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