) {
  98             if(dump(str, pos - str, data))
  99                 return -1;
 100         }
 101
 102         if(end == pos)
 103             break;
 104
 105         /* handle \, ", and control codes */
 106         length = 2;
 107         switch(codepoint)
 108         {
 109             case '\\': text = "\\\\"; break;
 110             case '\"': text = "\\\""; break;
 111             case '\b': text = "\\b"; break;
 112             case '\f': text = "\\f"; break;
 113             case '\n': text = "\\n"; break;
 114             case '\r': text = "\\r"; break;
 115             case '\t': text = "\\t"; break;
 116             default:
 117             {
 118                 /* codepoint is in BMP */
 119                 if(codepoint < 0x10000)
 120                 {
 121                     sprintf(seq, "\\u%04x", codepoint);
 122                     length = 6;
 123                 }
 124
 125                 /* not in BMP -> construct a UTF-16 surrogate pair */
 126                 else
 127                 {
 128                     int32_t first, last;
 129
 130                     codepoint -= 0x10000;
 131                     first = 0xD800 | ((codepoint & 0xffc00) >> 10);
 132                     last = 0xDC00 | (codepoint & 0x003ff);
 133
 134                     sprintf(seq, "\\u%04x\\u%04x", first, last);
 135                     length = 12;
 136                 }
 137
 138                 text = seq;
 139                 break;
 140             }
 141         }
 142
 143         if(dump(text, length, data))
 144             return -1;
 145
 146         str = pos = end;
 147     }
 148
 149     return dump("\"", 1, data);
 150 }
 151
 152 static int object_key_compare_keys(const void *key1, const void *key2)
 153 {
 154     return strcmp(((const struct object_key *)key1)->key,
 155                   ((const struct object_key *)key2)->key);
 156 }
 157
 158 static int object_key_compare_serials(const void *key1, const void *key2)
 159 {
 160     size_t a = ((const struct object_key *)key1)->serial;
 161     size_t b = ((const struct object_key *)key2)->serial;
 162
 163     return a < b ? -1 : a == b ? 0 : 1;
 164 }
 165
 166 static int do_dump(const json_t *json, size_t flags, int depth,
 167                    json_dump_callback_t dump, void *data)
 168 {
 169     int ascii = flags & JSON_ENSURE_ASCII ? 1 : 0;
 170
 171     switch(json_typeof(json)) {
 172         case JSON_NULL:
 173             return dump("null", 4, data);
 174
 175         case JSON_TRUE:
 176             return dump("true", 4, data);
 177
 178         case JSON_FALSE:
 179             return dump("false", 5, data);
 180
 181         case JSON_INTEGER:
 182         {
 183             char buffer[MAX_INTEGER_STR_LENGTH];
 184             int size;
 185
 186             size = snprintf(buffer, MAX_INTEGER_STR_LENGTH,
 187                             "%" JSON_INTEGER_FORMAT,
 188                             json_integer_value(json));
 189             if(size >= MAX_INTEGER_STR_LENGTH)
 190                 return -1;
 191
 192             return dump(buffer, size, data);
 193         }
 194
 195         case JSON_REAL:
 196         {
 197             char buffer[MAX_REAL_STR_LENGTH];
 198             int size;
 199             double value = json_real_value(json);
 200
 201             size = jsonp_dtostr(buffer, MAX_REAL_STR_LENGTH, value);
 202             if(size < 0)
 203                 return -1;
 204
 205             return dump(buffer, size, data);
 206         }
 207
 208         case JSON_STRING:
 209             return dump_string(json_string_value(json), ascii, dump, data);
 210
 211         case JSON_ARRAY:
 212         {
 213             int i;
 214             int n;
 215             json_array_t *array;
 216
 217             /* detect circular references */
 218             array = json_to_array(json);
 219             if(array->visited)
 220                 goto array_error;
 221             array->visited = 1;
 222
 223             n = json_array_size(json);
 224
 225             if(dump("[", 1, data))
 226                 goto array_error;
 227             if(n == 0) {
 228                 array->visited = 0;
 229                 return dump("]", 1, data);
 230             }
 231             if(dump_indent(flags, depth + 1, 0, dump, data))
 232                 goto array_error;
 233
 234             for(i = 0; i < n; ++i) {
 235                 if(do_dump(json_array_get(json, i), flags, depth + 1,
 236                            dump, data))
 237                     goto array_error;
 238
 239                 if(i < n - 1)
 240                 {
 241                     if(dump(",", 1, data) ||
 242                        dump_indent(flags, depth + 1, 1, dump, data))
 243                         goto array_error;
 244                 }
 245                 else
 246                 {
 247                     if(dump_indent(flags, depth, 0, dump, data))
 248                         goto array_error;
 249                 }
 250             }
 251
 252             array->visited = 0;
 253             return dump("]", 1, data);
 254
 255         array_error:
 256             array->visited = 0;
 257             return -1;
 258         }
 259
 260         case JSON_OBJECT:
 261         {
 262             json_object_t *object;
 263             void *iter;
 264             const char *separator;
 265             int separator_length;
 266
 267             if(flags & JSON_COMPACT) {
 268                 separator = ":";
 269                 separator_length = 1;
 270             }
 271             else {
 272                 separator = ": ";
 273                 separator_length = 2;
 274             }
 275
 276             /* detect circular references */
 277             object = json_to_object(json);
 278             if(object->visited)
 279                 goto object_error;
 280             object->visited = 1;
 281
 282             iter = json_object_iter((json_t *)json);
 283
 284             if(dump("{", 1, data))
 285                 goto object_error;
 286             if(!iter) {
 287                 object->visited = 0;
 288                 return dump("}", 1, data);
 289             }
 290             if(dump_indent(flags, depth + 1, 0, dump, data))
 291                 goto object_error;
 292
 293             if(flags & JSON_SORT_KEYS || flags & JSON_PRESERVE_ORDER)
 294             {
 295                 struct object_key *keys;
 296                 size_t size, i;
 297                 int (*cmp_func)(const void *, const void *);
 298
 299                 size = json_object_size(json);
 300                 keys = jsonp_malloc(size * sizeof(struct object_key));
 301                 if(!keys)
 302                     goto object_error;
 303
 304                 i = 0;
 305                 while(iter)
 306                 {
 307                     keys[i].serial = hashtable_iter_serial(iter);
 308                     keys[i].key = json_object_iter_key(iter);
 309                     iter = json_object_iter_next((json_t *)json, iter);
 310                     i++;
 311                 }
 312                 assert(i == size);
 313
 314                 if(flags & JSON_SORT_KEYS)
 315                     cmp_func = object_key_compare_keys;
 316                 else
 317                     cmp_func = object_key_compare_serials;
 318
 319                 qsort(keys, size, sizeof(struct object_key), cmp_func);
 320
 321                 for(i = 0; i < size; i++)
 322                 {
 323                     const char *key;
 324                     json_t *value;
 325
 326                     key = keys[i].key;
 327                     value = json_object_get(json, key);
 328                     assert(value);
 329
 330                     dump_string(key, ascii, dump, data);
 331                     if(dump(separator, separator_length, data) ||
 332                        do_dump(value, flags, depth + 1, dump, data))
 333                     {
 334                         jsonp_free(keys);
 335                         goto object_error;
 336                     }
 337
 338                     if(i < size - 1)
 339                     {
 340                         if(dump(",", 1, data) ||
 341                            dump_indent(flags, depth + 1, 1, dump, data))
 342                         {
 343                             jsonp_free(keys);
 344                             goto object_error;
 345                         }
 346                     }
 347                     else
 348                     {
 349                         if(dump_indent(flags, depth, 0, dump, data))
 350                         {
 351                             jsonp_free(keys);
 352                             goto object_error;
 353                         }
 354                     }
 355                 }
 356
 357                 jsonp_free(keys);
 358             }
 359             else
 360             {
 361                 /* Don't sort keys */
 362
 363                 while(iter)
 364                 {
 365                     void *next = json_object_iter_next((json_t *)json, iter);
 366
 367                     dump_string(json_object_iter_key(iter), ascii, dump, data);
 368                     if(dump(separator, separator_length, data) ||
 369                        do_dump(json_object_iter_value(iter), flags, depth + 1,
 370                                dump, data))
 371                         goto object_error;
 372
 373                     if(next)
 374                     {
 375                         if(dump(",", 1, data) ||
 376                            dump_indent(flags, depth + 1, 1, dump, data))
 377                             goto object_error;
 378                     }
 379                     else
 380                     {
 381                         if(dump_indent(flags, depth, 0, dump, data))
 382                             goto object_error;
 383                     }
 384
 385                     iter = next;
 386                 }
 387             }
 388
 389             object->visited = 0;
 390             return dump("}", 1, data);
 391
 392         object_error:
 393             object->visited = 0;
 394             return -1;
 395         }
 396
 397         default:
 398             /* not reached */
 399             return -1;
 400     }
 401 }
 402
 403 char *json_dumps(const json_t *json, size_t flags)
 404 {
 405     strbuffer_t strbuff;
 406     char *result;
 407
 408     if(strbuffer_init(&strbuff))
 409         return NULL;
 410
 411     if(json_dump_callback(json, dump_to_strbuffer, (void *)&strbuff, flags))
 412         result = NULL;
 413     else
 414         result = jsonp_strdup(strbuffer_value(&strbuff));
 415
 416     strbuffer_close(&strbuff);
 417     return result;
 418 }
 419
 420 int json_dumpf(const json_t *json, FILE *output, size_t flags)
 421 {
 422     return json_dump_callback(json, dump_to_file, (void *)output, flags);
 423 }
 424
 425 int json_dump_file(const json_t *json, const char *path, size_t flags)
 426 {
 427     int result;
 428
 429     FILE *output = fopen(path, "w");
 430     if(!output)
 431         return -1;
 432
 433     result = json_dumpf(json, output, flags);
 434
 435     fclose(output);
 436     return result;
 437 }
 438
 439 int json_dump_callback(const json_t *json, json_dump_callback_t callback, void *data, size_t flags)
 440 {
 441     if(!(flags & JSON_ENCODE_ANY)) {
 442         if(!json_is_array(json) && !json_is_object(json))
 443            return -1;
 444     }
 445
 446     return do_dump(json, flags, 0, callback, data);
 447 }