include/vlc_arrays.h

   1 /*****************************************************************************
   2  * vlc_arrays.h : Arrays and data structures handling
   3  *****************************************************************************
   4  * Copyright (C) 1999-2004 VLC authors and VideoLAN
   5  *
   6  * Authors: Samuel Hocevar <sam@zoy.org>
   7  *          Clément Stenac <zorglub@videolan.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, write to the Free Software Foundation,
  21  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 #ifndef VLC_ARRAYS_H_
  25 #define VLC_ARRAYS_H_
  26
  27 /**
  28  * \file
  29  * This file defines functions, structures and macros for handling arrays in vlc
  30  */
  31
  32 /* realloc() that never fails *if* downsizing */
  33 static inline void *realloc_down( void *ptr, size_t size )
  34 {
  35     void *ret = realloc( ptr, size );
  36     return ret ? ret : ptr;
  37 }
  38
  39 /**
  40  * This wrapper around realloc() will free the input pointer when
  41  * realloc() returns NULL. The use case ptr = realloc(ptr, newsize) will
  42  * cause a memory leak when ptr pointed to a heap allocation before,
  43  * leaving the buffer allocated but unreferenced. vlc_realloc() is a
  44  * drop-in replacement for that use case (and only that use case).
  45  */
  46 static inline void *realloc_or_free( void *p, size_t sz )
  47 {
  48     void *n = realloc(p,sz);
  49     if( !n )
  50         free(p);
  51     return n;
  52 }
  53
  54 #define TAB_INIT( count, tab )                  \
  55   do {                                          \
  56     (count) = 0;                                \
  57     (tab) = NULL;                               \
  58   } while(0)
  59
  60 #define TAB_CLEAN( count, tab )                 \
  61   do {                                          \
  62     free( tab );                                \
  63     (count)= 0;                                 \
  64     (tab)= NULL;                                \
  65   } while(0)
  66
  67 #define TAB_APPEND_CAST( cast, count, tab, p )             \
  68   do {                                          \
  69     if( (count) > 0 )                           \
  70         (tab) = cast realloc( tab, sizeof( *(tab) ) * ( (count) + 1 ) ); \
  71     else                                        \
  72         (tab) = cast malloc( sizeof( *(tab) ) );    \
  73     if( !(tab) ) abort();                       \
  74     (tab)[count] = (p);                         \
  75     (count)++;                                  \
  76   } while(0)
  77
  78 #define TAB_APPEND( count, tab, p )             \
  79     TAB_APPEND_CAST( , count, tab, p )
  80
  81 #define TAB_FIND( count, tab, p, idx )          \
  82   do {                                          \
  83     for( (idx) = 0; (idx) < (count); (idx)++ )  \
  84         if( (tab)[(idx)] == (p) )               \
  85             break;                              \
  86     if( (idx) >= (count) )                      \
  87         (idx) = -1;                             \
  88   } while(0)
  89
  90
  91 #define TAB_ERASE( count, tab, index )      \
  92   do {                                      \
  93         if( (count) > 1 )                   \
  94             memmove( (tab) + (index),       \
  95                      (tab) + (index) + 1,   \
  96                      ((count) - (index) - 1 ) * sizeof( *(tab) ) );\
  97         (count)--;                          \
  98         if( (count) == 0 )                  \
  99         {                                   \
 100             free( tab );                    \
 101             (tab) = NULL;                   \
 102         }                                   \
 103   } while(0)
 104
 105 #define TAB_REMOVE( count, tab, p )             \
 106   do {                                          \
 107         int i_index;                            \
 108         TAB_FIND( count, tab, p, i_index );     \
 109         if( i_index >= 0 )                      \
 110             TAB_ERASE( count, tab, i_index );   \
 111   } while(0)
 112
 113 #define TAB_INSERT_CAST( cast, count, tab, p, index ) do { \
 114     if( (count) > 0 )                           \
 115         (tab) = cast realloc( tab, sizeof( *(tab) ) * ( (count) + 1 ) ); \
 116     else                                        \
 117         (tab) = cast malloc( sizeof( *(tab) ) );       \
 118     if( !(tab) ) abort();                       \
 119     if( (count) - (index) > 0 )                 \
 120         memmove( (tab) + (index) + 1,           \
 121                  (tab) + (index),               \
 122                  ((count) - (index)) * sizeof( *(tab) ) );\
 123     (tab)[(index)] = (p);                       \
 124     (count)++;                                  \
 125 } while(0)
 126
 127 #define TAB_INSERT( count, tab, p, index )      \
 128     TAB_INSERT_CAST( , count, tab, p, index )
 129
 130 /**
 131  * Binary search in a sorted array. The key must be comparable by < and >
 132  * \param entries array of entries
 133  * \param count number of entries
 134  * \param elem key to check within an entry (like .id, or ->i_id)
 135  * \param zetype type of the key
 136  * \param key value of the key
 137  * \param answer index of answer within the array. -1 if not found
 138  */
 139 #define BSEARCH( entries, count, elem, zetype, key, answer ) \
 140    do {  \
 141     int low = 0, high = count - 1;   \
 142     answer = -1; \
 143     while( low <= high ) {\
 144         int mid = ((unsigned int)low + (unsigned int)high) >> 1;\
 145         zetype mid_val = entries[mid] elem;\
 146         if( mid_val < key ) \
 147             low = mid + 1; \
 148         else if ( mid_val > key ) \
 149             high = mid -1;  \
 150         else    \
 151         {   \
 152             answer = mid;  break;   \
 153         }\
 154     } \
 155  } while(0)
 156
 157
 158 /************************************************************************
 159  * Dynamic arrays with progressive allocation
 160  ************************************************************************/
 161
 162 /* Internal functions */
 163 #define _ARRAY_ALLOC(array, newsize) {                                      \
 164     (array).i_alloc = newsize;                                              \
 165     (array).p_elems = realloc( (array).p_elems, (array).i_alloc *           \
 166                                sizeof(*(array).p_elems) );                  \
 167     if( !(array).p_elems ) abort();                                         \
 168 }
 169
 170 #define _ARRAY_GROW1(array) {                                               \
 171     if( (array).i_alloc < 10 )                                              \
 172         _ARRAY_ALLOC(array, 10 )                                            \
 173     else if( (array).i_alloc == (array).i_size )                            \
 174         _ARRAY_ALLOC(array, (int)((array).i_alloc * 1.5) )                    \
 175 }
 176
 177 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 178
 179 /* API */
 180 #define DECL_ARRAY(type) struct {                                           \
 181     int i_alloc;                                                            \
 182     int i_size;                                                             \
 183     type *p_elems;                                                          \
 184 }
 185
 186 #define TYPEDEF_ARRAY(type, name) typedef DECL_ARRAY(type) name;
 187
 188 #define ARRAY_INIT(array)                                                   \
 189   do {                                                                      \
 190     (array).i_alloc = 0;                                                    \
 191     (array).i_size = 0;                                                     \
 192     (array).p_elems = NULL;                                                 \
 193   } while(0)
 194
 195 #define ARRAY_RESET(array)                                                  \
 196   do {                                                                      \
 197     (array).i_alloc = 0;                                                    \
 198     (array).i_size = 0;                                                     \
 199     free( (array).p_elems ); (array).p_elems = NULL;                        \
 200   } while(0)
 201
 202 #define ARRAY_APPEND(array, elem)                                           \
 203   do {                                                                      \
 204     _ARRAY_GROW1(array);                                                    \
 205     (array).p_elems[(array).i_size] = elem;                                 \
 206     (array).i_size++;                                                       \
 207   } while(0)
 208
 209 #define ARRAY_INSERT(array,elem,pos)                                        \
 210   do {                                                                      \
 211     _ARRAY_GROW1(array);                                                    \
 212     if( (array).i_size - (pos) ) {                                          \
 213         memmove( (array).p_elems + (pos) + 1, (array).p_elems + (pos),      \
 214                  ((array).i_size-(pos)) * sizeof(*(array).p_elems) );       \
 215     }                                                                       \
 216     (array).p_elems[pos] = elem;                                            \
 217     (array).i_size++;                                                       \
 218   } while(0)
 219
 220 #define _ARRAY_SHRINK(array) {                                              \
 221     if( (array).i_size > 10 && (array).i_size < (int)((array).i_alloc / 1.5) ) {  \
 222         _ARRAY_ALLOC(array, (array).i_size + 5);                            \
 223     }                                                                       \
 224 }
 225
 226 #define ARRAY_FIND(array, p, idx)                                           \
 227   TAB_FIND((array).i_size, (array).p_elems, p, idx)
 228
 229 #define ARRAY_REMOVE(array,pos)                                             \
 230   do {                                                                      \
 231     if( (array).i_size - (pos) - 1 )                                        \
 232     {                                                                       \
 233         memmove( (array).p_elems + (pos), (array).p_elems + (pos) + 1,      \
 234                  ( (array).i_size - (pos) - 1 ) *sizeof(*(array).p_elems) );\
 235     }                                                                       \
 236     (array).i_size--;                                                       \
 237     _ARRAY_SHRINK(array);                                                   \
 238   } while(0)
 239
 240 #define ARRAY_VAL(array, pos) array.p_elems[pos]
 241
 242 #define ARRAY_BSEARCH(array, elem, zetype, key, answer) \
 243     BSEARCH( (array).p_elems, (array).i_size, elem, zetype, key, answer)
 244
 245 /* append ##item to index variable name to avoid variable shadowing warnings for
 246  * nested loops */
 247 #define ARRAY_FOREACH(item, array) \
 248     for (int array_index_##item = 0; \
 249          array_index_##item < (array).i_size && \
 250             ((item) = (array).p_elems[array_index_##item], 1); \
 251          ++array_index_##item)
 252
 253
 254 /************************************************************************
 255  * Dynamic arrays with progressive allocation (Preferred API)
 256  ************************************************************************/
 257 typedef struct vlc_array_t
 258 {
 259     size_t i_count;
 260     void ** pp_elems;
 261 } vlc_array_t;
 262
 263 static inline void vlc_array_init( vlc_array_t * p_array )
 264 {
 265     p_array->i_count = 0;
 266     p_array->pp_elems = NULL;
 267 }
 268
 269 static inline void vlc_array_clear( vlc_array_t * p_array )
 270 {
 271     free( p_array->pp_elems );
 272     vlc_array_init( p_array );
 273 }
 274
 275 /* Read */
 276 static inline size_t vlc_array_count( vlc_array_t * p_array )
 277 {
 278     return p_array->i_count;
 279 }
 280
 281 #ifndef __cplusplus
 282 # define vlc_array_item_at_index(ar, idx) \
 283     _Generic((ar), \
 284         const vlc_array_t *: ((ar)->pp_elems[idx]), \
 285         vlc_array_t *: ((ar)->pp_elems[idx]))
 286 #else
 287 static inline void *vlc_array_item_at_index( vlc_array_t *ar, size_t idx )
 288 {
 289     return ar->pp_elems[idx];
 290 }
 291
 292 static inline const void *vlc_array_item_at_index( const vlc_array_t *ar,
 293                                                    size_t idx )
 294 {
 295     return ar->pp_elems[idx];
 296 }
 297 #endif
 298
 299 static inline ssize_t vlc_array_index_of_item( const vlc_array_t *ar,
 300                                                const void *elem )
 301 {
 302     for( size_t i = 0; i < ar->i_count; i++ )
 303     {
 304         if( ar->pp_elems[i] == elem )
 305             return i;
 306     }
 307     return -1;
 308 }
 309
 310 /* Write */
 311 static inline int vlc_array_insert( vlc_array_t *ar, void *elem, int idx )
 312 {
 313     void **pp = (void **)realloc( ar->pp_elems,
 314                                   sizeof( void * ) * (ar->i_count + 1) );
 315     if( unlikely(pp == NULL) )
 316         return -1;
 317
 318     size_t tail = ar->i_count - idx;
 319     if( tail > 0 )
 320         memmove( pp + idx + 1, pp + idx, sizeof( void * ) * tail );
 321
 322     pp[idx] = elem;
 323     ar->i_count++;
 324     ar->pp_elems = pp;
 325     return 0;
 326 }
 327
 328 static inline void vlc_array_insert_or_abort( vlc_array_t *ar, void *elem, int idx )
 329 {
 330     if( vlc_array_insert( ar, elem, idx ) )
 331         abort();
 332 }
 333
 334 static inline int vlc_array_append( vlc_array_t *ar, void *elem )
 335 {
 336     void **pp = (void **)realloc( ar->pp_elems,
 337                                   sizeof( void * ) * (ar->i_count + 1) );
 338     if( unlikely(pp == NULL) )
 339         return -1;
 340
 341     pp[ar->i_count++] = elem;
 342     ar->pp_elems = pp;
 343     return 0;
 344 }
 345
 346 static inline void vlc_array_append_or_abort( vlc_array_t *ar, void *elem )
 347 {
 348     if( vlc_array_append( ar, elem ) != 0 )
 349         abort();
 350 }
 351
 352 static inline void vlc_array_remove( vlc_array_t *ar, size_t idx )
 353 {
 354     void **pp = ar->pp_elems;
 355     size_t tail = ar->i_count - idx - 1;
 356
 357     if( tail > 0 )
 358         memmove( pp + idx, pp + idx + 1, sizeof( void * ) * tail );
 359
 360     ar->i_count--;
 361
 362     if( ar->i_count > 0 )
 363     {
 364         pp = (void **)realloc( pp, sizeof( void * ) * ar->i_count );
 365         if( likely(pp != NULL) )
 366             ar->pp_elems = pp;
 367     }
 368     else
 369     {
 370         free( pp );
 371         ar->pp_elems = NULL;
 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 typedef struct vlc_dictionary_entry_t
 400 {
 401     char *   psz_key;
 402     void *   p_value;
 403     struct vlc_dictionary_entry_t * p_next;
 404 } vlc_dictionary_entry_t;
 405
 406 typedef struct vlc_dictionary_t
 407 {
 408     int i_size;
 409     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     p_dict->p_entries = NULL;
 417
 418     if( i_size > 0 )
 419     {
 420         p_dict->p_entries = (vlc_dictionary_entry_t **)calloc( i_size, sizeof(*p_dict->p_entries) );
 421         if( !p_dict->p_entries )
 422             i_size = 0;
 423     }
 424     p_dict->i_size = i_size;
 425 }
 426
 427 static inline void vlc_dictionary_clear( vlc_dictionary_t * p_dict,
 428                                          void ( * pf_free )( void * p_data, void * p_obj ),
 429                                          void * p_obj )
 430 {
 431     if( p_dict->p_entries )
 432     {
 433         for( int i = 0; i < p_dict->i_size; i++ )
 434         {
 435             vlc_dictionary_entry_t * p_current, * p_next;
 436             p_current = p_dict->p_entries[i];
 437             while( p_current )
 438             {
 439                 p_next = p_current->p_next;
 440                 if( pf_free != NULL )
 441                     ( * pf_free )( p_current->p_value, p_obj );
 442                 free( p_current->psz_key );
 443                 free( p_current );
 444                 p_current = p_next;
 445             }
 446         }
 447         free( p_dict->p_entries );
 448         p_dict->p_entries = NULL;
 449     }
 450     p_dict->i_size = 0;
 451 }
 452
 453 static inline int
 454 vlc_dictionary_has_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 455 {
 456     if( !p_dict->p_entries )
 457         return 0;
 458
 459     int i_pos = DictHash( psz_key, p_dict->i_size );
 460     const vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 461     for( ; p_entry != NULL; p_entry = p_entry->p_next )
 462     {
 463         if( !strcmp( psz_key, p_entry->psz_key ) )
 464             break;
 465     }
 466     return p_entry != NULL;
 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 bool
 508 vlc_dictionary_is_empty( const vlc_dictionary_t * p_dict )
 509 {
 510     if( p_dict->p_entries )
 511         for( int i = 0; i < p_dict->i_size; i++ )
 512             if( p_dict->p_entries[i] )
 513                 return false;
 514     return true;
 515 }
 516
 517 static inline char **
 518 vlc_dictionary_all_keys( const vlc_dictionary_t * p_dict )
 519 {
 520     vlc_dictionary_entry_t * p_entry;
 521     char ** ppsz_ret;
 522     int i, count = vlc_dictionary_keys_count( p_dict );
 523
 524     ppsz_ret = (char**)malloc(sizeof(char *) * (count + 1));
 525     if( unlikely(!ppsz_ret) )
 526         return NULL;
 527
 528     count = 0;
 529     for( i = 0; i < p_dict->i_size; i++ )
 530     {
 531         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next )
 532             ppsz_ret[count++] = strdup( p_entry->psz_key );
 533     }
 534     ppsz_ret[count] = NULL;
 535     return ppsz_ret;
 536 }
 537
 538 static inline void
 539 vlc_dictionary_insert_impl_( vlc_dictionary_t * p_dict, const char * psz_key,
 540                              void * p_value, bool rebuild )
 541 {
 542     if( !p_dict->p_entries )
 543         vlc_dictionary_init( p_dict, 1 );
 544
 545     int i_pos = DictHash( psz_key, p_dict->i_size );
 546     vlc_dictionary_entry_t * p_entry;
 547
 548     p_entry = (vlc_dictionary_entry_t *)malloc(sizeof(*p_entry));
 549     p_entry->psz_key = strdup( psz_key );
 550     p_entry->p_value = p_value;
 551     p_entry->p_next = p_dict->p_entries[i_pos];
 552     p_dict->p_entries[i_pos] = p_entry;
 553     if( rebuild )
 554     {
 555         /* Count how many items there was */
 556         int count;
 557         for( count = 1; p_entry->p_next; count++ )
 558             p_entry = p_entry->p_next;
 559         if( count > 3 ) /* XXX: this need tuning */
 560         {
 561             /* Here it starts to be not good, rebuild a bigger dictionary */
 562             struct vlc_dictionary_t new_dict;
 563             int i_new_size = ( (p_dict->i_size+2) * 3) / 2; /* XXX: this need tuning */
 564             int i;
 565             vlc_dictionary_init( &new_dict, i_new_size );
 566             for( i = 0; i < p_dict->i_size; i++ )
 567             {
 568                 p_entry = p_dict->p_entries[i];
 569                 while( p_entry )
 570                 {
 571                     vlc_dictionary_insert_impl_( &new_dict, p_entry->psz_key,
 572                                              p_entry->p_value,
 573                                              false /* To avoid multiple rebuild loop */);
 574                     p_entry = p_entry->p_next;
 575                 }
 576             }
 577
 578             vlc_dictionary_clear( p_dict, NULL, NULL );
 579             p_dict->i_size = new_dict.i_size;
 580             p_dict->p_entries = new_dict.p_entries;
 581         }
 582     }
 583 }
 584
 585 static inline void
 586 vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key, void * p_value )
 587 {
 588     vlc_dictionary_insert_impl_( p_dict, psz_key, p_value, true );
 589 }
 590
 591 static inline void
 592 vlc_dictionary_remove_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key,
 593                                      void ( * pf_free )( void * p_data, void * p_obj ),
 594                                      void * p_obj )
 595 {
 596     if( !p_dict->p_entries )
 597         return;
 598
 599     int i_pos = DictHash( psz_key, p_dict->i_size );
 600     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 601     vlc_dictionary_entry_t * p_prev;
 602
 603     if( !p_entry )
 604         return; /* Not found, nothing to do */
 605
 606     /* Hash collision */
 607     p_prev = NULL;
 608     do {
 609         if( !strcmp( psz_key, p_entry->psz_key ) )
 610         {
 611             if( pf_free != NULL )
 612                 ( * pf_free )( p_entry->p_value, p_obj );
 613             if( !p_prev )
 614                 p_dict->p_entries[i_pos] = p_entry->p_next;
 615             else
 616                 p_prev->p_next = p_entry->p_next;
 617             free( p_entry->psz_key );
 618             free( p_entry );
 619             return;
 620         }
 621         p_prev = p_entry;
 622         p_entry = p_entry->p_next;
 623     } while( p_entry );
 624
 625     /* No key was found */
 626 }
 627
 628 #ifdef __cplusplus
 629 // C++ helpers
 630 template <typename T>
 631 void vlc_delete_all( T &container )
 632 {
 633     typename T::iterator it = container.begin();
 634     while ( it != container.end() )
 635     {
 636         delete *it;
 637         ++it;
 638     }
 639     container.clear();
 640 }
 641
 642 #endif
 643
 644 #endif