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, int ascii, json_dump_callback_t dump, void *data)
  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 == '"' || codepoint < 0x20)
  88                 break;
  89
  90             /* non-ASCII */
  91             if(ascii && codepoint > 0x7F)
  92                 break;
  93
  94             pos = end;
  95         }
  96
  97         if(pos != str) {
  98             if(dump(str, pos - str, data))
  99                 return -1;
 100         }
 101
 102         if(end == pos)
 103             break;
 104
 105         /* handle \, /, ", and control codes */
 106         length = 2;
 107         switch(codepoint)
 108         {
 109             case '\\': text = "\\\\"; break;
 110             case '/': text = "\\/"; break;
 111             case '\"': text = "\\\""; break;
 112             case '\b': text = "\\b"; break;
 113             case '\f': text = "\\f"; break;
 114             case '\n': text = "\\n"; break;
 115             case '\r': text = "\\r"; break;
 116             case '\t': text = "\\t"; break;
 117             default:
 118             {
 119                 /* codepoint is in BMP */
 120                 if(codepoint < 0x10000)
 121                 {
 122                     sprintf(seq, "\\u%04x", codepoint);
 123                     length = 6;
 124                 }
 125
 126                 /* not in BMP -> construct a UTF-16 surrogate pair */
 127                 else
 128                 {
 129                     int32_t first, last;
 130
 131                     codepoint -= 0x10000;
 132                     first = 0xD800 | ((codepoint & 0xffc00) >> 10);
 133                     last = 0xDC00 | (codepoint & 0x003ff);
 134
 135                     sprintf(seq, "\\u%04x\\u%04x", first, last);
 136                     length = 12;
 137                 }
 138
 139                 text = seq;
 140                 break;
 141             }
 142         }
 143
 144         if(dump(text, length, data))
 145             return -1;
 146
 147         str = pos = end;
 148     }
 149
 150     return dump("\"", 1, data);
 151 }
 152
 153 static int object_key_compare_keys(const void *key1, const void *key2)
 154 {
 155     return strcmp(((const struct object_key *)key1)->key,
 156                   ((const struct object_key *)key2)->key);
 157 }
 158
 159 static int object_key_compare_serials(const void *key1, const void *key2)
 160 {
 161     size_t a = ((const struct object_key *)key1)->serial;
 162     size_t b = ((const struct object_key *)key2)->serial;
 163
 164     return a < b ? -1 : a == b ? 0 : 1;
 165 }
 166
 167 static int do_dump(const json_t *json, size_t flags, int depth,
 168                    json_dump_callback_t dump, void *data)
 169 {
 170     int ascii = flags & JSON_ENSURE_ASCII ? 1 : 0;
 171
 172     switch(json_typeof(json)) {
 173         case JSON_NULL:
 174             return dump("null", 4, data);
 175
 176         case JSON_TRUE:
 177             return dump("true", 4, data);
 178
 179         case JSON_FALSE:
 180             return dump("false", 5, data);
 181
 182         case JSON_INTEGER:
 183         {
 184             char buffer[MAX_INTEGER_STR_LENGTH];
 185             int size;
 186
 187             size = snprintf(buffer, MAX_INTEGER_STR_LENGTH,
 188                             "%" JSON_INTEGER_FORMAT,
 189                             json_integer_value(json));
 190             if(size >= MAX_INTEGER_STR_LENGTH)
 191                 return -1;
 192
 193             return dump(buffer, size, data);
 194         }
 195
 196         case JSON_REAL:
 197         {
 198             char buffer[MAX_REAL_STR_LENGTH];
 199             int size;
 200             double value = json_real_value(json);
 201
 202             size = jsonp_dtostr(buffer, MAX_REAL_STR_LENGTH, value);
 203             if(size < 0)
 204                 return -1;
 205
 206             return dump(buffer, size, data);
 207         }
 208
 209         case JSON_STRING:
 210             return dump_string(json_string_value(json), ascii, dump, data);
 211
 212         case JSON_ARRAY:
 213         {
 214             int i;
 215             int n;
 216             json_array_t *array;
 217
 218             /* detect circular references */
 219             array = json_to_array(json);
 220             if(array->visited)
 221                 goto array_error;
 222             array->visited = 1;
 223
 224             n = json_array_size(json);
 225
 226             if(dump("[", 1, data))
 227                 goto array_error;
 228             if(n == 0) {
 229                 array->visited = 0;
 230                 return dump("]", 1, data);
 231             }
 232             if(dump_indent(flags, depth + 1, 0, dump, data))
 233                 goto array_error;
 234
 235             for(i = 0; i < n; ++i) {
 236                 if(do_dump(json_array_get(json, i), flags, depth + 1,
 237                            dump, data))
 238                     goto array_error;
 239
 240                 if(i < n - 1)
 241                 {
 242                     if(dump(",", 1, data) ||
 243                        dump_indent(flags, depth + 1, 1, dump, data))
 244                         goto array_error;
 245                 }
 246                 else
 247                 {
 248                     if(dump_indent(flags, depth, 0, dump, data))
 249                         goto array_error;
 250                 }
 251             }
 252
 253             array->visited = 0;
 254             return dump("]", 1, data);
 255
 256         array_error:
 257             array->visited = 0;
 258             return -1;
 259         }
 260
 261         case JSON_OBJECT:
 262         {
 263             json_object_t *object;
 264             void *iter;
 265             const char *separator;
 266             int separator_length;
 267
 268             if(flags & JSON_COMPACT) {
 269                 separator = ":";
 270                 separator_length = 1;
 271             }
 272             else {
 273                 separator = ": ";
 274                 separator_length = 2;
 275             }
 276
 277             /* detect circular references */
 278             object = json_to_object(json);
 279             if(object->visited)
 280                 goto object_error;
 281             object->visited = 1;
 282
 283             iter = json_object_iter((json_t *)json);
 284
 285             if(dump("{", 1, data))
 286                 goto object_error;
 287             if(!iter) {
 288                 object->visited = 0;
 289                 return dump("}", 1, data);
 290             }
 291             if(dump_indent(flags, depth + 1, 0, dump, data))
 292                 goto object_error;
 293
 294             if(flags & JSON_SORT_KEYS || flags & JSON_PRESERVE_ORDER)
 295             {
 296                 struct object_key *keys;
 297                 size_t size, i;
 298                 int (*cmp_func)(const void *, const void *);
 299
 300                 size = json_object_size(json);
 301                 keys = jsonp_malloc(size * sizeof(struct object_key));
 302                 if(!keys)
 303                     goto object_error;
 304
 305                 i = 0;
 306                 while(iter)
 307                 {
 308                     keys[i].serial = hashtable_iter_serial(iter);
 309                     keys[i].key = json_object_iter_key(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(struct object_key), 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 }