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
  25 #ifndef VLC_ARRAYS_H_
  26 #define VLC_ARRAYS_H_
  27
  28 /**
  29  * \file
  30  * This file defines functions, structures and macros for handling arrays in vlc
  31  */
  32
  33 /* realloc() that never fails *if* downsizing */
  34 static inline void *realloc_down( void *ptr, size_t size )
  35 {
  36     void *ret = realloc( ptr, size );
  37     return ret ? ret : ptr;
  38 }
  39
  40 /**
  41  * Simple dynamic array handling. Array is realloced at each insert/removal
  42  */
  43 #if defined( _MSC_VER ) && _MSC_VER < 1300 && !defined( UNDER_CE )
  44 #   define VLCCVP (void**) /* Work-around for broken compiler */
  45 #else
  46 #   define VLCCVP
  47 #endif
  48 #define INSERT_ELEM( p_ar, i_oldsize, i_pos, elem )                           \
  49     do                                                                        \
  50     {                                                                         \
  51         if( !i_oldsize ) (p_ar) = NULL;                                       \
  52         (p_ar) = VLCCVP realloc( p_ar, ((i_oldsize) + 1) * sizeof(*(p_ar)) ); \
  53         if( (i_oldsize) - (i_pos) )                                           \
  54         {                                                                     \
  55             memmove( (p_ar) + (i_pos) + 1, (p_ar) + (i_pos),                  \
  56                      ((i_oldsize) - (i_pos)) * sizeof( *(p_ar) ) );           \
  57         }                                                                     \
  58         (p_ar)[i_pos] = elem;                                                 \
  59         (i_oldsize)++;                                                        \
  60     }                                                                         \
  61     while( 0 )
  62
  63 #define REMOVE_ELEM( p_ar, i_size, i_pos )                                    \
  64     do                                                                        \
  65     {                                                                         \
  66         if( (i_size) - (i_pos) - 1 )                                          \
  67         {                                                                     \
  68             memmove( (p_ar) + (i_pos),                                        \
  69                      (p_ar) + (i_pos) + 1,                                    \
  70                      ((i_size) - (i_pos) - 1) * sizeof( *(p_ar) ) );          \
  71         }                                                                     \
  72         if( i_size > 1 )                                                      \
  73             (p_ar) = realloc_down( p_ar, ((i_size) - 1) * sizeof( *(p_ar) ) );\
  74         else                                                                  \
  75         {                                                                     \
  76             free( p_ar );                                                     \
  77             (p_ar) = NULL;                                                    \
  78         }                                                                     \
  79         (i_size)--;                                                           \
  80     }                                                                         \
  81     while( 0 )
  82
  83 #define TAB_INIT( count, tab )                  \
  84   do {                                          \
  85     (count) = 0;                                \
  86     (tab) = NULL;                               \
  87   } while(0)
  88
  89 #define TAB_CLEAN( count, tab )                 \
  90   do {                                          \
  91     free( tab );                                \
  92     (count)= 0;                                 \
  93     (tab)= NULL;                                \
  94   } while(0)
  95
  96 #define TAB_APPEND_CAST( cast, count, tab, p )             \
  97   do {                                          \
  98     if( (count) > 0 )                           \
  99         (tab) = cast realloc( tab, sizeof( void ** ) * ( (count) + 1 ) ); \
 100     else                                        \
 101         (tab) = cast malloc( sizeof( void ** ) );    \
 102     (tab)[count] = (p);                         \
 103     (count)++;                                  \
 104   } while(0)
 105
 106 #define TAB_APPEND( count, tab, p )             \
 107     TAB_APPEND_CAST( , count, tab, p )
 108 #define TAB_APPEND_CPP( type, count, tab, p )   \
 109     TAB_APPEND_CAST( (type**), count, tab, p )
 110
 111 #define TAB_FIND( count, tab, p, index )        \
 112   do {                                          \
 113         int _i_;                                \
 114         (index) = -1;                           \
 115         for( _i_ = 0; _i_ < (count); _i_++ )    \
 116         {                                       \
 117             if( (tab)[_i_] == (p) )             \
 118             {                                   \
 119                 (index) = _i_;                  \
 120                 break;                          \
 121             }                                   \
 122         }                                       \
 123   } while(0)
 124
 125
 126 #define TAB_REMOVE( count, tab, p )             \
 127   do {                                          \
 128         int _i_index_;                          \
 129         TAB_FIND( count, tab, p, _i_index_ );   \
 130         if( _i_index_ >= 0 )                    \
 131         {                                       \
 132             if( (count) > 1 )                   \
 133             {                                   \
 134                 memmove( ((void**)(tab) + _i_index_),    \
 135                          ((void**)(tab) + _i_index_+1),  \
 136                          ( (count) - _i_index_ - 1 ) * sizeof( void* ) );\
 137             }                                   \
 138             (count)--;                          \
 139             if( (count) == 0 )                  \
 140             {                                   \
 141                 free( tab );                    \
 142                 (tab) = NULL;                   \
 143             }                                   \
 144         }                                       \
 145   } while(0)
 146
 147 #define TAB_INSERT_CAST( cast, count, tab, p, index ) do { \
 148     if( (count) > 0 )                           \
 149         (tab) = cast realloc( tab, sizeof( void ** ) * ( (count) + 1 ) ); \
 150     else                                        \
 151         (tab) = cast malloc( sizeof( void ** ) );       \
 152     if( (count) - (index) > 0 )                 \
 153         memmove( (void**)(tab) + (index) + 1,   \
 154                  (void**)(tab) + (index),       \
 155                  ((count) - (index)) * sizeof(*(tab)) );\
 156     (tab)[(index)] = (p);                       \
 157     (count)++;                                  \
 158 } while(0)
 159
 160 #define TAB_INSERT( count, tab, p, index )      \
 161     TAB_INSERT_CAST( , count, tab, p, index )
 162
 163 /**
 164  * Binary search in a sorted array. The key must be comparable by < and >
 165  * \param entries array of entries
 166  * \param count number of entries
 167  * \param elem key to check within an entry (like .id, or ->i_id)
 168  * \param zetype type of the key
 169  * \param key value of the key
 170  * \param answer index of answer within the array. -1 if not found
 171  */
 172 #define BSEARCH( entries, count, elem, zetype, key, answer ) \
 173    do {  \
 174     int low = 0, high = count - 1;   \
 175     answer = -1; \
 176     while( low <= high ) {\
 177         int mid = (low + high ) / 2; /* Just don't care about 2^30 tables */ \
 178         zetype mid_val = entries[mid] elem;\
 179         if( mid_val < key ) \
 180             low = mid + 1; \
 181         else if ( mid_val > key ) \
 182             high = mid -1;  \
 183         else    \
 184         {   \
 185             answer = mid;  break;   \
 186         }\
 187     } \
 188  } while(0)
 189
 190
 191 /************************************************************************
 192  * Dynamic arrays with progressive allocation
 193  ************************************************************************/
 194
 195 /* Internal functions */
 196 #define _ARRAY_ALLOC(array, newsize) {                                      \
 197     (array).i_alloc = newsize;                                              \
 198     (array).p_elems = VLCCVP realloc( (array).p_elems, (array).i_alloc *    \
 199                                     sizeof(*(array).p_elems) );             \
 200 }
 201
 202 #define _ARRAY_GROW1(array) {                                               \
 203     if( (array).i_alloc < 10 )                                              \
 204         _ARRAY_ALLOC(array, 10 )                                            \
 205     else if( (array).i_alloc == (array).i_size )                            \
 206         _ARRAY_ALLOC(array, (int)(array.i_alloc * 1.5) )                    \
 207 }
 208
 209 #define _ARRAY_GROW(array,additional) {                                     \
 210      int i_first = (array).i_alloc;                                         \
 211      while( (array).i_alloc - i_first < additional )                        \
 212      {                                                                      \
 213          if( (array).i_alloc < 10 )                                         \
 214             _ARRAY_ALLOC(array, 10 )                                        \
 215         else if( (array).i_alloc == (array).i_size )                        \
 216             _ARRAY_ALLOC(array, (int)((array).i_alloc * 1.5) )              \
 217         else break;                                                         \
 218      }                                                                      \
 219 }
 220
 221 #define _ARRAY_SHRINK(array) {                                              \
 222     if( (array).i_size > 10 && (array).i_size < (int)((array).i_alloc / 1.5) ) {  \
 223         _ARRAY_ALLOC(array, (array).i_size + 5);                            \
 224     }                                                                       \
 225 }
 226
 227 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 228
 229 /* API */
 230 #define DECL_ARRAY(type) struct {                                           \
 231     int i_alloc;                                                            \
 232     int i_size;                                                             \
 233     type *p_elems;                                                          \
 234 }
 235
 236 #define TYPEDEF_ARRAY(type, name) typedef DECL_ARRAY(type) name;
 237
 238 #define ARRAY_INIT(array)                                                   \
 239   do {                                                                      \
 240     (array).i_alloc = 0;                                                    \
 241     (array).i_size = 0;                                                     \
 242     (array).p_elems = NULL;                                                 \
 243   } while(0)
 244
 245 #define ARRAY_RESET(array)                                                  \
 246   do {                                                                      \
 247     (array).i_alloc = 0;                                                    \
 248     (array).i_size = 0;                                                     \
 249     free( (array).p_elems ); (array).p_elems = NULL;                        \
 250   } while(0)
 251
 252 #define ARRAY_APPEND(array, elem)                                           \
 253   do {                                                                      \
 254     _ARRAY_GROW1(array);                                                    \
 255     (array).p_elems[(array).i_size] = elem;                                 \
 256     (array).i_size++;                                                       \
 257   } while(0)
 258
 259 #define ARRAY_INSERT(array,elem,pos)                                        \
 260   do {                                                                      \
 261     _ARRAY_GROW1(array);                                                    \
 262     if( (array).i_size - pos ) {                                            \
 263         memmove( (array).p_elems + pos + 1, (array).p_elems + pos,          \
 264                  ((array).i_size-pos) * sizeof(*(array).p_elems) );         \
 265     }                                                                       \
 266     (array).p_elems[pos] = elem;                                            \
 267     (array).i_size++;                                                       \
 268   } while(0)
 269
 270 #define ARRAY_REMOVE(array,pos)                                             \
 271   do {                                                                      \
 272     if( (array).i_size - (pos) - 1 )                                        \
 273     {                                                                       \
 274         memmove( (array).p_elems + pos, (array).p_elems + pos + 1,          \
 275                  ( (array).i_size - pos - 1 ) *sizeof(*(array).p_elems) );  \
 276     }                                                                       \
 277     (array).i_size--;                                                       \
 278     _ARRAY_SHRINK(array);                                                   \
 279   } while(0)
 280
 281 #define ARRAY_VAL(array, pos) array.p_elems[pos]
 282
 283 #define ARRAY_BSEARCH(array, elem, zetype, key, answer) \
 284     BSEARCH( (array).p_elems, (array).i_size, elem, zetype, key, answer)
 285
 286 #define FOREACH_ARRAY( item, array ) { \
 287     int fe_idx; \
 288     for( fe_idx = 0 ; fe_idx < (array).i_size ; fe_idx++ ) \
 289     { \
 290         item = (array).p_elems[fe_idx];
 291
 292 #define FOREACH_END() } }
 293
 294
 295 /************************************************************************
 296  * Dynamic arrays with progressive allocation (Preferred API)
 297  ************************************************************************/
 298 typedef struct vlc_array_t
 299 {
 300     int i_count;
 301     void ** pp_elems;
 302 } vlc_array_t;
 303
 304 static inline void vlc_array_init( vlc_array_t * p_array )
 305 {
 306     memset( p_array, 0, sizeof(vlc_array_t) );
 307 }
 308
 309 static inline void vlc_array_clear( vlc_array_t * p_array )
 310 {
 311     free( p_array->pp_elems );
 312     memset( p_array, 0, sizeof(vlc_array_t) );
 313 }
 314
 315 static inline vlc_array_t * vlc_array_new( void )
 316 {
 317     vlc_array_t * ret = (vlc_array_t *)malloc( sizeof(vlc_array_t) );
 318     if( ret ) vlc_array_init( ret );
 319     return ret;
 320 }
 321
 322 static inline void vlc_array_destroy( vlc_array_t * p_array )
 323 {
 324     if( !p_array )
 325         return;
 326     vlc_array_clear( p_array );
 327     free( p_array );
 328 }
 329
 330
 331 /* Read */
 332 static inline int
 333 vlc_array_count( vlc_array_t * p_array )
 334 {
 335     return p_array->i_count;
 336 }
 337
 338 static inline void *
 339 vlc_array_item_at_index( vlc_array_t * p_array, int i_index )
 340 {
 341     return p_array->pp_elems[i_index];
 342 }
 343
 344 static inline int
 345 vlc_array_index_of_item( vlc_array_t * p_array, void * item )
 346 {
 347     int i;
 348     for( i = 0; i < p_array->i_count; i++)
 349     {
 350         if( p_array->pp_elems[i] == item )
 351             return i;
 352     }
 353     return -1;
 354 }
 355
 356 /* Write */
 357 static inline void
 358 vlc_array_insert( vlc_array_t * p_array, void * p_elem, int i_index )
 359 {
 360     TAB_INSERT_CAST( (void **), p_array->i_count, p_array->pp_elems, p_elem, i_index );
 361 }
 362
 363 static inline void
 364 vlc_array_append( vlc_array_t * p_array, void * p_elem )
 365 {
 366     vlc_array_insert( p_array, p_elem, p_array->i_count );
 367 }
 368
 369 static inline void
 370 vlc_array_remove( vlc_array_t * p_array, int i_index )
 371 {
 372     if( i_index >= 0 )
 373     {
 374         if( p_array->i_count > 1 )
 375         {
 376             memmove( p_array->pp_elems + i_index,
 377                      p_array->pp_elems + i_index+1,
 378                      ( p_array->i_count - i_index - 1 ) * sizeof( void* ) );
 379         }
 380         p_array->i_count--;
 381         if( p_array->i_count == 0 )
 382         {
 383             free( p_array->pp_elems );
 384             p_array->pp_elems = NULL;
 385         }
 386     }
 387 }
 388
 389
 390 /************************************************************************
 391  * Dictionaries
 392  ************************************************************************/
 393
 394 /* This function is not intended to be crypto-secure, we only want it to be
 395  * fast and not suck too much. This one is pretty fast and did 0 collisions
 396  * in wenglish's dictionary.
 397  */
 398 static inline uint64_t DictHash( const char *psz_string, int hashsize )
 399 {
 400     uint64_t i_hash = 0;
 401     if( psz_string )
 402     {
 403         while( *psz_string )
 404         {
 405             i_hash += *psz_string++;
 406             i_hash += i_hash << 10;
 407             i_hash ^= i_hash >> 8;
 408         }
 409     }
 410     return i_hash % hashsize;
 411 }
 412
 413 typedef struct vlc_dictionary_entry_t
 414 {
 415     char *   psz_key;
 416     void *   p_value;
 417     struct vlc_dictionary_entry_t * p_next;
 418 } vlc_dictionary_entry_t;
 419
 420 typedef struct vlc_dictionary_t
 421 {
 422     int i_size;
 423     vlc_dictionary_entry_t ** p_entries;
 424 } vlc_dictionary_t;
 425
 426 static void * const kVLCDictionaryNotFound = NULL;
 427
 428 static inline void vlc_dictionary_init( vlc_dictionary_t * p_dict, int i_size )
 429 {
 430     p_dict->p_entries = NULL;
 431
 432     if( i_size > 0 )
 433     {
 434         p_dict->p_entries = (vlc_dictionary_entry_t **)calloc( i_size, sizeof(*p_dict->p_entries) );
 435         if( !p_dict->p_entries )
 436             i_size = 0;
 437     }
 438     p_dict->i_size = i_size;
 439 }
 440
 441 static inline void vlc_dictionary_clear( vlc_dictionary_t * p_dict,
 442                                          void ( * pf_free )( void * p_data, void * p_obj ),
 443                                          void * p_obj )
 444 {
 445     if( p_dict->p_entries )
 446     {
 447         for( int i = 0; i < p_dict->i_size; i++ )
 448         {
 449             vlc_dictionary_entry_t * p_current, * p_next;
 450             p_current = p_dict->p_entries[i];
 451             while( p_current )
 452             {
 453                 p_next = p_current->p_next;
 454                 if( pf_free != NULL )
 455                     ( * pf_free )( p_current->p_value, p_obj );
 456                 free( p_current->psz_key );
 457                 free( p_current );
 458                 p_current = p_next;
 459             }
 460         }
 461         free( p_dict->p_entries );
 462         p_dict->p_entries = NULL;
 463     }
 464     p_dict->i_size = 0;
 465 }
 466
 467
 468
 469 static inline void *
 470 vlc_dictionary_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 471 {
 472     if( !p_dict->p_entries )
 473         return kVLCDictionaryNotFound;
 474
 475     int i_pos = DictHash( psz_key, p_dict->i_size );
 476     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 477
 478     if( !p_entry )
 479         return kVLCDictionaryNotFound;
 480
 481     /* Make sure we return the right item. (Hash collision) */
 482     do {
 483         if( !strcmp( psz_key, p_entry->psz_key ) )
 484             return p_entry->p_value;
 485         p_entry = p_entry->p_next;
 486     } while( p_entry );
 487
 488     return kVLCDictionaryNotFound;
 489 }
 490
 491 static inline int
 492 vlc_dictionary_keys_count( const vlc_dictionary_t * p_dict )
 493 {
 494     vlc_dictionary_entry_t * p_entry;
 495     int i, count = 0;
 496
 497     if( !p_dict->p_entries )
 498         return 0;
 499
 500     for( i = 0; i < p_dict->i_size; i++ )
 501     {
 502         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next ) count++;
 503     }
 504     return count;
 505 }
 506
 507 static inline char **
 508 vlc_dictionary_all_keys( const vlc_dictionary_t * p_dict )
 509 {
 510     vlc_dictionary_entry_t * p_entry;
 511     char ** ppsz_ret;
 512     int i, count = vlc_dictionary_keys_count( p_dict );
 513
 514     ppsz_ret = (char**)malloc(sizeof(char *) * (count + 1));
 515
 516     count = 0;
 517     for( i = 0; i < p_dict->i_size; i++ )
 518     {
 519         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next )
 520             ppsz_ret[count++] = strdup( p_entry->psz_key );
 521     }
 522     ppsz_ret[count] = NULL;
 523     return ppsz_ret;
 524 }
 525
 526 static inline void
 527 __vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key,
 528                          void * p_value, bool rebuild )
 529 {
 530     if( !p_dict->p_entries )
 531         vlc_dictionary_init( p_dict, 1 );
 532
 533     int i_pos = DictHash( psz_key, p_dict->i_size );
 534     vlc_dictionary_entry_t * p_entry;
 535
 536     p_entry = (vlc_dictionary_entry_t *)malloc(sizeof(*p_entry));
 537     p_entry->psz_key = strdup( psz_key );
 538     p_entry->p_value = p_value;
 539     p_entry->p_next = p_dict->p_entries[i_pos];
 540     p_dict->p_entries[i_pos] = p_entry;
 541     if( rebuild )
 542     {
 543         /* Count how many items there was */
 544         int count;
 545         for( count = 1; p_entry->p_next; count++ )
 546             p_entry = p_entry->p_next;
 547         if( count > 3 ) /* XXX: this need tuning */
 548         {
 549             /* Here it starts to be not good, rebuild a bigger dictionary */
 550             struct vlc_dictionary_t new_dict;
 551             int i_new_size = ( (p_dict->i_size+2) * 3) / 2; /* XXX: this need tuning */
 552             int i;
 553             vlc_dictionary_init( &new_dict, i_new_size );
 554             for( i = 0; i < p_dict->i_size; i++ )
 555             {
 556                 p_entry = p_dict->p_entries[i];
 557                 while( p_entry )
 558                 {
 559                     __vlc_dictionary_insert( &new_dict, p_entry->psz_key,
 560                                              p_entry->p_value,
 561                                              false /* To avoid multiple rebuild loop */);
 562                     p_entry = p_entry->p_next;
 563                 }
 564             }
 565
 566             vlc_dictionary_clear( p_dict, NULL, NULL );
 567             p_dict->i_size = new_dict.i_size;
 568             p_dict->p_entries = new_dict.p_entries;
 569         }
 570     }
 571 }
 572
 573 static inline void
 574 vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key, void * p_value )
 575 {
 576     __vlc_dictionary_insert( p_dict, psz_key, p_value, true );
 577 }
 578
 579 static inline void
 580 vlc_dictionary_remove_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key,
 581                                      void ( * pf_free )( void * p_data, void * p_obj ),
 582                                      void * p_obj )
 583 {
 584     if( !p_dict->p_entries )
 585         return;
 586
 587     int i_pos = DictHash( psz_key, p_dict->i_size );
 588     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 589     vlc_dictionary_entry_t * p_prev;
 590
 591     if( !p_entry )
 592         return; /* Not found, nothing to do */
 593
 594     /* Hash collision */
 595     p_prev = NULL;
 596     do {
 597         if( !strcmp( psz_key, p_entry->psz_key ) )
 598         {
 599             if( pf_free != NULL )
 600                 ( * pf_free )( p_entry->p_value, p_obj );
 601             if( !p_prev )
 602                 p_dict->p_entries[i_pos] = p_entry->p_next;
 603             else
 604                 p_prev->p_next = p_entry->p_next;
 605             free( p_entry->psz_key );
 606             free( p_entry );
 607             return;
 608         }
 609         p_prev = p_entry;
 610         p_entry = p_entry->p_next;
 611     } while( p_entry );
 612
 613     /* No key was found */
 614 }
 615
 616 #endif