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_cmp(const void *key1, const void *key2)
 158 {
 159     return strcmp(*(const char **)key1, *(const char **)key2);
 160 }
 161
 162 static int do_dump(const json_t *json, unsigned long flags, int depth,
 163                    dump_func dump, void *data)
 164 {
 165     int ascii = flags & JSON_ENSURE_ASCII ? 1 : 0;
 166
 167     switch(json_typeof(json)) {
 168         case JSON_NULL:
 169             return dump("null", 4, data);
 170
 171         case JSON_TRUE:
 172             return dump("true", 4, data);
 173
 174         case JSON_FALSE:
 175             return dump("false", 5, data);
 176
 177         case JSON_INTEGER:
 178         {
 179             char buffer[MAX_INTEGER_STR_LENGTH];
 180             int size;
 181
 182             size = snprintf(buffer, MAX_INTEGER_STR_LENGTH, "%d", json_integer_value(json));
 183             if(size >= MAX_INTEGER_STR_LENGTH)
 184                 return -1;
 185
 186             return dump(buffer, size, data);
 187         }
 188
 189         case JSON_REAL:
 190         {
 191             char buffer[MAX_REAL_STR_LENGTH];
 192             int size;
 193
 194             size = snprintf(buffer, MAX_REAL_STR_LENGTH, "%.17g",
 195                             json_real_value(json));
 196             if(size >= MAX_REAL_STR_LENGTH)
 197                 return -1;
 198
 199             /* Make sure there's a dot or 'e' in the output. Otherwise
 200                a real is converted to an integer when decoding */
 201             if(strchr(buffer, '.') == NULL &&
 202                strchr(buffer, 'e') == NULL)
 203             {
 204                 if(size + 2 >= MAX_REAL_STR_LENGTH) {
 205                     /* No space to append ".0" */
 206                     return -1;
 207                 }
 208                 buffer[size] = '.';
 209                 buffer[size + 1] = '0';
 210                 size += 2;
 211             }
 212
 213             return dump(buffer, size, data);
 214         }
 215
 216         case JSON_STRING:
 217             return dump_string(json_string_value(json), ascii, dump, data);
 218
 219         case JSON_ARRAY:
 220         {
 221             int i;
 222             int n;
 223             json_array_t *array;
 224
 225             /* detect circular references */
 226             array = json_to_array(json);
 227             if(array->visited)
 228                 return -1;
 229             array->visited = 1;
 230
 231             n = json_array_size(json);
 232
 233             if(dump("[", 1, data))
 234                 return -1;
 235             if(n == 0)
 236                 return dump("]", 1, data);
 237             if(dump_indent(flags, depth + 1, 0, dump, data))
 238                 return -1;
 239
 240             for(i = 0; i < n; ++i) {
 241                 if(do_dump(json_array_get(json, i), flags, depth + 1,
 242                            dump, data))
 243                     return -1;
 244
 245                 if(i < n - 1)
 246                 {
 247                     if(dump(",", 1, data) ||
 248                        dump_indent(flags, depth + 1, 1, dump, data))
 249                         return -1;
 250                 }
 251                 else
 252                 {
 253                     if(dump_indent(flags, depth, 0, dump, data))
 254                         return -1;
 255                 }
 256             }
 257
 258             array->visited = 0;
 259             return dump("]", 1, data);
 260         }
 261
 262         case JSON_OBJECT:
 263         {
 264             json_object_t *object;
 265             void *iter;
 266             const char *separator;
 267             int separator_length;
 268
 269             if(flags & JSON_COMPACT) {
 270                 separator = ":";
 271                 separator_length = 1;
 272             }
 273             else {
 274                 separator = ": ";
 275                 separator_length = 2;
 276             }
 277
 278             /* detect circular references */
 279             object = json_to_object(json);
 280             if(object->visited)
 281                 return -1;
 282             object->visited = 1;
 283
 284             iter = json_object_iter((json_t *)json);
 285
 286             if(dump("{", 1, data))
 287                 return -1;
 288             if(!iter)
 289                 return dump("}", 1, data);
 290             if(dump_indent(flags, depth + 1, 0, dump, data))
 291                 return -1;
 292
 293             if(flags & JSON_SORT_KEYS)
 294             {
 295                 /* Sort keys */
 296
 297                 const char **keys;
 298                 unsigned int size;
 299                 unsigned int i;
 300
 301                 size = json_object_size(json);
 302                 keys = malloc(size * sizeof(const char *));
 303                 if(!keys)
 304                     return -1;
 305
 306                 i = 0;
 307                 while(iter)
 308                 {
 309                     keys[i] = json_object_iter_key(iter);
 310                     iter = json_object_iter_next((json_t *)json, iter);
 311                     i++;
 312                 }
 313                 assert(i == size);
 314
 315                 qsort(keys, size, sizeof(const char *), object_key_cmp);
 316
 317                 for(i = 0; i < size; i++)
 318                 {
 319                     const char *key;
 320                     json_t *value;
 321
 322                     key = keys[i];
 323                     value = json_object_get(json, key);
 324                     assert(value);
 325
 326                     dump_string(key, ascii, dump, data);
 327                     if(dump(separator, separator_length, data) ||
 328                        do_dump(value, flags, depth + 1, dump, data))
 329                     {
 330                         free(keys);
 331                         return -1;
 332                     }
 333
 334                     if(i < size - 1)
 335                     {
 336                         if(dump(",", 1, data) ||
 337                            dump_indent(flags, depth + 1, 1, dump, data))
 338                         {
 339                             free(keys);
 340                             return -1;
 341                         }
 342                     }
 343                     else
 344                     {
 345                         if(dump_indent(flags, depth, 0, dump, data))
 346                         {
 347                             free(keys);
 348                             return -1;
 349                         }
 350                     }
 351                 }
 352
 353                 free(keys);
 354             }
 355             else
 356             {
 357                 /* Don't sort keys */
 358
 359                 while(iter)
 360                 {
 361                     void *next = json_object_iter_next((json_t *)json, iter);
 362
 363                     dump_string(json_object_iter_key(iter), ascii, dump, data);
 364                     if(dump(separator, separator_length, data) ||
 365                        do_dump(json_object_iter_value(iter), flags, depth + 1,
 366                                dump, data))
 367                         return -1;
 368
 369                     if(next)
 370                     {
 371                         if(dump(",", 1, data) ||
 372                            dump_indent(flags, depth + 1, 1, dump, data))
 373                             return -1;
 374                     }
 375                     else
 376                     {
 377                         if(dump_indent(flags, depth, 0, dump, data))
 378                             return -1;
 379                     }
 380
 381                     iter = next;
 382                 }
 383             }
 384
 385             object->visited = 0;
 386             return dump("}", 1, data);
 387         }
 388
 389         default:
 390             /* not reached */
 391             return -1;
 392     }
 393 }
 394
 395
 396 char *json_dumps(const json_t *json, unsigned long flags)
 397 {
 398     strbuffer_t strbuff;
 399     char *result;
 400
 401     if(!json_is_array(json) && !json_is_object(json))
 402         return NULL;
 403
 404     if(strbuffer_init(&strbuff))
 405         return NULL;
 406
 407     if(do_dump(json, flags, 0, dump_to_strbuffer, (void *)&strbuff)) {
 408         strbuffer_close(&strbuff);
 409         return NULL;
 410     }
 411
 412     result = strdup(strbuffer_value(&strbuff));
 413     strbuffer_close(&strbuff);
 414
 415     return result;
 416 }
 417
 418 int json_dumpf(const json_t *json, FILE *output, unsigned long flags)
 419 {
 420     if(!json_is_array(json) && !json_is_object(json))
 421         return -1;
 422
 423     return do_dump(json, flags, 0, dump_to_file, (void *)output);
 424 }
 425
 426 int json_dump_file(const json_t *json, const char *path, unsigned long flags)
 427 {
 428     int result;
 429
 430     FILE *output = fopen(path, "w");
 431     if(!output)
 432         return -1;
 433
 434     result = json_dumpf(json, output, flags);
 435
 436     fclose(output);
 437     return result;
 438 }