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 #include <assert.h>
  32
  33 /**
  34  * Simple dynamic array handling. Array is realloced at each insert/removal
  35  */
  36 #if defined( _MSC_VER ) && _MSC_VER < 1300 && !defined( UNDER_CE )
  37 #   define VLCCVP (void**) /* Work-around for broken compiler */
  38 #else
  39 #   define VLCCVP
  40 #endif
  41 #define INSERT_ELEM( p_ar, i_oldsize, i_pos, elem )                           \
  42     do                                                                        \
  43     {                                                                         \
  44         if( !i_oldsize ) (p_ar) = NULL;                                       \
  45         (p_ar) = VLCCVP realloc( p_ar, ((i_oldsize) + 1) * sizeof(*(p_ar)) ); \
  46         if( (i_oldsize) - (i_pos) )                                           \
  47         {                                                                     \
  48             memmove( (p_ar) + (i_pos) + 1, (p_ar) + (i_pos),                  \
  49                      ((i_oldsize) - (i_pos)) * sizeof( *(p_ar) ) );           \
  50         }                                                                     \
  51         (p_ar)[i_pos] = elem;                                                 \
  52         (i_oldsize)++;                                                        \
  53     }                                                                         \
  54     while( 0 )
  55
  56 #define REMOVE_ELEM( p_ar, i_oldsize, i_pos )                                 \
  57     do                                                                        \
  58     {                                                                         \
  59         if( (i_oldsize) - (i_pos) - 1 )                                       \
  60         {                                                                     \
  61             memmove( (p_ar) + (i_pos),                                        \
  62                      (p_ar) + (i_pos) + 1,                                    \
  63                      ((i_oldsize) - (i_pos) - 1) * sizeof( *(p_ar) ) );       \
  64         }                                                                     \
  65         if( i_oldsize > 1 )                                                   \
  66         {                                                                     \
  67             (p_ar) = realloc( p_ar, ((i_oldsize) - 1) * sizeof( *(p_ar) ) );  \
  68         }                                                                     \
  69         else                                                                  \
  70         {                                                                     \
  71             free( p_ar );                                                     \
  72             (p_ar) = NULL;                                                    \
  73         }                                                                     \
  74         (i_oldsize)--;                                                        \
  75     }                                                                         \
  76     while( 0 )
  77
  78 #define TAB_INIT( count, tab )                  \
  79   do {                                          \
  80     (count) = 0;                                \
  81     (tab) = NULL;                               \
  82   } while(0)
  83
  84 #define TAB_CLEAN( count, tab )                 \
  85   do {                                          \
  86     if( tab ) free( tab );                      \
  87     (count)= 0;                                 \
  88     (tab)= NULL;                                \
  89   } while(0)
  90
  91 #define TAB_APPEND_CAST( cast, count, tab, p )             \
  92   do {                                          \
  93     if( (count) > 0 )                           \
  94         (tab) = cast realloc( tab, sizeof( void ** ) * ( (count) + 1 ) ); \
  95     else                                        \
  96         (tab) = cast malloc( sizeof( void ** ) );    \
  97     (tab)[count] = (p);                         \
  98     (count)++;                                  \
  99   } while(0)
 100
 101 #define TAB_APPEND( count, tab, p )             \
 102     TAB_APPEND_CAST( , count, tab, p )
 103 #define TAB_APPEND_CPP( type, count, tab, p )   \
 104     TAB_APPEND_CAST( (type**), count, tab, p )
 105
 106 #define TAB_FIND( count, tab, p, index )        \
 107   do {                                          \
 108         int _i_;                                \
 109         (index) = -1;                           \
 110         for( _i_ = 0; _i_ < (count); _i_++ )    \
 111         {                                       \
 112             if( (tab)[_i_] == (p) )             \
 113             {                                   \
 114                 (index) = _i_;                  \
 115                 break;                          \
 116             }                                   \
 117         }                                       \
 118   } while(0)
 119
 120
 121 #define TAB_REMOVE( count, tab, p )             \
 122   do {                                          \
 123         int _i_index_;                          \
 124         TAB_FIND( count, tab, p, _i_index_ );   \
 125         if( _i_index_ >= 0 )                    \
 126         {                                       \
 127             if( (count) > 1 )                   \
 128             {                                   \
 129                 memmove( ((void**)(tab) + _i_index_),    \
 130                          ((void**)(tab) + _i_index_+1),  \
 131                          ( (count) - _i_index_ - 1 ) * sizeof( void* ) );\
 132             }                                   \
 133             (count)--;                          \
 134             if( (count) == 0 )                  \
 135             {                                   \
 136                 free( tab );                    \
 137                 (tab) = NULL;                   \
 138             }                                   \
 139         }                                       \
 140   } while(0)
 141
 142 #define TAB_INSERT_CAST( cast, count, tab, p, index ) do { \
 143     if( (count) > 0 )                           \
 144         (tab) = cast realloc( tab, sizeof( void ** ) * ( (count) + 1 ) ); \
 145     else                                        \
 146         (tab) = cast malloc( sizeof( void ** ) );       \
 147     if( (count) - (index) > 0 )                 \
 148         memmove( (void**)(tab) + (index) + 1,   \
 149                  (void**)(tab) + (index),       \
 150                  ((count) - (index)) * sizeof(*(tab)) );\
 151     (tab)[(index)] = (p);                       \
 152     (count)++;                                  \
 153 } while(0)
 154
 155 #define TAB_INSERT( count, tab, p, index )      \
 156     TAB_INSERT_CAST( , count, tab, p, index )
 157
 158 /**
 159  * Binary search in a sorted array. The key must be comparable by < and >
 160  * \param entries array of entries
 161  * \param count number of entries
 162  * \param elem key to check within an entry (like .id, or ->i_id)
 163  * \param zetype type of the key
 164  * \param key value of the key
 165  * \param answer index of answer within the array. -1 if not found
 166  */
 167 #define BSEARCH( entries, count, elem, zetype, key, answer ) \
 168    do {  \
 169     int low = 0, high = count - 1;   \
 170     answer = -1; \
 171     while( low <= high ) {\
 172         int mid = (low + high ) / 2; /* Just don't care about 2^30 tables */ \
 173         zetype mid_val = entries[mid] elem;\
 174         if( mid_val < key ) \
 175             low = mid + 1; \
 176         else if ( mid_val > key ) \
 177             high = mid -1;  \
 178         else    \
 179         {   \
 180             answer = mid;  break;   \
 181         }\
 182     } \
 183  } while(0)
 184
 185
 186 /************************************************************************
 187  * Dynamic arrays with progressive allocation
 188  ************************************************************************/
 189
 190 /* Internal functions */
 191 #define _ARRAY_ALLOC(array, newsize) {                                      \
 192     array.i_alloc = newsize;                                                \
 193     array.p_elems = VLCCVP realloc( array.p_elems, array.i_alloc *          \
 194                                     sizeof(*array.p_elems) );               \
 195     assert(array.p_elems);                                                  \
 196 }
 197
 198 #define _ARRAY_GROW1(array) {                                               \
 199     if( array.i_alloc < 10 )                                                \
 200         _ARRAY_ALLOC(array, 10 )                                            \
 201     else if( array.i_alloc == array.i_size )                                \
 202         _ARRAY_ALLOC(array, (int)(array.i_alloc * 1.5) )                    \
 203 }
 204
 205 #define _ARRAY_GROW(array,additional) {                                     \
 206      int i_first = array.i_alloc;                                           \
 207      while( array.i_alloc - i_first < additional )                          \
 208      {                                                                      \
 209          if( array.i_alloc < 10 )                                           \
 210             _ARRAY_ALLOC(array, 10 )                                        \
 211         else if( array.i_alloc == array.i_size )                            \
 212             _ARRAY_ALLOC(array, (int)(array.i_alloc * 1.5) )                \
 213         else break;                                                         \
 214      }                                                                      \
 215 }
 216
 217 #define _ARRAY_SHRINK(array) {                                              \
 218     if( array.i_size > 10 && array.i_size < (int)(array.i_alloc / 1.5) ) {  \
 219         _ARRAY_ALLOC(array, array.i_size + 5);                              \
 220     }                                                                       \
 221 }
 222
 223 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 224
 225 /* API */
 226 #define DECL_ARRAY(type) struct {                                           \
 227     int i_alloc;                                                            \
 228     int i_size;                                                             \
 229     type *p_elems;                                                          \
 230 }
 231
 232 #define TYPEDEF_ARRAY(type, name) typedef DECL_ARRAY(type) name;
 233
 234 #define ARRAY_INIT(array)                                                   \
 235     array.i_alloc = 0;                                                      \
 236     array.i_size = 0;                                                       \
 237     array.p_elems = NULL;
 238
 239 #define ARRAY_RESET(array)                                                  \
 240     array.i_alloc = 0;                                                      \
 241     array.i_size = 0;                                                       \
 242     free( array.p_elems ); array.p_elems = NULL;
 243
 244 #define ARRAY_APPEND(array, elem) {                                         \
 245     _ARRAY_GROW1(array);                                                    \
 246     array.p_elems[array.i_size] = elem;                                     \
 247     array.i_size++;                                                         \
 248 }
 249
 250 #define ARRAY_INSERT(array,elem,pos) {                                      \
 251     _ARRAY_GROW1(array);                                                    \
 252     if( array.i_size - pos ) {                                              \
 253         memmove( array.p_elems + pos + 1, array.p_elems + pos,              \
 254                  (array.i_size-pos) * sizeof(*array.p_elems) );             \
 255     }                                                                       \
 256     array.p_elems[pos] = elem;                                              \
 257     array.i_size++;                                                         \
 258 }
 259
 260 #define ARRAY_REMOVE(array,pos) {                                           \
 261     if( array.i_size - (pos) - 1 )                                          \
 262     {                                                                       \
 263         memmove( array.p_elems + pos, array.p_elems + pos + 1,              \
 264                  ( array.i_size - pos - 1 ) *sizeof(*array.p_elems) );      \
 265     }                                                                       \
 266     array.i_size--;                                                         \
 267     _ARRAY_SHRINK(array);                                                   \
 268 }
 269
 270 #define ARRAY_VAL(array, pos) array.p_elems[pos]
 271
 272 #define ARRAY_BSEARCH(array, elem, zetype, key, answer) \
 273     BSEARCH( array.p_elems, array.i_size, elem, zetype, key, answer)
 274
 275 #define FOREACH_ARRAY( item, array ) { \
 276     int fe_idx; \
 277     for( fe_idx = 0 ; fe_idx < array.i_size ; fe_idx++ ) \
 278     { \
 279         item = array.p_elems[fe_idx];
 280
 281 #define FOREACH_END() } }
 282
 283
 284 /************************************************************************
 285  * Dynamic arrays with progressive allocation (Prefered API)
 286  ************************************************************************/
 287 typedef struct vlc_array_t
 288 {
 289     int i_count;
 290     void ** pp_elems;
 291 } vlc_array_t;
 292
 293 static inline void vlc_array_init( vlc_array_t * p_array )
 294 {
 295     memset( p_array, 0, sizeof(vlc_array_t) );
 296 }
 297
 298 static inline void vlc_array_clear( vlc_array_t * p_array )
 299 {
 300     free( p_array->pp_elems );
 301     memset( p_array, 0, sizeof(vlc_array_t) );
 302 }
 303
 304 static inline vlc_array_t * vlc_array_new( void )
 305 {
 306     vlc_array_t * ret = (vlc_array_t *)malloc( sizeof(vlc_array_t) );
 307     if( ret ) vlc_array_init( ret );
 308     return ret;
 309 }
 310
 311 static inline void vlc_array_destroy( vlc_array_t * p_array )
 312 {
 313     if( !p_array )
 314         return;
 315     vlc_array_clear( p_array );
 316     free( p_array );
 317 }
 318
 319
 320 /* Read */
 321 static inline int
 322 vlc_array_count( vlc_array_t * p_array )
 323 {
 324     return p_array->i_count;
 325 }
 326
 327 static inline void *
 328 vlc_array_item_at_index( vlc_array_t * p_array, int i_index )
 329 {
 330     return p_array->pp_elems[i_index];
 331 }
 332
 333 static inline int
 334 vlc_array_index_of_item( vlc_array_t * p_array, void * item )
 335 {
 336     int i;
 337     for( i = 0; i < p_array->i_count; i++)
 338     {
 339         if( p_array->pp_elems[i] == item )
 340             return i;
 341     }
 342     return -1;
 343 }
 344
 345 /* Write */
 346 static inline void
 347 vlc_array_insert( vlc_array_t * p_array, void * p_elem, int i_index )
 348 {
 349     TAB_INSERT_CAST( (void **), p_array->i_count, p_array->pp_elems, p_elem, i_index );
 350 }
 351
 352 static inline void
 353 vlc_array_append( vlc_array_t * p_array, void * p_elem )
 354 {
 355     vlc_array_insert( p_array, p_elem, p_array->i_count );
 356 }
 357
 358 static inline void
 359 vlc_array_remove( vlc_array_t * p_array, int i_index )
 360 {
 361     if( i_index >= 0 )
 362     {
 363         if( p_array->i_count > 1 )
 364         {
 365             memmove( p_array->pp_elems + i_index,
 366                      p_array->pp_elems + i_index+1,
 367                      ( p_array->i_count - i_index - 1 ) * sizeof( void* ) );
 368         }
 369         p_array->i_count--;
 370         if( p_array->i_count == 0 )
 371         {
 372             free( p_array->pp_elems );
 373             p_array->pp_elems = NULL;
 374         }
 375     }
 376 }
 377
 378
 379 /************************************************************************
 380  * Dictionaries
 381  ************************************************************************/
 382
 383 /* This function is not intended to be crypto-secure, we only want it to be
 384  * fast and not suck too much. This one is pretty fast and did 0 collisions
 385  * in wenglish's dictionary.
 386  */
 387 static inline uint64_t DictHash( const char *psz_string, int hashsize )
 388 {
 389     uint64_t i_hash = 0;
 390     if( psz_string )
 391     {
 392         while( *psz_string )
 393         {
 394             i_hash += *psz_string++;
 395             i_hash += i_hash << 10;
 396             i_hash ^= i_hash >> 8;
 397         }
 398     }
 399     return i_hash % hashsize;
 400 }
 401
 402 struct vlc_dictionary_entry_t
 403 {
 404     char *   psz_key;
 405     void *   p_value;
 406     struct vlc_dictionary_entry_t * p_next;
 407 };
 408
 409 typedef struct vlc_dictionary_t
 410 {
 411     int i_size;
 412     struct vlc_dictionary_entry_t ** p_entries;
 413 } vlc_dictionary_t;
 414
 415 static void * const kVLCDictionaryNotFound = NULL;
 416
 417 static inline void vlc_dictionary_init( vlc_dictionary_t * p_dict, int i_size )
 418 {
 419     if( i_size > 0 )
 420     {
 421         p_dict->p_entries = (struct vlc_dictionary_entry_t **)malloc(sizeof(struct vlc_dictionary_entry_t *) * i_size);
 422         assert( p_dict->p_entries );
 423         memset( p_dict->p_entries, 0, sizeof(struct vlc_dictionary_entry_t *) * i_size );
 424     }
 425     else
 426         p_dict->p_entries = NULL;
 427     p_dict->i_size = i_size;
 428 }
 429
 430 static inline void vlc_dictionary_clear( vlc_dictionary_t * p_dict )
 431 {
 432     int i;
 433     struct vlc_dictionary_entry_t * p_current, * p_next;
 434     if( p_dict->p_entries )
 435     {
 436         for( i = 0; i < p_dict->i_size; i++ )
 437         {
 438             p_current = p_dict->p_entries[i];
 439             while( p_current )
 440             {
 441                 p_next = p_current->p_next;
 442                 free( p_current->psz_key );
 443                 free( p_current );
 444                 p_current = p_next;
 445             }
 446         }
 447         free( p_dict->p_entries );
 448     }
 449     p_dict->i_size = 0;
 450 }
 451
 452
 453
 454 static inline void *
 455 vlc_dictionary_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 456 {
 457     if( !p_dict->p_entries )
 458         return kVLCDictionaryNotFound;
 459
 460     int i_pos = DictHash( psz_key, p_dict->i_size );
 461     struct vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 462
 463     if( !p_entry )
 464         return kVLCDictionaryNotFound;
 465
 466     /* Make sure we return the right item. (Hash collision) */
 467     do {
 468         if( !strcmp( psz_key, p_entry->psz_key ) )
 469             return p_entry->p_value;
 470         p_entry = p_entry->p_next;
 471     } while( p_entry );
 472
 473     return kVLCDictionaryNotFound;
 474 }
 475
 476 static inline int
 477 vlc_dictionary_keys_count( const vlc_dictionary_t * p_dict )
 478 {
 479     struct vlc_dictionary_entry_t * p_entry;
 480     int i, count = 0;
 481
 482     if( !p_dict->p_entries )
 483         return 0;
 484
 485     for( i = 0; i < p_dict->i_size; i++ )
 486     {
 487         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next ) count++;
 488     }
 489     return count;
 490 }
 491
 492 static inline char **
 493 vlc_dictionary_all_keys( const vlc_dictionary_t * p_dict )
 494 {
 495     struct vlc_dictionary_entry_t * p_entry;
 496     char ** ppsz_ret;
 497     int i, count = vlc_dictionary_keys_count( p_dict );
 498
 499     ppsz_ret = (char**)malloc(sizeof(char *) * (count + 1));
 500     assert( ppsz_ret );
 501
 502     count = 0;
 503     for( i = 0; i < p_dict->i_size; i++ )
 504     {
 505         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next )
 506         {
 507             ppsz_ret[count++] = strdup( p_entry->psz_key );
 508             assert( ppsz_ret );
 509         }
 510     }
 511     ppsz_ret[count] = NULL;
 512     return ppsz_ret;
 513 }
 514
 515 static inline void
 516 __vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key,
 517                          void * p_value, vlc_bool_t rebuild )
 518 {
 519     if( !p_dict->p_entries )
 520         vlc_dictionary_init( p_dict, 1 );
 521
 522     int i_pos = DictHash( psz_key, p_dict->i_size );
 523     struct vlc_dictionary_entry_t * p_entry;
 524
 525     p_entry = (struct vlc_dictionary_entry_t *)malloc(sizeof(struct vlc_dictionary_entry_t));
 526     assert( p_entry );
 527     p_entry->psz_key = strdup( psz_key );
 528     p_entry->p_value = p_value;
 529     p_entry->p_next = p_dict->p_entries[i_pos];
 530     p_dict->p_entries[i_pos] = p_entry;
 531     if( rebuild )
 532     {
 533         /* Count how many items there was */
 534         int count;
 535         for( count = 1; p_entry->p_next; count++ ) p_entry = p_entry->p_next;
 536         if( count > 3 ) /* XXX: this need tuning */
 537         {
 538             /* Here it starts to be not good, rebuild a bigger dictionary */
 539             struct vlc_dictionary_t new_dict;
 540             int i_new_size = ( (p_dict->i_size+2) * 3) / 2; /* XXX: this need tuning */
 541             int i;
 542             vlc_dictionary_init( &new_dict, i_new_size );
 543             for( i = 0; i < p_dict->i_size; i++ )
 544             {
 545                 p_entry = p_dict->p_entries[i];
 546                 while( p_entry )
 547                 {
 548                     __vlc_dictionary_insert( &new_dict, p_entry->psz_key,
 549                                              p_entry->p_value,
 550                                              0 /* To avoid multiple rebuild loop */);
 551                     p_entry = p_entry->p_next;
 552                 }
 553             }
 554
 555             vlc_dictionary_clear( p_dict );
 556             p_dict->i_size = new_dict.i_size;
 557             p_dict->p_entries = new_dict.p_entries;
 558         }
 559     }
 560 }
 561
 562 static inline void
 563 vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key, void * p_value )
 564 {
 565     __vlc_dictionary_insert( p_dict, psz_key, p_value, 1 );
 566 }
 567
 568 static inline void
 569 vlc_dictionary_remove_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 570 {
 571     if( !p_dict->p_entries )
 572         return;
 573
 574     int i_pos = DictHash( psz_key, p_dict->i_size );
 575     struct vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 576     struct vlc_dictionary_entry_t * p_prev;
 577
 578     if( !p_entry )
 579         return; /* Not found, nothing to do */
 580
 581     /* Hash collision */
 582     p_prev = NULL;
 583     do {
 584         if( !strcmp( psz_key, p_entry->psz_key ) )
 585         {
 586             if( !p_prev )
 587                 p_dict->p_entries[i_pos] = p_entry->p_next;
 588             else
 589                 p_prev->p_next = p_entry->p_next;
 590             free( p_entry->psz_key );
 591             free( p_entry );
 592             return;
 593         }
 594         p_prev = p_entry;
 595         p_entry = p_entry->p_next;
 596     } while( p_entry );
 597
 598     /* No key was found */
 599 }
 600
 601 #endif