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 #ifndef VLC_ARRAYS_H_
  25 #define VLC_ARRAYS_H_
  26
  27 /**
  28  * \file
  29  * This file defines functions, structures and macros for handling arrays in vlc
  30  */
  31
  32 /**
  33  * Simple dynamic array handling. Array is realloced at each insert/removal
  34  */
  35 #if defined( _MSC_VER ) && _MSC_VER < 1300 && !defined( UNDER_CE )
  36 #   define VLCCVP (void**) /* Work-around for broken compiler */
  37 #else
  38 #   define VLCCVP
  39 #endif
  40 #define INSERT_ELEM( p_ar, i_oldsize, i_pos, elem )                           \
  41     do                                                                        \
  42     {                                                                         \
  43         if( !i_oldsize ) (p_ar) = NULL;                                       \
  44         (p_ar) = VLCCVP realloc( p_ar, ((i_oldsize) + 1) * sizeof(*(p_ar)) ); \
  45         if( (i_oldsize) - (i_pos) )                                           \
  46         {                                                                     \
  47             memmove( (p_ar) + (i_pos) + 1, (p_ar) + (i_pos),                  \
  48                      ((i_oldsize) - (i_pos)) * sizeof( *(p_ar) ) );           \
  49         }                                                                     \
  50         (p_ar)[i_pos] = elem;                                                 \
  51         (i_oldsize)++;                                                        \
  52     }                                                                         \
  53     while( 0 )
  54
  55 #define REMOVE_ELEM( p_ar, i_oldsize, i_pos )                                 \
  56     do                                                                        \
  57     {                                                                         \
  58         if( (i_oldsize) - (i_pos) - 1 )                                       \
  59         {                                                                     \
  60             memmove( (p_ar) + (i_pos),                                        \
  61                      (p_ar) + (i_pos) + 1,                                    \
  62                      ((i_oldsize) - (i_pos) - 1) * sizeof( *(p_ar) ) );       \
  63         }                                                                     \
  64         if( i_oldsize > 1 )                                                   \
  65         {                                                                     \
  66             (p_ar) = realloc( p_ar, ((i_oldsize) - 1) * sizeof( *(p_ar) ) );  \
  67         }                                                                     \
  68         else                                                                  \
  69         {                                                                     \
  70             free( p_ar );                                                     \
  71             (p_ar) = NULL;                                                    \
  72         }                                                                     \
  73         (i_oldsize)--;                                                        \
  74     }                                                                         \
  75     while( 0 )
  76
  77 #define TAB_INIT( count, tab )                  \
  78   do {                                          \
  79     (count) = 0;                                \
  80     (tab) = NULL;                               \
  81   } while(0)
  82
  83 #define TAB_CLEAN( count, tab )                 \
  84   do {                                          \
  85     free( tab );                                \
  86     (count)= 0;                                 \
  87     (tab)= NULL;                                \
  88   } while(0)
  89
  90 #define TAB_APPEND_CAST( cast, count, tab, p )             \
  91   do {                                          \
  92     if( (count) > 0 )                           \
  93         (tab) = cast realloc( tab, sizeof( void ** ) * ( (count) + 1 ) ); \
  94     else                                        \
  95         (tab) = cast malloc( sizeof( void ** ) );    \
  96     (tab)[count] = (p);                         \
  97     (count)++;                                  \
  98   } while(0)
  99
 100 #define TAB_APPEND( count, tab, p )             \
 101     TAB_APPEND_CAST( , count, tab, p )
 102 #define TAB_APPEND_CPP( type, count, tab, p )   \
 103     TAB_APPEND_CAST( (type**), count, tab, p )
 104
 105 #define TAB_FIND( count, tab, p, index )        \
 106   do {                                          \
 107         int _i_;                                \
 108         (index) = -1;                           \
 109         for( _i_ = 0; _i_ < (count); _i_++ )    \
 110         {                                       \
 111             if( (tab)[_i_] == (p) )             \
 112             {                                   \
 113                 (index) = _i_;                  \
 114                 break;                          \
 115             }                                   \
 116         }                                       \
 117   } while(0)
 118
 119
 120 #define TAB_REMOVE( count, tab, p )             \
 121   do {                                          \
 122         int _i_index_;                          \
 123         TAB_FIND( count, tab, p, _i_index_ );   \
 124         if( _i_index_ >= 0 )                    \
 125         {                                       \
 126             if( (count) > 1 )                   \
 127             {                                   \
 128                 memmove( ((void**)(tab) + _i_index_),    \
 129                          ((void**)(tab) + _i_index_+1),  \
 130                          ( (count) - _i_index_ - 1 ) * sizeof( void* ) );\
 131             }                                   \
 132             (count)--;                          \
 133             if( (count) == 0 )                  \
 134             {                                   \
 135                 free( tab );                    \
 136                 (tab) = NULL;                   \
 137             }                                   \
 138         }                                       \
 139   } while(0)
 140
 141 #define TAB_INSERT_CAST( cast, count, tab, p, index ) do { \
 142     if( (count) > 0 )                           \
 143         (tab) = cast realloc( tab, sizeof( void ** ) * ( (count) + 1 ) ); \
 144     else                                        \
 145         (tab) = cast malloc( sizeof( void ** ) );       \
 146     if( (count) - (index) > 0 )                 \
 147         memmove( (void**)(tab) + (index) + 1,   \
 148                  (void**)(tab) + (index),       \
 149                  ((count) - (index)) * sizeof(*(tab)) );\
 150     (tab)[(index)] = (p);                       \
 151     (count)++;                                  \
 152 } while(0)
 153
 154 #define TAB_INSERT( count, tab, p, index )      \
 155     TAB_INSERT_CAST( , count, tab, p, index )
 156
 157 /**
 158  * Binary search in a sorted array. The key must be comparable by < and >
 159  * \param entries array of entries
 160  * \param count number of entries
 161  * \param elem key to check within an entry (like .id, or ->i_id)
 162  * \param zetype type of the key
 163  * \param key value of the key
 164  * \param answer index of answer within the array. -1 if not found
 165  */
 166 #define BSEARCH( entries, count, elem, zetype, key, answer ) \
 167    do {  \
 168     int low = 0, high = count - 1;   \
 169     answer = -1; \
 170     while( low <= high ) {\
 171         int mid = (low + high ) / 2; /* Just don't care about 2^30 tables */ \
 172         zetype mid_val = entries[mid] elem;\
 173         if( mid_val < key ) \
 174             low = mid + 1; \
 175         else if ( mid_val > key ) \
 176             high = mid -1;  \
 177         else    \
 178         {   \
 179             answer = mid;  break;   \
 180         }\
 181     } \
 182  } while(0)
 183
 184
 185 /************************************************************************
 186  * Dynamic arrays with progressive allocation
 187  ************************************************************************/
 188
 189 /* Internal functions */
 190 #define _ARRAY_ALLOC(array, newsize) {                                      \
 191     array.i_alloc = newsize;                                                \
 192     array.p_elems = VLCCVP realloc( array.p_elems, array.i_alloc *          \
 193                                     sizeof(*array.p_elems) );               \
 194 }
 195
 196 #define _ARRAY_GROW1(array) {                                               \
 197     if( array.i_alloc < 10 )                                                \
 198         _ARRAY_ALLOC(array, 10 )                                            \
 199     else if( array.i_alloc == array.i_size )                                \
 200         _ARRAY_ALLOC(array, (int)(array.i_alloc * 1.5) )                    \
 201 }
 202
 203 #define _ARRAY_GROW(array,additional) {                                     \
 204      int i_first = array.i_alloc;                                           \
 205      while( array.i_alloc - i_first < additional )                          \
 206      {                                                                      \
 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         else break;                                                         \
 212      }                                                                      \
 213 }
 214
 215 #define _ARRAY_SHRINK(array) {                                              \
 216     if( array.i_size > 10 && array.i_size < (int)(array.i_alloc / 1.5) ) {  \
 217         _ARRAY_ALLOC(array, array.i_size + 5);                              \
 218     }                                                                       \
 219 }
 220
 221 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 222
 223 /* API */
 224 #define DECL_ARRAY(type) struct {                                           \
 225     int i_alloc;                                                            \
 226     int i_size;                                                             \
 227     type *p_elems;                                                          \
 228 }
 229
 230 #define TYPEDEF_ARRAY(type, name) typedef DECL_ARRAY(type) name;
 231
 232 #define ARRAY_INIT(array)                                                   \
 233     array.i_alloc = 0;                                                      \
 234     array.i_size = 0;                                                       \
 235     array.p_elems = NULL;
 236
 237 #define ARRAY_RESET(array)                                                  \
 238     array.i_alloc = 0;                                                      \
 239     array.i_size = 0;                                                       \
 240     free( array.p_elems ); array.p_elems = NULL;
 241
 242 #define ARRAY_APPEND(array, elem) {                                         \
 243     _ARRAY_GROW1(array);                                                    \
 244     array.p_elems[array.i_size] = elem;                                     \
 245     array.i_size++;                                                         \
 246 }
 247
 248 #define ARRAY_INSERT(array,elem,pos) {                                      \
 249     _ARRAY_GROW1(array);                                                    \
 250     if( array.i_size - pos ) {                                              \
 251         memmove( array.p_elems + pos + 1, array.p_elems + pos,              \
 252                  (array.i_size-pos) * sizeof(*array.p_elems) );             \
 253     }                                                                       \
 254     array.p_elems[pos] = elem;                                              \
 255     array.i_size++;                                                         \
 256 }
 257
 258 #define ARRAY_REMOVE(array,pos) {                                           \
 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 }
 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 struct vlc_dictionary_entry_t
 401 {
 402     char *   psz_key;
 403     void *   p_value;
 404     struct vlc_dictionary_entry_t * p_next;
 405 };
 406
 407 typedef struct vlc_dictionary_t
 408 {
 409     int i_size;
 410     struct 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     if( i_size > 0 )
 418     {
 419         p_dict->p_entries = (struct vlc_dictionary_entry_t **)malloc(sizeof(struct vlc_dictionary_entry_t *) * i_size);
 420         memset( p_dict->p_entries, 0, sizeof(struct vlc_dictionary_entry_t *) * i_size );
 421     }
 422     else
 423         p_dict->p_entries = NULL;
 424     p_dict->i_size = i_size;
 425 }
 426
 427 static inline void vlc_dictionary_clear( vlc_dictionary_t * p_dict )
 428 {
 429     int i;
 430     struct vlc_dictionary_entry_t * p_current, * p_next;
 431     if( p_dict->p_entries )
 432     {
 433         for( i = 0; i < p_dict->i_size; i++ )
 434         {
 435             p_current = p_dict->p_entries[i];
 436             while( p_current )
 437             {
 438                 p_next = p_current->p_next;
 439                 free( p_current->psz_key );
 440                 free( p_current );
 441                 p_current = p_next;
 442             }
 443         }
 444         free( p_dict->p_entries );
 445     }
 446     p_dict->i_size = 0;
 447 }
 448
 449
 450
 451 static inline void *
 452 vlc_dictionary_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 453 {
 454     if( !p_dict->p_entries )
 455         return kVLCDictionaryNotFound;
 456
 457     int i_pos = DictHash( psz_key, p_dict->i_size );
 458     struct vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 459
 460     if( !p_entry )
 461         return kVLCDictionaryNotFound;
 462
 463     /* Make sure we return the right item. (Hash collision) */
 464     do {
 465         if( !strcmp( psz_key, p_entry->psz_key ) )
 466             return p_entry->p_value;
 467         p_entry = p_entry->p_next;
 468     } while( p_entry );
 469
 470     return kVLCDictionaryNotFound;
 471 }
 472
 473 static inline int
 474 vlc_dictionary_keys_count( const vlc_dictionary_t * p_dict )
 475 {
 476     struct vlc_dictionary_entry_t * p_entry;
 477     int i, count = 0;
 478
 479     if( !p_dict->p_entries )
 480         return 0;
 481
 482     for( i = 0; i < p_dict->i_size; i++ )
 483     {
 484         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next ) count++;
 485     }
 486     return count;
 487 }
 488
 489 static inline char **
 490 vlc_dictionary_all_keys( const vlc_dictionary_t * p_dict )
 491 {
 492     struct vlc_dictionary_entry_t * p_entry;
 493     char ** ppsz_ret;
 494     int i, count = vlc_dictionary_keys_count( p_dict );
 495
 496     ppsz_ret = (char**)malloc(sizeof(char *) * (count + 1));
 497
 498     count = 0;
 499     for( i = 0; i < p_dict->i_size; i++ )
 500     {
 501         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next )
 502             ppsz_ret[count++] = strdup( p_entry->psz_key );
 503     }
 504     ppsz_ret[count] = NULL;
 505     return ppsz_ret;
 506 }
 507
 508 static inline void
 509 __vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key,
 510                          void * p_value, bool rebuild )
 511 {
 512     if( !p_dict->p_entries )
 513         vlc_dictionary_init( p_dict, 1 );
 514
 515     int i_pos = DictHash( psz_key, p_dict->i_size );
 516     struct vlc_dictionary_entry_t * p_entry;
 517
 518     p_entry = (struct vlc_dictionary_entry_t *)malloc(sizeof(struct vlc_dictionary_entry_t));
 519     p_entry->psz_key = strdup( psz_key );
 520     p_entry->p_value = p_value;
 521     p_entry->p_next = p_dict->p_entries[i_pos];
 522     p_dict->p_entries[i_pos] = p_entry;
 523     if( rebuild )
 524     {
 525         /* Count how many items there was */
 526         int count;
 527         for( count = 1; p_entry->p_next; count++ ) p_entry = p_entry->p_next;
 528         if( count > 3 ) /* XXX: this need tuning */
 529         {
 530             /* Here it starts to be not good, rebuild a bigger dictionary */
 531             struct vlc_dictionary_t new_dict;
 532             int i_new_size = ( (p_dict->i_size+2) * 3) / 2; /* XXX: this need tuning */
 533             int i;
 534             vlc_dictionary_init( &new_dict, i_new_size );
 535             for( i = 0; i < p_dict->i_size; i++ )
 536             {
 537                 p_entry = p_dict->p_entries[i];
 538                 while( p_entry )
 539                 {
 540                     __vlc_dictionary_insert( &new_dict, p_entry->psz_key,
 541                                              p_entry->p_value,
 542                                              0 /* To avoid multiple rebuild loop */);
 543                     p_entry = p_entry->p_next;
 544                 }
 545             }
 546
 547             vlc_dictionary_clear( p_dict );
 548             p_dict->i_size = new_dict.i_size;
 549             p_dict->p_entries = new_dict.p_entries;
 550         }
 551     }
 552 }
 553
 554 static inline void
 555 vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key, void * p_value )
 556 {
 557     __vlc_dictionary_insert( p_dict, psz_key, p_value, 1 );
 558 }
 559
 560 static inline void
 561 vlc_dictionary_remove_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 562 {
 563     if( !p_dict->p_entries )
 564         return;
 565
 566     int i_pos = DictHash( psz_key, p_dict->i_size );
 567     struct vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 568     struct vlc_dictionary_entry_t * p_prev;
 569
 570     if( !p_entry )
 571         return; /* Not found, nothing to do */
 572
 573     /* Hash collision */
 574     p_prev = NULL;
 575     do {
 576         if( !strcmp( psz_key, p_entry->psz_key ) )
 577         {
 578             if( !p_prev )
 579                 p_dict->p_entries[i_pos] = p_entry->p_next;
 580             else
 581                 p_prev->p_next = p_entry->p_next;
 582             free( p_entry->psz_key );
 583             free( p_entry );
 584             return;
 585         }
 586         p_prev = p_entry;
 587         p_entry = p_entry->p_next;
 588     } while( p_entry );
 589
 590     /* No key was found */
 591 }
 592
 593 #endif