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: vlc_playlist.h 17108 2006-10-15 15:28:34Z zorglub $
   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 #if !defined( __LIBVLC__ )
  25   #error You are not libvlc or one of its plugins. You cannot include this file
  26 #endif
  27
  28 #ifndef _VLC_ARRAYS_H_
  29 #define _VLC_ARRAYS_H_
  30
  31 #include <assert.h>
  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     if( tab ) 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 #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     assert(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
 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  * Dictionaries
 283  ************************************************************************/
 284
 285 /* This function is not intended to be crypto-secure, we only want it to be
 286  * fast and not suck too much. This one is pretty fast and did 0 collisions
 287  * in wenglish's dictionary.
 288  */
 289 static inline uint64_t DictHash( const char *psz_string, int hashsize )
 290 {
 291     uint64_t i_hash = 0;
 292     if( psz_string )
 293     {
 294         while( *psz_string )
 295         {
 296             i_hash += *psz_string++;
 297             i_hash += i_hash << 10;
 298             i_hash ^= i_hash >> 8;
 299         }
 300     }
 301     return i_hash % hashsize;
 302 }
 303
 304 struct vlc_dictionary_entry_t
 305 {
 306     char *   psz_key;
 307     void *   p_value;
 308     struct vlc_dictionary_entry_t * p_next;
 309 };
 310
 311 typedef struct vlc_dictionary_t
 312 {
 313     int i_size;
 314     struct vlc_dictionary_entry_t ** p_entries;
 315 } vlc_dictionary_t;
 316
 317 static void * const kVLCDictionaryNotFound = NULL;
 318
 319 static inline void vlc_dictionary_init( vlc_dictionary_t * p_dict, int i_size )
 320 {
 321     p_dict->p_entries = malloc(sizeof(struct vlc_dictionary_entry_t *) * i_size);
 322     assert( p_dict->p_entries );
 323     memset( p_dict->p_entries, 0, sizeof(struct vlc_dictionary_entry_t *) * i_size );
 324     p_dict->i_size = i_size;
 325 }
 326
 327 static inline void vlc_dictionary_clear( vlc_dictionary_t * p_dict )
 328 {
 329     int i;
 330     struct vlc_dictionary_entry_t * p_current, * p_next;
 331     for( i = 0; i < p_dict->i_size; i++ )
 332     {
 333         p_current = p_dict->p_entries[i];
 334         while( p_current )
 335         {
 336             p_next = p_dict->p_entries[i]->p_next;
 337             free( p_dict->p_entries[i]->psz_key );
 338             free( p_current );
 339             p_current = p_next;
 340         }
 341     }
 342     free( p_dict->p_entries );
 343     p_dict->i_size = 0;
 344 }
 345
 346
 347
 348 static inline void *
 349 vlc_dictionary_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 350 {
 351     int i_pos = DictHash( psz_key, p_dict->i_size );
 352     struct vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 353
 354     if( p_entry && !p_entry->p_next )
 355         return p_entry->p_value;
 356
 357     if( !p_entry )
 358         return kVLCDictionaryNotFound;
 359
 360     /* Hash collision */
 361     do {
 362         if( !strcmp( psz_key, p_entry->psz_key ) )
 363             return p_entry->p_value;
 364         p_entry = p_entry->p_next;
 365     } while( p_entry );
 366
 367 }
 368
 369 static inline int
 370 vlc_dictionary_keys_count( const vlc_dictionary_t * p_dict )
 371 {
 372     struct vlc_dictionary_entry_t * p_entry;
 373     int i, count = 0;
 374     for( i = 0; i < p_dict->i_size; i++ )
 375     {
 376         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next ) count++;
 377     }
 378     return count;
 379 }
 380
 381 static inline char **
 382 vlc_dictionary_all_keys( const vlc_dictionary_t * p_dict )
 383 {
 384     struct vlc_dictionary_entry_t * p_entry;
 385     char ** ppsz_ret;
 386     int i, count = vlc_dictionary_keys_count( p_dict );
 387     if( !count )
 388         return NULL;
 389
 390     ppsz_ret = malloc(sizeof(char *) * (count + 1));
 391     assert( ppsz_ret );
 392
 393     count = 0;
 394     for( i = 0; i < p_dict->i_size; i++ )
 395     {
 396         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next )
 397         {
 398             ppsz_ret[count++] = strdup( p_entry->psz_key );
 399             assert( ppsz_ret );
 400         }
 401     }
 402     ppsz_ret[count] = NULL;
 403     return ppsz_ret;
 404 }
 405
 406 static inline void
 407 __vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key,
 408                          void * p_value, vlc_bool_t rebuild )
 409 {
 410     int i_pos = DictHash( psz_key, p_dict->i_size );
 411     struct vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 412
 413     if( !p_entry )
 414     {
 415         p_entry = p_dict->p_entries[i_pos] = malloc(sizeof(struct vlc_dictionary_entry_t));
 416         assert( p_entry );
 417
 418         p_entry->psz_key = strdup( psz_key );
 419         assert( p_entry->psz_key );
 420         p_entry->p_value = p_value;
 421         p_dict->p_entries[i_pos]->p_next = NULL;
 422         return;
 423     }
 424     if( p_entry->p_value == kVLCDictionaryNotFound )
 425     {
 426         /* This one is fine, just high jack */
 427         p_entry->psz_key = strdup( psz_key );
 428         p_entry->p_value = p_value;
 429         return;
 430     }
 431
 432     /* Hash collision here */
 433     p_entry = malloc(sizeof(struct vlc_dictionary_entry_t));
 434     assert( p_entry );
 435     p_entry->psz_key = strdup( psz_key );
 436     p_entry->p_value = p_value;
 437     p_entry->p_next = p_dict->p_entries[i_pos];
 438     p_dict->p_entries[i_pos] = p_entry;
 439
 440     if( rebuild )
 441     {
 442         /* Count how many items there was */
 443         int count;
 444         for( count = 1; p_entry->p_next; count++ ) p_entry = p_entry->p_next;
 445         if( count > 3 ) /* XXX: this need tuning */
 446         {
 447             /* Here it starts to be not good, rebuild a bigger dictionary */
 448             struct vlc_dictionary_t new_dict;
 449             int i_new_size = ( p_dict->i_size * 3) / 2; /* XXX: this need tuning */
 450             int i;
 451
 452             vlc_dictionary_init( &new_dict, i_new_size );
 453             for( i = 0; i < p_dict->i_size; i++ )
 454             {
 455                 p_entry = p_dict->p_entries[i];
 456                 while( p_entry );
 457                 {
 458                     __vlc_dictionary_insert( &new_dict, p_entry->psz_key,
 459                                              p_entry->p_value,
 460                                              0 /* To avoid multiple rebuild loop */);
 461                     p_entry = p_entry->p_next;
 462                 }
 463             }
 464             vlc_dictionary_clear( p_dict );
 465             p_dict->i_size = new_dict.i_size;
 466             p_dict->p_entries= new_dict.p_entries;
 467         }
 468     }
 469 }
 470
 471 static inline void
 472 vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key, void * p_value )
 473 {
 474     __vlc_dictionary_insert( p_dict, psz_key, p_value, 1 );
 475 }
 476
 477 static inline void
 478 vlc_dictionary_remove_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 479 {
 480     int i_pos = DictHash( psz_key, p_dict->i_size );
 481     struct vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 482     struct vlc_dictionary_entry_t * p_prev;
 483
 484     if( !p_entry )
 485         return; /* Not found, nothing to do */
 486
 487     if( !p_entry->p_next )
 488     {
 489         free( p_entry->psz_key );
 490         free( p_entry );
 491         p_dict->p_entries[i_pos] = NULL;
 492     }
 493
 494     /* Hash collision */
 495     p_prev = NULL;
 496     do {
 497         if( !strcmp( psz_key, p_entry->psz_key ) )
 498         {
 499             if( !p_prev )
 500                 p_dict->p_entries[i_pos] = p_entry->p_next;
 501             else
 502                 p_prev->p_next = p_entry->p_next;
 503             free( p_entry->psz_key );
 504             free( p_entry );
 505             return;
 506         }
 507         p_prev = p_entry;
 508         p_entry = p_entry->p_next;
 509     } while( p_entry );
 510
 511     /* No key was found */
 512 }
 513
 514 #endif