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 #if defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L)
 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 #elif defined (__cplusplus)
 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 void 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         abort();
 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 }
 309
 310 static inline void vlc_array_append( vlc_array_t *ar, void *elem )
 311 {
 312     void **pp = (void **)realloc( ar->pp_elems,
 313                                   sizeof( void * ) * (ar->i_count + 1) );
 314     if( unlikely(pp == NULL) )
 315         abort();
 316
 317     pp[ar->i_count++] = elem;
 318     ar->pp_elems = pp;
 319 }
 320
 321 static inline void vlc_array_remove( vlc_array_t *ar, size_t idx )
 322 {
 323     void **pp = ar->pp_elems;
 324     size_t tail = ar->i_count - idx - 1;
 325
 326     if( tail > 0 )
 327         memmove( pp + idx, pp + idx + 1, sizeof( void * ) * tail );
 328
 329     ar->i_count--;
 330
 331     if( ar->i_count > 0 )
 332     {
 333         pp = (void **)realloc( pp, sizeof( void * ) * ar->i_count );
 334         if( likely(pp != NULL) )
 335             ar->pp_elems = pp;
 336     }
 337     else
 338     {
 339         free( pp );
 340         ar->pp_elems = NULL;
 341     }
 342 }
 343
 344
 345 /************************************************************************
 346  * Dictionaries
 347  ************************************************************************/
 348
 349 /* This function is not intended to be crypto-secure, we only want it to be
 350  * fast and not suck too much. This one is pretty fast and did 0 collisions
 351  * in wenglish's dictionary.
 352  */
 353 static inline uint64_t DictHash( const char *psz_string, int hashsize )
 354 {
 355     uint64_t i_hash = 0;
 356     if( psz_string )
 357     {
 358         while( *psz_string )
 359         {
 360             i_hash += *psz_string++;
 361             i_hash += i_hash << 10;
 362             i_hash ^= i_hash >> 8;
 363         }
 364     }
 365     return i_hash % hashsize;
 366 }
 367
 368 typedef struct vlc_dictionary_entry_t
 369 {
 370     char *   psz_key;
 371     void *   p_value;
 372     struct vlc_dictionary_entry_t * p_next;
 373 } vlc_dictionary_entry_t;
 374
 375 typedef struct vlc_dictionary_t
 376 {
 377     int i_size;
 378     vlc_dictionary_entry_t ** p_entries;
 379 } vlc_dictionary_t;
 380
 381 static void * const kVLCDictionaryNotFound = NULL;
 382
 383 static inline void vlc_dictionary_init( vlc_dictionary_t * p_dict, int i_size )
 384 {
 385     p_dict->p_entries = NULL;
 386
 387     if( i_size > 0 )
 388     {
 389         p_dict->p_entries = (vlc_dictionary_entry_t **)calloc( i_size, sizeof(*p_dict->p_entries) );
 390         if( !p_dict->p_entries )
 391             i_size = 0;
 392     }
 393     p_dict->i_size = i_size;
 394 }
 395
 396 static inline void vlc_dictionary_clear( vlc_dictionary_t * p_dict,
 397                                          void ( * pf_free )( void * p_data, void * p_obj ),
 398                                          void * p_obj )
 399 {
 400     if( p_dict->p_entries )
 401     {
 402         for( int i = 0; i < p_dict->i_size; i++ )
 403         {
 404             vlc_dictionary_entry_t * p_current, * p_next;
 405             p_current = p_dict->p_entries[i];
 406             while( p_current )
 407             {
 408                 p_next = p_current->p_next;
 409                 if( pf_free != NULL )
 410                     ( * pf_free )( p_current->p_value, p_obj );
 411                 free( p_current->psz_key );
 412                 free( p_current );
 413                 p_current = p_next;
 414             }
 415         }
 416         free( p_dict->p_entries );
 417         p_dict->p_entries = NULL;
 418     }
 419     p_dict->i_size = 0;
 420 }
 421
 422 static inline int
 423 vlc_dictionary_has_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 424 {
 425     if( !p_dict->p_entries )
 426         return 0;
 427
 428     int i_pos = DictHash( psz_key, p_dict->i_size );
 429     const vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 430     for( ; p_entry != NULL; p_entry = p_entry->p_next )
 431     {
 432         if( !strcmp( psz_key, p_entry->psz_key ) )
 433             break;
 434     }
 435     return p_entry != NULL;
 436 }
 437
 438 static inline void *
 439 vlc_dictionary_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 440 {
 441     if( !p_dict->p_entries )
 442         return kVLCDictionaryNotFound;
 443
 444     int i_pos = DictHash( psz_key, p_dict->i_size );
 445     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 446
 447     if( !p_entry )
 448         return kVLCDictionaryNotFound;
 449
 450     /* Make sure we return the right item. (Hash collision) */
 451     do {
 452         if( !strcmp( psz_key, p_entry->psz_key ) )
 453             return p_entry->p_value;
 454         p_entry = p_entry->p_next;
 455     } while( p_entry );
 456
 457     return kVLCDictionaryNotFound;
 458 }
 459
 460 static inline int
 461 vlc_dictionary_keys_count( const vlc_dictionary_t * p_dict )
 462 {
 463     vlc_dictionary_entry_t * p_entry;
 464     int i, count = 0;
 465
 466     if( !p_dict->p_entries )
 467         return 0;
 468
 469     for( i = 0; i < p_dict->i_size; i++ )
 470     {
 471         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next ) count++;
 472     }
 473     return count;
 474 }
 475
 476 static inline bool
 477 vlc_dictionary_is_empty( const vlc_dictionary_t * p_dict )
 478 {
 479     if( p_dict->p_entries )
 480         for( int i = 0; i < p_dict->i_size; i++ )
 481             if( p_dict->p_entries[i] )
 482                 return false;
 483     return true;
 484 }
 485
 486 static inline char **
 487 vlc_dictionary_all_keys( const vlc_dictionary_t * p_dict )
 488 {
 489     vlc_dictionary_entry_t * p_entry;
 490     char ** ppsz_ret;
 491     int i, count = vlc_dictionary_keys_count( p_dict );
 492
 493     ppsz_ret = (char**)malloc(sizeof(char *) * (count + 1));
 494     if( unlikely(!ppsz_ret) )
 495         return NULL;
 496
 497     count = 0;
 498     for( i = 0; i < p_dict->i_size; i++ )
 499     {
 500         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next )
 501             ppsz_ret[count++] = strdup( p_entry->psz_key );
 502     }
 503     ppsz_ret[count] = NULL;
 504     return ppsz_ret;
 505 }
 506
 507 static inline void
 508 vlc_dictionary_insert_impl_( vlc_dictionary_t * p_dict, const char * psz_key,
 509                              void * p_value, bool rebuild )
 510 {
 511     if( !p_dict->p_entries )
 512         vlc_dictionary_init( p_dict, 1 );
 513
 514     int i_pos = DictHash( psz_key, p_dict->i_size );
 515     vlc_dictionary_entry_t * p_entry;
 516
 517     p_entry = (vlc_dictionary_entry_t *)malloc(sizeof(*p_entry));
 518     p_entry->psz_key = strdup( psz_key );
 519     p_entry->p_value = p_value;
 520     p_entry->p_next = p_dict->p_entries[i_pos];
 521     p_dict->p_entries[i_pos] = p_entry;
 522     if( rebuild )
 523     {
 524         /* Count how many items there was */
 525         int count;
 526         for( count = 1; p_entry->p_next; count++ )
 527             p_entry = p_entry->p_next;
 528         if( count > 3 ) /* XXX: this need tuning */
 529         {
 530             /* Here it starts to be not good, rebuild a bigger dictionary */
 531             struct vlc_dictionary_t new_dict;
 532             int i_new_size = ( (p_dict->i_size+2) * 3) / 2; /* XXX: this need tuning */
 533             int i;
 534             vlc_dictionary_init( &new_dict, i_new_size );
 535             for( i = 0; i < p_dict->i_size; i++ )
 536             {
 537                 p_entry = p_dict->p_entries[i];
 538                 while( p_entry )
 539                 {
 540                     vlc_dictionary_insert_impl_( &new_dict, p_entry->psz_key,
 541                                              p_entry->p_value,
 542                                              false /* To avoid multiple rebuild loop */);
 543                     p_entry = p_entry->p_next;
 544                 }
 545             }
 546
 547             vlc_dictionary_clear( p_dict, NULL, NULL );
 548             p_dict->i_size = new_dict.i_size;
 549             p_dict->p_entries = new_dict.p_entries;
 550         }
 551     }
 552 }
 553
 554 static inline void
 555 vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key, void * p_value )
 556 {
 557     vlc_dictionary_insert_impl_( p_dict, psz_key, p_value, true );
 558 }
 559
 560 static inline void
 561 vlc_dictionary_remove_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key,
 562                                      void ( * pf_free )( void * p_data, void * p_obj ),
 563                                      void * p_obj )
 564 {
 565     if( !p_dict->p_entries )
 566         return;
 567
 568     int i_pos = DictHash( psz_key, p_dict->i_size );
 569     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 570     vlc_dictionary_entry_t * p_prev;
 571
 572     if( !p_entry )
 573         return; /* Not found, nothing to do */
 574
 575     /* Hash collision */
 576     p_prev = NULL;
 577     do {
 578         if( !strcmp( psz_key, p_entry->psz_key ) )
 579         {
 580             if( pf_free != NULL )
 581                 ( * pf_free )( p_entry->p_value, p_obj );
 582             if( !p_prev )
 583                 p_dict->p_entries[i_pos] = p_entry->p_next;
 584             else
 585                 p_prev->p_next = p_entry->p_next;
 586             free( p_entry->psz_key );
 587             free( p_entry );
 588             return;
 589         }
 590         p_prev = p_entry;
 591         p_entry = p_entry->p_next;
 592     } while( p_entry );
 593
 594     /* No key was found */
 595 }
 596
 597 #ifdef __cplusplus
 598 // C++ helpers
 599 template <typename T>
 600 void vlc_delete_all( T &container )
 601 {
 602     typename T::iterator it = container.begin();
 603     while ( it != container.end() )
 604     {
 605         delete *it;
 606         ++it;
 607     }
 608     container.clear();
 609 }
 610
 611 #endif
 612
 613 #endif