src/dump.c

   1 /*
   2  * Copyright (c) 2009 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, "%0.17f", json_real_value(json));
 195             if(size >= MAX_REAL_STR_LENGTH)
 196                 return -1;
 197
 198             return dump(buffer, size, data);
 199         }
 200
 201         case JSON_STRING:
 202             return dump_string(json_string_value(json), ascii, dump, data);
 203
 204         case JSON_ARRAY:
 205         {
 206             int i;
 207             int n;
 208             json_array_t *array;
 209
 210             /* detect circular references */
 211             array = json_to_array(json);
 212             if(array->visited)
 213                 return -1;
 214             array->visited = 1;
 215
 216             n = json_array_size(json);
 217
 218             if(dump("[", 1, data))
 219                 return -1;
 220             if(n == 0)
 221                 return dump("]", 1, data);
 222             if(dump_indent(flags, depth + 1, 0, dump, data))
 223                 return -1;
 224
 225             for(i = 0; i < n; ++i) {
 226                 if(do_dump(json_array_get(json, i), flags, depth + 1,
 227                            dump, data))
 228                     return -1;
 229
 230                 if(i < n - 1)
 231                 {
 232                     if(dump(",", 1, data) ||
 233                        dump_indent(flags, depth + 1, 1, dump, data))
 234                         return -1;
 235                 }
 236                 else
 237                 {
 238                     if(dump_indent(flags, depth, 0, dump, data))
 239                         return -1;
 240                 }
 241             }
 242
 243             array->visited = 0;
 244             return dump("]", 1, data);
 245         }
 246
 247         case JSON_OBJECT:
 248         {
 249             json_object_t *object;
 250             void *iter;
 251             const char *separator;
 252             int separator_length;
 253
 254             if(flags & JSON_COMPACT) {
 255                 separator = ":";
 256                 separator_length = 1;
 257             }
 258             else {
 259                 separator = ": ";
 260                 separator_length = 2;
 261             }
 262
 263             /* detect circular references */
 264             object = json_to_object(json);
 265             if(object->visited)
 266                 return -1;
 267             object->visited = 1;
 268
 269             iter = json_object_iter((json_t *)json);
 270
 271             if(dump("{", 1, data))
 272                 return -1;
 273             if(!iter)
 274                 return dump("}", 1, data);
 275             if(dump_indent(flags, depth + 1, 0, dump, data))
 276                 return -1;
 277
 278             if(flags & JSON_SORT_KEYS)
 279             {
 280                 /* Sort keys */
 281
 282                 const char **keys;
 283                 unsigned int size;
 284                 unsigned int i;
 285
 286                 size = json_object_size(json);
 287                 keys = malloc(size * sizeof(const char *));
 288                 if(!keys)
 289                     return -1;
 290
 291                 i = 0;
 292                 while(iter)
 293                 {
 294                     keys[i] = json_object_iter_key(iter);
 295                     iter = json_object_iter_next((json_t *)json, iter);
 296                     i++;
 297                 }
 298                 assert(i == size);
 299
 300                 qsort(keys, size, sizeof(const char *), object_key_cmp);
 301
 302                 for(i = 0; i < size; i++)
 303                 {
 304                     const char *key;
 305                     json_t *value;
 306
 307                     key = keys[i];
 308                     value = json_object_get(json, key);
 309                     assert(value);
 310
 311                     dump_string(key, ascii, dump, data);
 312                     if(dump(separator, separator_length, data) ||
 313                        do_dump(value, flags, depth + 1, dump, data))
 314                     {
 315                         free(keys);
 316                         return -1;
 317                     }
 318
 319                     if(i < size - 1)
 320                     {
 321                         if(dump(",", 1, data) ||
 322                            dump_indent(flags, depth + 1, 1, dump, data))
 323                         {
 324                             free(keys);
 325                             return -1;
 326                         }
 327                     }
 328                     else
 329                     {
 330                         if(dump_indent(flags, depth, 0, dump, data))
 331                         {
 332                             free(keys);
 333                             return -1;
 334                         }
 335                     }
 336                 }
 337
 338                 free(keys);
 339             }
 340             else
 341             {
 342                 /* Don't sort keys */
 343
 344                 while(iter)
 345                 {
 346                     void *next = json_object_iter_next((json_t *)json, iter);
 347
 348                     dump_string(json_object_iter_key(iter), ascii, dump, data);
 349                     if(dump(separator, separator_length, data) ||
 350                        do_dump(json_object_iter_value(iter), flags, depth + 1,
 351                                dump, data))
 352                         return -1;
 353
 354                     if(next)
 355                     {
 356                         if(dump(",", 1, data) ||
 357                            dump_indent(flags, depth + 1, 1, dump, data))
 358                             return -1;
 359                     }
 360                     else
 361                     {
 362                         if(dump_indent(flags, depth, 0, dump, data))
 363                             return -1;
 364                     }
 365
 366                     iter = next;
 367                 }
 368             }
 369
 370             object->visited = 0;
 371             return dump("}", 1, data);
 372         }
 373
 374         default:
 375             /* not reached */
 376             return -1;
 377     }
 378 }
 379
 380
 381 char *json_dumps(const json_t *json, unsigned long flags)
 382 {
 383     strbuffer_t strbuff;
 384     char *result;
 385
 386     if(!json_is_array(json) && !json_is_object(json))
 387         return NULL;
 388
 389     if(strbuffer_init(&strbuff))
 390         return NULL;
 391
 392     if(do_dump(json, flags, 0, dump_to_strbuffer, (void *)&strbuff)) {
 393         strbuffer_close(&strbuff);
 394         return NULL;
 395     }
 396
 397     result = strdup(strbuffer_value(&strbuff));
 398     strbuffer_close(&strbuff);
 399
 400     return result;
 401 }
 402
 403 int json_dumpf(const json_t *json, FILE *output, unsigned long flags)
 404 {
 405     if(!json_is_array(json) && !json_is_object(json))
 406         return -1;
 407
 408     return do_dump(json, flags, 0, dump_to_file, (void *)output);
 409 }
 410
 411 int json_dump_file(const json_t *json, const char *path, unsigned long flags)
 412 {
 413     int result;
 414
 415     FILE *output = fopen(path, "w");
 416     if(!output)
 417         return -1;
 418
 419     result = json_dumpf(json, output, flags);
 420
 421     fclose(output);
 422     return result;
 423 }