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_cmp(const void *key1, const void *key2)
 157 {
 158     return strcmp(*(const char **)key1, *(const char **)key2);
 159 }
 160
 161 static int do_dump(const json_t *json, unsigned long flags, int depth,
 162                    dump_func dump, void *data)
 163 {
 164     int ascii = flags & JSON_ENSURE_ASCII ? 1 : 0;
 165
 166     switch(json_typeof(json)) {
 167         case JSON_NULL:
 168             return dump("null", 4, data);
 169
 170         case JSON_TRUE:
 171             return dump("true", 4, data);
 172
 173         case JSON_FALSE:
 174             return dump("false", 5, data);
 175
 176         case JSON_INTEGER:
 177         {
 178             char buffer[MAX_INTEGER_STR_LENGTH];
 179             int size;
 180
 181             size = snprintf(buffer, MAX_INTEGER_STR_LENGTH, "%d", json_integer_value(json));
 182             if(size >= MAX_INTEGER_STR_LENGTH)
 183                 return -1;
 184
 185             return dump(buffer, size, data);
 186         }
 187
 188         case JSON_REAL:
 189         {
 190             char buffer[MAX_REAL_STR_LENGTH];
 191             int size;
 192
 193             size = snprintf(buffer, MAX_REAL_STR_LENGTH, "%.17g",
 194                             json_real_value(json));
 195             if(size >= MAX_REAL_STR_LENGTH)
 196                 return -1;
 197
 198             /* Make sure there's a dot or 'e' in the output. Otherwise
 199                a real is converted to an integer when decoding */
 200             if(strchr(buffer, '.') == NULL &&
 201                strchr(buffer, 'e') == NULL)
 202             {
 203                 if(size + 2 >= MAX_REAL_STR_LENGTH) {
 204                     /* No space to append ".0" */
 205                     return -1;
 206                 }
 207                 buffer[size] = '.';
 208                 buffer[size + 1] = '0';
 209                 size += 2;
 210             }
 211
 212             return dump(buffer, size, data);
 213         }
 214
 215         case JSON_STRING:
 216             return dump_string(json_string_value(json), ascii, dump, data);
 217
 218         case JSON_ARRAY:
 219         {
 220             int i;
 221             int n;
 222             json_array_t *array;
 223
 224             /* detect circular references */
 225             array = json_to_array(json);
 226             if(array->visited)
 227                 return -1;
 228             array->visited = 1;
 229
 230             n = json_array_size(json);
 231
 232             if(dump("[", 1, data))
 233                 return -1;
 234             if(n == 0) {
 235                 array->visited = 0;
 236                 return dump("]", 1, data);
 237             }
 238             if(dump_indent(flags, depth + 1, 0, dump, data))
 239                 return -1;
 240
 241             for(i = 0; i < n; ++i) {
 242                 if(do_dump(json_array_get(json, i), flags, depth + 1,
 243                            dump, data))
 244                     return -1;
 245
 246                 if(i < n - 1)
 247                 {
 248                     if(dump(",", 1, data) ||
 249                        dump_indent(flags, depth + 1, 1, dump, data))
 250                         return -1;
 251                 }
 252                 else
 253                 {
 254                     if(dump_indent(flags, depth, 0, dump, data))
 255                         return -1;
 256                 }
 257             }
 258
 259             array->visited = 0;
 260             return dump("]", 1, data);
 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                 return -1;
 283             object->visited = 1;
 284
 285             iter = json_object_iter((json_t *)json);
 286
 287             if(dump("{", 1, data))
 288                 return -1;
 289             if(!iter) {
 290                 object->visited = 0;
 291                 return dump("}", 1, data);
 292             }
 293             if(dump_indent(flags, depth + 1, 0, dump, data))
 294                 return -1;
 295
 296             if(flags & JSON_SORT_KEYS)
 297             {
 298                 /* Sort keys */
 299
 300                 const char **keys;
 301                 unsigned int size;
 302                 unsigned int i;
 303
 304                 size = json_object_size(json);
 305                 keys = malloc(size * sizeof(const char *));
 306                 if(!keys)
 307                     return -1;
 308
 309                 i = 0;
 310                 while(iter)
 311                 {
 312                     keys[i] = json_object_iter_key(iter);
 313                     iter = json_object_iter_next((json_t *)json, iter);
 314                     i++;
 315                 }
 316                 assert(i == size);
 317
 318                 qsort(keys, size, sizeof(const char *), object_key_cmp);
 319
 320                 for(i = 0; i < size; i++)
 321                 {
 322                     const char *key;
 323                     json_t *value;
 324
 325                     key = keys[i];
 326                     value = json_object_get(json, key);
 327                     assert(value);
 328
 329                     dump_string(key, ascii, dump, data);
 330                     if(dump(separator, separator_length, data) ||
 331                        do_dump(value, flags, depth + 1, dump, data))
 332                     {
 333                         free(keys);
 334                         return -1;
 335                     }
 336
 337                     if(i < size - 1)
 338                     {
 339                         if(dump(",", 1, data) ||
 340                            dump_indent(flags, depth + 1, 1, dump, data))
 341                         {
 342                             free(keys);
 343                             return -1;
 344                         }
 345                     }
 346                     else
 347                     {
 348                         if(dump_indent(flags, depth, 0, dump, data))
 349                         {
 350                             free(keys);
 351                             return -1;
 352                         }
 353                     }
 354                 }
 355
 356                 free(keys);
 357             }
 358             else
 359             {
 360                 /* Don't sort keys */
 361
 362                 while(iter)
 363                 {
 364                     void *next = json_object_iter_next((json_t *)json, iter);
 365
 366                     dump_string(json_object_iter_key(iter), ascii, dump, data);
 367                     if(dump(separator, separator_length, data) ||
 368                        do_dump(json_object_iter_value(iter), flags, depth + 1,
 369                                dump, data))
 370                         return -1;
 371
 372                     if(next)
 373                     {
 374                         if(dump(",", 1, data) ||
 375                            dump_indent(flags, depth + 1, 1, dump, data))
 376                             return -1;
 377                     }
 378                     else
 379                     {
 380                         if(dump_indent(flags, depth, 0, dump, data))
 381                             return -1;
 382                     }
 383
 384                     iter = next;
 385                 }
 386             }
 387
 388             object->visited = 0;
 389             return dump("}", 1, data);
 390         }
 391
 392         default:
 393             /* not reached */
 394             return -1;
 395     }
 396 }
 397
 398
 399 char *json_dumps(const json_t *json, unsigned long flags)
 400 {
 401     strbuffer_t strbuff;
 402     char *result;
 403
 404     if(!json_is_array(json) && !json_is_object(json))
 405         return NULL;
 406
 407     if(strbuffer_init(&strbuff))
 408         return NULL;
 409
 410     if(do_dump(json, flags, 0, dump_to_strbuffer, (void *)&strbuff)) {
 411         strbuffer_close(&strbuff);
 412         return NULL;
 413     }
 414
 415     result = strdup(strbuffer_value(&strbuff));
 416     strbuffer_close(&strbuff);
 417
 418     return result;
 419 }
 420
 421 int json_dumpf(const json_t *json, FILE *output, unsigned long flags)
 422 {
 423     if(!json_is_array(json) && !json_is_object(json))
 424         return -1;
 425
 426     return do_dump(json, flags, 0, dump_to_file, (void *)output);
 427 }
 428
 429 int json_dump_file(const json_t *json, const char *path, unsigned long flags)
 430 {
 431     int result;
 432
 433     FILE *output = fopen(path, "w");
 434     if(!output)
 435         return -1;
 436
 437     result = json_dumpf(json, output, flags);
 438
 439     fclose(output);
 440     return result;
 441 }