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     return (*(const object_key_t **)key1)->serial -
 163            (*(const object_key_t **)key2)->serial;
 164 }
 165
 166 static int do_dump(const json_t *json, size_t flags, int depth,
 167                    json_dump_callback_t dump, void *data)
 168 {
 169     int ascii = flags & JSON_ENSURE_ASCII ? 1 : 0;
 170
 171     switch(json_typeof(json)) {
 172         case JSON_NULL:
 173             return dump("null", 4, data);
 174
 175         case JSON_TRUE:
 176             return dump("true", 4, data);
 177
 178         case JSON_FALSE:
 179             return dump("false", 5, data);
 180
 181         case JSON_INTEGER:
 182         {
 183             char buffer[MAX_INTEGER_STR_LENGTH];
 184             int size;
 185
 186             size = snprintf(buffer, MAX_INTEGER_STR_LENGTH,
 187                             "%" JSON_INTEGER_FORMAT,
 188                             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                 goto array_error;
 235             array->visited = 1;
 236
 237             n = json_array_size(json);
 238
 239             if(dump("[", 1, data))
 240                 goto array_error;
 241             if(n == 0) {
 242                 array->visited = 0;
 243                 return dump("]", 1, data);
 244             }
 245             if(dump_indent(flags, depth + 1, 0, dump, data))
 246                 goto array_error;
 247
 248             for(i = 0; i < n; ++i) {
 249                 if(do_dump(json_array_get(json, i), flags, depth + 1,
 250                            dump, data))
 251                     goto array_error;
 252
 253                 if(i < n - 1)
 254                 {
 255                     if(dump(",", 1, data) ||
 256                        dump_indent(flags, depth + 1, 1, dump, data))
 257                         goto array_error;
 258                 }
 259                 else
 260                 {
 261                     if(dump_indent(flags, depth, 0, dump, data))
 262                         goto array_error;
 263                 }
 264             }
 265
 266             array->visited = 0;
 267             return dump("]", 1, data);
 268
 269         array_error:
 270             array->visited = 0;
 271             return -1;
 272         }
 273
 274         case JSON_OBJECT:
 275         {
 276             json_object_t *object;
 277             void *iter;
 278             const char *separator;
 279             int separator_length;
 280
 281             if(flags & JSON_COMPACT) {
 282                 separator = ":";
 283                 separator_length = 1;
 284             }
 285             else {
 286                 separator = ": ";
 287                 separator_length = 2;
 288             }
 289
 290             /* detect circular references */
 291             object = json_to_object(json);
 292             if(object->visited)
 293                 goto object_error;
 294             object->visited = 1;
 295
 296             iter = json_object_iter((json_t *)json);
 297
 298             if(dump("{", 1, data))
 299                 goto object_error;
 300             if(!iter) {
 301                 object->visited = 0;
 302                 return dump("}", 1, data);
 303             }
 304             if(dump_indent(flags, depth + 1, 0, dump, data))
 305                 goto object_error;
 306
 307             if(flags & JSON_SORT_KEYS || flags & JSON_PRESERVE_ORDER)
 308             {
 309                 const object_key_t **keys;
 310                 size_t size, i;
 311                 int (*cmp_func)(const void *, const void *);
 312
 313                 size = json_object_size(json);
 314                 keys = jsonp_malloc(size * sizeof(object_key_t *));
 315                 if(!keys)
 316                     goto object_error;
 317
 318                 i = 0;
 319                 while(iter)
 320                 {
 321                     keys[i] = jsonp_object_iter_fullkey(iter);
 322                     iter = json_object_iter_next((json_t *)json, iter);
 323                     i++;
 324                 }
 325                 assert(i == size);
 326
 327                 if(flags & JSON_SORT_KEYS)
 328                     cmp_func = object_key_compare_keys;
 329                 else
 330                     cmp_func = object_key_compare_serials;
 331
 332                 qsort(keys, size, sizeof(object_key_t *), cmp_func);
 333
 334                 for(i = 0; i < size; i++)
 335                 {
 336                     const char *key;
 337                     json_t *value;
 338
 339                     key = keys[i]->key;
 340                     value = json_object_get(json, key);
 341                     assert(value);
 342
 343                     dump_string(key, ascii, dump, data);
 344                     if(dump(separator, separator_length, data) ||
 345                        do_dump(value, flags, depth + 1, dump, data))
 346                     {
 347                         jsonp_free(keys);
 348                         goto object_error;
 349                     }
 350
 351                     if(i < size - 1)
 352                     {
 353                         if(dump(",", 1, data) ||
 354                            dump_indent(flags, depth + 1, 1, dump, data))
 355                         {
 356                             jsonp_free(keys);
 357                             goto object_error;
 358                         }
 359                     }
 360                     else
 361                     {
 362                         if(dump_indent(flags, depth, 0, dump, data))
 363                         {
 364                             jsonp_free(keys);
 365                             goto object_error;
 366                         }
 367                     }
 368                 }
 369
 370                 jsonp_free(keys);
 371             }
 372             else
 373             {
 374                 /* Don't sort keys */
 375
 376                 while(iter)
 377                 {
 378                     void *next = json_object_iter_next((json_t *)json, iter);
 379
 380                     dump_string(json_object_iter_key(iter), ascii, dump, data);
 381                     if(dump(separator, separator_length, data) ||
 382                        do_dump(json_object_iter_value(iter), flags, depth + 1,
 383                                dump, data))
 384                         goto object_error;
 385
 386                     if(next)
 387                     {
 388                         if(dump(",", 1, data) ||
 389                            dump_indent(flags, depth + 1, 1, dump, data))
 390                             goto object_error;
 391                     }
 392                     else
 393                     {
 394                         if(dump_indent(flags, depth, 0, dump, data))
 395                             goto object_error;
 396                     }
 397
 398                     iter = next;
 399                 }
 400             }
 401
 402             object->visited = 0;
 403             return dump("}", 1, data);
 404
 405         object_error:
 406             object->visited = 0;
 407             return -1;
 408         }
 409
 410         default:
 411             /* not reached */
 412             return -1;
 413     }
 414 }
 415
 416 char *json_dumps(const json_t *json, size_t flags)
 417 {
 418     strbuffer_t strbuff;
 419     char *result;
 420
 421     if(strbuffer_init(&strbuff))
 422         return NULL;
 423
 424     if(json_dump_callback(json, dump_to_strbuffer, (void *)&strbuff, flags))
 425         result = NULL;
 426     else
 427         result = jsonp_strdup(strbuffer_value(&strbuff));
 428
 429     strbuffer_close(&strbuff);
 430     return result;
 431 }
 432
 433 int json_dumpf(const json_t *json, FILE *output, size_t flags)
 434 {
 435     return json_dump_callback(json, dump_to_file, (void *)output, flags);
 436 }
 437
 438 int json_dump_file(const json_t *json, const char *path, size_t flags)
 439 {
 440     int result;
 441
 442     FILE *output = fopen(path, "w");
 443     if(!output)
 444         return -1;
 445
 446     result = json_dumpf(json, output, flags);
 447
 448     fclose(output);
 449     return result;
 450 }
 451
 452 int json_dump_callback(const json_t *json, json_dump_callback_t callback, void *data, size_t flags)
 453 {
 454     if(!(flags & JSON_ENCODE_ANY)) {
 455         if(!json_is_array(json) && !json_is_object(json))
 456            return -1;
 457     }
 458
 459     return do_dump(json, flags, 0, callback, data);
 460 }