src/dump.c

   1 /*
   2  * Copyright (c) 2009-2012 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, json_dump_callback_t dump, void *data, size_t flags)
  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             /* slash */
  91             if((flags & JSON_ESCAPE_SLASH) && codepoint == '/')
  92                 break;
  93
  94             /* non-ASCII */
  95             if((flags & JSON_ENSURE_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             case '/':  text = "\\/"; 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 struct object_key *)key1)->key,
 160                   ((const struct object_key *)key2)->key);
 161 }
 162
 163 static int object_key_compare_serials(const void *key1, const void *key2)
 164 {
 165     size_t a = ((const struct object_key *)key1)->serial;
 166     size_t b = ((const struct object_key *)key2)->serial;
 167
 168     return a < b ? -1 : a == b ? 0 : 1;
 169 }
 170
 171 static int do_dump(const json_t *json, size_t flags, int depth,
 172                    json_dump_callback_t dump, void *data)
 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,
 190                             "%" JSON_INTEGER_FORMAT,
 191                             json_integer_value(json));
 192             if(size < 0 || size >= MAX_INTEGER_STR_LENGTH)
 193                 return -1;
 194
 195             return dump(buffer, size, data);
 196         }
 197
 198         case JSON_REAL:
 199         {
 200             char buffer[MAX_REAL_STR_LENGTH];
 201             int size;
 202             double value = json_real_value(json);
 203
 204             size = jsonp_dtostr(buffer, MAX_REAL_STR_LENGTH, value);
 205             if(size < 0)
 206                 return -1;
 207
 208             return dump(buffer, size, data);
 209         }
 210
 211         case JSON_STRING:
 212             return dump_string(json_string_value(json), dump, data, flags);
 213
 214         case JSON_ARRAY:
 215         {
 216             int i;
 217             int n;
 218             json_array_t *array;
 219
 220             /* detect circular references */
 221             array = json_to_array(json);
 222             if(array->visited)
 223                 goto array_error;
 224             array->visited = 1;
 225
 226             n = json_array_size(json);
 227
 228             if(dump("[", 1, data))
 229                 goto array_error;
 230             if(n == 0) {
 231                 array->visited = 0;
 232                 return dump("]", 1, data);
 233             }
 234             if(dump_indent(flags, depth + 1, 0, dump, data))
 235                 goto array_error;
 236
 237             for(i = 0; i < n; ++i) {
 238                 if(do_dump(json_array_get(json, i), flags, depth + 1,
 239                            dump, data))
 240                     goto array_error;
 241
 242                 if(i < n - 1)
 243                 {
 244                     if(dump(",", 1, data) ||
 245                        dump_indent(flags, depth + 1, 1, dump, data))
 246                         goto array_error;
 247                 }
 248                 else
 249                 {
 250                     if(dump_indent(flags, depth, 0, dump, data))
 251                         goto array_error;
 252                 }
 253             }
 254
 255             array->visited = 0;
 256             return dump("]", 1, data);
 257
 258         array_error:
 259             array->visited = 0;
 260             return -1;
 261         }
 262
 263         case JSON_OBJECT:
 264         {
 265             json_object_t *object;
 266             void *iter;
 267             const char *separator;
 268             int separator_length;
 269
 270             if(flags & JSON_COMPACT) {
 271                 separator = ":";
 272                 separator_length = 1;
 273             }
 274             else {
 275                 separator = ": ";
 276                 separator_length = 2;
 277             }
 278
 279             /* detect circular references */
 280             object = json_to_object(json);
 281             if(object->visited)
 282                 goto object_error;
 283             object->visited = 1;
 284
 285             iter = json_object_iter((json_t *)json);
 286
 287             if(dump("{", 1, data))
 288                 goto object_error;
 289             if(!iter) {
 290                 object->visited = 0;
 291                 return dump("}", 1, data);
 292             }
 293             if(dump_indent(flags, depth + 1, 0, dump, data))
 294                 goto object_error;
 295
 296             if(flags & JSON_SORT_KEYS || flags & JSON_PRESERVE_ORDER)
 297             {
 298                 struct object_key *keys;
 299                 size_t size, i;
 300                 int (*cmp_func)(const void *, const void *);
 301
 302                 size = json_object_size(json);
 303                 keys = jsonp_malloc(size * sizeof(struct object_key));
 304                 if(!keys)
 305                     goto object_error;
 306
 307                 i = 0;
 308                 while(iter)
 309                 {
 310                     keys[i].serial = hashtable_iter_serial(iter);
 311                     keys[i].key = json_object_iter_key(iter);
 312                     iter = json_object_iter_next((json_t *)json, iter);
 313                     i++;
 314                 }
 315                 assert(i == size);
 316
 317                 if(flags & JSON_SORT_KEYS)
 318                     cmp_func = object_key_compare_keys;
 319                 else
 320                     cmp_func = object_key_compare_serials;
 321
 322                 qsort(keys, size, sizeof(struct object_key), cmp_func);
 323
 324                 for(i = 0; i < size; i++)
 325                 {
 326                     const char *key;
 327                     json_t *value;
 328
 329                     key = keys[i].key;
 330                     value = json_object_get(json, key);
 331                     assert(value);
 332
 333                     dump_string(key, dump, data, flags);
 334                     if(dump(separator, separator_length, data) ||
 335                        do_dump(value, flags, depth + 1, dump, data))
 336                     {
 337                         jsonp_free(keys);
 338                         goto object_error;
 339                     }
 340
 341                     if(i < size - 1)
 342                     {
 343                         if(dump(",", 1, data) ||
 344                            dump_indent(flags, depth + 1, 1, dump, data))
 345                         {
 346                             jsonp_free(keys);
 347                             goto object_error;
 348                         }
 349                     }
 350                     else
 351                     {
 352                         if(dump_indent(flags, depth, 0, dump, data))
 353                         {
 354                             jsonp_free(keys);
 355                             goto object_error;
 356                         }
 357                     }
 358                 }
 359
 360                 jsonp_free(keys);
 361             }
 362             else
 363             {
 364                 /* Don't sort keys */
 365
 366                 while(iter)
 367                 {
 368                     void *next = json_object_iter_next((json_t *)json, iter);
 369
 370                     dump_string(json_object_iter_key(iter), dump, data, flags);
 371                     if(dump(separator, separator_length, data) ||
 372                        do_dump(json_object_iter_value(iter), flags, depth + 1,
 373                                dump, data))
 374                         goto object_error;
 375
 376                     if(next)
 377                     {
 378                         if(dump(",", 1, data) ||
 379                            dump_indent(flags, depth + 1, 1, dump, data))
 380                             goto object_error;
 381                     }
 382                     else
 383                     {
 384                         if(dump_indent(flags, depth, 0, dump, data))
 385                             goto object_error;
 386                     }
 387
 388                     iter = next;
 389                 }
 390             }
 391
 392             object->visited = 0;
 393             return dump("}", 1, data);
 394
 395         object_error:
 396             object->visited = 0;
 397             return -1;
 398         }
 399
 400         default:
 401             /* not reached */
 402             return -1;
 403     }
 404 }
 405
 406 char *json_dumps(const json_t *json, size_t flags)
 407 {
 408     strbuffer_t strbuff;
 409     char *result;
 410
 411     if(strbuffer_init(&strbuff))
 412         return NULL;
 413
 414     if(json_dump_callback(json, dump_to_strbuffer, (void *)&strbuff, flags))
 415         result = NULL;
 416     else
 417         result = jsonp_strdup(strbuffer_value(&strbuff));
 418
 419     strbuffer_close(&strbuff);
 420     return result;
 421 }
 422
 423 int json_dumpf(const json_t *json, FILE *output, size_t flags)
 424 {
 425     return json_dump_callback(json, dump_to_file, (void *)output, flags);
 426 }
 427
 428 int json_dump_file(const json_t *json, const char *path, size_t flags)
 429 {
 430     int result;
 431
 432     FILE *output = fopen(path, "w");
 433     if(!output)
 434         return -1;
 435
 436     result = json_dumpf(json, output, flags);
 437
 438     fclose(output);
 439     return result;
 440 }
 441
 442 int json_dump_callback(const json_t *json, json_dump_callback_t callback, void *data, size_t flags)
 443 {
 444     if(!(flags & JSON_ENCODE_ANY)) {
 445         if(!json_is_array(json) && !json_is_object(json))
 446            return -1;
 447     }
 448
 449     return do_dump(json, flags, 0, callback, data);
 450 }