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