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 #define TAB_APPEND_CPP( type, count, tab, p )   \
 111     TAB_APPEND_CAST( (type**), count, tab, p )
 112
 113 #define TAB_FIND( count, tab, p, index )        \
 114   do {                                          \
 115         int _i_;                                \
 116         (index) = -1;                           \
 117         for( _i_ = 0; _i_ < (count); _i_++ )    \
 118         {                                       \
 119             if( (tab)[_i_] == (p) )             \
 120             {                                   \
 121                 (index) = _i_;                  \
 122                 break;                          \
 123             }                                   \
 124         }                                       \
 125   } while(0)
 126
 127
 128 #define TAB_REMOVE( count, tab, p )             \
 129   do {                                          \
 130         int _i_index_;                          \
 131         TAB_FIND( count, tab, p, _i_index_ );   \
 132         if( _i_index_ >= 0 )                    \
 133         {                                       \
 134             if( (count) > 1 )                   \
 135             {                                   \
 136                 memmove( ((void**)(tab) + _i_index_),    \
 137                          ((void**)(tab) + _i_index_+1),  \
 138                          ( (count) - _i_index_ - 1 ) * sizeof( void* ) );\
 139             }                                   \
 140             (count)--;                          \
 141             if( (count) == 0 )                  \
 142             {                                   \
 143                 free( tab );                    \
 144                 (tab) = NULL;                   \
 145             }                                   \
 146         }                                       \
 147   } while(0)
 148
 149 #define TAB_INSERT_CAST( cast, count, tab, p, index ) do { \
 150     if( (count) > 0 )                           \
 151         (tab) = cast realloc( tab, sizeof( void ** ) * ( (count) + 1 ) ); \
 152     else                                        \
 153         (tab) = cast malloc( sizeof( void ** ) );       \
 154     if( !(tab) ) abort();                       \
 155     if( (count) - (index) > 0 )                 \
 156         memmove( (void**)(tab) + (index) + 1,   \
 157                  (void**)(tab) + (index),       \
 158                  ((count) - (index)) * sizeof(*(tab)) );\
 159     (tab)[(index)] = (p);                       \
 160     (count)++;                                  \
 161 } while(0)
 162
 163 #define TAB_INSERT( count, tab, p, index )      \
 164     TAB_INSERT_CAST( , count, tab, p, index )
 165
 166 /**
 167  * Binary search in a sorted array. The key must be comparable by < and >
 168  * \param entries array of entries
 169  * \param count number of entries
 170  * \param elem key to check within an entry (like .id, or ->i_id)
 171  * \param zetype type of the key
 172  * \param key value of the key
 173  * \param answer index of answer within the array. -1 if not found
 174  */
 175 #define BSEARCH( entries, count, elem, zetype, key, answer ) \
 176    do {  \
 177     int low = 0, high = count - 1;   \
 178     answer = -1; \
 179     while( low <= high ) {\
 180         int mid = (low + high ) / 2; /* Just don't care about 2^30 tables */ \
 181         zetype mid_val = entries[mid] elem;\
 182         if( mid_val < key ) \
 183             low = mid + 1; \
 184         else if ( mid_val > key ) \
 185             high = mid -1;  \
 186         else    \
 187         {   \
 188             answer = mid;  break;   \
 189         }\
 190     } \
 191  } while(0)
 192
 193
 194 /************************************************************************
 195  * Dynamic arrays with progressive allocation
 196  ************************************************************************/
 197
 198 /* Internal functions */
 199 #define _ARRAY_ALLOC(array, newsize) {                                      \
 200     (array).i_alloc = newsize;                                              \
 201     (array).p_elems = VLCCVP realloc( (array).p_elems, (array).i_alloc *    \
 202                                     sizeof(*(array).p_elems) );             \
 203     if( !(array).p_elems ) abort();                                         \
 204 }
 205
 206 #define _ARRAY_GROW1(array) {                                               \
 207     if( (array).i_alloc < 10 )                                              \
 208         _ARRAY_ALLOC(array, 10 )                                            \
 209     else if( (array).i_alloc == (array).i_size )                            \
 210         _ARRAY_ALLOC(array, (int)(array.i_alloc * 1.5) )                    \
 211 }
 212
 213 #define _ARRAY_GROW(array,additional) {                                     \
 214      int i_first = (array).i_alloc;                                         \
 215      while( (array).i_alloc - i_first < additional )                        \
 216      {                                                                      \
 217          if( (array).i_alloc < 10 )                                         \
 218             _ARRAY_ALLOC(array, 10 )                                        \
 219         else if( (array).i_alloc == (array).i_size )                        \
 220             _ARRAY_ALLOC(array, (int)((array).i_alloc * 1.5) )              \
 221         else break;                                                         \
 222      }                                                                      \
 223 }
 224
 225 #define _ARRAY_SHRINK(array) {                                              \
 226     if( (array).i_size > 10 && (array).i_size < (int)((array).i_alloc / 1.5) ) {  \
 227         _ARRAY_ALLOC(array, (array).i_size + 5);                            \
 228     }                                                                       \
 229 }
 230
 231 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 232
 233 /* API */
 234 #define DECL_ARRAY(type) struct {                                           \
 235     int i_alloc;                                                            \
 236     int i_size;                                                             \
 237     type *p_elems;                                                          \
 238 }
 239
 240 #define TYPEDEF_ARRAY(type, name) typedef DECL_ARRAY(type) name;
 241
 242 #define ARRAY_INIT(array)                                                   \
 243   do {                                                                      \
 244     (array).i_alloc = 0;                                                    \
 245     (array).i_size = 0;                                                     \
 246     (array).p_elems = NULL;                                                 \
 247   } while(0)
 248
 249 #define ARRAY_RESET(array)                                                  \
 250   do {                                                                      \
 251     (array).i_alloc = 0;                                                    \
 252     (array).i_size = 0;                                                     \
 253     free( (array).p_elems ); (array).p_elems = NULL;                        \
 254   } while(0)
 255
 256 #define ARRAY_APPEND(array, elem)                                           \
 257   do {                                                                      \
 258     _ARRAY_GROW1(array);                                                    \
 259     (array).p_elems[(array).i_size] = elem;                                 \
 260     (array).i_size++;                                                       \
 261   } while(0)
 262
 263 #define ARRAY_INSERT(array,elem,pos)                                        \
 264   do {                                                                      \
 265     _ARRAY_GROW1(array);                                                    \
 266     if( (array).i_size - pos ) {                                            \
 267         memmove( (array).p_elems + pos + 1, (array).p_elems + pos,          \
 268                  ((array).i_size-pos) * sizeof(*(array).p_elems) );         \
 269     }                                                                       \
 270     (array).p_elems[pos] = elem;                                            \
 271     (array).i_size++;                                                       \
 272   } while(0)
 273
 274 #define ARRAY_REMOVE(array,pos)                                             \
 275   do {                                                                      \
 276     if( (array).i_size - (pos) - 1 )                                        \
 277     {                                                                       \
 278         memmove( (array).p_elems + pos, (array).p_elems + pos + 1,          \
 279                  ( (array).i_size - pos - 1 ) *sizeof(*(array).p_elems) );  \
 280     }                                                                       \
 281     (array).i_size--;                                                       \
 282     _ARRAY_SHRINK(array);                                                   \
 283   } while(0)
 284
 285 #define ARRAY_VAL(array, pos) array.p_elems[pos]
 286
 287 #define ARRAY_BSEARCH(array, elem, zetype, key, answer) \
 288     BSEARCH( (array).p_elems, (array).i_size, elem, zetype, key, answer)
 289
 290 #define FOREACH_ARRAY( item, array ) { \
 291     int fe_idx; \
 292     for( fe_idx = 0 ; fe_idx < (array).i_size ; fe_idx++ ) \
 293     { \
 294         item = (array).p_elems[fe_idx];
 295
 296 #define FOREACH_END() } }
 297
 298
 299 /************************************************************************
 300  * Dynamic arrays with progressive allocation (Preferred API)
 301  ************************************************************************/
 302 typedef struct vlc_array_t
 303 {
 304     int i_count;
 305     void ** pp_elems;
 306 } vlc_array_t;
 307
 308 static inline void vlc_array_init( vlc_array_t * p_array )
 309 {
 310     memset( p_array, 0, sizeof(vlc_array_t) );
 311 }
 312
 313 static inline void vlc_array_clear( vlc_array_t * p_array )
 314 {
 315     free( p_array->pp_elems );
 316     memset( p_array, 0, sizeof(vlc_array_t) );
 317 }
 318
 319 static inline vlc_array_t * vlc_array_new( void )
 320 {
 321     vlc_array_t * ret = (vlc_array_t *)malloc( sizeof(vlc_array_t) );
 322     if( ret ) vlc_array_init( ret );
 323     return ret;
 324 }
 325
 326 static inline void vlc_array_destroy( vlc_array_t * p_array )
 327 {
 328     if( !p_array )
 329         return;
 330     vlc_array_clear( p_array );
 331     free( p_array );
 332 }
 333
 334
 335 /* Read */
 336 static inline int
 337 vlc_array_count( vlc_array_t * p_array )
 338 {
 339     return p_array->i_count;
 340 }
 341
 342 static inline void *
 343 vlc_array_item_at_index( vlc_array_t * p_array, int i_index )
 344 {
 345     return p_array->pp_elems[i_index];
 346 }
 347
 348 static inline int
 349 vlc_array_index_of_item( vlc_array_t * p_array, void * item )
 350 {
 351     int i;
 352     for( i = 0; i < p_array->i_count; i++)
 353     {
 354         if( p_array->pp_elems[i] == item )
 355             return i;
 356     }
 357     return -1;
 358 }
 359
 360 /* Write */
 361 static inline void
 362 vlc_array_insert( vlc_array_t * p_array, void * p_elem, int i_index )
 363 {
 364     TAB_INSERT_CAST( (void **), p_array->i_count, p_array->pp_elems, p_elem, i_index );
 365 }
 366
 367 static inline void
 368 vlc_array_append( vlc_array_t * p_array, void * p_elem )
 369 {
 370     vlc_array_insert( p_array, p_elem, p_array->i_count );
 371 }
 372
 373 static inline void
 374 vlc_array_remove( vlc_array_t * p_array, int i_index )
 375 {
 376     if( i_index >= 0 )
 377     {
 378         if( p_array->i_count > 1 )
 379         {
 380             memmove( p_array->pp_elems + i_index,
 381                      p_array->pp_elems + i_index+1,
 382                      ( p_array->i_count - i_index - 1 ) * sizeof( void* ) );
 383         }
 384         p_array->i_count--;
 385         if( p_array->i_count == 0 )
 386         {
 387             free( p_array->pp_elems );
 388             p_array->pp_elems = NULL;
 389         }
 390     }
 391 }
 392
 393
 394 /************************************************************************
 395  * Dictionaries
 396  ************************************************************************/
 397
 398 /* This function is not intended to be crypto-secure, we only want it to be
 399  * fast and not suck too much. This one is pretty fast and did 0 collisions
 400  * in wenglish's dictionary.
 401  */
 402 static inline uint64_t DictHash( const char *psz_string, int hashsize )
 403 {
 404     uint64_t i_hash = 0;
 405     if( psz_string )
 406     {
 407         while( *psz_string )
 408         {
 409             i_hash += *psz_string++;
 410             i_hash += i_hash << 10;
 411             i_hash ^= i_hash >> 8;
 412         }
 413     }
 414     return i_hash % hashsize;
 415 }
 416
 417 typedef struct vlc_dictionary_entry_t
 418 {
 419     char *   psz_key;
 420     void *   p_value;
 421     struct vlc_dictionary_entry_t * p_next;
 422 } vlc_dictionary_entry_t;
 423
 424 typedef struct vlc_dictionary_t
 425 {
 426     int i_size;
 427     vlc_dictionary_entry_t ** p_entries;
 428 } vlc_dictionary_t;
 429
 430 static void * const kVLCDictionaryNotFound = NULL;
 431
 432 static inline void vlc_dictionary_init( vlc_dictionary_t * p_dict, int i_size )
 433 {
 434     p_dict->p_entries = NULL;
 435
 436     if( i_size > 0 )
 437     {
 438         p_dict->p_entries = (vlc_dictionary_entry_t **)calloc( i_size, sizeof(*p_dict->p_entries) );
 439         if( !p_dict->p_entries )
 440             i_size = 0;
 441     }
 442     p_dict->i_size = i_size;
 443 }
 444
 445 static inline void vlc_dictionary_clear( vlc_dictionary_t * p_dict,
 446                                          void ( * pf_free )( void * p_data, void * p_obj ),
 447                                          void * p_obj )
 448 {
 449     if( p_dict->p_entries )
 450     {
 451         for( int i = 0; i < p_dict->i_size; i++ )
 452         {
 453             vlc_dictionary_entry_t * p_current, * p_next;
 454             p_current = p_dict->p_entries[i];
 455             while( p_current )
 456             {
 457                 p_next = p_current->p_next;
 458                 if( pf_free != NULL )
 459                     ( * pf_free )( p_current->p_value, p_obj );
 460                 free( p_current->psz_key );
 461                 free( p_current );
 462                 p_current = p_next;
 463             }
 464         }
 465         free( p_dict->p_entries );
 466         p_dict->p_entries = NULL;
 467     }
 468     p_dict->i_size = 0;
 469 }
 470
 471
 472
 473 static inline void *
 474 vlc_dictionary_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 475 {
 476     if( !p_dict->p_entries )
 477         return kVLCDictionaryNotFound;
 478
 479     int i_pos = DictHash( psz_key, p_dict->i_size );
 480     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 481
 482     if( !p_entry )
 483         return kVLCDictionaryNotFound;
 484
 485     /* Make sure we return the right item. (Hash collision) */
 486     do {
 487         if( !strcmp( psz_key, p_entry->psz_key ) )
 488             return p_entry->p_value;
 489         p_entry = p_entry->p_next;
 490     } while( p_entry );
 491
 492     return kVLCDictionaryNotFound;
 493 }
 494
 495 static inline int
 496 vlc_dictionary_keys_count( const vlc_dictionary_t * p_dict )
 497 {
 498     vlc_dictionary_entry_t * p_entry;
 499     int i, count = 0;
 500
 501     if( !p_dict->p_entries )
 502         return 0;
 503
 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 ) count++;
 507     }
 508     return count;
 509 }
 510
 511 static inline char **
 512 vlc_dictionary_all_keys( const vlc_dictionary_t * p_dict )
 513 {
 514     vlc_dictionary_entry_t * p_entry;
 515     char ** ppsz_ret;
 516     int i, count = vlc_dictionary_keys_count( p_dict );
 517
 518     ppsz_ret = (char**)malloc(sizeof(char *) * (count + 1));
 519
 520     count = 0;
 521     for( i = 0; i < p_dict->i_size; i++ )
 522     {
 523         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next )
 524             ppsz_ret[count++] = strdup( p_entry->psz_key );
 525     }
 526     ppsz_ret[count] = NULL;
 527     return ppsz_ret;
 528 }
 529
 530 static inline void
 531 __vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key,
 532                          void * p_value, bool rebuild )
 533 {
 534     if( !p_dict->p_entries )
 535         vlc_dictionary_init( p_dict, 1 );
 536
 537     int i_pos = DictHash( psz_key, p_dict->i_size );
 538     vlc_dictionary_entry_t * p_entry;
 539
 540     p_entry = (vlc_dictionary_entry_t *)malloc(sizeof(*p_entry));
 541     p_entry->psz_key = strdup( psz_key );
 542     p_entry->p_value = p_value;
 543     p_entry->p_next = p_dict->p_entries[i_pos];
 544     p_dict->p_entries[i_pos] = p_entry;
 545     if( rebuild )
 546     {
 547         /* Count how many items there was */
 548         int count;
 549         for( count = 1; p_entry->p_next; count++ )
 550             p_entry = p_entry->p_next;
 551         if( count > 3 ) /* XXX: this need tuning */
 552         {
 553             /* Here it starts to be not good, rebuild a bigger dictionary */
 554             struct vlc_dictionary_t new_dict;
 555             int i_new_size = ( (p_dict->i_size+2) * 3) / 2; /* XXX: this need tuning */
 556             int i;
 557             vlc_dictionary_init( &new_dict, i_new_size );
 558             for( i = 0; i < p_dict->i_size; i++ )
 559             {
 560                 p_entry = p_dict->p_entries[i];
 561                 while( p_entry )
 562                 {
 563                     __vlc_dictionary_insert( &new_dict, p_entry->psz_key,
 564                                              p_entry->p_value,
 565                                              false /* To avoid multiple rebuild loop */);
 566                     p_entry = p_entry->p_next;
 567                 }
 568             }
 569
 570             vlc_dictionary_clear( p_dict, NULL, NULL );
 571             p_dict->i_size = new_dict.i_size;
 572             p_dict->p_entries = new_dict.p_entries;
 573         }
 574     }
 575 }
 576
 577 static inline void
 578 vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key, void * p_value )
 579 {
 580     __vlc_dictionary_insert( p_dict, psz_key, p_value, true );
 581 }
 582
 583 static inline void
 584 vlc_dictionary_remove_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key,
 585                                      void ( * pf_free )( void * p_data, void * p_obj ),
 586                                      void * p_obj )
 587 {
 588     if( !p_dict->p_entries )
 589         return;
 590
 591     int i_pos = DictHash( psz_key, p_dict->i_size );
 592     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 593     vlc_dictionary_entry_t * p_prev;
 594
 595     if( !p_entry )
 596         return; /* Not found, nothing to do */
 597
 598     /* Hash collision */
 599     p_prev = NULL;
 600     do {
 601         if( !strcmp( psz_key, p_entry->psz_key ) )
 602         {
 603             if( pf_free != NULL )
 604                 ( * pf_free )( p_entry->p_value, p_obj );
 605             if( !p_prev )
 606                 p_dict->p_entries[i_pos] = p_entry->p_next;
 607             else
 608                 p_prev->p_next = p_entry->p_next;
 609             free( p_entry->psz_key );
 610             free( p_entry );
 611             return;
 612         }
 613         p_prev = p_entry;
 614         p_entry = p_entry->p_next;
 615     } while( p_entry );
 616
 617     /* No key was found */
 618 }
 619
 620 #endif