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 /**
  32  * Simple dynamic array handling. Array is realloced at each insert/removal
  33  */
  34 #if defined( _MSC_VER ) && _MSC_VER < 1300 && !defined( UNDER_CE )
  35 #   define VLCCVP (void**) /* Work-around for broken compiler */
  36 #else
  37 #   define VLCCVP
  38 #endif
  39 #define INSERT_ELEM( p_ar, i_oldsize, i_pos, elem )                           \
  40     do                                                                        \
  41     {                                                                         \
  42         if( !i_oldsize ) (p_ar) = NULL;                                       \
  43         (p_ar) = VLCCVP realloc( p_ar, ((i_oldsize) + 1) * sizeof(*(p_ar)) ); \
  44         if( (i_oldsize) - (i_pos) )                                           \
  45         {                                                                     \
  46             memmove( (p_ar) + (i_pos) + 1, (p_ar) + (i_pos),                  \
  47                      ((i_oldsize) - (i_pos)) * sizeof( *(p_ar) ) );           \
  48         }                                                                     \
  49         (p_ar)[i_pos] = elem;                                                 \
  50         (i_oldsize)++;                                                        \
  51     }                                                                         \
  52     while( 0 )
  53
  54 #define REMOVE_ELEM( p_ar, i_oldsize, i_pos )                                 \
  55     do                                                                        \
  56     {                                                                         \
  57         if( (i_oldsize) - (i_pos) - 1 )                                       \
  58         {                                                                     \
  59             memmove( (p_ar) + (i_pos),                                        \
  60                      (p_ar) + (i_pos) + 1,                                    \
  61                      ((i_oldsize) - (i_pos) - 1) * sizeof( *(p_ar) ) );       \
  62         }                                                                     \
  63         if( i_oldsize > 1 )                                                   \
  64         {                                                                     \
  65             (p_ar) = realloc( p_ar, ((i_oldsize) - 1) * sizeof( *(p_ar) ) );  \
  66         }                                                                     \
  67         else                                                                  \
  68         {                                                                     \
  69             free( p_ar );                                                     \
  70             (p_ar) = NULL;                                                    \
  71         }                                                                     \
  72         (i_oldsize)--;                                                        \
  73     }                                                                         \
  74     while( 0 )
  75
  76 #define TAB_INIT( count, tab )                  \
  77   do {                                          \
  78     (count) = 0;                                \
  79     (tab) = NULL;                               \
  80   } while(0)
  81
  82 #define TAB_CLEAN( count, tab )                 \
  83   do {                                          \
  84     if( tab ) free( tab );                      \
  85     (count)= 0;                                 \
  86     (tab)= NULL;                                \
  87   } while(0)
  88
  89 #define TAB_APPEND( count, tab, p )             \
  90   do {                                          \
  91     if( (count) > 0 )                           \
  92         (tab) = realloc( tab, sizeof( void ** ) * ( (count) + 1 ) ); \
  93     else                                        \
  94         (tab) = malloc( sizeof( void ** ) );    \
  95     (tab)[count] = (p);                         \
  96     (count)++;                                  \
  97   } while(0)
  98
  99 #define TAB_FIND( count, tab, p, index )        \
 100   do {                                          \
 101         int _i_;                                \
 102         (index) = -1;                           \
 103         for( _i_ = 0; _i_ < (count); _i_++ )    \
 104         {                                       \
 105             if( (tab)[_i_] == (p) )             \
 106             {                                   \
 107                 (index) = _i_;                  \
 108                 break;                          \
 109             }                                   \
 110         }                                       \
 111   } while(0)
 112
 113 #define TAB_REMOVE( count, tab, p )             \
 114   do {                                          \
 115         int _i_index_;                          \
 116         TAB_FIND( count, tab, p, _i_index_ );   \
 117         if( _i_index_ >= 0 )                    \
 118         {                                       \
 119             if( (count) > 1 )                   \
 120             {                                   \
 121                 memmove( ((void**)(tab) + _i_index_),    \
 122                          ((void**)(tab) + _i_index_+1),  \
 123                          ( (count) - _i_index_ - 1 ) * sizeof( void* ) );\
 124             }                                   \
 125             (count)--;                          \
 126             if( (count) == 0 )                  \
 127             {                                   \
 128                 free( tab );                    \
 129                 (tab) = NULL;                   \
 130             }                                   \
 131         }                                       \
 132   } while(0)
 133
 134 /**
 135  * Binary search in a sorted array. The key must be comparable by < and >
 136  * \param entries array of entries
 137  * \param count number of entries
 138  * \param elem key to check within an entry (like .id, or ->i_id)
 139  * \param zetype type of the key
 140  * \param key value of the key
 141  * \param answer index of answer within the array. -1 if not found
 142  */
 143 #define BSEARCH( entries, count, elem, zetype, key, answer ) \
 144    do {  \
 145     int low = 0, high = count - 1;   \
 146     answer = -1; \
 147     while( low <= high ) {\
 148         int mid = (low + high ) / 2; /* Just don't care about 2^30 tables */ \
 149         zetype mid_val = entries[mid] elem;\
 150         if( mid_val < key ) \
 151             low = mid + 1; \
 152         else if ( mid_val > key ) \
 153             high = mid -1;  \
 154         else    \
 155         {   \
 156             answer = mid;  break;   \
 157         }\
 158     } \
 159  } while(0)
 160
 161 /************************************************************************
 162  * Dictionaries
 163  ************************************************************************/
 164
 165 /* This function is not intended to be crypto-secure, we only want it to be
 166  * fast and not suck too much. This one is pretty fast and did 0 collisions
 167  * in wenglish's dictionary.
 168  */
 169 static inline uint64_t DictHash( const char *psz_string, int i_int )
 170 {
 171     uint64_t i_hash = 0;
 172     if( psz_string )
 173     {
 174         while( *psz_string )
 175         {
 176             i_hash += *psz_string++;
 177             i_hash += i_hash << 10;
 178             i_hash ^= i_hash >> 8;
 179         }
 180     }
 181     return i_hash + ( (uint64_t)i_int << 32 );
 182 }
 183
 184 #define DICT_TYPE(name,type)                                                  \
 185     typedef struct dict_entry_##name##_t {                                    \
 186         int i_int;                                                            \
 187         char *psz_string;                                                     \
 188         uint64_t i_hash;                                                      \
 189         type data;                                                            \
 190     } dict_entry_##name##_t;                                                  \
 191     typedef struct dict_##name##_t {                                          \
 192         dict_entry_##name##_t *p_entries;                                     \
 193         int i_entries;                                                        \
 194     } dict_##name##_t;
 195
 196 #define DICT_NEW( p_dict ) {                                                  \
 197     p_dict = malloc( sizeof(int)+sizeof(void*) );                             \
 198     p_dict->i_entries = 0;                                                    \
 199     p_dict->p_entries = NULL;                                                 \
 200 }
 201
 202 #define DICT_CLEAR( zdict ) {                                                 \
 203     int _i_dict = 0;                                                          \
 204     for ( _i_dict = 0; _i_dict < zdict->i_entries; _i_dict++ )                \
 205     {                                                                         \
 206         FREE( zdict->p_entries[_i_dict].psz_string );                         \
 207     }                                                                         \
 208     FREE( zdict->p_entries );                                                 \
 209     free( zdict );                                                            \
 210 }
 211
 212 #define DICT_INSERT( zdict, zint, zstring, zdata ) {                          \
 213     uint64_t i_hash = DictHash( (zstring), (zint) );                          \
 214     int i_new;                                                                \
 215     /* Find a free slot */                                                    \
 216     if( zdict->i_entries == 0 || i_hash <= zdict->p_entries[0].i_hash )       \
 217         i_new = 0;                                                            \
 218     else if( i_hash >= zdict->p_entries[zdict->i_entries-1].i_hash )          \
 219         i_new = zdict->i_entries;\
 220     else                                                                      \
 221     {                                                                         \
 222         int i_low = 0, i_high = zdict->i_entries - 1;                         \
 223         while( i_high - i_low > 1 )                                           \
 224         {                                                                     \
 225             int i_mid = (i_low + i_high)/2;                                   \
 226             fprintf(stderr, "Low %i, high %i\n", i_low, i_high);              \
 227             if( zdict->p_entries[i_mid].i_hash < i_hash ) {                   \
 228                 i_low = i_mid;                                                \
 229             } else if( zdict->p_entries[i_mid].i_hash > i_hash ) {            \
 230                 i_high = i_mid;                                               \
 231             }                                                                 \
 232         }                                                                     \
 233         if( zdict->p_entries[i_low].i_hash < i_hash )                         \
 234             i_new = i_high;                                                   \
 235         else                                                                  \
 236             i_new = i_low;                                                    \
 237     }                                                                         \
 238     zdict->p_entries = realloc( zdict->p_entries, (zdict->i_entries + 1) *    \
 239         ( sizeof(zdata) + sizeof(int) + sizeof(void*) + sizeof(uint64_t) ) ); \
 240     zdict->i_entries++;                                                       \
 241     if( i_new != zdict->i_entries -1 )                                        \
 242         memmove( &zdict->p_entries[i_new+1], &zdict->p_entries[i_new],        \
 243          ( zdict->i_entries - i_new - 1 ) *                                   \
 244          ( sizeof(zdata) + sizeof(int) + sizeof(void*) + sizeof(uint64_t) ) );\
 245                                                                               \
 246     zdict->p_entries[i_new].i_hash = i_hash;                                  \
 247     zdict->p_entries[i_new].i_int = (zint);                                   \
 248     if( (zstring) ) {                                                         \
 249         zdict->p_entries[i_new].psz_string = strdup( (zstring) );             \
 250     } else {                                                                  \
 251         zdict->p_entries[i_new].psz_string = NULL;                            \
 252     }                                                                         \
 253     zdict->p_entries[i_new].data = zdata;                                     \
 254 }
 255
 256 #define DICT_LOOKUP( zdict, zint, zstring, answer ) do {                      \
 257     uint64_t i_hash;                                                          \
 258     int i, i_pos;                                                             \
 259     vlc_bool_t b_found = VLC_FALSE;                                           \
 260     if( zdict->i_entries == 0 ) {                                             \
 261         answer = -1;                                                          \
 262         break;                                                                \
 263     }                                                                         \
 264                                                                               \
 265     i_hash = DictHash( (zstring), (zint) );                                   \
 266     BSEARCH( zdict->p_entries, zdict->i_entries, .i_hash, uint64_t,           \
 267              i_hash, i_pos );                                                 \
 268     if( i_pos == -1 ) {                                                       \
 269         answer = -1;                                                          \
 270         break;                                                                \
 271     }                                                                         \
 272                                                                               \
 273     /* Hash found, let's check it looks like the entry */                     \
 274     if( !strcmp( (zstring), zdict->p_entries[i_pos].psz_string ) ) {          \
 275         answer = i_pos;                                                       \
 276         break;                                                                \
 277     }                                                                         \
 278                                                                               \
 279     /* Hash collision! This should be very rare, but we cannot guarantee      \
 280      * it will never happen. Just do an exhaustive search amongst all         \
 281      * entries with the same hash. */                                         \
 282     for( i = i_pos - 1 ; i > 0 && i_hash == zdict->p_entries[i].i_hash ; i-- )\
 283     {                                                                         \
 284         if( !strcmp( (zstring), zdict->p_entries[i].psz_string ) &&           \
 285                    zdict->p_entries[i].i_int == (zint) ) {                    \
 286             b_found = VLC_TRUE;                                               \
 287             answer = i;                                                       \
 288             break;                                                            \
 289         }                                                                     \
 290     }                                                                         \
 291     if( b_found == VLC_TRUE )                                                 \
 292         break;                                                                \
 293     for( i = i_pos + 1 ; i < zdict->i_entries &&                              \
 294                          i_hash == zdict->p_entries[i].i_hash ; i++ )         \
 295     {                                                                         \
 296          if( !strcmp( (zstring), zdict->p_entries[i].psz_string ) &&          \
 297                       zdict->p_entries[i].i_int == (zint) ) {                 \
 298             b_found = VLC_TRUE;                                               \
 299             answer = i;                                                       \
 300             break;                                                            \
 301         }                                                                     \
 302     }                                                                         \
 303     /* Hash found, but entry not found (quite strange !) */                   \
 304     assert( 0 );                                                              \
 305 } while(0)
 306
 307 #define DICT_GET( zdict, i_int, psz_string, answer ) {                        \
 308     int int_answer;                                                           \
 309     DICT_LOOKUP( zdict, i_int, psz_string, int_answer );                      \
 310     if( int_answer >=  0 )                                                    \
 311         answer = zdict->p_entries[int_answer].data;                           \
 312 }
 313
 314 /************************************************************************
 315  * Dynamic arrays with progressive allocation
 316  ************************************************************************/
 317
 318 /* Internal functions */
 319 #define _ARRAY_ALLOC(array, newsize) {                                      \
 320     array.i_alloc = newsize;                                                \
 321     array.p_elems = VLCCVP realloc( array.p_elems, array.i_alloc *          \
 322                                     sizeof(*array.p_elems) );               \
 323     assert(array.p_elems);                                                  \
 324 }
 325
 326 #define _ARRAY_GROW1(array) {                                               \
 327     if( array.i_alloc < 10 )                                                \
 328         _ARRAY_ALLOC(array, 10 )                                            \
 329     else if( array.i_alloc == array.i_size )                                \
 330         _ARRAY_ALLOC(array, (int)(array.i_alloc * 1.5) )                    \
 331 }
 332
 333 #define _ARRAY_GROW(array,additional) {                                     \
 334      int i_first = array.i_alloc;                                           \
 335      while( array.i_alloc - i_first < additional )                          \
 336      {                                                                      \
 337          if( array.i_alloc < 10 )                                           \
 338             _ARRAY_ALLOC(array, 10 )                                        \
 339         else if( array.i_alloc == array.i_size )                            \
 340             _ARRAY_ALLOC(array, (int)(array.i_alloc * 1.5) )                \
 341         else break;                                                         \
 342      }                                                                      \
 343 }
 344
 345 #define _ARRAY_SHRINK(array) {                                              \
 346     if( array.i_size > 10 && array.i_size < (int)(array.i_alloc / 1.5) ) {  \
 347         _ARRAY_ALLOC(array, array.i_size + 5);                              \
 348     }                                                                       \
 349 }
 350
 351
 352 /* API */
 353 #define DECL_ARRAY(type) struct {                                           \
 354     int i_alloc;                                                            \
 355     int i_size;                                                             \
 356     type *p_elems;                                                          \
 357 }
 358
 359 #define TYPEDEF_ARRAY(type, name) typedef DECL_ARRAY(type) name;
 360
 361 #define ARRAY_INIT(array)                                                   \
 362     array.i_alloc = 0;                                                      \
 363     array.i_size = 0;                                                       \
 364     array.p_elems = NULL;
 365
 366 #define ARRAY_RESET(array)                                                  \
 367     array.i_alloc = 0;                                                      \
 368     array.i_size = 0;                                                       \
 369     free( array.p_elems ); array.p_elems = NULL;
 370
 371 #define ARRAY_APPEND(array, elem) {                                         \
 372     _ARRAY_GROW1(array);                                                    \
 373     array.p_elems[array.i_size] = elem;                                     \
 374     array.i_size++;                                                         \
 375 }
 376
 377 #define ARRAY_INSERT(array,elem,pos) {                                      \
 378     _ARRAY_GROW1(array);                                                    \
 379     if( array.i_size - pos ) {                                              \
 380         memmove( array.p_elems + pos + 1, array.p_elems + pos,              \
 381                  (array.i_size-pos) * sizeof(*array.p_elems) );             \
 382     }                                                                       \
 383     array.p_elems[pos] = elem;                                              \
 384     array.i_size++;                                                         \
 385 }
 386
 387 #define ARRAY_REMOVE(array,pos) {                                           \
 388     if( array.i_size - (pos) - 1 )                                          \
 389     {                                                                       \
 390         memmove( array.p_elems + pos, array.p_elems + pos + 1,              \
 391                  ( array.i_size - pos - 1 ) *sizeof(*array.p_elems) );      \
 392     }                                                                       \
 393     array.i_size--;                                                         \
 394     _ARRAY_SHRINK(array);                                                   \
 395 }
 396
 397 #define ARRAY_VAL(array, pos) array.p_elems[pos]
 398
 399 #define ARRAY_BSEARCH(array, elem, zetype, key, answer) \
 400     BSEARCH( array.p_elems, array.i_size, elem, zetype, key, answer)
 401
 402 #define FOREACH_ARRAY( item, array ) { \
 403     int fe_idx; \
 404     for( fe_idx = 0 ; fe_idx < array.i_size ; fe_idx++ ) \
 405     { \
 406         item = array.p_elems[fe_idx];
 407
 408 #define FOREACH_END() } }
 409
 410 #endif