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_CAST( cast, count, tab, p )             \
  90   do {                                          \
  91     if( (count) > 0 )                           \
  92         (tab) = cast realloc( tab, sizeof( void ** ) * ( (count) + 1 ) ); \
  93     else                                        \
  94         (tab) = cast malloc( sizeof( void ** ) );    \
  95     (tab)[count] = (p);                         \
  96     (count)++;                                  \
  97   } while(0)
  98
  99 #define TAB_APPEND( count, tab, p )             \
 100     TAB_APPEND_CAST( , count, tab, p )
 101 #define TAB_APPEND_CPP( type, count, tab, p )   \
 102     TAB_APPEND_CAST( (type**), count, tab, p )
 103
 104 #define TAB_FIND( count, tab, p, index )        \
 105   do {                                          \
 106         int _i_;                                \
 107         (index) = -1;                           \
 108         for( _i_ = 0; _i_ < (count); _i_++ )    \
 109         {                                       \
 110             if( (tab)[_i_] == (p) )             \
 111             {                                   \
 112                 (index) = _i_;                  \
 113                 break;                          \
 114             }                                   \
 115         }                                       \
 116   } while(0)
 117
 118 #define TAB_REMOVE( count, tab, p )             \
 119   do {                                          \
 120         int _i_index_;                          \
 121         TAB_FIND( count, tab, p, _i_index_ );   \
 122         if( _i_index_ >= 0 )                    \
 123         {                                       \
 124             if( (count) > 1 )                   \
 125             {                                   \
 126                 memmove( ((void**)(tab) + _i_index_),    \
 127                          ((void**)(tab) + _i_index_+1),  \
 128                          ( (count) - _i_index_ - 1 ) * sizeof( void* ) );\
 129             }                                   \
 130             (count)--;                          \
 131             if( (count) == 0 )                  \
 132             {                                   \
 133                 free( tab );                    \
 134                 (tab) = NULL;                   \
 135             }                                   \
 136         }                                       \
 137   } while(0)
 138
 139 /**
 140  * Binary search in a sorted array. The key must be comparable by < and >
 141  * \param entries array of entries
 142  * \param count number of entries
 143  * \param elem key to check within an entry (like .id, or ->i_id)
 144  * \param zetype type of the key
 145  * \param key value of the key
 146  * \param answer index of answer within the array. -1 if not found
 147  */
 148 #define BSEARCH( entries, count, elem, zetype, key, answer ) \
 149    do {  \
 150     int low = 0, high = count - 1;   \
 151     answer = -1; \
 152     while( low <= high ) {\
 153         int mid = (low + high ) / 2; /* Just don't care about 2^30 tables */ \
 154         zetype mid_val = entries[mid] elem;\
 155         if( mid_val < key ) \
 156             low = mid + 1; \
 157         else if ( mid_val > key ) \
 158             high = mid -1;  \
 159         else    \
 160         {   \
 161             answer = mid;  break;   \
 162         }\
 163     } \
 164  } while(0)
 165
 166 /************************************************************************
 167  * Dictionaries
 168  ************************************************************************/
 169
 170 /* This function is not intended to be crypto-secure, we only want it to be
 171  * fast and not suck too much. This one is pretty fast and did 0 collisions
 172  * in wenglish's dictionary.
 173  */
 174 static inline uint64_t DictHash( const char *psz_string, int i_int )
 175 {
 176     uint64_t i_hash = 0;
 177     if( psz_string )
 178     {
 179         while( *psz_string )
 180         {
 181             i_hash += *psz_string++;
 182             i_hash += i_hash << 10;
 183             i_hash ^= i_hash >> 8;
 184         }
 185     }
 186     return i_hash + ( (uint64_t)i_int << 32 );
 187 }
 188
 189 #define DICT_TYPE(name,type)                                                  \
 190     typedef struct dict_entry_##name##_t {                                    \
 191         int i_int;                                                            \
 192         char *psz_string;                                                     \
 193         uint64_t i_hash;                                                      \
 194         type data;                                                            \
 195     } dict_entry_##name##_t;                                                  \
 196     typedef struct dict_##name##_t {                                          \
 197         dict_entry_##name##_t *p_entries;                                     \
 198         int i_entries;                                                        \
 199     } dict_##name##_t;
 200
 201 #define DICT_NEW( p_dict ) {                                                  \
 202     p_dict = malloc( sizeof(int)+sizeof(void*) );                             \
 203     p_dict->i_entries = 0;                                                    \
 204     p_dict->p_entries = NULL;                                                 \
 205 }
 206
 207 #define DICT_CLEAR( zdict ) {                                                 \
 208     int _i_dict = 0;                                                          \
 209     for ( _i_dict = 0; _i_dict < zdict->i_entries; _i_dict++ )                \
 210     {                                                                         \
 211         FREE( zdict->p_entries[_i_dict].psz_string );                         \
 212     }                                                                         \
 213     FREE( zdict->p_entries );                                                 \
 214     free( zdict );                                                            \
 215 }
 216
 217 #define DICT_INSERT( zdict, zint, zstring, zdata ) {                          \
 218     uint64_t i_hash = DictHash( (zstring), (zint) );                          \
 219     int i_new;                                                                \
 220     /* Find a free slot */                                                    \
 221     if( zdict->i_entries == 0 || i_hash <= zdict->p_entries[0].i_hash )       \
 222         i_new = 0;                                                            \
 223     else if( i_hash >= zdict->p_entries[zdict->i_entries-1].i_hash )          \
 224         i_new = zdict->i_entries;\
 225     else                                                                      \
 226     {                                                                         \
 227         int i_low = 0, i_high = zdict->i_entries - 1;                         \
 228         while( i_high - i_low > 1 )                                           \
 229         {                                                                     \
 230             int i_mid = (i_low + i_high)/2;                                   \
 231             fprintf(stderr, "Low %i, high %i\n", i_low, i_high);              \
 232             if( zdict->p_entries[i_mid].i_hash < i_hash ) {                   \
 233                 i_low = i_mid;                                                \
 234             } else if( zdict->p_entries[i_mid].i_hash > i_hash ) {            \
 235                 i_high = i_mid;                                               \
 236             }                                                                 \
 237         }                                                                     \
 238         if( zdict->p_entries[i_low].i_hash < i_hash )                         \
 239             i_new = i_high;                                                   \
 240         else                                                                  \
 241             i_new = i_low;                                                    \
 242     }                                                                         \
 243     zdict->p_entries = realloc( zdict->p_entries, (zdict->i_entries + 1) *    \
 244         ( sizeof(zdata) + sizeof(int) + sizeof(void*) + sizeof(uint64_t) ) ); \
 245     zdict->i_entries++;                                                       \
 246     if( i_new != zdict->i_entries -1 )                                        \
 247         memmove( &zdict->p_entries[i_new+1], &zdict->p_entries[i_new],        \
 248          ( zdict->i_entries - i_new - 1 ) *                                   \
 249          ( sizeof(zdata) + sizeof(int) + sizeof(void*) + sizeof(uint64_t) ) );\
 250                                                                               \
 251     zdict->p_entries[i_new].i_hash = i_hash;                                  \
 252     zdict->p_entries[i_new].i_int = (zint);                                   \
 253     if( (zstring) ) {                                                         \
 254         zdict->p_entries[i_new].psz_string = strdup( (zstring) );             \
 255     } else {                                                                  \
 256         zdict->p_entries[i_new].psz_string = NULL;                            \
 257     }                                                                         \
 258     zdict->p_entries[i_new].data = zdata;                                     \
 259 }
 260
 261 #define DICT_LOOKUP( zdict, zint, zstring, answer ) do {                      \
 262     uint64_t i_hash;                                                          \
 263     int i, i_pos;                                                             \
 264     vlc_bool_t b_found = VLC_FALSE;                                           \
 265     if( zdict->i_entries == 0 ) {                                             \
 266         answer = -1;                                                          \
 267         break;                                                                \
 268     }                                                                         \
 269                                                                               \
 270     i_hash = DictHash( (zstring), (zint) );                                   \
 271     BSEARCH( zdict->p_entries, zdict->i_entries, .i_hash, uint64_t,           \
 272              i_hash, i_pos );                                                 \
 273     if( i_pos == -1 ) {                                                       \
 274         answer = -1;                                                          \
 275         break;                                                                \
 276     }                                                                         \
 277                                                                               \
 278     /* Hash found, let's check it looks like the entry */                     \
 279     if( !strcmp( (zstring), zdict->p_entries[i_pos].psz_string ) ) {          \
 280         answer = i_pos;                                                       \
 281         break;                                                                \
 282     }                                                                         \
 283                                                                               \
 284     /* Hash collision! This should be very rare, but we cannot guarantee      \
 285      * it will never happen. Just do an exhaustive search amongst all         \
 286      * entries with the same hash. */                                         \
 287     for( i = i_pos - 1 ; i > 0 && i_hash == zdict->p_entries[i].i_hash ; i-- )\
 288     {                                                                         \
 289         if( !strcmp( (zstring), zdict->p_entries[i].psz_string ) &&           \
 290                    zdict->p_entries[i].i_int == (zint) ) {                    \
 291             b_found = VLC_TRUE;                                               \
 292             answer = i;                                                       \
 293             break;                                                            \
 294         }                                                                     \
 295     }                                                                         \
 296     if( b_found == VLC_TRUE )                                                 \
 297         break;                                                                \
 298     for( i = i_pos + 1 ; i < zdict->i_entries &&                              \
 299                          i_hash == zdict->p_entries[i].i_hash ; i++ )         \
 300     {                                                                         \
 301          if( !strcmp( (zstring), zdict->p_entries[i].psz_string ) &&          \
 302                       zdict->p_entries[i].i_int == (zint) ) {                 \
 303             b_found = VLC_TRUE;                                               \
 304             answer = i;                                                       \
 305             break;                                                            \
 306         }                                                                     \
 307     }                                                                         \
 308     /* Hash found, but entry not found (quite strange !) */                   \
 309     assert( 0 );                                                              \
 310 } while(0)
 311
 312 #define DICT_GET( zdict, i_int, psz_string, answer ) {                        \
 313     int int_answer;                                                           \
 314     DICT_LOOKUP( zdict, i_int, psz_string, int_answer );                      \
 315     if( int_answer >=  0 )                                                    \
 316         answer = zdict->p_entries[int_answer].data;                           \
 317 }
 318
 319 /************************************************************************
 320  * Dynamic arrays with progressive allocation
 321  ************************************************************************/
 322
 323 /* Internal functions */
 324 #define _ARRAY_ALLOC(array, newsize) {                                      \
 325     array.i_alloc = newsize;                                                \
 326     array.p_elems = VLCCVP realloc( array.p_elems, array.i_alloc *          \
 327                                     sizeof(*array.p_elems) );               \
 328     assert(array.p_elems);                                                  \
 329 }
 330
 331 #define _ARRAY_GROW1(array) {                                               \
 332     if( array.i_alloc < 10 )                                                \
 333         _ARRAY_ALLOC(array, 10 )                                            \
 334     else if( array.i_alloc == array.i_size )                                \
 335         _ARRAY_ALLOC(array, (int)(array.i_alloc * 1.5) )                    \
 336 }
 337
 338 #define _ARRAY_GROW(array,additional) {                                     \
 339      int i_first = array.i_alloc;                                           \
 340      while( array.i_alloc - i_first < additional )                          \
 341      {                                                                      \
 342          if( array.i_alloc < 10 )                                           \
 343             _ARRAY_ALLOC(array, 10 )                                        \
 344         else if( array.i_alloc == array.i_size )                            \
 345             _ARRAY_ALLOC(array, (int)(array.i_alloc * 1.5) )                \
 346         else break;                                                         \
 347      }                                                                      \
 348 }
 349
 350 #define _ARRAY_SHRINK(array) {                                              \
 351     if( array.i_size > 10 && array.i_size < (int)(array.i_alloc / 1.5) ) {  \
 352         _ARRAY_ALLOC(array, array.i_size + 5);                              \
 353     }                                                                       \
 354 }
 355
 356
 357 /* API */
 358 #define DECL_ARRAY(type) struct {                                           \
 359     int i_alloc;                                                            \
 360     int i_size;                                                             \
 361     type *p_elems;                                                          \
 362 }
 363
 364 #define TYPEDEF_ARRAY(type, name) typedef DECL_ARRAY(type) name;
 365
 366 #define ARRAY_INIT(array)                                                   \
 367     array.i_alloc = 0;                                                      \
 368     array.i_size = 0;                                                       \
 369     array.p_elems = NULL;
 370
 371 #define ARRAY_RESET(array)                                                  \
 372     array.i_alloc = 0;                                                      \
 373     array.i_size = 0;                                                       \
 374     free( array.p_elems ); array.p_elems = NULL;
 375
 376 #define ARRAY_APPEND(array, elem) {                                         \
 377     _ARRAY_GROW1(array);                                                    \
 378     array.p_elems[array.i_size] = elem;                                     \
 379     array.i_size++;                                                         \
 380 }
 381
 382 #define ARRAY_INSERT(array,elem,pos) {                                      \
 383     _ARRAY_GROW1(array);                                                    \
 384     if( array.i_size - pos ) {                                              \
 385         memmove( array.p_elems + pos + 1, array.p_elems + pos,              \
 386                  (array.i_size-pos) * sizeof(*array.p_elems) );             \
 387     }                                                                       \
 388     array.p_elems[pos] = elem;                                              \
 389     array.i_size++;                                                         \
 390 }
 391
 392 #define ARRAY_REMOVE(array,pos) {                                           \
 393     if( array.i_size - (pos) - 1 )                                          \
 394     {                                                                       \
 395         memmove( array.p_elems + pos, array.p_elems + pos + 1,              \
 396                  ( array.i_size - pos - 1 ) *sizeof(*array.p_elems) );      \
 397     }                                                                       \
 398     array.i_size--;                                                         \
 399     _ARRAY_SHRINK(array);                                                   \
 400 }
 401
 402 #define ARRAY_VAL(array, pos) array.p_elems[pos]
 403
 404 #define ARRAY_BSEARCH(array, elem, zetype, key, answer) \
 405     BSEARCH( array.p_elems, array.i_size, elem, zetype, key, answer)
 406
 407 #define FOREACH_ARRAY( item, array ) { \
 408     int fe_idx; \
 409     for( fe_idx = 0 ; fe_idx < array.i_size ; fe_idx++ ) \
 410     { \
 411         item = array.p_elems[fe_idx];
 412
 413 #define FOREACH_END() } }
 414
 415 #endif