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