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 VLC authors and VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Samuel Hocevar <sam@zoy.org>
   8  *          Clément Stenac <zorglub@videolan.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU Lesser General Public License as published by
  12  * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License
  21  * along with this program; if not, write to the Free Software Foundation,
  22  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 #ifndef VLC_ARRAYS_H_
  26 #define VLC_ARRAYS_H_
  27
  28 /**
  29  * \file
  30  * This file defines functions, structures and macros for handling arrays in vlc
  31  */
  32
  33 /* realloc() that never fails *if* downsizing */
  34 static inline void *realloc_down( void *ptr, size_t size )
  35 {
  36     void *ret = realloc( ptr, size );
  37     return ret ? ret : ptr;
  38 }
  39
  40 /**
  41  * Simple dynamic array handling. Array is realloced at each insert/removal
  42  */
  43 #define INSERT_ELEM( p_ar, i_oldsize, i_pos, elem )                           \
  44     do                                                                        \
  45     {                                                                         \
  46         if( !(i_oldsize) ) (p_ar) = NULL;                                       \
  47         (p_ar) = realloc( p_ar, ((i_oldsize) + 1) * sizeof(*(p_ar)) ); \
  48         if( !(p_ar) ) abort();                                                \
  49         if( (i_oldsize) - (i_pos) )                                           \
  50         {                                                                     \
  51             memmove( (p_ar) + (i_pos) + 1, (p_ar) + (i_pos),                  \
  52                      ((i_oldsize) - (i_pos)) * sizeof( *(p_ar) ) );           \
  53         }                                                                     \
  54         (p_ar)[(i_pos)] = elem;                                                 \
  55         (i_oldsize)++;                                                        \
  56     }                                                                         \
  57     while( 0 )
  58
  59 #define REMOVE_ELEM( p_ar, i_size, i_pos )                                    \
  60     do                                                                        \
  61     {                                                                         \
  62         if( (i_size) - (i_pos) - 1 )                                          \
  63         {                                                                     \
  64             memmove( (p_ar) + (i_pos),                                        \
  65                      (p_ar) + (i_pos) + 1,                                    \
  66                      ((i_size) - (i_pos) - 1) * sizeof( *(p_ar) ) );          \
  67         }                                                                     \
  68         if( i_size > 1 )                                                      \
  69             (p_ar) = realloc_down( p_ar, ((i_size) - 1) * sizeof( *(p_ar) ) );\
  70         else                                                                  \
  71         {                                                                     \
  72             free( p_ar );                                                     \
  73             (p_ar) = NULL;                                                    \
  74         }                                                                     \
  75         (i_size)--;                                                           \
  76     }                                                                         \
  77     while( 0 )
  78
  79 #define TAB_INIT( count, tab )                  \
  80   do {                                          \
  81     (count) = 0;                                \
  82     (tab) = NULL;                               \
  83   } while(0)
  84
  85 #define TAB_CLEAN( count, tab )                 \
  86   do {                                          \
  87     free( tab );                                \
  88     (count)= 0;                                 \
  89     (tab)= NULL;                                \
  90   } while(0)
  91
  92 #define TAB_APPEND_CAST( cast, count, tab, p )             \
  93   do {                                          \
  94     if( (count) > 0 )                           \
  95         (tab) = cast realloc( tab, sizeof( void ** ) * ( (count) + 1 ) ); \
  96     else                                        \
  97         (tab) = cast malloc( sizeof( void ** ) );    \
  98     if( !(tab) ) abort();                       \
  99     (tab)[count] = (p);                         \
 100     (count)++;                                  \
 101   } while(0)
 102
 103 #define TAB_APPEND( count, tab, p )             \
 104     TAB_APPEND_CAST( , count, tab, p )
 105
 106 #define TAB_FIND( count, tab, p, index )        \
 107   do {                                          \
 108     (index) = -1;                               \
 109     for( int i = 0; i < (count); i++ )          \
 110         if( (tab)[i] == (p) )                   \
 111         {                                       \
 112             (index) = i;                        \
 113             break;                              \
 114         }                                       \
 115   } while(0)
 116
 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 #define TAB_INSERT_CAST( cast, count, tab, p, index ) do { \
 140     if( (count) > 0 )                           \
 141         (tab) = cast realloc( tab, sizeof( void ** ) * ( (count) + 1 ) ); \
 142     else                                        \
 143         (tab) = cast malloc( sizeof( void ** ) );       \
 144     if( !(tab) ) abort();                       \
 145     if( (count) - (index) > 0 )                 \
 146         memmove( (void**)(tab) + (index) + 1,   \
 147                  (void**)(tab) + (index),       \
 148                  ((count) - (index)) * sizeof(*(tab)) );\
 149     (tab)[(index)] = (p);                       \
 150     (count)++;                                  \
 151 } while(0)
 152
 153 #define TAB_INSERT( count, tab, p, index )      \
 154     TAB_INSERT_CAST( , count, tab, p, index )
 155
 156 /**
 157  * Binary search in a sorted array. The key must be comparable by < and >
 158  * \param entries array of entries
 159  * \param count number of entries
 160  * \param elem key to check within an entry (like .id, or ->i_id)
 161  * \param zetype type of the key
 162  * \param key value of the key
 163  * \param answer index of answer within the array. -1 if not found
 164  */
 165 #define BSEARCH( entries, count, elem, zetype, key, answer ) \
 166    do {  \
 167     int low = 0, high = count - 1;   \
 168     answer = -1; \
 169     while( low <= high ) {\
 170         int mid = (low + high ) / 2; /* Just don't care about 2^30 tables */ \
 171         zetype mid_val = entries[mid] elem;\
 172         if( mid_val < key ) \
 173             low = mid + 1; \
 174         else if ( mid_val > key ) \
 175             high = mid -1;  \
 176         else    \
 177         {   \
 178             answer = mid;  break;   \
 179         }\
 180     } \
 181  } while(0)
 182
 183
 184 /************************************************************************
 185  * Dynamic arrays with progressive allocation
 186  ************************************************************************/
 187
 188 /* Internal functions */
 189 #define _ARRAY_ALLOC(array, newsize) {                                      \
 190     (array).i_alloc = newsize;                                              \
 191     (array).p_elems = realloc( (array).p_elems, (array).i_alloc *           \
 192                                sizeof(*(array).p_elems) );                  \
 193     if( !(array).p_elems ) abort();                                         \
 194 }
 195
 196 #define _ARRAY_GROW1(array) {                                               \
 197     if( (array).i_alloc < 10 )                                              \
 198         _ARRAY_ALLOC(array, 10 )                                            \
 199     else if( (array).i_alloc == (array).i_size )                            \
 200         _ARRAY_ALLOC(array, (int)(array.i_alloc * 1.5) )                    \
 201 }
 202
 203 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 204
 205 /* API */
 206 #define DECL_ARRAY(type) struct {                                           \
 207     int i_alloc;                                                            \
 208     int i_size;                                                             \
 209     type *p_elems;                                                          \
 210 }
 211
 212 #define TYPEDEF_ARRAY(type, name) typedef DECL_ARRAY(type) name;
 213
 214 #define ARRAY_INIT(array)                                                   \
 215   do {                                                                      \
 216     (array).i_alloc = 0;                                                    \
 217     (array).i_size = 0;                                                     \
 218     (array).p_elems = NULL;                                                 \
 219   } while(0)
 220
 221 #define ARRAY_RESET(array)                                                  \
 222   do {                                                                      \
 223     (array).i_alloc = 0;                                                    \
 224     (array).i_size = 0;                                                     \
 225     free( (array).p_elems ); (array).p_elems = NULL;                        \
 226   } while(0)
 227
 228 #define ARRAY_APPEND(array, elem)                                           \
 229   do {                                                                      \
 230     _ARRAY_GROW1(array);                                                    \
 231     (array).p_elems[(array).i_size] = elem;                                 \
 232     (array).i_size++;                                                       \
 233   } while(0)
 234
 235 #define ARRAY_INSERT(array,elem,pos)                                        \
 236   do {                                                                      \
 237     _ARRAY_GROW1(array);                                                    \
 238     if( (array).i_size - pos ) {                                            \
 239         memmove( (array).p_elems + pos + 1, (array).p_elems + pos,          \
 240                  ((array).i_size-pos) * sizeof(*(array).p_elems) );         \
 241     }                                                                       \
 242     (array).p_elems[pos] = elem;                                            \
 243     (array).i_size++;                                                       \
 244   } while(0)
 245
 246 #define _ARRAY_SHRINK(array) {                                              \
 247     if( (array).i_size > 10 && (array).i_size < (int)((array).i_alloc / 1.5) ) {  \
 248         _ARRAY_ALLOC(array, (array).i_size + 5);                            \
 249     }                                                                       \
 250 }
 251
 252 #define ARRAY_REMOVE(array,pos)                                             \
 253   do {                                                                      \
 254     if( (array).i_size - (pos) - 1 )                                        \
 255     {                                                                       \
 256         memmove( (array).p_elems + pos, (array).p_elems + pos + 1,          \
 257                  ( (array).i_size - pos - 1 ) *sizeof(*(array).p_elems) );  \
 258     }                                                                       \
 259     (array).i_size--;                                                       \
 260     _ARRAY_SHRINK(array);                                                   \
 261   } while(0)
 262
 263 #define ARRAY_VAL(array, pos) array.p_elems[pos]
 264
 265 #define ARRAY_BSEARCH(array, elem, zetype, key, answer) \
 266     BSEARCH( (array).p_elems, (array).i_size, elem, zetype, key, answer)
 267
 268 #define FOREACH_ARRAY( item, array ) { \
 269     int fe_idx; \
 270     for( fe_idx = 0 ; fe_idx < (array).i_size ; fe_idx++ ) \
 271     { \
 272         item = (array).p_elems[fe_idx];
 273
 274 #define FOREACH_END() } }
 275
 276
 277 /************************************************************************
 278  * Dynamic arrays with progressive allocation (Preferred API)
 279  ************************************************************************/
 280 typedef struct vlc_array_t
 281 {
 282     int i_count;
 283     void ** pp_elems;
 284 } vlc_array_t;
 285
 286 static inline void vlc_array_init( vlc_array_t * p_array )
 287 {
 288     memset( p_array, 0, sizeof(vlc_array_t) );
 289 }
 290
 291 static inline void vlc_array_clear( vlc_array_t * p_array )
 292 {
 293     free( p_array->pp_elems );
 294     memset( p_array, 0, sizeof(vlc_array_t) );
 295 }
 296
 297 static inline vlc_array_t * vlc_array_new( void )
 298 {
 299     vlc_array_t * ret = (vlc_array_t *)malloc( sizeof(vlc_array_t) );
 300     if( ret ) vlc_array_init( ret );
 301     return ret;
 302 }
 303
 304 static inline void vlc_array_destroy( vlc_array_t * p_array )
 305 {
 306     if( !p_array )
 307         return;
 308     vlc_array_clear( p_array );
 309     free( p_array );
 310 }
 311
 312
 313 /* Read */
 314 static inline int
 315 vlc_array_count( vlc_array_t * p_array )
 316 {
 317     return p_array->i_count;
 318 }
 319
 320 static inline void *
 321 vlc_array_item_at_index( vlc_array_t * p_array, int i_index )
 322 {
 323     return p_array->pp_elems[i_index];
 324 }
 325
 326 static inline int
 327 vlc_array_index_of_item( vlc_array_t * p_array, void * item )
 328 {
 329     int i;
 330     for( i = 0; i < p_array->i_count; i++)
 331     {
 332         if( p_array->pp_elems[i] == item )
 333             return i;
 334     }
 335     return -1;
 336 }
 337
 338 /* Write */
 339 static inline void
 340 vlc_array_insert( vlc_array_t * p_array, void * p_elem, int i_index )
 341 {
 342     TAB_INSERT_CAST( (void **), p_array->i_count, p_array->pp_elems, p_elem, i_index );
 343 }
 344
 345 static inline void
 346 vlc_array_append( vlc_array_t * p_array, void * p_elem )
 347 {
 348     vlc_array_insert( p_array, p_elem, p_array->i_count );
 349 }
 350
 351 static inline void
 352 vlc_array_remove( vlc_array_t * p_array, int i_index )
 353 {
 354     if( i_index >= 0 )
 355     {
 356         if( p_array->i_count > 1 )
 357         {
 358             memmove( p_array->pp_elems + i_index,
 359                      p_array->pp_elems + i_index+1,
 360                      ( p_array->i_count - i_index - 1 ) * sizeof( void* ) );
 361         }
 362         p_array->i_count--;
 363         if( p_array->i_count == 0 )
 364         {
 365             free( p_array->pp_elems );
 366             p_array->pp_elems = NULL;
 367         }
 368     }
 369 }
 370
 371
 372 /************************************************************************
 373  * Dictionaries
 374  ************************************************************************/
 375
 376 /* This function is not intended to be crypto-secure, we only want it to be
 377  * fast and not suck too much. This one is pretty fast and did 0 collisions
 378  * in wenglish's dictionary.
 379  */
 380 static inline uint64_t DictHash( const char *psz_string, int hashsize )
 381 {
 382     uint64_t i_hash = 0;
 383     if( psz_string )
 384     {
 385         while( *psz_string )
 386         {
 387             i_hash += *psz_string++;
 388             i_hash += i_hash << 10;
 389             i_hash ^= i_hash >> 8;
 390         }
 391     }
 392     return i_hash % hashsize;
 393 }
 394
 395 typedef struct vlc_dictionary_entry_t
 396 {
 397     char *   psz_key;
 398     void *   p_value;
 399     struct vlc_dictionary_entry_t * p_next;
 400 } vlc_dictionary_entry_t;
 401
 402 typedef struct vlc_dictionary_t
 403 {
 404     int i_size;
 405     vlc_dictionary_entry_t ** p_entries;
 406 } vlc_dictionary_t;
 407
 408 static void * const kVLCDictionaryNotFound = NULL;
 409
 410 static inline void vlc_dictionary_init( vlc_dictionary_t * p_dict, int i_size )
 411 {
 412     p_dict->p_entries = NULL;
 413
 414     if( i_size > 0 )
 415     {
 416         p_dict->p_entries = (vlc_dictionary_entry_t **)calloc( i_size, sizeof(*p_dict->p_entries) );
 417         if( !p_dict->p_entries )
 418             i_size = 0;
 419     }
 420     p_dict->i_size = i_size;
 421 }
 422
 423 static inline void vlc_dictionary_clear( vlc_dictionary_t * p_dict,
 424                                          void ( * pf_free )( void * p_data, void * p_obj ),
 425                                          void * p_obj )
 426 {
 427     if( p_dict->p_entries )
 428     {
 429         for( int i = 0; i < p_dict->i_size; i++ )
 430         {
 431             vlc_dictionary_entry_t * p_current, * p_next;
 432             p_current = p_dict->p_entries[i];
 433             while( p_current )
 434             {
 435                 p_next = p_current->p_next;
 436                 if( pf_free != NULL )
 437                     ( * pf_free )( p_current->p_value, p_obj );
 438                 free( p_current->psz_key );
 439                 free( p_current );
 440                 p_current = p_next;
 441             }
 442         }
 443         free( p_dict->p_entries );
 444         p_dict->p_entries = NULL;
 445     }
 446     p_dict->i_size = 0;
 447 }
 448
 449 static inline int
 450 vlc_dictionary_has_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 451 {
 452     if( !p_dict->p_entries )
 453         return 0;
 454
 455     int i_pos = DictHash( psz_key, p_dict->i_size );
 456     return p_dict->p_entries[i_pos] != NULL;
 457 }
 458
 459 static inline void *
 460 vlc_dictionary_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 461 {
 462     if( !p_dict->p_entries )
 463         return kVLCDictionaryNotFound;
 464
 465     int i_pos = DictHash( psz_key, p_dict->i_size );
 466     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 467
 468     if( !p_entry )
 469         return kVLCDictionaryNotFound;
 470
 471     /* Make sure we return the right item. (Hash collision) */
 472     do {
 473         if( !strcmp( psz_key, p_entry->psz_key ) )
 474             return p_entry->p_value;
 475         p_entry = p_entry->p_next;
 476     } while( p_entry );
 477
 478     return kVLCDictionaryNotFound;
 479 }
 480
 481 static inline int
 482 vlc_dictionary_keys_count( const vlc_dictionary_t * p_dict )
 483 {
 484     vlc_dictionary_entry_t * p_entry;
 485     int i, count = 0;
 486
 487     if( !p_dict->p_entries )
 488         return 0;
 489
 490     for( i = 0; i < p_dict->i_size; i++ )
 491     {
 492         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next ) count++;
 493     }
 494     return count;
 495 }
 496
 497 static inline char **
 498 vlc_dictionary_all_keys( const vlc_dictionary_t * p_dict )
 499 {
 500     vlc_dictionary_entry_t * p_entry;
 501     char ** ppsz_ret;
 502     int i, count = vlc_dictionary_keys_count( p_dict );
 503
 504     ppsz_ret = (char**)malloc(sizeof(char *) * (count + 1));
 505     if( unlikely(!ppsz_ret) )
 506         return NULL;
 507
 508     count = 0;
 509     for( i = 0; i < p_dict->i_size; i++ )
 510     {
 511         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next )
 512             ppsz_ret[count++] = strdup( p_entry->psz_key );
 513     }
 514     ppsz_ret[count] = NULL;
 515     return ppsz_ret;
 516 }
 517
 518 static inline void
 519 __vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key,
 520                          void * p_value, bool rebuild )
 521 {
 522     if( !p_dict->p_entries )
 523         vlc_dictionary_init( p_dict, 1 );
 524
 525     int i_pos = DictHash( psz_key, p_dict->i_size );
 526     vlc_dictionary_entry_t * p_entry;
 527
 528     p_entry = (vlc_dictionary_entry_t *)malloc(sizeof(*p_entry));
 529     p_entry->psz_key = strdup( psz_key );
 530     p_entry->p_value = p_value;
 531     p_entry->p_next = p_dict->p_entries[i_pos];
 532     p_dict->p_entries[i_pos] = p_entry;
 533     if( rebuild )
 534     {
 535         /* Count how many items there was */
 536         int count;
 537         for( count = 1; p_entry->p_next; count++ )
 538             p_entry = p_entry->p_next;
 539         if( count > 3 ) /* XXX: this need tuning */
 540         {
 541             /* Here it starts to be not good, rebuild a bigger dictionary */
 542             struct vlc_dictionary_t new_dict;
 543             int i_new_size = ( (p_dict->i_size+2) * 3) / 2; /* XXX: this need tuning */
 544             int i;
 545             vlc_dictionary_init( &new_dict, i_new_size );
 546             for( i = 0; i < p_dict->i_size; i++ )
 547             {
 548                 p_entry = p_dict->p_entries[i];
 549                 while( p_entry )
 550                 {
 551                     __vlc_dictionary_insert( &new_dict, p_entry->psz_key,
 552                                              p_entry->p_value,
 553                                              false /* To avoid multiple rebuild loop */);
 554                     p_entry = p_entry->p_next;
 555                 }
 556             }
 557
 558             vlc_dictionary_clear( p_dict, NULL, NULL );
 559             p_dict->i_size = new_dict.i_size;
 560             p_dict->p_entries = new_dict.p_entries;
 561         }
 562     }
 563 }
 564
 565 static inline void
 566 vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key, void * p_value )
 567 {
 568     __vlc_dictionary_insert( p_dict, psz_key, p_value, true );
 569 }
 570
 571 static inline void
 572 vlc_dictionary_remove_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key,
 573                                      void ( * pf_free )( void * p_data, void * p_obj ),
 574                                      void * p_obj )
 575 {
 576     if( !p_dict->p_entries )
 577         return;
 578
 579     int i_pos = DictHash( psz_key, p_dict->i_size );
 580     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 581     vlc_dictionary_entry_t * p_prev;
 582
 583     if( !p_entry )
 584         return; /* Not found, nothing to do */
 585
 586     /* Hash collision */
 587     p_prev = NULL;
 588     do {
 589         if( !strcmp( psz_key, p_entry->psz_key ) )
 590         {
 591             if( pf_free != NULL )
 592                 ( * pf_free )( p_entry->p_value, p_obj );
 593             if( !p_prev )
 594                 p_dict->p_entries[i_pos] = p_entry->p_next;
 595             else
 596                 p_prev->p_next = p_entry->p_next;
 597             free( p_entry->psz_key );
 598             free( p_entry );
 599             return;
 600         }
 601         p_prev = p_entry;
 602         p_entry = p_entry->p_next;
 603     } while( p_entry );
 604
 605     /* No key was found */
 606 }
 607
 608 #ifdef __cplusplus
 609 // C++ helpers
 610 template <typename T>
 611 void vlc_delete_all( T &container )
 612 {
 613     typename T::iterator it = container.begin();
 614     while ( it != container.end() )
 615     {
 616         delete *it;
 617         ++it;
 618     }
 619     container.clear();
 620 }
 621
 622 #endif
 623
 624 #endif