src/dump.c

   1 /*
   2  * Copyright (c) 2009, 2010 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 <stdint.h>
  13 #include <assert.h>
  14
  15 #include <jansson.h>
  16 #include "jansson_private.h"
  17 #include "strbuffer.h"
  18 #include "utf.h"
  19
  20 #define MAX_INTEGER_STR_LENGTH  100
  21 #define MAX_REAL_STR_LENGTH     100
  22
  23 typedef int (*dump_func)(const char *buffer, int size, void *data);
  24
  25 struct string
  26 {
  27     char *buffer;
  28     int length;
  29     int size;
  30 };
  31
  32 static int dump_to_strbuffer(const char *buffer, int size, void *data)
  33 {
  34     return strbuffer_append_bytes((strbuffer_t *)data, buffer, size);
  35 }
  36
  37 static int dump_to_file(const char *buffer, int size, void *data)
  38 {
  39     FILE *dest = (FILE *)data;
  40     if(fwrite(buffer, size, 1, dest) != 1)
  41         return -1;
  42     return 0;
  43 }
  44
  45 /* 256 spaces (the maximum indentation size) */
  46 static char whitespace[] = "                                                                                                                                                                                                                                                                ";
  47
  48 static int dump_indent(unsigned long flags, int depth, int space, dump_func dump, void *data)
  49 {
  50     if(JSON_INDENT(flags) > 0)
  51     {
  52         int i, ws_count = JSON_INDENT(flags);
  53
  54         if(dump("\n", 1, data))
  55             return -1;
  56
  57         for(i = 0; i < depth; i++)
  58         {
  59             if(dump(whitespace, ws_count, data))
  60                 return -1;
  61         }
  62     }
  63     else if(space && !(flags & JSON_COMPACT))
  64     {
  65         return dump(" ", 1, data);
  66     }
  67     return 0;
  68 }
  69
  70 static int dump_string(const char *str, int ascii, dump_func dump, void *data)
  71 {
  72     const char *pos, *end;
  73     int32_t codepoint;
  74
  75     if(dump("\"", 1, data))
  76         return -1;
  77
  78     end = pos = str;
  79     while(1)
  80     {
  81         const char *text;
  82         char seq[13];
  83         int length;
  84
  85         while(*end)
  86         {
  87             end = utf8_iterate(pos, &codepoint);
  88             if(!end)
  89                 return -1;
  90
  91             /* mandatory escape or control char */
  92             if(codepoint == '\\' || codepoint == '"' || codepoint < 0x20)
  93                 break;
  94
  95             /* non-ASCII */
  96             if(ascii && codepoint > 0x7F)
  97                 break;
  98
  99             pos = end;
 100         }
 101
 102         if(pos != str) {
 103             if(dump(str, pos - str, data))
 104                 return -1;
 105         }
 106
 107         if(end == pos)
 108             break;
 109
 110         /* handle \, ", and control codes */
 111         length = 2;
 112         switch(codepoint)
 113         {
 114             case '\\': text = "\\\\"; break;
 115             case '\"': text = "\\\""; break;
 116             case '\b': text = "\\b"; break;
 117             case '\f': text = "\\f"; break;
 118             case '\n': text = "\\n"; break;
 119             case '\r': text = "\\r"; break;
 120             case '\t': text = "\\t"; break;
 121             default:
 122             {
 123                 /* codepoint is in BMP */
 124                 if(codepoint < 0x10000)
 125                 {
 126                     sprintf(seq, "\\u%04x", codepoint);
 127                     length = 6;
 128                 }
 129
 130                 /* not in BMP -> construct a UTF-16 surrogate pair */
 131                 else
 132                 {
 133                     int32_t first, last;
 134
 135                     codepoint -= 0x10000;
 136                     first = 0xD800 | ((codepoint & 0xffc00) >> 10);
 137                     last = 0xDC00 | (codepoint & 0x003ff);
 138
 139                     sprintf(seq, "\\u%04x\\u%04x", first, last);
 140                     length = 12;
 141                 }
 142
 143                 text = seq;
 144                 break;
 145             }
 146         }
 147
 148         if(dump(text, length, data))
 149             return -1;
 150
 151         str = pos = end;
 152     }
 153
 154     return dump("\"", 1, data);
 155 }
 156
 157 static int object_key_compare_keys(const void *key1, const void *key2)
 158 {
 159     return strcmp((*(const object_key_t **)key1)->key,
 160                   (*(const object_key_t **)key2)->key);
 161 }
 162
 163 static int object_key_compare_serials(const void *key1, const void *key2)
 164 {
 165     return (*(const object_key_t **)key1)->serial -
 166            (*(const object_key_t **)key2)->serial;
 167 }
 168
 169 static int do_dump(const json_t *json, unsigned long flags, int depth,
 170                    dump_func dump, void *data)
 171 {
 172     int ascii = flags & JSON_ENSURE_ASCII ? 1 : 0;
 173
 174     switch(json_typeof(json)) {
 175         case JSON_NULL:
 176             return dump("null", 4, data);
 177
 178         case JSON_TRUE:
 179             return dump("true", 4, data);
 180
 181         case JSON_FALSE:
 182             return dump("false", 5, data);
 183
 184         case JSON_INTEGER:
 185         {
 186             char buffer[MAX_INTEGER_STR_LENGTH];
 187             int size;
 188
 189             size = snprintf(buffer, MAX_INTEGER_STR_LENGTH, "%d", json_integer_value(json));
 190             if(size >= MAX_INTEGER_STR_LENGTH)
 191                 return -1;
 192
 193             return dump(buffer, size, data);
 194         }
 195
 196         case JSON_REAL:
 197         {
 198             char buffer[MAX_REAL_STR_LENGTH];
 199             int size;
 200
 201             size = snprintf(buffer, MAX_REAL_STR_LENGTH, "%.17g",
 202                             json_real_value(json));
 203             if(size >= MAX_REAL_STR_LENGTH)
 204                 return -1;
 205
 206             /* Make sure there's a dot or 'e' in the output. Otherwise
 207                a real is converted to an integer when decoding */
 208             if(strchr(buffer, '.') == NULL &&
 209                strchr(buffer, 'e') == NULL)
 210             {
 211                 if(size + 2 >= MAX_REAL_STR_LENGTH) {
 212                     /* No space to append ".0" */
 213                     return -1;
 214                 }
 215                 buffer[size] = '.';
 216                 buffer[size + 1] = '0';
 217                 size += 2;
 218             }
 219
 220             return dump(buffer, size, data);
 221         }
 222
 223         case JSON_STRING:
 224             return dump_string(json_string_value(json), ascii, dump, data);
 225
 226         case JSON_ARRAY:
 227         {
 228             int i;
 229             int n;
 230             json_array_t *array;
 231
 232             /* detect circular references */
 233             array = json_to_array(json);
 234             if(array->visited)
 235                 return -1;
 236             array->visited = 1;
 237
 238             n = json_array_size(json);
 239
 240             if(dump("[", 1, data))
 241                 return -1;
 242             if(n == 0)
 243                 return dump("]", 1, data);
 244             if(dump_indent(flags, depth + 1, 0, dump, data))
 245                 return -1;
 246
 247             for(i = 0; i < n; ++i) {
 248                 if(do_dump(json_array_get(json, i), flags, depth + 1,
 249                            dump, data))
 250                     return -1;
 251
 252                 if(i < n - 1)
 253                 {
 254                     if(dump(",", 1, data) ||
 255                        dump_indent(flags, depth + 1, 1, dump, data))
 256                         return -1;
 257                 }
 258                 else
 259                 {
 260                     if(dump_indent(flags, depth, 0, dump, data))
 261                         return -1;
 262                 }
 263             }
 264
 265             array->visited = 0;
 266             return dump("]", 1, data);
 267         }
 268
 269         case JSON_OBJECT:
 270         {
 271             json_object_t *object;
 272             void *iter;
 273             const char *separator;
 274             int separator_length;
 275
 276             if(flags & JSON_COMPACT) {
 277                 separator = ":";
 278                 separator_length = 1;
 279             }
 280             else {
 281                 separator = ": ";
 282                 separator_length = 2;
 283             }
 284
 285             /* detect circular references */
 286             object = json_to_object(json);
 287             if(object->visited)
 288                 return -1;
 289             object->visited = 1;
 290
 291             iter = json_object_iter((json_t *)json);
 292
 293             if(dump("{", 1, data))
 294                 return -1;
 295             if(!iter)
 296                 return dump("}", 1, data);
 297             if(dump_indent(flags, depth + 1, 0, dump, data))
 298                 return -1;
 299
 300             if(flags & JSON_SORT_KEYS || flags & JSON_PRESERVE_ORDER)
 301             {
 302                 const object_key_t **keys;
 303                 unsigned int size;
 304                 unsigned int i;
 305                 int (*cmp_func)(const void *, const void *);
 306
 307                 size = json_object_size(json);
 308                 keys = malloc(size * sizeof(object_key_t *));
 309                 if(!keys)
 310                     return -1;
 311
 312                 i = 0;
 313                 while(iter)
 314                 {
 315                     keys[i] = jsonp_object_iter_fullkey(iter);
 316                     iter = json_object_iter_next((json_t *)json, iter);
 317                     i++;
 318                 }
 319                 assert(i == size);
 320
 321                 if(flags & JSON_SORT_KEYS)
 322                     cmp_func = object_key_compare_keys;
 323                 else
 324                     cmp_func = object_key_compare_serials;
 325
 326                 qsort(keys, size, sizeof(object_key_t *), cmp_func);
 327
 328                 for(i = 0; i < size; i++)
 329                 {
 330                     const char *key;
 331                     json_t *value;
 332
 333                     key = keys[i]->key;
 334                     value = json_object_get(json, key);
 335                     assert(value);
 336
 337                     dump_string(key, ascii, dump, data);
 338                     if(dump(separator, separator_length, data) ||
 339                        do_dump(value, flags, depth + 1, dump, data))
 340                     {
 341                         free(keys);
 342                         return -1;
 343                     }
 344
 345                     if(i < size - 1)
 346                     {
 347                         if(dump(",", 1, data) ||
 348                            dump_indent(flags, depth + 1, 1, dump, data))
 349                         {
 350                             free(keys);
 351                             return -1;
 352                         }
 353                     }
 354                     else
 355                     {
 356                         if(dump_indent(flags, depth, 0, dump, data))
 357                         {
 358                             free(keys);
 359                             return -1;
 360                         }
 361                     }
 362                 }
 363
 364                 free(keys);
 365             }
 366             else
 367             {
 368                 /* Don't sort keys */
 369
 370                 while(iter)
 371                 {
 372                     void *next = json_object_iter_next((json_t *)json, iter);
 373
 374                     dump_string(json_object_iter_key(iter), ascii, dump, data);
 375                     if(dump(separator, separator_length, data) ||
 376                        do_dump(json_object_iter_value(iter), flags, depth + 1,
 377                                dump, data))
 378                         return -1;
 379
 380                     if(next)
 381                     {
 382                         if(dump(",", 1, data) ||
 383                            dump_indent(flags, depth + 1, 1, dump, data))
 384                             return -1;
 385                     }
 386                     else
 387                     {
 388                         if(dump_indent(flags, depth, 0, dump, data))
 389                             return -1;
 390                     }
 391
 392                     iter = next;
 393                 }
 394             }
 395
 396             object->visited = 0;
 397             return dump("}", 1, data);
 398         }
 399
 400         default:
 401             /* not reached */
 402             return -1;
 403     }
 404 }
 405
 406
 407 char *json_dumps(const json_t *json, unsigned long flags)
 408 {
 409     strbuffer_t strbuff;
 410     char *result;
 411
 412     if(!json_is_array(json) && !json_is_object(json))
 413         return NULL;
 414
 415     if(strbuffer_init(&strbuff))
 416         return NULL;
 417
 418     if(do_dump(json, flags, 0, dump_to_strbuffer, (void *)&strbuff)) {
 419         strbuffer_close(&strbuff);
 420         return NULL;
 421     }
 422
 423     result = strdup(strbuffer_value(&strbuff));
 424     strbuffer_close(&strbuff);
 425
 426     return result;
 427 }
 428
 429 int json_dumpf(const json_t *json, FILE *output, unsigned long flags)
 430 {
 431     if(!json_is_array(json) && !json_is_object(json))
 432         return -1;
 433
 434     return do_dump(json, flags, 0, dump_to_file, (void *)output);
 435 }
 436
 437 int json_dump_file(const json_t *json, const char *path, unsigned long flags)
 438 {
 439     int result;
 440
 441     FILE *output = fopen(path, "w");
 442     if(!output)
 443         return -1;
 444
 445     result = json_dumpf(json, output, flags);
 446
 447     fclose(output);
 448     return result;
 449 }