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 #define INSERT_ELEM( p_ar, i_oldsize, i_pos, elem ) \
 117     TAB_INSERT( i_oldsize, p_ar, elem, i_pos )
 118
 119 #define REMOVE_ELEM( p_ar, i_size, i_pos )  \
 120     TAB_ERASE( i_size, p_ar, i_pos )
 121
 122 /**
 123  * Binary search in a sorted array. The key must be comparable by < and >
 124  * \param entries array of entries
 125  * \param count number of entries
 126  * \param elem key to check within an entry (like .id, or ->i_id)
 127  * \param zetype type of the key
 128  * \param key value of the key
 129  * \param answer index of answer within the array. -1 if not found
 130  */
 131 #define BSEARCH( entries, count, elem, zetype, key, answer ) \
 132    do {  \
 133     int low = 0, high = count - 1;   \
 134     answer = -1; \
 135     while( low <= high ) {\
 136         int mid = ((unsigned int)low + (unsigned int)high) >> 1;\
 137         zetype mid_val = entries[mid] elem;\
 138         if( mid_val < key ) \
 139             low = mid + 1; \
 140         else if ( mid_val > key ) \
 141             high = mid -1;  \
 142         else    \
 143         {   \
 144             answer = mid;  break;   \
 145         }\
 146     } \
 147  } while(0)
 148
 149
 150 /************************************************************************
 151  * Dynamic arrays with progressive allocation
 152  ************************************************************************/
 153
 154 /* Internal functions */
 155 #define _ARRAY_ALLOC(array, newsize) {                                      \
 156     (array).i_alloc = newsize;                                              \
 157     (array).p_elems = realloc( (array).p_elems, (array).i_alloc *           \
 158                                sizeof(*(array).p_elems) );                  \
 159     if( !(array).p_elems ) abort();                                         \
 160 }
 161
 162 #define _ARRAY_GROW1(array) {                                               \
 163     if( (array).i_alloc < 10 )                                              \
 164         _ARRAY_ALLOC(array, 10 )                                            \
 165     else if( (array).i_alloc == (array).i_size )                            \
 166         _ARRAY_ALLOC(array, (int)(array.i_alloc * 1.5) )                    \
 167 }
 168
 169 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 170
 171 /* API */
 172 #define DECL_ARRAY(type) struct {                                           \
 173     int i_alloc;                                                            \
 174     int i_size;                                                             \
 175     type *p_elems;                                                          \
 176 }
 177
 178 #define TYPEDEF_ARRAY(type, name) typedef DECL_ARRAY(type) name;
 179
 180 #define ARRAY_INIT(array)                                                   \
 181   do {                                                                      \
 182     (array).i_alloc = 0;                                                    \
 183     (array).i_size = 0;                                                     \
 184     (array).p_elems = NULL;                                                 \
 185   } while(0)
 186
 187 #define ARRAY_RESET(array)                                                  \
 188   do {                                                                      \
 189     (array).i_alloc = 0;                                                    \
 190     (array).i_size = 0;                                                     \
 191     free( (array).p_elems ); (array).p_elems = NULL;                        \
 192   } while(0)
 193
 194 #define ARRAY_APPEND(array, elem)                                           \
 195   do {                                                                      \
 196     _ARRAY_GROW1(array);                                                    \
 197     (array).p_elems[(array).i_size] = elem;                                 \
 198     (array).i_size++;                                                       \
 199   } while(0)
 200
 201 #define ARRAY_INSERT(array,elem,pos)                                        \
 202   do {                                                                      \
 203     _ARRAY_GROW1(array);                                                    \
 204     if( (array).i_size - pos ) {                                            \
 205         memmove( (array).p_elems + pos + 1, (array).p_elems + pos,          \
 206                  ((array).i_size-pos) * sizeof(*(array).p_elems) );         \
 207     }                                                                       \
 208     (array).p_elems[pos] = elem;                                            \
 209     (array).i_size++;                                                       \
 210   } while(0)
 211
 212 #define _ARRAY_SHRINK(array) {                                              \
 213     if( (array).i_size > 10 && (array).i_size < (int)((array).i_alloc / 1.5) ) {  \
 214         _ARRAY_ALLOC(array, (array).i_size + 5);                            \
 215     }                                                                       \
 216 }
 217
 218 #define ARRAY_REMOVE(array,pos)                                             \
 219   do {                                                                      \
 220     if( (array).i_size - (pos) - 1 )                                        \
 221     {                                                                       \
 222         memmove( (array).p_elems + pos, (array).p_elems + pos + 1,          \
 223                  ( (array).i_size - pos - 1 ) *sizeof(*(array).p_elems) );  \
 224     }                                                                       \
 225     (array).i_size--;                                                       \
 226     _ARRAY_SHRINK(array);                                                   \
 227   } while(0)
 228
 229 #define ARRAY_VAL(array, pos) array.p_elems[pos]
 230
 231 #define ARRAY_BSEARCH(array, elem, zetype, key, answer) \
 232     BSEARCH( (array).p_elems, (array).i_size, elem, zetype, key, answer)
 233
 234 #define FOREACH_ARRAY( item, array ) { \
 235     int fe_idx; \
 236     for( fe_idx = 0 ; fe_idx < (array).i_size ; fe_idx++ ) \
 237     { \
 238         item = (array).p_elems[fe_idx];
 239
 240 #define FOREACH_END() } }
 241
 242
 243 /************************************************************************
 244  * Dynamic arrays with progressive allocation (Preferred API)
 245  ************************************************************************/
 246 typedef struct vlc_array_t
 247 {
 248     size_t i_count;
 249     void ** pp_elems;
 250 } vlc_array_t;
 251
 252 static inline void vlc_array_init( vlc_array_t * p_array )
 253 {
 254     p_array->i_count = 0;
 255     p_array->pp_elems = NULL;
 256 }
 257
 258 static inline void vlc_array_clear( vlc_array_t * p_array )
 259 {
 260     free( p_array->pp_elems );
 261     vlc_array_init( p_array );
 262 }
 263
 264 /* Read */
 265 static inline size_t vlc_array_count( vlc_array_t * p_array )
 266 {
 267     return p_array->i_count;
 268 }
 269
 270 #if defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L)
 271 # define vlc_array_item_at_index(ar, idx) \
 272     _Generic((ar), \
 273         const vlc_array_t *: ((ar)->pp_elems[idx]), \
 274         vlc_array_t *: ((ar)->pp_elems[idx]))
 275 #elif defined (__cplusplus)
 276 static inline void *vlc_array_item_at_index( vlc_array_t *ar, size_t idx )
 277 {
 278     return ar->pp_elems[idx];
 279 }
 280
 281 static inline const void *vlc_array_item_at_index( const vlc_array_t *ar,
 282                                                    size_t idx )
 283 {
 284     return ar->pp_elems[idx];
 285 }
 286 #endif
 287
 288 static inline ssize_t vlc_array_index_of_item( const vlc_array_t *ar,
 289                                                const void *elem )
 290 {
 291     for( size_t i = 0; i < ar->i_count; i++ )
 292     {
 293         if( ar->pp_elems[i] == elem )
 294             return i;
 295     }
 296     return -1;
 297 }
 298
 299 /* Write */
 300 static inline void vlc_array_insert( vlc_array_t *ar, void *elem, int idx )
 301 {
 302     void **pp = (void **)realloc( ar->pp_elems,
 303                                   sizeof( void * ) * (ar->i_count + 1) );
 304     if( unlikely(pp == NULL) )
 305         abort();
 306
 307     size_t tail = ar->i_count - idx;
 308     if( tail > 0 )
 309         memmove( pp + idx + 1, pp + idx, sizeof( void * ) * tail );
 310
 311     pp[idx] = elem;
 312     ar->i_count++;
 313     ar->pp_elems = pp;
 314 }
 315
 316 static inline void vlc_array_append( vlc_array_t *ar, void *elem )
 317 {
 318     void **pp = (void **)realloc( ar->pp_elems,
 319                                   sizeof( void * ) * (ar->i_count + 1) );
 320     if( unlikely(pp == NULL) )
 321         abort();
 322
 323     pp[ar->i_count++] = elem;
 324     ar->pp_elems = pp;
 325 }
 326
 327 static inline void vlc_array_remove( vlc_array_t *ar, size_t idx )
 328 {
 329     void **pp = ar->pp_elems;
 330     size_t tail = ar->i_count - idx - 1;
 331
 332     if( tail > 0 )
 333         memmove( pp + idx, pp + idx + 1, sizeof( void * ) * tail );
 334
 335     ar->i_count--;
 336
 337     if( ar->i_count > 0 )
 338     {
 339         pp = (void **)realloc( pp, sizeof( void * ) * ar->i_count );
 340         if( likely(pp != NULL) )
 341             ar->pp_elems = pp;
 342     }
 343     else
 344     {
 345         free( pp );
 346         ar->pp_elems = NULL;
 347     }
 348 }
 349
 350
 351 /************************************************************************
 352  * Dictionaries
 353  ************************************************************************/
 354
 355 /* This function is not intended to be crypto-secure, we only want it to be
 356  * fast and not suck too much. This one is pretty fast and did 0 collisions
 357  * in wenglish's dictionary.
 358  */
 359 static inline uint64_t DictHash( const char *psz_string, int hashsize )
 360 {
 361     uint64_t i_hash = 0;
 362     if( psz_string )
 363     {
 364         while( *psz_string )
 365         {
 366             i_hash += *psz_string++;
 367             i_hash += i_hash << 10;
 368             i_hash ^= i_hash >> 8;
 369         }
 370     }
 371     return i_hash % hashsize;
 372 }
 373
 374 typedef struct vlc_dictionary_entry_t
 375 {
 376     char *   psz_key;
 377     void *   p_value;
 378     struct vlc_dictionary_entry_t * p_next;
 379 } vlc_dictionary_entry_t;
 380
 381 typedef struct vlc_dictionary_t
 382 {
 383     int i_size;
 384     vlc_dictionary_entry_t ** p_entries;
 385 } vlc_dictionary_t;
 386
 387 static void * const kVLCDictionaryNotFound = NULL;
 388
 389 static inline void vlc_dictionary_init( vlc_dictionary_t * p_dict, int i_size )
 390 {
 391     p_dict->p_entries = NULL;
 392
 393     if( i_size > 0 )
 394     {
 395         p_dict->p_entries = (vlc_dictionary_entry_t **)calloc( i_size, sizeof(*p_dict->p_entries) );
 396         if( !p_dict->p_entries )
 397             i_size = 0;
 398     }
 399     p_dict->i_size = i_size;
 400 }
 401
 402 static inline void vlc_dictionary_clear( vlc_dictionary_t * p_dict,
 403                                          void ( * pf_free )( void * p_data, void * p_obj ),
 404                                          void * p_obj )
 405 {
 406     if( p_dict->p_entries )
 407     {
 408         for( int i = 0; i < p_dict->i_size; i++ )
 409         {
 410             vlc_dictionary_entry_t * p_current, * p_next;
 411             p_current = p_dict->p_entries[i];
 412             while( p_current )
 413             {
 414                 p_next = p_current->p_next;
 415                 if( pf_free != NULL )
 416                     ( * pf_free )( p_current->p_value, p_obj );
 417                 free( p_current->psz_key );
 418                 free( p_current );
 419                 p_current = p_next;
 420             }
 421         }
 422         free( p_dict->p_entries );
 423         p_dict->p_entries = NULL;
 424     }
 425     p_dict->i_size = 0;
 426 }
 427
 428 static inline int
 429 vlc_dictionary_has_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 430 {
 431     if( !p_dict->p_entries )
 432         return 0;
 433
 434     int i_pos = DictHash( psz_key, p_dict->i_size );
 435     return p_dict->p_entries[i_pos] != 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 char **
 477 vlc_dictionary_all_keys( const vlc_dictionary_t * p_dict )
 478 {
 479     vlc_dictionary_entry_t * p_entry;
 480     char ** ppsz_ret;
 481     int i, count = vlc_dictionary_keys_count( p_dict );
 482
 483     ppsz_ret = (char**)malloc(sizeof(char *) * (count + 1));
 484     if( unlikely(!ppsz_ret) )
 485         return NULL;
 486
 487     count = 0;
 488     for( i = 0; i < p_dict->i_size; i++ )
 489     {
 490         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next )
 491             ppsz_ret[count++] = strdup( p_entry->psz_key );
 492     }
 493     ppsz_ret[count] = NULL;
 494     return ppsz_ret;
 495 }
 496
 497 static inline void
 498 __vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key,
 499                          void * p_value, bool rebuild )
 500 {
 501     if( !p_dict->p_entries )
 502         vlc_dictionary_init( p_dict, 1 );
 503
 504     int i_pos = DictHash( psz_key, p_dict->i_size );
 505     vlc_dictionary_entry_t * p_entry;
 506
 507     p_entry = (vlc_dictionary_entry_t *)malloc(sizeof(*p_entry));
 508     p_entry->psz_key = strdup( psz_key );
 509     p_entry->p_value = p_value;
 510     p_entry->p_next = p_dict->p_entries[i_pos];
 511     p_dict->p_entries[i_pos] = p_entry;
 512     if( rebuild )
 513     {
 514         /* Count how many items there was */
 515         int count;
 516         for( count = 1; p_entry->p_next; count++ )
 517             p_entry = p_entry->p_next;
 518         if( count > 3 ) /* XXX: this need tuning */
 519         {
 520             /* Here it starts to be not good, rebuild a bigger dictionary */
 521             struct vlc_dictionary_t new_dict;
 522             int i_new_size = ( (p_dict->i_size+2) * 3) / 2; /* XXX: this need tuning */
 523             int i;
 524             vlc_dictionary_init( &new_dict, i_new_size );
 525             for( i = 0; i < p_dict->i_size; i++ )
 526             {
 527                 p_entry = p_dict->p_entries[i];
 528                 while( p_entry )
 529                 {
 530                     __vlc_dictionary_insert( &new_dict, p_entry->psz_key,
 531                                              p_entry->p_value,
 532                                              false /* To avoid multiple rebuild loop */);
 533                     p_entry = p_entry->p_next;
 534                 }
 535             }
 536
 537             vlc_dictionary_clear( p_dict, NULL, NULL );
 538             p_dict->i_size = new_dict.i_size;
 539             p_dict->p_entries = new_dict.p_entries;
 540         }
 541     }
 542 }
 543
 544 static inline void
 545 vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key, void * p_value )
 546 {
 547     __vlc_dictionary_insert( p_dict, psz_key, p_value, true );
 548 }
 549
 550 static inline void
 551 vlc_dictionary_remove_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key,
 552                                      void ( * pf_free )( void * p_data, void * p_obj ),
 553                                      void * p_obj )
 554 {
 555     if( !p_dict->p_entries )
 556         return;
 557
 558     int i_pos = DictHash( psz_key, p_dict->i_size );
 559     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 560     vlc_dictionary_entry_t * p_prev;
 561
 562     if( !p_entry )
 563         return; /* Not found, nothing to do */
 564
 565     /* Hash collision */
 566     p_prev = NULL;
 567     do {
 568         if( !strcmp( psz_key, p_entry->psz_key ) )
 569         {
 570             if( pf_free != NULL )
 571                 ( * pf_free )( p_entry->p_value, p_obj );
 572             if( !p_prev )
 573                 p_dict->p_entries[i_pos] = p_entry->p_next;
 574             else
 575                 p_prev->p_next = p_entry->p_next;
 576             free( p_entry->psz_key );
 577             free( p_entry );
 578             return;
 579         }
 580         p_prev = p_entry;
 581         p_entry = p_entry->p_next;
 582     } while( p_entry );
 583
 584     /* No key was found */
 585 }
 586
 587 #ifdef __cplusplus
 588 // C++ helpers
 589 template <typename T>
 590 void vlc_delete_all( T &container )
 591 {
 592     typename T::iterator it = container.begin();
 593     while ( it != container.end() )
 594     {
 595         delete *it;
 596         ++it;
 597     }
 598     container.clear();
 599 }
 600
 601 #endif
 602
 603 #endif