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  * $Id$
   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 it
  11  * under the terms of the GNU Lesser General Public License as published by
  12  * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License
  21  * along with this program; if not, write to the Free Software Foundation,
  22  * 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 #define TAB_INIT( count, tab )                  \
  41   do {                                          \
  42     (count) = 0;                                \
  43     (tab) = NULL;                               \
  44   } while(0)
  45
  46 #define TAB_CLEAN( count, tab )                 \
  47   do {                                          \
  48     free( tab );                                \
  49     (count)= 0;                                 \
  50     (tab)= NULL;                                \
  51   } while(0)
  52
  53 #define TAB_APPEND_CAST( cast, count, tab, p )             \
  54   do {                                          \
  55     if( (count) > 0 )                           \
  56         (tab) = cast realloc( tab, sizeof( *(tab) ) * ( (count) + 1 ) ); \
  57     else                                        \
  58         (tab) = cast malloc( sizeof( *(tab) ) );    \
  59     if( !(tab) ) abort();                       \
  60     (tab)[count] = (p);                         \
  61     (count)++;                                  \
  62   } while(0)
  63
  64 #define TAB_APPEND( count, tab, p )             \
  65     TAB_APPEND_CAST( , count, tab, p )
  66
  67 #define TAB_FIND( count, tab, p, idx )          \
  68   do {                                          \
  69     for( (idx) = 0; (idx) < (count); (idx)++ )  \
  70         if( (tab)[(idx)] == (p) )               \
  71             break;                              \
  72     if( (idx) >= (count) )                      \
  73         (idx) = -1;                             \
  74   } while(0)
  75
  76
  77 #define TAB_ERASE( count, tab, index )      \
  78   do {                                      \
  79         if( (count) > 1 )                   \
  80             memmove( (tab) + (index),       \
  81                      (tab) + (index) + 1,   \
  82                      ((count) - (index) - 1 ) * sizeof( *(tab) ) );\
  83         (count)--;                          \
  84         if( (count) == 0 )                  \
  85         {                                   \
  86             free( tab );                    \
  87             (tab) = NULL;                   \
  88         }                                   \
  89   } while(0)
  90
  91 #define TAB_REMOVE( count, tab, p )             \
  92   do {                                          \
  93         int i_index;                            \
  94         TAB_FIND( count, tab, p, i_index );     \
  95         if( i_index >= 0 )                      \
  96             TAB_ERASE( count, tab, i_index );   \
  97   } while(0)
  98
  99 #define TAB_INSERT_CAST( cast, count, tab, p, index ) do { \
 100     if( (count) > 0 )                           \
 101         (tab) = cast realloc( tab, sizeof( *(tab) ) * ( (count) + 1 ) ); \
 102     else                                        \
 103         (tab) = cast malloc( sizeof( *(tab) ) );       \
 104     if( !(tab) ) abort();                       \
 105     if( (count) - (index) > 0 )                 \
 106         memmove( (tab) + (index) + 1,           \
 107                  (tab) + (index),               \
 108                  ((count) - (index)) * sizeof( *(tab) ) );\
 109     (tab)[(index)] = (p);                       \
 110     (count)++;                                  \
 111 } while(0)
 112
 113 #define TAB_INSERT( count, tab, p, index )      \
 114     TAB_INSERT_CAST( , count, tab, p, index )
 115
 116 /**
 117  * Binary search in a sorted array. The key must be comparable by < and >
 118  * \param entries array of entries
 119  * \param count number of entries
 120  * \param elem key to check within an entry (like .id, or ->i_id)
 121  * \param zetype type of the key
 122  * \param key value of the key
 123  * \param answer index of answer within the array. -1 if not found
 124  */
 125 #define BSEARCH( entries, count, elem, zetype, key, answer ) \
 126    do {  \
 127     int low = 0, high = count - 1;   \
 128     answer = -1; \
 129     while( low <= high ) {\
 130         int mid = ((unsigned int)low + (unsigned int)high) >> 1;\
 131         zetype mid_val = entries[mid] elem;\
 132         if( mid_val < key ) \
 133             low = mid + 1; \
 134         else if ( mid_val > key ) \
 135             high = mid -1;  \
 136         else    \
 137         {   \
 138             answer = mid;  break;   \
 139         }\
 140     } \
 141  } while(0)
 142
 143
 144 /************************************************************************
 145  * Dynamic arrays with progressive allocation
 146  ************************************************************************/
 147
 148 /* Internal functions */
 149 #define _ARRAY_ALLOC(array, newsize) {                                      \
 150     (array).i_alloc = newsize;                                              \
 151     (array).p_elems = realloc( (array).p_elems, (array).i_alloc *           \
 152                                sizeof(*(array).p_elems) );                  \
 153     if( !(array).p_elems ) abort();                                         \
 154 }
 155
 156 #define _ARRAY_GROW1(array) {                                               \
 157     if( (array).i_alloc < 10 )                                              \
 158         _ARRAY_ALLOC(array, 10 )                                            \
 159     else if( (array).i_alloc == (array).i_size )                            \
 160         _ARRAY_ALLOC(array, (int)((array).i_alloc * 1.5) )                    \
 161 }
 162
 163 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 164
 165 /* API */
 166 #define DECL_ARRAY(type) struct {                                           \
 167     int i_alloc;                                                            \
 168     int i_size;                                                             \
 169     type *p_elems;                                                          \
 170 }
 171
 172 #define TYPEDEF_ARRAY(type, name) typedef DECL_ARRAY(type) name;
 173
 174 #define ARRAY_INIT(array)                                                   \
 175   do {                                                                      \
 176     (array).i_alloc = 0;                                                    \
 177     (array).i_size = 0;                                                     \
 178     (array).p_elems = NULL;                                                 \
 179   } while(0)
 180
 181 #define ARRAY_RESET(array)                                                  \
 182   do {                                                                      \
 183     (array).i_alloc = 0;                                                    \
 184     (array).i_size = 0;                                                     \
 185     free( (array).p_elems ); (array).p_elems = NULL;                        \
 186   } while(0)
 187
 188 #define ARRAY_APPEND(array, elem)                                           \
 189   do {                                                                      \
 190     _ARRAY_GROW1(array);                                                    \
 191     (array).p_elems[(array).i_size] = elem;                                 \
 192     (array).i_size++;                                                       \
 193   } while(0)
 194
 195 #define ARRAY_INSERT(array,elem,pos)                                        \
 196   do {                                                                      \
 197     _ARRAY_GROW1(array);                                                    \
 198     if( (array).i_size - pos ) {                                            \
 199         memmove( (array).p_elems + pos + 1, (array).p_elems + pos,          \
 200                  ((array).i_size-pos) * sizeof(*(array).p_elems) );         \
 201     }                                                                       \
 202     (array).p_elems[pos] = elem;                                            \
 203     (array).i_size++;                                                       \
 204   } while(0)
 205
 206 #define _ARRAY_SHRINK(array) {                                              \
 207     if( (array).i_size > 10 && (array).i_size < (int)((array).i_alloc / 1.5) ) {  \
 208         _ARRAY_ALLOC(array, (array).i_size + 5);                            \
 209     }                                                                       \
 210 }
 211
 212 #define ARRAY_REMOVE(array,pos)                                             \
 213   do {                                                                      \
 214     if( (array).i_size - (pos) - 1 )                                        \
 215     {                                                                       \
 216         memmove( (array).p_elems + pos, (array).p_elems + pos + 1,          \
 217                  ( (array).i_size - pos - 1 ) *sizeof(*(array).p_elems) );  \
 218     }                                                                       \
 219     (array).i_size--;                                                       \
 220     _ARRAY_SHRINK(array);                                                   \
 221   } while(0)
 222
 223 #define ARRAY_VAL(array, pos) array.p_elems[pos]
 224
 225 #define ARRAY_BSEARCH(array, elem, zetype, key, answer) \
 226     BSEARCH( (array).p_elems, (array).i_size, elem, zetype, key, answer)
 227
 228 #define FOREACH_ARRAY( item, array ) { \
 229     int fe_idx; \
 230     for( fe_idx = 0 ; fe_idx < (array).i_size ; fe_idx++ ) \
 231     { \
 232         item = (array).p_elems[fe_idx];
 233
 234 #define FOREACH_END() } }
 235
 236
 237 /************************************************************************
 238  * Dynamic arrays with progressive allocation (Preferred API)
 239  ************************************************************************/
 240 typedef struct vlc_array_t
 241 {
 242     size_t i_count;
 243     void ** pp_elems;
 244 } vlc_array_t;
 245
 246 static inline void vlc_array_init( vlc_array_t * p_array )
 247 {
 248     p_array->i_count = 0;
 249     p_array->pp_elems = NULL;
 250 }
 251
 252 static inline void vlc_array_clear( vlc_array_t * p_array )
 253 {
 254     free( p_array->pp_elems );
 255     vlc_array_init( p_array );
 256 }
 257
 258 /* Read */
 259 static inline size_t vlc_array_count( vlc_array_t * p_array )
 260 {
 261     return p_array->i_count;
 262 }
 263
 264 #ifndef __cplusplus
 265 # define vlc_array_item_at_index(ar, idx) \
 266     _Generic((ar), \
 267         const vlc_array_t *: ((ar)->pp_elems[idx]), \
 268         vlc_array_t *: ((ar)->pp_elems[idx]))
 269 #else
 270 static inline void *vlc_array_item_at_index( vlc_array_t *ar, size_t idx )
 271 {
 272     return ar->pp_elems[idx];
 273 }
 274
 275 static inline const void *vlc_array_item_at_index( const vlc_array_t *ar,
 276                                                    size_t idx )
 277 {
 278     return ar->pp_elems[idx];
 279 }
 280 #endif
 281
 282 static inline ssize_t vlc_array_index_of_item( const vlc_array_t *ar,
 283                                                const void *elem )
 284 {
 285     for( size_t i = 0; i < ar->i_count; i++ )
 286     {
 287         if( ar->pp_elems[i] == elem )
 288             return i;
 289     }
 290     return -1;
 291 }
 292
 293 /* Write */
 294 static inline int vlc_array_insert( vlc_array_t *ar, void *elem, int idx )
 295 {
 296     void **pp = (void **)realloc( ar->pp_elems,
 297                                   sizeof( void * ) * (ar->i_count + 1) );
 298     if( unlikely(pp == NULL) )
 299         return -1;
 300
 301     size_t tail = ar->i_count - idx;
 302     if( tail > 0 )
 303         memmove( pp + idx + 1, pp + idx, sizeof( void * ) * tail );
 304
 305     pp[idx] = elem;
 306     ar->i_count++;
 307     ar->pp_elems = pp;
 308     return 0;
 309 }
 310
 311 static inline void vlc_array_insert_or_abort( vlc_array_t *ar, void *elem, int idx )
 312 {
 313     if( vlc_array_insert( ar, elem, idx ) )
 314         abort();
 315 }
 316
 317 static inline int vlc_array_append( vlc_array_t *ar, void *elem )
 318 {
 319     void **pp = (void **)realloc( ar->pp_elems,
 320                                   sizeof( void * ) * (ar->i_count + 1) );
 321     if( unlikely(pp == NULL) )
 322         return -1;
 323
 324     pp[ar->i_count++] = elem;
 325     ar->pp_elems = pp;
 326     return 0;
 327 }
 328
 329 static inline void vlc_array_append_or_abort( vlc_array_t *ar, void *elem )
 330 {
 331     if( vlc_array_append( ar, elem ) != 0 )
 332         abort();
 333 }
 334
 335 static inline void vlc_array_remove( vlc_array_t *ar, size_t idx )
 336 {
 337     void **pp = ar->pp_elems;
 338     size_t tail = ar->i_count - idx - 1;
 339
 340     if( tail > 0 )
 341         memmove( pp + idx, pp + idx + 1, sizeof( void * ) * tail );
 342
 343     ar->i_count--;
 344
 345     if( ar->i_count > 0 )
 346     {
 347         pp = (void **)realloc( pp, sizeof( void * ) * ar->i_count );
 348         if( likely(pp != NULL) )
 349             ar->pp_elems = pp;
 350     }
 351     else
 352     {
 353         free( pp );
 354         ar->pp_elems = NULL;
 355     }
 356 }
 357
 358
 359 /************************************************************************
 360  * Dictionaries
 361  ************************************************************************/
 362
 363 /* This function is not intended to be crypto-secure, we only want it to be
 364  * fast and not suck too much. This one is pretty fast and did 0 collisions
 365  * in wenglish's dictionary.
 366  */
 367 static inline uint64_t DictHash( const char *psz_string, int hashsize )
 368 {
 369     uint64_t i_hash = 0;
 370     if( psz_string )
 371     {
 372         while( *psz_string )
 373         {
 374             i_hash += *psz_string++;
 375             i_hash += i_hash << 10;
 376             i_hash ^= i_hash >> 8;
 377         }
 378     }
 379     return i_hash % hashsize;
 380 }
 381
 382 typedef struct vlc_dictionary_entry_t
 383 {
 384     char *   psz_key;
 385     void *   p_value;
 386     struct vlc_dictionary_entry_t * p_next;
 387 } vlc_dictionary_entry_t;
 388
 389 typedef struct vlc_dictionary_t
 390 {
 391     int i_size;
 392     vlc_dictionary_entry_t ** p_entries;
 393 } vlc_dictionary_t;
 394
 395 static void * const kVLCDictionaryNotFound = NULL;
 396
 397 static inline void vlc_dictionary_init( vlc_dictionary_t * p_dict, int i_size )
 398 {
 399     p_dict->p_entries = NULL;
 400
 401     if( i_size > 0 )
 402     {
 403         p_dict->p_entries = (vlc_dictionary_entry_t **)calloc( i_size, sizeof(*p_dict->p_entries) );
 404         if( !p_dict->p_entries )
 405             i_size = 0;
 406     }
 407     p_dict->i_size = i_size;
 408 }
 409
 410 static inline void vlc_dictionary_clear( vlc_dictionary_t * p_dict,
 411                                          void ( * pf_free )( void * p_data, void * p_obj ),
 412                                          void * p_obj )
 413 {
 414     if( p_dict->p_entries )
 415     {
 416         for( int i = 0; i < p_dict->i_size; i++ )
 417         {
 418             vlc_dictionary_entry_t * p_current, * p_next;
 419             p_current = p_dict->p_entries[i];
 420             while( p_current )
 421             {
 422                 p_next = p_current->p_next;
 423                 if( pf_free != NULL )
 424                     ( * pf_free )( p_current->p_value, p_obj );
 425                 free( p_current->psz_key );
 426                 free( p_current );
 427                 p_current = p_next;
 428             }
 429         }
 430         free( p_dict->p_entries );
 431         p_dict->p_entries = NULL;
 432     }
 433     p_dict->i_size = 0;
 434 }
 435
 436 static inline int
 437 vlc_dictionary_has_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 438 {
 439     if( !p_dict->p_entries )
 440         return 0;
 441
 442     int i_pos = DictHash( psz_key, p_dict->i_size );
 443     const vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 444     for( ; p_entry != NULL; p_entry = p_entry->p_next )
 445     {
 446         if( !strcmp( psz_key, p_entry->psz_key ) )
 447             break;
 448     }
 449     return p_entry != NULL;
 450 }
 451
 452 static inline void *
 453 vlc_dictionary_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 454 {
 455     if( !p_dict->p_entries )
 456         return kVLCDictionaryNotFound;
 457
 458     int i_pos = DictHash( psz_key, p_dict->i_size );
 459     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 460
 461     if( !p_entry )
 462         return kVLCDictionaryNotFound;
 463
 464     /* Make sure we return the right item. (Hash collision) */
 465     do {
 466         if( !strcmp( psz_key, p_entry->psz_key ) )
 467             return p_entry->p_value;
 468         p_entry = p_entry->p_next;
 469     } while( p_entry );
 470
 471     return kVLCDictionaryNotFound;
 472 }
 473
 474 static inline int
 475 vlc_dictionary_keys_count( const vlc_dictionary_t * p_dict )
 476 {
 477     vlc_dictionary_entry_t * p_entry;
 478     int i, count = 0;
 479
 480     if( !p_dict->p_entries )
 481         return 0;
 482
 483     for( i = 0; i < p_dict->i_size; i++ )
 484     {
 485         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next ) count++;
 486     }
 487     return count;
 488 }
 489
 490 static inline bool
 491 vlc_dictionary_is_empty( const vlc_dictionary_t * p_dict )
 492 {
 493     if( p_dict->p_entries )
 494         for( int i = 0; i < p_dict->i_size; i++ )
 495             if( p_dict->p_entries[i] )
 496                 return false;
 497     return true;
 498 }
 499
 500 static inline char **
 501 vlc_dictionary_all_keys( const vlc_dictionary_t * p_dict )
 502 {
 503     vlc_dictionary_entry_t * p_entry;
 504     char ** ppsz_ret;
 505     int i, count = vlc_dictionary_keys_count( p_dict );
 506
 507     ppsz_ret = (char**)malloc(sizeof(char *) * (count + 1));
 508     if( unlikely(!ppsz_ret) )
 509         return NULL;
 510
 511     count = 0;
 512     for( i = 0; i < p_dict->i_size; i++ )
 513     {
 514         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next )
 515             ppsz_ret[count++] = strdup( p_entry->psz_key );
 516     }
 517     ppsz_ret[count] = NULL;
 518     return ppsz_ret;
 519 }
 520
 521 static inline void
 522 vlc_dictionary_insert_impl_( vlc_dictionary_t * p_dict, const char * psz_key,
 523                              void * p_value, bool rebuild )
 524 {
 525     if( !p_dict->p_entries )
 526         vlc_dictionary_init( p_dict, 1 );
 527
 528     int i_pos = DictHash( psz_key, p_dict->i_size );
 529     vlc_dictionary_entry_t * p_entry;
 530
 531     p_entry = (vlc_dictionary_entry_t *)malloc(sizeof(*p_entry));
 532     p_entry->psz_key = strdup( psz_key );
 533     p_entry->p_value = p_value;
 534     p_entry->p_next = p_dict->p_entries[i_pos];
 535     p_dict->p_entries[i_pos] = p_entry;
 536     if( rebuild )
 537     {
 538         /* Count how many items there was */
 539         int count;
 540         for( count = 1; p_entry->p_next; count++ )
 541             p_entry = p_entry->p_next;
 542         if( count > 3 ) /* XXX: this need tuning */
 543         {
 544             /* Here it starts to be not good, rebuild a bigger dictionary */
 545             struct vlc_dictionary_t new_dict;
 546             int i_new_size = ( (p_dict->i_size+2) * 3) / 2; /* XXX: this need tuning */
 547             int i;
 548             vlc_dictionary_init( &new_dict, i_new_size );
 549             for( i = 0; i < p_dict->i_size; i++ )
 550             {
 551                 p_entry = p_dict->p_entries[i];
 552                 while( p_entry )
 553                 {
 554                     vlc_dictionary_insert_impl_( &new_dict, p_entry->psz_key,
 555                                              p_entry->p_value,
 556                                              false /* To avoid multiple rebuild loop */);
 557                     p_entry = p_entry->p_next;
 558                 }
 559             }
 560
 561             vlc_dictionary_clear( p_dict, NULL, NULL );
 562             p_dict->i_size = new_dict.i_size;
 563             p_dict->p_entries = new_dict.p_entries;
 564         }
 565     }
 566 }
 567
 568 static inline void
 569 vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key, void * p_value )
 570 {
 571     vlc_dictionary_insert_impl_( p_dict, psz_key, p_value, true );
 572 }
 573
 574 static inline void
 575 vlc_dictionary_remove_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key,
 576                                      void ( * pf_free )( void * p_data, void * p_obj ),
 577                                      void * p_obj )
 578 {
 579     if( !p_dict->p_entries )
 580         return;
 581
 582     int i_pos = DictHash( psz_key, p_dict->i_size );
 583     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 584     vlc_dictionary_entry_t * p_prev;
 585
 586     if( !p_entry )
 587         return; /* Not found, nothing to do */
 588
 589     /* Hash collision */
 590     p_prev = NULL;
 591     do {
 592         if( !strcmp( psz_key, p_entry->psz_key ) )
 593         {
 594             if( pf_free != NULL )
 595                 ( * pf_free )( p_entry->p_value, p_obj );
 596             if( !p_prev )
 597                 p_dict->p_entries[i_pos] = p_entry->p_next;
 598             else
 599                 p_prev->p_next = p_entry->p_next;
 600             free( p_entry->psz_key );
 601             free( p_entry );
 602             return;
 603         }
 604         p_prev = p_entry;
 605         p_entry = p_entry->p_next;
 606     } while( p_entry );
 607
 608     /* No key was found */
 609 }
 610
 611 #ifdef __cplusplus
 612 // C++ helpers
 613 template <typename T>
 614 void vlc_delete_all( T &container )
 615 {
 616     typename T::iterator it = container.begin();
 617     while ( it != container.end() )
 618     {
 619         delete *it;
 620         ++it;
 621     }
 622     container.clear();
 623 }
 624
 625 #endif
 626
 627 #endif