git.sesse.net Git - vlc/blob - include/vlc_arrays.h

   1 /*****************************************************************************
   2  * vlc_arrays.h : Arrays and data structures handling
   3  *****************************************************************************
   4  * Copyright (C) 1999-2004 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Samuel Hocevar <sam@zoy.org>
   8  *          Clément Stenac <zorglub@videolan.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA. *****************************************************************************/
  23
  24 #ifndef _VLC_ARRAYS_H_
  25 #define _VLC_ARRAYS_H_
  26
  27 /**
  28  * Simple dynamic array handling. Array is realloced at each insert/removal
  29  */
  30 #if defined( _MSC_VER ) && _MSC_VER < 1300 && !defined( UNDER_CE )
  31 #   define VLCCVP (void**) /* Work-around for broken compiler */
  32 #else
  33 #   define VLCCVP
  34 #endif
  35 #define INSERT_ELEM( p_ar, i_oldsize, i_pos, elem )                           \
  36     do                                                                        \
  37     {                                                                         \
  38         if( !i_oldsize ) (p_ar) = NULL;                                       \
  39         (p_ar) = VLCCVP realloc( p_ar, ((i_oldsize) + 1) * sizeof(*(p_ar)) ); \
  40         if( (i_oldsize) - (i_pos) )                                           \
  41         {                                                                     \
  42             memmove( (p_ar) + (i_pos) + 1, (p_ar) + (i_pos),                  \
  43                      ((i_oldsize) - (i_pos)) * sizeof( *(p_ar) ) );           \
  44         }                                                                     \
  45         (p_ar)[i_pos] = elem;                                                 \
  46         (i_oldsize)++;                                                        \
  47     }                                                                         \
  48     while( 0 )
  49
  50 #define REMOVE_ELEM( p_ar, i_oldsize, i_pos )                                 \
  51     do                                                                        \
  52     {                                                                         \
  53         if( (i_oldsize) - (i_pos) - 1 )                                       \
  54         {                                                                     \
  55             memmove( (p_ar) + (i_pos),                                        \
  56                      (p_ar) + (i_pos) + 1,                                    \
  57                      ((i_oldsize) - (i_pos) - 1) * sizeof( *(p_ar) ) );       \
  58         }                                                                     \
  59         if( i_oldsize > 1 )                                                   \
  60         {                                                                     \
  61             (p_ar) = realloc( p_ar, ((i_oldsize) - 1) * sizeof( *(p_ar) ) );  \
  62         }                                                                     \
  63         else                                                                  \
  64         {                                                                     \
  65             free( p_ar );                                                     \
  66             (p_ar) = NULL;                                                    \
  67         }                                                                     \
  68         (i_oldsize)--;                                                        \
  69     }                                                                         \
  70     while( 0 )
  71
  72 #define TAB_INIT( count, tab )                  \
  73   do {                                          \
  74     (count) = 0;                                \
  75     (tab) = NULL;                               \
  76   } while(0)
  77
  78 #define TAB_CLEAN( count, tab )                 \
  79   do {                                          \
  80     free( tab );                                \
  81     (count)= 0;                                 \
  82     (tab)= NULL;                                \
  83   } while(0)
  84
  85 #define TAB_APPEND_CAST( cast, count, tab, p )             \
  86   do {                                          \
  87     if( (count) > 0 )                           \
  88         (tab) = cast realloc( tab, sizeof( void ** ) * ( (count) + 1 ) ); \
  89     else                                        \
  90         (tab) = cast malloc( sizeof( void ** ) );    \
  91     (tab)[count] = (p);                         \
  92     (count)++;                                  \
  93   } while(0)
  94
  95 #define TAB_APPEND( count, tab, p )             \
  96     TAB_APPEND_CAST( , count, tab, p )
  97 #define TAB_APPEND_CPP( type, count, tab, p )   \
  98     TAB_APPEND_CAST( (type**), count, tab, p )
  99
 100 #define TAB_FIND( count, tab, p, index )        \
 101   do {                                          \
 102         int _i_;                                \
 103         (index) = -1;                           \
 104         for( _i_ = 0; _i_ < (count); _i_++ )    \
 105         {                                       \
 106             if( (tab)[_i_] == (p) )             \
 107             {                                   \
 108                 (index) = _i_;                  \
 109                 break;                          \
 110             }                                   \
 111         }                                       \
 112   } while(0)
 113
 114
 115 #define TAB_REMOVE( count, tab, p )             \
 116   do {                                          \
 117         int _i_index_;                          \
 118         TAB_FIND( count, tab, p, _i_index_ );   \
 119         if( _i_index_ >= 0 )                    \
 120         {                                       \
 121             if( (count) > 1 )                   \
 122             {                                   \
 123                 memmove( ((void**)(tab) + _i_index_),    \
 124                          ((void**)(tab) + _i_index_+1),  \
 125                          ( (count) - _i_index_ - 1 ) * sizeof( void* ) );\
 126             }                                   \
 127             (count)--;                          \
 128             if( (count) == 0 )                  \
 129             {                                   \
 130                 free( tab );                    \
 131                 (tab) = NULL;                   \
 132             }                                   \
 133         }                                       \
 134   } while(0)
 135
 136 #define TAB_INSERT_CAST( cast, count, tab, p, index ) do { \
 137     if( (count) > 0 )                           \
 138         (tab) = cast realloc( tab, sizeof( void ** ) * ( (count) + 1 ) ); \
 139     else                                        \
 140         (tab) = cast malloc( sizeof( void ** ) );       \
 141     if( (count) - (index) > 0 )                 \
 142         memmove( (void**)(tab) + (index) + 1,   \
 143                  (void**)(tab) + (index),       \
 144                  ((count) - (index)) * sizeof(*(tab)) );\
 145     (tab)[(index)] = (p);                       \
 146     (count)++;                                  \
 147 } while(0)
 148
 149 #define TAB_INSERT( count, tab, p, index )      \
 150     TAB_INSERT_CAST( , count, tab, p, index )
 151
 152 /**
 153  * Binary search in a sorted array. The key must be comparable by < and >
 154  * \param entries array of entries
 155  * \param count number of entries
 156  * \param elem key to check within an entry (like .id, or ->i_id)
 157  * \param zetype type of the key
 158  * \param key value of the key
 159  * \param answer index of answer within the array. -1 if not found
 160  */
 161 #define BSEARCH( entries, count, elem, zetype, key, answer ) \
 162    do {  \
 163     int low = 0, high = count - 1;   \
 164     answer = -1; \
 165     while( low <= high ) {\
 166         int mid = (low + high ) / 2; /* Just don't care about 2^30 tables */ \
 167         zetype mid_val = entries[mid] elem;\
 168         if( mid_val < key ) \
 169             low = mid + 1; \
 170         else if ( mid_val > key ) \
 171             high = mid -1;  \
 172         else    \
 173         {   \
 174             answer = mid;  break;   \
 175         }\
 176     } \
 177  } while(0)
 178
 179
 180 /************************************************************************
 181  * Dynamic arrays with progressive allocation
 182  ************************************************************************/
 183
 184 /* Internal functions */
 185 #define _ARRAY_ALLOC(array, newsize) {                                      \
 186     array.i_alloc = newsize;                                                \
 187     array.p_elems = VLCCVP realloc( array.p_elems, array.i_alloc *          \
 188                                     sizeof(*array.p_elems) );               \
 189 }
 190
 191 #define _ARRAY_GROW1(array) {                                               \
 192     if( array.i_alloc < 10 )                                                \
 193         _ARRAY_ALLOC(array, 10 )                                            \
 194     else if( array.i_alloc == array.i_size )                                \
 195         _ARRAY_ALLOC(array, (int)(array.i_alloc * 1.5) )                    \
 196 }
 197
 198 #define _ARRAY_GROW(array,additional) {                                     \
 199      int i_first = array.i_alloc;                                           \
 200      while( array.i_alloc - i_first < additional )                          \
 201      {                                                                      \
 202          if( array.i_alloc < 10 )                                           \
 203             _ARRAY_ALLOC(array, 10 )                                        \
 204         else if( array.i_alloc == array.i_size )                            \
 205             _ARRAY_ALLOC(array, (int)(array.i_alloc * 1.5) )                \
 206         else break;                                                         \
 207      }                                                                      \
 208 }
 209
 210 #define _ARRAY_SHRINK(array) {                                              \
 211     if( array.i_size > 10 && array.i_size < (int)(array.i_alloc / 1.5) ) {  \
 212         _ARRAY_ALLOC(array, array.i_size + 5);                              \
 213     }                                                                       \
 214 }
 215
 216 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 217
 218 /* API */
 219 #define DECL_ARRAY(type) struct {                                           \
 220     int i_alloc;                                                            \
 221     int i_size;                                                             \
 222     type *p_elems;                                                          \
 223 }
 224
 225 #define TYPEDEF_ARRAY(type, name) typedef DECL_ARRAY(type) name;
 226
 227 #define ARRAY_INIT(array)                                                   \
 228     array.i_alloc = 0;                                                      \
 229     array.i_size = 0;                                                       \
 230     array.p_elems = NULL;
 231
 232 #define ARRAY_RESET(array)                                                  \
 233     array.i_alloc = 0;                                                      \
 234     array.i_size = 0;                                                       \
 235     free( array.p_elems ); array.p_elems = NULL;
 236
 237 #define ARRAY_APPEND(array, elem) {                                         \
 238     _ARRAY_GROW1(array);                                                    \
 239     array.p_elems[array.i_size] = elem;                                     \
 240     array.i_size++;                                                         \
 241 }
 242
 243 #define ARRAY_INSERT(array,elem,pos) {                                      \
 244     _ARRAY_GROW1(array);                                                    \
 245     if( array.i_size - pos ) {                                              \
 246         memmove( array.p_elems + pos + 1, array.p_elems + pos,              \
 247                  (array.i_size-pos) * sizeof(*array.p_elems) );             \
 248     }                                                                       \
 249     array.p_elems[pos] = elem;                                              \
 250     array.i_size++;                                                         \
 251 }
 252
 253 #define ARRAY_REMOVE(array,pos) {                                           \
 254     if( array.i_size - (pos) - 1 )                                          \
 255     {                                                                       \
 256         memmove( array.p_elems + pos, array.p_elems + pos + 1,              \
 257                  ( array.i_size - pos - 1 ) *sizeof(*array.p_elems) );      \
 258     }                                                                       \
 259     array.i_size--;                                                         \
 260     _ARRAY_SHRINK(array);                                                   \
 261 }
 262
 263 #define ARRAY_VAL(array, pos) array.p_elems[pos]
 264
 265 #define ARRAY_BSEARCH(array, elem, zetype, key, answer) \
 266     BSEARCH( array.p_elems, array.i_size, elem, zetype, key, answer)
 267
 268 #define FOREACH_ARRAY( item, array ) { \
 269     int fe_idx; \
 270     for( fe_idx = 0 ; fe_idx < array.i_size ; fe_idx++ ) \
 271     { \
 272         item = array.p_elems[fe_idx];
 273
 274 #define FOREACH_END() } }
 275
 276
 277 /************************************************************************
 278  * Dynamic arrays with progressive allocation (Preferred API)
 279  ************************************************************************/
 280 typedef struct vlc_array_t
 281 {
 282     int i_count;
 283     void ** pp_elems;
 284 } vlc_array_t;
 285
 286 static inline void vlc_array_init( vlc_array_t * p_array )
 287 {
 288     memset( p_array, 0, sizeof(vlc_array_t) );
 289 }
 290
 291 static inline void vlc_array_clear( vlc_array_t * p_array )
 292 {
 293     free( p_array->pp_elems );
 294     memset( p_array, 0, sizeof(vlc_array_t) );
 295 }
 296
 297 static inline vlc_array_t * vlc_array_new( void )
 298 {
 299     vlc_array_t * ret = (vlc_array_t *)malloc( sizeof(vlc_array_t) );
 300     if( ret ) vlc_array_init( ret );
 301     return ret;
 302 }
 303
 304 static inline void vlc_array_destroy( vlc_array_t * p_array )
 305 {
 306     if( !p_array )
 307         return;
 308     vlc_array_clear( p_array );
 309     free( p_array );
 310 }
 311
 312
 313 /* Read */
 314 static inline int
 315 vlc_array_count( vlc_array_t * p_array )
 316 {
 317     return p_array->i_count;
 318 }
 319
 320 static inline void *
 321 vlc_array_item_at_index( vlc_array_t * p_array, int i_index )
 322 {
 323     return p_array->pp_elems[i_index];
 324 }
 325
 326 static inline int
 327 vlc_array_index_of_item( vlc_array_t * p_array, void * item )
 328 {
 329     int i;
 330     for( i = 0; i < p_array->i_count; i++)
 331     {
 332         if( p_array->pp_elems[i] == item )
 333             return i;
 334     }
 335     return -1;
 336 }
 337
 338 /* Write */
 339 static inline void
 340 vlc_array_insert( vlc_array_t * p_array, void * p_elem, int i_index )
 341 {
 342     TAB_INSERT_CAST( (void **), p_array->i_count, p_array->pp_elems, p_elem, i_index );
 343 }
 344
 345 static inline void
 346 vlc_array_append( vlc_array_t * p_array, void * p_elem )
 347 {
 348     vlc_array_insert( p_array, p_elem, p_array->i_count );
 349 }
 350
 351 static inline void
 352 vlc_array_remove( vlc_array_t * p_array, int i_index )
 353 {
 354     if( i_index >= 0 )
 355     {
 356         if( p_array->i_count > 1 )
 357         {
 358             memmove( p_array->pp_elems + i_index,
 359                      p_array->pp_elems + i_index+1,
 360                      ( p_array->i_count - i_index - 1 ) * sizeof( void* ) );
 361         }
 362         p_array->i_count--;
 363         if( p_array->i_count == 0 )
 364         {
 365             free( p_array->pp_elems );
 366             p_array->pp_elems = NULL;
 367         }
 368     }
 369 }
 370
 371
 372 /************************************************************************
 373  * Dictionaries
 374  ************************************************************************/
 375
 376 /* This function is not intended to be crypto-secure, we only want it to be
 377  * fast and not suck too much. This one is pretty fast and did 0 collisions
 378  * in wenglish's dictionary.
 379  */
 380 static inline uint64_t DictHash( const char *psz_string, int hashsize )
 381 {
 382     uint64_t i_hash = 0;
 383     if( psz_string )
 384     {
 385         while( *psz_string )
 386         {
 387             i_hash += *psz_string++;
 388             i_hash += i_hash << 10;
 389             i_hash ^= i_hash >> 8;
 390         }
 391     }
 392     return i_hash % hashsize;
 393 }
 394
 395 struct vlc_dictionary_entry_t
 396 {
 397     char *   psz_key;
 398     void *   p_value;
 399     struct vlc_dictionary_entry_t * p_next;
 400 };
 401
 402 typedef struct vlc_dictionary_t
 403 {
 404     int i_size;
 405     struct vlc_dictionary_entry_t ** p_entries;
 406 } vlc_dictionary_t;
 407
 408 static void * const kVLCDictionaryNotFound = NULL;
 409
 410 static inline void vlc_dictionary_init( vlc_dictionary_t * p_dict, int i_size )
 411 {
 412     if( i_size > 0 )
 413     {
 414         p_dict->p_entries = (struct vlc_dictionary_entry_t **)malloc(sizeof(struct vlc_dictionary_entry_t *) * i_size);
 415         memset( p_dict->p_entries, 0, sizeof(struct vlc_dictionary_entry_t *) * i_size );
 416     }
 417     else
 418         p_dict->p_entries = NULL;
 419     p_dict->i_size = i_size;
 420 }
 421
 422 static inline void vlc_dictionary_clear( vlc_dictionary_t * p_dict )
 423 {
 424     int i;
 425     struct vlc_dictionary_entry_t * p_current, * p_next;
 426     if( p_dict->p_entries )
 427     {
 428         for( i = 0; i < p_dict->i_size; i++ )
 429         {
 430             p_current = p_dict->p_entries[i];
 431             while( p_current )
 432             {
 433                 p_next = p_current->p_next;
 434                 free( p_current->psz_key );
 435                 free( p_current );
 436                 p_current = p_next;
 437             }
 438         }
 439         free( p_dict->p_entries );
 440     }
 441     p_dict->i_size = 0;
 442 }
 443
 444
 445
 446 static inline void *
 447 vlc_dictionary_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 448 {
 449     if( !p_dict->p_entries )
 450         return kVLCDictionaryNotFound;
 451
 452     int i_pos = DictHash( psz_key, p_dict->i_size );
 453     struct vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 454
 455     if( !p_entry )
 456         return kVLCDictionaryNotFound;
 457
 458     /* Make sure we return the right item. (Hash collision) */
 459     do {
 460         if( !strcmp( psz_key, p_entry->psz_key ) )
 461             return p_entry->p_value;
 462         p_entry = p_entry->p_next;
 463     } while( p_entry );
 464
 465     return kVLCDictionaryNotFound;
 466 }
 467
 468 static inline int
 469 vlc_dictionary_keys_count( const vlc_dictionary_t * p_dict )
 470 {
 471     struct vlc_dictionary_entry_t * p_entry;
 472     int i, count = 0;
 473
 474     if( !p_dict->p_entries )
 475         return 0;
 476
 477     for( i = 0; i < p_dict->i_size; i++ )
 478     {
 479         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next ) count++;
 480     }
 481     return count;
 482 }
 483
 484 static inline char **
 485 vlc_dictionary_all_keys( const vlc_dictionary_t * p_dict )
 486 {
 487     struct vlc_dictionary_entry_t * p_entry;
 488     char ** ppsz_ret;
 489     int i, count = vlc_dictionary_keys_count( p_dict );
 490
 491     ppsz_ret = (char**)malloc(sizeof(char *) * (count + 1));
 492
 493     count = 0;
 494     for( i = 0; i < p_dict->i_size; i++ )
 495     {
 496         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next )
 497             ppsz_ret[count++] = strdup( p_entry->psz_key );
 498     }
 499     ppsz_ret[count] = NULL;
 500     return ppsz_ret;
 501 }
 502
 503 static inline void
 504 __vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key,
 505                          void * p_value, bool rebuild )
 506 {
 507     if( !p_dict->p_entries )
 508         vlc_dictionary_init( p_dict, 1 );
 509
 510     int i_pos = DictHash( psz_key, p_dict->i_size );
 511     struct vlc_dictionary_entry_t * p_entry;
 512
 513     p_entry = (struct vlc_dictionary_entry_t *)malloc(sizeof(struct vlc_dictionary_entry_t));
 514     p_entry->psz_key = strdup( psz_key );
 515     p_entry->p_value = p_value;
 516     p_entry->p_next = p_dict->p_entries[i_pos];
 517     p_dict->p_entries[i_pos] = p_entry;
 518     if( rebuild )
 519     {
 520         /* Count how many items there was */
 521         int count;
 522         for( count = 1; p_entry->p_next; count++ ) p_entry = p_entry->p_next;
 523         if( count > 3 ) /* XXX: this need tuning */
 524         {
 525             /* Here it starts to be not good, rebuild a bigger dictionary */
 526             struct vlc_dictionary_t new_dict;
 527             int i_new_size = ( (p_dict->i_size+2) * 3) / 2; /* XXX: this need tuning */
 528             int i;
 529             vlc_dictionary_init( &new_dict, i_new_size );
 530             for( i = 0; i < p_dict->i_size; i++ )
 531             {
 532                 p_entry = p_dict->p_entries[i];
 533                 while( p_entry )
 534                 {
 535                     __vlc_dictionary_insert( &new_dict, p_entry->psz_key,
 536                                              p_entry->p_value,
 537                                              0 /* To avoid multiple rebuild loop */);
 538                     p_entry = p_entry->p_next;
 539                 }
 540             }
 541
 542             vlc_dictionary_clear( p_dict );
 543             p_dict->i_size = new_dict.i_size;
 544             p_dict->p_entries = new_dict.p_entries;
 545         }
 546     }
 547 }
 548
 549 static inline void
 550 vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key, void * p_value )
 551 {
 552     __vlc_dictionary_insert( p_dict, psz_key, p_value, 1 );
 553 }
 554
 555 static inline void
 556 vlc_dictionary_remove_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 557 {
 558     if( !p_dict->p_entries )
 559         return;
 560
 561     int i_pos = DictHash( psz_key, p_dict->i_size );
 562     struct vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 563     struct vlc_dictionary_entry_t * p_prev;
 564
 565     if( !p_entry )
 566         return; /* Not found, nothing to do */
 567
 568     /* Hash collision */
 569     p_prev = NULL;
 570     do {
 571         if( !strcmp( psz_key, p_entry->psz_key ) )
 572         {
 573             if( !p_prev )
 574                 p_dict->p_entries[i_pos] = p_entry->p_next;
 575             else
 576                 p_prev->p_next = p_entry->p_next;
 577             free( p_entry->psz_key );
 578             free( p_entry );
 579             return;
 580         }
 581         p_prev = p_entry;
 582         p_entry = p_entry->p_next;
 583     } while( p_entry );
 584
 585     /* No key was found */
 586 }
 587
 588 #endif