git.sesse.net Git - vlc/blob - include/vlc_arrays.h

   1 /*****************************************************************************
   2  * vlc_arrays.h : Arrays and data structures handling
   3  *****************************************************************************
   4  * Copyright (C) 1999-2004 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Samuel Hocevar <sam@zoy.org>
   8  *          Clément Stenac <zorglub@videolan.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 #ifndef VLC_ARRAYS_H_
  26 #define VLC_ARRAYS_H_
  27
  28 /**
  29  * \file
  30  * This file defines functions, structures and macros for handling arrays in vlc
  31  */
  32
  33 /* realloc() that never fails *if* downsizing */
  34 static inline void *realloc_down( void *ptr, size_t size )
  35 {
  36     void *ret = realloc( ptr, size );
  37     return ret ? ret : ptr;
  38 }
  39
  40 /**
  41  * Simple dynamic array handling. Array is realloced at each insert/removal
  42  */
  43 #if defined( _MSC_VER ) && _MSC_VER < 1300 && !defined( UNDER_CE )
  44 #   define VLCCVP (void**) /* Work-around for broken compiler */
  45 #else
  46 #   define VLCCVP
  47 #endif
  48 #define INSERT_ELEM( p_ar, i_oldsize, i_pos, elem )                           \
  49     do                                                                        \
  50     {                                                                         \
  51         if( !(i_oldsize) ) (p_ar) = NULL;                                       \
  52         (p_ar) = VLCCVP realloc( p_ar, ((i_oldsize) + 1) * sizeof(*(p_ar)) ); \
  53         if( !(p_ar) ) abort();                                                \
  54         if( (i_oldsize) - (i_pos) )                                           \
  55         {                                                                     \
  56             memmove( (p_ar) + (i_pos) + 1, (p_ar) + (i_pos),                  \
  57                      ((i_oldsize) - (i_pos)) * sizeof( *(p_ar) ) );           \
  58         }                                                                     \
  59         (p_ar)[(i_pos)] = elem;                                                 \
  60         (i_oldsize)++;                                                        \
  61     }                                                                         \
  62     while( 0 )
  63
  64 #define REMOVE_ELEM( p_ar, i_size, i_pos )                                    \
  65     do                                                                        \
  66     {                                                                         \
  67         if( (i_size) - (i_pos) - 1 )                                          \
  68         {                                                                     \
  69             memmove( (p_ar) + (i_pos),                                        \
  70                      (p_ar) + (i_pos) + 1,                                    \
  71                      ((i_size) - (i_pos) - 1) * sizeof( *(p_ar) ) );          \
  72         }                                                                     \
  73         if( i_size > 1 )                                                      \
  74             (p_ar) = realloc_down( p_ar, ((i_size) - 1) * sizeof( *(p_ar) ) );\
  75         else                                                                  \
  76         {                                                                     \
  77             free( p_ar );                                                     \
  78             (p_ar) = NULL;                                                    \
  79         }                                                                     \
  80         (i_size)--;                                                           \
  81     }                                                                         \
  82     while( 0 )
  83
  84 #define TAB_INIT( count, tab )                  \
  85   do {                                          \
  86     (count) = 0;                                \
  87     (tab) = NULL;                               \
  88   } while(0)
  89
  90 #define TAB_CLEAN( count, tab )                 \
  91   do {                                          \
  92     free( tab );                                \
  93     (count)= 0;                                 \
  94     (tab)= NULL;                                \
  95   } while(0)
  96
  97 #define TAB_APPEND_CAST( cast, count, tab, p )             \
  98   do {                                          \
  99     if( (count) > 0 )                           \
 100         (tab) = cast realloc( tab, sizeof( void ** ) * ( (count) + 1 ) ); \
 101     else                                        \
 102         (tab) = cast malloc( sizeof( void ** ) );    \
 103     if( !(tab) ) abort();                       \
 104     (tab)[count] = (p);                         \
 105     (count)++;                                  \
 106   } while(0)
 107
 108 #define TAB_APPEND( count, tab, p )             \
 109     TAB_APPEND_CAST( , count, tab, p )
 110
 111 #define TAB_FIND( count, tab, p, index )        \
 112   do {                                          \
 113     (index) = -1;                               \
 114     for( int i = 0; i < (count); i++ )          \
 115         if( (tab)[i] == (p) )                   \
 116         {                                       \
 117             (index) = i;                        \
 118             break;                              \
 119         }                                       \
 120   } while(0)
 121
 122
 123 #define TAB_REMOVE( count, tab, p )             \
 124   do {                                          \
 125         int i_index;                            \
 126         TAB_FIND( count, tab, p, i_index );     \
 127         if( i_index >= 0 )                      \
 128         {                                       \
 129             if( (count) > 1 )                   \
 130             {                                   \
 131                 memmove( ((void**)(tab) + i_index),    \
 132                          ((void**)(tab) + i_index+1),  \
 133                          ( (count) - i_index - 1 ) * sizeof( void* ) );\
 134             }                                   \
 135             (count)--;                          \
 136             if( (count) == 0 )                  \
 137             {                                   \
 138                 free( tab );                    \
 139                 (tab) = NULL;                   \
 140             }                                   \
 141         }                                       \
 142   } while(0)
 143
 144 #define TAB_INSERT_CAST( cast, count, tab, p, index ) do { \
 145     if( (count) > 0 )                           \
 146         (tab) = cast realloc( tab, sizeof( void ** ) * ( (count) + 1 ) ); \
 147     else                                        \
 148         (tab) = cast malloc( sizeof( void ** ) );       \
 149     if( !(tab) ) abort();                       \
 150     if( (count) - (index) > 0 )                 \
 151         memmove( (void**)(tab) + (index) + 1,   \
 152                  (void**)(tab) + (index),       \
 153                  ((count) - (index)) * sizeof(*(tab)) );\
 154     (tab)[(index)] = (p);                       \
 155     (count)++;                                  \
 156 } while(0)
 157
 158 #define TAB_INSERT( count, tab, p, index )      \
 159     TAB_INSERT_CAST( , count, tab, p, index )
 160
 161 /**
 162  * Binary search in a sorted array. The key must be comparable by < and >
 163  * \param entries array of entries
 164  * \param count number of entries
 165  * \param elem key to check within an entry (like .id, or ->i_id)
 166  * \param zetype type of the key
 167  * \param key value of the key
 168  * \param answer index of answer within the array. -1 if not found
 169  */
 170 #define BSEARCH( entries, count, elem, zetype, key, answer ) \
 171    do {  \
 172     int low = 0, high = count - 1;   \
 173     answer = -1; \
 174     while( low <= high ) {\
 175         int mid = (low + high ) / 2; /* Just don't care about 2^30 tables */ \
 176         zetype mid_val = entries[mid] elem;\
 177         if( mid_val < key ) \
 178             low = mid + 1; \
 179         else if ( mid_val > key ) \
 180             high = mid -1;  \
 181         else    \
 182         {   \
 183             answer = mid;  break;   \
 184         }\
 185     } \
 186  } while(0)
 187
 188
 189 /************************************************************************
 190  * Dynamic arrays with progressive allocation
 191  ************************************************************************/
 192
 193 /* Internal functions */
 194 #define _ARRAY_ALLOC(array, newsize) {                                      \
 195     (array).i_alloc = newsize;                                              \
 196     (array).p_elems = VLCCVP realloc( (array).p_elems, (array).i_alloc *    \
 197                                     sizeof(*(array).p_elems) );             \
 198     if( !(array).p_elems ) abort();                                         \
 199 }
 200
 201 #define _ARRAY_GROW1(array) {                                               \
 202     if( (array).i_alloc < 10 )                                              \
 203         _ARRAY_ALLOC(array, 10 )                                            \
 204     else if( (array).i_alloc == (array).i_size )                            \
 205         _ARRAY_ALLOC(array, (int)(array.i_alloc * 1.5) )                    \
 206 }
 207
 208 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 209
 210 /* API */
 211 #define DECL_ARRAY(type) struct {                                           \
 212     int i_alloc;                                                            \
 213     int i_size;                                                             \
 214     type *p_elems;                                                          \
 215 }
 216
 217 #define TYPEDEF_ARRAY(type, name) typedef DECL_ARRAY(type) name;
 218
 219 #define ARRAY_INIT(array)                                                   \
 220   do {                                                                      \
 221     (array).i_alloc = 0;                                                    \
 222     (array).i_size = 0;                                                     \
 223     (array).p_elems = NULL;                                                 \
 224   } while(0)
 225
 226 #define ARRAY_RESET(array)                                                  \
 227   do {                                                                      \
 228     (array).i_alloc = 0;                                                    \
 229     (array).i_size = 0;                                                     \
 230     free( (array).p_elems ); (array).p_elems = NULL;                        \
 231   } while(0)
 232
 233 #define ARRAY_APPEND(array, elem)                                           \
 234   do {                                                                      \
 235     _ARRAY_GROW1(array);                                                    \
 236     (array).p_elems[(array).i_size] = elem;                                 \
 237     (array).i_size++;                                                       \
 238   } while(0)
 239
 240 #define ARRAY_INSERT(array,elem,pos)                                        \
 241   do {                                                                      \
 242     _ARRAY_GROW1(array);                                                    \
 243     if( (array).i_size - pos ) {                                            \
 244         memmove( (array).p_elems + pos + 1, (array).p_elems + pos,          \
 245                  ((array).i_size-pos) * sizeof(*(array).p_elems) );         \
 246     }                                                                       \
 247     (array).p_elems[pos] = elem;                                            \
 248     (array).i_size++;                                                       \
 249   } while(0)
 250
 251 #define _ARRAY_SHRINK(array) {                                              \
 252     if( (array).i_size > 10 && (array).i_size < (int)((array).i_alloc / 1.5) ) {  \
 253         _ARRAY_ALLOC(array, (array).i_size + 5);                            \
 254     }                                                                       \
 255 }
 256
 257 #define ARRAY_REMOVE(array,pos)                                             \
 258   do {                                                                      \
 259     if( (array).i_size - (pos) - 1 )                                        \
 260     {                                                                       \
 261         memmove( (array).p_elems + pos, (array).p_elems + pos + 1,          \
 262                  ( (array).i_size - pos - 1 ) *sizeof(*(array).p_elems) );  \
 263     }                                                                       \
 264     (array).i_size--;                                                       \
 265     _ARRAY_SHRINK(array);                                                   \
 266   } while(0)
 267
 268 #define ARRAY_VAL(array, pos) array.p_elems[pos]
 269
 270 #define ARRAY_BSEARCH(array, elem, zetype, key, answer) \
 271     BSEARCH( (array).p_elems, (array).i_size, elem, zetype, key, answer)
 272
 273 #define FOREACH_ARRAY( item, array ) { \
 274     int fe_idx; \
 275     for( fe_idx = 0 ; fe_idx < (array).i_size ; fe_idx++ ) \
 276     { \
 277         item = (array).p_elems[fe_idx];
 278
 279 #define FOREACH_END() } }
 280
 281
 282 /************************************************************************
 283  * Dynamic arrays with progressive allocation (Preferred API)
 284  ************************************************************************/
 285 typedef struct vlc_array_t
 286 {
 287     int i_count;
 288     void ** pp_elems;
 289 } vlc_array_t;
 290
 291 static inline void vlc_array_init( vlc_array_t * p_array )
 292 {
 293     memset( p_array, 0, sizeof(vlc_array_t) );
 294 }
 295
 296 static inline void vlc_array_clear( vlc_array_t * p_array )
 297 {
 298     free( p_array->pp_elems );
 299     memset( p_array, 0, sizeof(vlc_array_t) );
 300 }
 301
 302 static inline vlc_array_t * vlc_array_new( void )
 303 {
 304     vlc_array_t * ret = (vlc_array_t *)malloc( sizeof(vlc_array_t) );
 305     if( ret ) vlc_array_init( ret );
 306     return ret;
 307 }
 308
 309 static inline void vlc_array_destroy( vlc_array_t * p_array )
 310 {
 311     if( !p_array )
 312         return;
 313     vlc_array_clear( p_array );
 314     free( p_array );
 315 }
 316
 317
 318 /* Read */
 319 static inline int
 320 vlc_array_count( vlc_array_t * p_array )
 321 {
 322     return p_array->i_count;
 323 }
 324
 325 static inline void *
 326 vlc_array_item_at_index( vlc_array_t * p_array, int i_index )
 327 {
 328     return p_array->pp_elems[i_index];
 329 }
 330
 331 static inline int
 332 vlc_array_index_of_item( vlc_array_t * p_array, void * item )
 333 {
 334     int i;
 335     for( i = 0; i < p_array->i_count; i++)
 336     {
 337         if( p_array->pp_elems[i] == item )
 338             return i;
 339     }
 340     return -1;
 341 }
 342
 343 /* Write */
 344 static inline void
 345 vlc_array_insert( vlc_array_t * p_array, void * p_elem, int i_index )
 346 {
 347     TAB_INSERT_CAST( (void **), p_array->i_count, p_array->pp_elems, p_elem, i_index );
 348 }
 349
 350 static inline void
 351 vlc_array_append( vlc_array_t * p_array, void * p_elem )
 352 {
 353     vlc_array_insert( p_array, p_elem, p_array->i_count );
 354 }
 355
 356 static inline void
 357 vlc_array_remove( vlc_array_t * p_array, int i_index )
 358 {
 359     if( i_index >= 0 )
 360     {
 361         if( p_array->i_count > 1 )
 362         {
 363             memmove( p_array->pp_elems + i_index,
 364                      p_array->pp_elems + i_index+1,
 365                      ( p_array->i_count - i_index - 1 ) * sizeof( void* ) );
 366         }
 367         p_array->i_count--;
 368         if( p_array->i_count == 0 )
 369         {
 370             free( p_array->pp_elems );
 371             p_array->pp_elems = NULL;
 372         }
 373     }
 374 }
 375
 376
 377 /************************************************************************
 378  * Dictionaries
 379  ************************************************************************/
 380
 381 /* This function is not intended to be crypto-secure, we only want it to be
 382  * fast and not suck too much. This one is pretty fast and did 0 collisions
 383  * in wenglish's dictionary.
 384  */
 385 static inline uint64_t DictHash( const char *psz_string, int hashsize )
 386 {
 387     uint64_t i_hash = 0;
 388     if( psz_string )
 389     {
 390         while( *psz_string )
 391         {
 392             i_hash += *psz_string++;
 393             i_hash += i_hash << 10;
 394             i_hash ^= i_hash >> 8;
 395         }
 396     }
 397     return i_hash % hashsize;
 398 }
 399
 400 typedef struct vlc_dictionary_entry_t
 401 {
 402     char *   psz_key;
 403     void *   p_value;
 404     struct vlc_dictionary_entry_t * p_next;
 405 } vlc_dictionary_entry_t;
 406
 407 typedef struct vlc_dictionary_t
 408 {
 409     int i_size;
 410     vlc_dictionary_entry_t ** p_entries;
 411 } vlc_dictionary_t;
 412
 413 static void * const kVLCDictionaryNotFound = NULL;
 414
 415 static inline void vlc_dictionary_init( vlc_dictionary_t * p_dict, int i_size )
 416 {
 417     p_dict->p_entries = NULL;
 418
 419     if( i_size > 0 )
 420     {
 421         p_dict->p_entries = (vlc_dictionary_entry_t **)calloc( i_size, sizeof(*p_dict->p_entries) );
 422         if( !p_dict->p_entries )
 423             i_size = 0;
 424     }
 425     p_dict->i_size = i_size;
 426 }
 427
 428 static inline void vlc_dictionary_clear( vlc_dictionary_t * p_dict,
 429                                          void ( * pf_free )( void * p_data, void * p_obj ),
 430                                          void * p_obj )
 431 {
 432     if( p_dict->p_entries )
 433     {
 434         for( int i = 0; i < p_dict->i_size; i++ )
 435         {
 436             vlc_dictionary_entry_t * p_current, * p_next;
 437             p_current = p_dict->p_entries[i];
 438             while( p_current )
 439             {
 440                 p_next = p_current->p_next;
 441                 if( pf_free != NULL )
 442                     ( * pf_free )( p_current->p_value, p_obj );
 443                 free( p_current->psz_key );
 444                 free( p_current );
 445                 p_current = p_next;
 446             }
 447         }
 448         free( p_dict->p_entries );
 449         p_dict->p_entries = NULL;
 450     }
 451     p_dict->i_size = 0;
 452 }
 453
 454
 455
 456 static inline void *
 457 vlc_dictionary_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 458 {
 459     if( !p_dict->p_entries )
 460         return kVLCDictionaryNotFound;
 461
 462     int i_pos = DictHash( psz_key, p_dict->i_size );
 463     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 464
 465     if( !p_entry )
 466         return kVLCDictionaryNotFound;
 467
 468     /* Make sure we return the right item. (Hash collision) */
 469     do {
 470         if( !strcmp( psz_key, p_entry->psz_key ) )
 471             return p_entry->p_value;
 472         p_entry = p_entry->p_next;
 473     } while( p_entry );
 474
 475     return kVLCDictionaryNotFound;
 476 }
 477
 478 static inline int
 479 vlc_dictionary_keys_count( const vlc_dictionary_t * p_dict )
 480 {
 481     vlc_dictionary_entry_t * p_entry;
 482     int i, count = 0;
 483
 484     if( !p_dict->p_entries )
 485         return 0;
 486
 487     for( i = 0; i < p_dict->i_size; i++ )
 488     {
 489         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next ) count++;
 490     }
 491     return count;
 492 }
 493
 494 static inline char **
 495 vlc_dictionary_all_keys( const vlc_dictionary_t * p_dict )
 496 {
 497     vlc_dictionary_entry_t * p_entry;
 498     char ** ppsz_ret;
 499     int i, count = vlc_dictionary_keys_count( p_dict );
 500
 501     ppsz_ret = (char**)malloc(sizeof(char *) * (count + 1));
 502
 503     count = 0;
 504     for( i = 0; i < p_dict->i_size; i++ )
 505     {
 506         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next )
 507             ppsz_ret[count++] = strdup( p_entry->psz_key );
 508     }
 509     ppsz_ret[count] = NULL;
 510     return ppsz_ret;
 511 }
 512
 513 static inline void
 514 __vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key,
 515                          void * p_value, bool rebuild )
 516 {
 517     if( !p_dict->p_entries )
 518         vlc_dictionary_init( p_dict, 1 );
 519
 520     int i_pos = DictHash( psz_key, p_dict->i_size );
 521     vlc_dictionary_entry_t * p_entry;
 522
 523     p_entry = (vlc_dictionary_entry_t *)malloc(sizeof(*p_entry));
 524     p_entry->psz_key = strdup( psz_key );
 525     p_entry->p_value = p_value;
 526     p_entry->p_next = p_dict->p_entries[i_pos];
 527     p_dict->p_entries[i_pos] = p_entry;
 528     if( rebuild )
 529     {
 530         /* Count how many items there was */
 531         int count;
 532         for( count = 1; p_entry->p_next; count++ )
 533             p_entry = p_entry->p_next;
 534         if( count > 3 ) /* XXX: this need tuning */
 535         {
 536             /* Here it starts to be not good, rebuild a bigger dictionary */
 537             struct vlc_dictionary_t new_dict;
 538             int i_new_size = ( (p_dict->i_size+2) * 3) / 2; /* XXX: this need tuning */
 539             int i;
 540             vlc_dictionary_init( &new_dict, i_new_size );
 541             for( i = 0; i < p_dict->i_size; i++ )
 542             {
 543                 p_entry = p_dict->p_entries[i];
 544                 while( p_entry )
 545                 {
 546                     __vlc_dictionary_insert( &new_dict, p_entry->psz_key,
 547                                              p_entry->p_value,
 548                                              false /* To avoid multiple rebuild loop */);
 549                     p_entry = p_entry->p_next;
 550                 }
 551             }
 552
 553             vlc_dictionary_clear( p_dict, NULL, NULL );
 554             p_dict->i_size = new_dict.i_size;
 555             p_dict->p_entries = new_dict.p_entries;
 556         }
 557     }
 558 }
 559
 560 static inline void
 561 vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key, void * p_value )
 562 {
 563     __vlc_dictionary_insert( p_dict, psz_key, p_value, true );
 564 }
 565
 566 static inline void
 567 vlc_dictionary_remove_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key,
 568                                      void ( * pf_free )( void * p_data, void * p_obj ),
 569                                      void * p_obj )
 570 {
 571     if( !p_dict->p_entries )
 572         return;
 573
 574     int i_pos = DictHash( psz_key, p_dict->i_size );
 575     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 576     vlc_dictionary_entry_t * p_prev;
 577
 578     if( !p_entry )
 579         return; /* Not found, nothing to do */
 580
 581     /* Hash collision */
 582     p_prev = NULL;
 583     do {
 584         if( !strcmp( psz_key, p_entry->psz_key ) )
 585         {
 586             if( pf_free != NULL )
 587                 ( * pf_free )( p_entry->p_value, p_obj );
 588             if( !p_prev )
 589                 p_dict->p_entries[i_pos] = p_entry->p_next;
 590             else
 591                 p_prev->p_next = p_entry->p_next;
 592             free( p_entry->psz_key );
 593             free( p_entry );
 594             return;
 595         }
 596         p_prev = p_entry;
 597         p_entry = p_entry->p_next;
 598     } while( p_entry );
 599
 600     /* No key was found */
 601 }
 602
 603 #ifdef __cplusplus
 604 // C++ helpers
 605 template <typename T>
 606 void vlc_delete_all( T &container )
 607 {
 608     typename T::iterator it = container.begin();
 609     while ( it != container.end() )
 610     {
 611         delete *it;
 612         ++it;
 613     }
 614     container.clear();
 615 }
 616
 617 #endif
 618
 619 #endif