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