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 #if !defined( __LIBVLC__ )
  25   #error You are not libvlc or one of its plugins. You cannot include this file
  26 #endif
  27
  28 #ifndef _VLC_ARRAYS_H_
  29 #define _VLC_ARRAYS_H_
  30
  31 /**
  32  * Simple dynamic array handling. Array is realloced at each insert/removal
  33  */
  34 #if defined( _MSC_VER ) && _MSC_VER < 1300 && !defined( UNDER_CE )
  35 #   define VLCCVP (void**) /* Work-around for broken compiler */
  36 #else
  37 #   define VLCCVP
  38 #endif
  39 #define INSERT_ELEM( p_ar, i_oldsize, i_pos, elem )                           \
  40     do                                                                        \
  41     {                                                                         \
  42         if( !i_oldsize ) (p_ar) = NULL;                                       \
  43         (p_ar) = VLCCVP realloc( p_ar, ((i_oldsize) + 1) * sizeof(*(p_ar)) ); \
  44         if( (i_oldsize) - (i_pos) )                                           \
  45         {                                                                     \
  46             memmove( (p_ar) + (i_pos) + 1, (p_ar) + (i_pos),                  \
  47                      ((i_oldsize) - (i_pos)) * sizeof( *(p_ar) ) );           \
  48         }                                                                     \
  49         (p_ar)[i_pos] = elem;                                                 \
  50         (i_oldsize)++;                                                        \
  51     }                                                                         \
  52     while( 0 )
  53
  54 #define REMOVE_ELEM( p_ar, i_oldsize, i_pos )                                 \
  55     do                                                                        \
  56     {                                                                         \
  57         if( (i_oldsize) - (i_pos) - 1 )                                       \
  58         {                                                                     \
  59             memmove( (p_ar) + (i_pos),                                        \
  60                      (p_ar) + (i_pos) + 1,                                    \
  61                      ((i_oldsize) - (i_pos) - 1) * sizeof( *(p_ar) ) );       \
  62         }                                                                     \
  63         if( i_oldsize > 1 )                                                   \
  64         {                                                                     \
  65             (p_ar) = realloc( p_ar, ((i_oldsize) - 1) * sizeof( *(p_ar) ) );  \
  66         }                                                                     \
  67         else                                                                  \
  68         {                                                                     \
  69             free( p_ar );                                                     \
  70             (p_ar) = NULL;                                                    \
  71         }                                                                     \
  72         (i_oldsize)--;                                                        \
  73     }                                                                         \
  74     while( 0 )
  75
  76 #define TAB_INIT( count, tab )                  \
  77   do {                                          \
  78     (count) = 0;                                \
  79     (tab) = NULL;                               \
  80   } while(0)
  81
  82 #define TAB_CLEAN( count, tab )                 \
  83   do {                                          \
  84     free( tab );                                \
  85     (count)= 0;                                 \
  86     (tab)= NULL;                                \
  87   } while(0)
  88
  89 #define TAB_APPEND_CAST( cast, count, tab, p )             \
  90   do {                                          \
  91     if( (count) > 0 )                           \
  92         (tab) = cast realloc( tab, sizeof( void ** ) * ( (count) + 1 ) ); \
  93     else                                        \
  94         (tab) = cast malloc( sizeof( void ** ) );    \
  95     (tab)[count] = (p);                         \
  96     (count)++;                                  \
  97   } while(0)
  98
  99 #define TAB_APPEND( count, tab, p )             \
 100     TAB_APPEND_CAST( , count, tab, p )
 101 #define TAB_APPEND_CPP( type, count, tab, p )   \
 102     TAB_APPEND_CAST( (type**), count, tab, p )
 103
 104 #define TAB_FIND( count, tab, p, index )        \
 105   do {                                          \
 106         int _i_;                                \
 107         (index) = -1;                           \
 108         for( _i_ = 0; _i_ < (count); _i_++ )    \
 109         {                                       \
 110             if( (tab)[_i_] == (p) )             \
 111             {                                   \
 112                 (index) = _i_;                  \
 113                 break;                          \
 114             }                                   \
 115         }                                       \
 116   } while(0)
 117
 118
 119 #define TAB_REMOVE( count, tab, p )             \
 120   do {                                          \
 121         int _i_index_;                          \
 122         TAB_FIND( count, tab, p, _i_index_ );   \
 123         if( _i_index_ >= 0 )                    \
 124         {                                       \
 125             if( (count) > 1 )                   \
 126             {                                   \
 127                 memmove( ((void**)(tab) + _i_index_),    \
 128                          ((void**)(tab) + _i_index_+1),  \
 129                          ( (count) - _i_index_ - 1 ) * sizeof( void* ) );\
 130             }                                   \
 131             (count)--;                          \
 132             if( (count) == 0 )                  \
 133             {                                   \
 134                 free( tab );                    \
 135                 (tab) = NULL;                   \
 136             }                                   \
 137         }                                       \
 138   } while(0)
 139
 140 #define TAB_INSERT_CAST( cast, count, tab, p, index ) do { \
 141     if( (count) > 0 )                           \
 142         (tab) = cast realloc( tab, sizeof( void ** ) * ( (count) + 1 ) ); \
 143     else                                        \
 144         (tab) = cast malloc( sizeof( void ** ) );       \
 145     if( (count) - (index) > 0 )                 \
 146         memmove( (void**)(tab) + (index) + 1,   \
 147                  (void**)(tab) + (index),       \
 148                  ((count) - (index)) * sizeof(*(tab)) );\
 149     (tab)[(index)] = (p);                       \
 150     (count)++;                                  \
 151 } while(0)
 152
 153 #define TAB_INSERT( count, tab, p, index )      \
 154     TAB_INSERT_CAST( , count, tab, p, index )
 155
 156 /**
 157  * Binary search in a sorted array. The key must be comparable by < and >
 158  * \param entries array of entries
 159  * \param count number of entries
 160  * \param elem key to check within an entry (like .id, or ->i_id)
 161  * \param zetype type of the key
 162  * \param key value of the key
 163  * \param answer index of answer within the array. -1 if not found
 164  */
 165 #define BSEARCH( entries, count, elem, zetype, key, answer ) \
 166    do {  \
 167     int low = 0, high = count - 1;   \
 168     answer = -1; \
 169     while( low <= high ) {\
 170         int mid = (low + high ) / 2; /* Just don't care about 2^30 tables */ \
 171         zetype mid_val = entries[mid] elem;\
 172         if( mid_val < key ) \
 173             low = mid + 1; \
 174         else if ( mid_val > key ) \
 175             high = mid -1;  \
 176         else    \
 177         {   \
 178             answer = mid;  break;   \
 179         }\
 180     } \
 181  } while(0)
 182
 183
 184 /************************************************************************
 185  * Dynamic arrays with progressive allocation
 186  ************************************************************************/
 187
 188 /* Internal functions */
 189 #define _ARRAY_ALLOC(array, newsize) {                                      \
 190     array.i_alloc = newsize;                                                \
 191     array.p_elems = VLCCVP realloc( array.p_elems, array.i_alloc *          \
 192                                     sizeof(*array.p_elems) );               \
 193 }
 194
 195 #define _ARRAY_GROW1(array) {                                               \
 196     if( array.i_alloc < 10 )                                                \
 197         _ARRAY_ALLOC(array, 10 )                                            \
 198     else if( array.i_alloc == array.i_size )                                \
 199         _ARRAY_ALLOC(array, (int)(array.i_alloc * 1.5) )                    \
 200 }
 201
 202 #define _ARRAY_GROW(array,additional) {                                     \
 203      int i_first = array.i_alloc;                                           \
 204      while( array.i_alloc - i_first < additional )                          \
 205      {                                                                      \
 206          if( array.i_alloc < 10 )                                           \
 207             _ARRAY_ALLOC(array, 10 )                                        \
 208         else if( array.i_alloc == array.i_size )                            \
 209             _ARRAY_ALLOC(array, (int)(array.i_alloc * 1.5) )                \
 210         else break;                                                         \
 211      }                                                                      \
 212 }
 213
 214 #define _ARRAY_SHRINK(array) {                                              \
 215     if( array.i_size > 10 && array.i_size < (int)(array.i_alloc / 1.5) ) {  \
 216         _ARRAY_ALLOC(array, array.i_size + 5);                              \
 217     }                                                                       \
 218 }
 219
 220 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 221
 222 /* API */
 223 #define DECL_ARRAY(type) struct {                                           \
 224     int i_alloc;                                                            \
 225     int i_size;                                                             \
 226     type *p_elems;                                                          \
 227 }
 228
 229 #define TYPEDEF_ARRAY(type, name) typedef DECL_ARRAY(type) name;
 230
 231 #define ARRAY_INIT(array)                                                   \
 232     array.i_alloc = 0;                                                      \
 233     array.i_size = 0;                                                       \
 234     array.p_elems = NULL;
 235
 236 #define ARRAY_RESET(array)                                                  \
 237     array.i_alloc = 0;                                                      \
 238     array.i_size = 0;                                                       \
 239     free( array.p_elems ); array.p_elems = NULL;
 240
 241 #define ARRAY_APPEND(array, elem) {                                         \
 242     _ARRAY_GROW1(array);                                                    \
 243     array.p_elems[array.i_size] = elem;                                     \
 244     array.i_size++;                                                         \
 245 }
 246
 247 #define ARRAY_INSERT(array,elem,pos) {                                      \
 248     _ARRAY_GROW1(array);                                                    \
 249     if( array.i_size - pos ) {                                              \
 250         memmove( array.p_elems + pos + 1, array.p_elems + pos,              \
 251                  (array.i_size-pos) * sizeof(*array.p_elems) );             \
 252     }                                                                       \
 253     array.p_elems[pos] = elem;                                              \
 254     array.i_size++;                                                         \
 255 }
 256
 257 #define ARRAY_REMOVE(array,pos) {                                           \
 258     if( array.i_size - (pos) - 1 )                                          \
 259     {                                                                       \
 260         memmove( array.p_elems + pos, array.p_elems + pos + 1,              \
 261                  ( array.i_size - pos - 1 ) *sizeof(*array.p_elems) );      \
 262     }                                                                       \
 263     array.i_size--;                                                         \
 264     _ARRAY_SHRINK(array);                                                   \
 265 }
 266
 267 #define ARRAY_VAL(array, pos) array.p_elems[pos]
 268
 269 #define ARRAY_BSEARCH(array, elem, zetype, key, answer) \
 270     BSEARCH( array.p_elems, array.i_size, elem, zetype, key, answer)
 271
 272 #define FOREACH_ARRAY( item, array ) { \
 273     int fe_idx; \
 274     for( fe_idx = 0 ; fe_idx < array.i_size ; fe_idx++ ) \
 275     { \
 276         item = array.p_elems[fe_idx];
 277
 278 #define FOREACH_END() } }
 279
 280
 281 /************************************************************************
 282  * Dynamic arrays with progressive allocation (Preferred API)
 283  ************************************************************************/
 284 typedef struct vlc_array_t
 285 {
 286     int i_count;
 287     void ** pp_elems;
 288 } vlc_array_t;
 289
 290 static inline void vlc_array_init( vlc_array_t * p_array )
 291 {
 292     memset( p_array, 0, sizeof(vlc_array_t) );
 293 }
 294
 295 static inline void vlc_array_clear( vlc_array_t * p_array )
 296 {
 297     free( p_array->pp_elems );
 298     memset( p_array, 0, sizeof(vlc_array_t) );
 299 }
 300
 301 static inline vlc_array_t * vlc_array_new( void )
 302 {
 303     vlc_array_t * ret = (vlc_array_t *)malloc( sizeof(vlc_array_t) );
 304     if( ret ) vlc_array_init( ret );
 305     return ret;
 306 }
 307
 308 static inline void vlc_array_destroy( vlc_array_t * p_array )
 309 {
 310     if( !p_array )
 311         return;
 312     vlc_array_clear( p_array );
 313     free( p_array );
 314 }
 315
 316
 317 /* Read */
 318 static inline int
 319 vlc_array_count( vlc_array_t * p_array )
 320 {
 321     return p_array->i_count;
 322 }
 323
 324 static inline void *
 325 vlc_array_item_at_index( vlc_array_t * p_array, int i_index )
 326 {
 327     return p_array->pp_elems[i_index];
 328 }
 329
 330 static inline int
 331 vlc_array_index_of_item( vlc_array_t * p_array, void * item )
 332 {
 333     int i;
 334     for( i = 0; i < p_array->i_count; i++)
 335     {
 336         if( p_array->pp_elems[i] == item )
 337             return i;
 338     }
 339     return -1;
 340 }
 341
 342 /* Write */
 343 static inline void
 344 vlc_array_insert( vlc_array_t * p_array, void * p_elem, int i_index )
 345 {
 346     TAB_INSERT_CAST( (void **), p_array->i_count, p_array->pp_elems, p_elem, i_index );
 347 }
 348
 349 static inline void
 350 vlc_array_append( vlc_array_t * p_array, void * p_elem )
 351 {
 352     vlc_array_insert( p_array, p_elem, p_array->i_count );
 353 }
 354
 355 static inline void
 356 vlc_array_remove( vlc_array_t * p_array, int i_index )
 357 {
 358     if( i_index >= 0 )
 359     {
 360         if( p_array->i_count > 1 )
 361         {
 362             memmove( p_array->pp_elems + i_index,
 363                      p_array->pp_elems + i_index+1,
 364                      ( p_array->i_count - i_index - 1 ) * sizeof( void* ) );
 365         }
 366         p_array->i_count--;
 367         if( p_array->i_count == 0 )
 368         {
 369             free( p_array->pp_elems );
 370             p_array->pp_elems = NULL;
 371         }
 372     }
 373 }
 374
 375
 376 /************************************************************************
 377  * Dictionaries
 378  ************************************************************************/
 379
 380 /* This function is not intended to be crypto-secure, we only want it to be
 381  * fast and not suck too much. This one is pretty fast and did 0 collisions
 382  * in wenglish's dictionary.
 383  */
 384 static inline uint64_t DictHash( const char *psz_string, int hashsize )
 385 {
 386     uint64_t i_hash = 0;
 387     if( psz_string )
 388     {
 389         while( *psz_string )
 390         {
 391             i_hash += *psz_string++;
 392             i_hash += i_hash << 10;
 393             i_hash ^= i_hash >> 8;
 394         }
 395     }
 396     return i_hash % hashsize;
 397 }
 398
 399 struct vlc_dictionary_entry_t
 400 {
 401     char *   psz_key;
 402     void *   p_value;
 403     struct vlc_dictionary_entry_t * p_next;
 404 };
 405
 406 typedef struct vlc_dictionary_t
 407 {
 408     int i_size;
 409     struct vlc_dictionary_entry_t ** p_entries;
 410 } vlc_dictionary_t;
 411
 412 static void * const kVLCDictionaryNotFound = NULL;
 413
 414 static inline void vlc_dictionary_init( vlc_dictionary_t * p_dict, int i_size )
 415 {
 416     if( i_size > 0 )
 417     {
 418         p_dict->p_entries = (struct vlc_dictionary_entry_t **)malloc(sizeof(struct vlc_dictionary_entry_t *) * i_size);
 419         memset( p_dict->p_entries, 0, sizeof(struct vlc_dictionary_entry_t *) * i_size );
 420     }
 421     else
 422         p_dict->p_entries = NULL;
 423     p_dict->i_size = i_size;
 424 }
 425
 426 static inline void vlc_dictionary_clear( vlc_dictionary_t * p_dict )
 427 {
 428     int i;
 429     struct vlc_dictionary_entry_t * p_current, * p_next;
 430     if( p_dict->p_entries )
 431     {
 432         for( i = 0; i < p_dict->i_size; i++ )
 433         {
 434             p_current = p_dict->p_entries[i];
 435             while( p_current )
 436             {
 437                 p_next = p_current->p_next;
 438                 free( p_current->psz_key );
 439                 free( p_current );
 440                 p_current = p_next;
 441             }
 442         }
 443         free( p_dict->p_entries );
 444     }
 445     p_dict->i_size = 0;
 446 }
 447
 448
 449
 450 static inline void *
 451 vlc_dictionary_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 452 {
 453     if( !p_dict->p_entries )
 454         return kVLCDictionaryNotFound;
 455
 456     int i_pos = DictHash( psz_key, p_dict->i_size );
 457     struct vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 458
 459     if( !p_entry )
 460         return kVLCDictionaryNotFound;
 461
 462     /* Make sure we return the right item. (Hash collision) */
 463     do {
 464         if( !strcmp( psz_key, p_entry->psz_key ) )
 465             return p_entry->p_value;
 466         p_entry = p_entry->p_next;
 467     } while( p_entry );
 468
 469     return kVLCDictionaryNotFound;
 470 }
 471
 472 static inline int
 473 vlc_dictionary_keys_count( const vlc_dictionary_t * p_dict )
 474 {
 475     struct vlc_dictionary_entry_t * p_entry;
 476     int i, count = 0;
 477
 478     if( !p_dict->p_entries )
 479         return 0;
 480
 481     for( i = 0; i < p_dict->i_size; i++ )
 482     {
 483         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next ) count++;
 484     }
 485     return count;
 486 }
 487
 488 static inline char **
 489 vlc_dictionary_all_keys( const vlc_dictionary_t * p_dict )
 490 {
 491     struct vlc_dictionary_entry_t * p_entry;
 492     char ** ppsz_ret;
 493     int i, count = vlc_dictionary_keys_count( p_dict );
 494
 495     ppsz_ret = (char**)malloc(sizeof(char *) * (count + 1));
 496
 497     count = 0;
 498     for( i = 0; i < p_dict->i_size; i++ )
 499     {
 500         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next )
 501             ppsz_ret[count++] = strdup( p_entry->psz_key );
 502     }
 503     ppsz_ret[count] = NULL;
 504     return ppsz_ret;
 505 }
 506
 507 static inline void
 508 __vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key,
 509                          void * p_value, bool rebuild )
 510 {
 511     if( !p_dict->p_entries )
 512         vlc_dictionary_init( p_dict, 1 );
 513
 514     int i_pos = DictHash( psz_key, p_dict->i_size );
 515     struct vlc_dictionary_entry_t * p_entry;
 516
 517     p_entry = (struct vlc_dictionary_entry_t *)malloc(sizeof(struct vlc_dictionary_entry_t));
 518     p_entry->psz_key = strdup( psz_key );
 519     p_entry->p_value = p_value;
 520     p_entry->p_next = p_dict->p_entries[i_pos];
 521     p_dict->p_entries[i_pos] = p_entry;
 522     if( rebuild )
 523     {
 524         /* Count how many items there was */
 525         int count;
 526         for( count = 1; p_entry->p_next; count++ ) p_entry = p_entry->p_next;
 527         if( count > 3 ) /* XXX: this need tuning */
 528         {
 529             /* Here it starts to be not good, rebuild a bigger dictionary */
 530             struct vlc_dictionary_t new_dict;
 531             int i_new_size = ( (p_dict->i_size+2) * 3) / 2; /* XXX: this need tuning */
 532             int i;
 533             vlc_dictionary_init( &new_dict, i_new_size );
 534             for( i = 0; i < p_dict->i_size; i++ )
 535             {
 536                 p_entry = p_dict->p_entries[i];
 537                 while( p_entry )
 538                 {
 539                     __vlc_dictionary_insert( &new_dict, p_entry->psz_key,
 540                                              p_entry->p_value,
 541                                              0 /* To avoid multiple rebuild loop */);
 542                     p_entry = p_entry->p_next;
 543                 }
 544             }
 545
 546             vlc_dictionary_clear( p_dict );
 547             p_dict->i_size = new_dict.i_size;
 548             p_dict->p_entries = new_dict.p_entries;
 549         }
 550     }
 551 }
 552
 553 static inline void
 554 vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key, void * p_value )
 555 {
 556     __vlc_dictionary_insert( p_dict, psz_key, p_value, 1 );
 557 }
 558
 559 static inline void
 560 vlc_dictionary_remove_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 561 {
 562     if( !p_dict->p_entries )
 563         return;
 564
 565     int i_pos = DictHash( psz_key, p_dict->i_size );
 566     struct vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 567     struct vlc_dictionary_entry_t * p_prev;
 568
 569     if( !p_entry )
 570         return; /* Not found, nothing to do */
 571
 572     /* Hash collision */
 573     p_prev = NULL;
 574     do {
 575         if( !strcmp( psz_key, p_entry->psz_key ) )
 576         {
 577             if( !p_prev )
 578                 p_dict->p_entries[i_pos] = p_entry->p_next;
 579             else
 580                 p_prev->p_next = p_entry->p_next;
 581             free( p_entry->psz_key );
 582             free( p_entry );
 583             return;
 584         }
 585         p_prev = p_entry;
 586         p_entry = p_entry->p_next;
 587     } while( p_entry );
 588
 589     /* No key was found */
 590 }
 591
 592 #endif