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( *(tab) ) * ( (count) + 1 ) ); \
  96     else                                        \
  97         (tab) = cast malloc( sizeof( *(tab) ) );    \
  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, idx )          \
 107   do {                                          \
 108     for( (idx) = 0; (idx) < (count); (idx)++ )  \
 109         if( (tab)[(idx)] == (p) )               \
 110             break;                              \
 111     if( (idx) >= (count) )                      \
 112         (idx) = -1;                             \
 113   } while(0)
 114
 115
 116 #define TAB_ERASE( count, tab, index )      \
 117   do {                                      \
 118         if( (count) > 1 )                   \
 119         {                                   \
 120             memmove( ((void**)(tab) + index),    \
 121                      ((void**)(tab) + index+1),  \
 122                      ( (count) - index - 1 ) * sizeof( *(tab) ) );\
 123         }                                   \
 124         (count)--;                          \
 125         if( (count) == 0 )                  \
 126         {                                   \
 127             free( tab );                    \
 128             (tab) = NULL;                   \
 129         }                                   \
 130   } while(0)
 131
 132 #define TAB_REMOVE( count, tab, p )             \
 133   do {                                          \
 134         int i_index;                            \
 135         TAB_FIND( count, tab, p, i_index );     \
 136         if( i_index >= 0 )                      \
 137             TAB_ERASE( count, tab, i_index );   \
 138   } while(0)
 139
 140 #define TAB_INSERT_CAST( cast, count, tab, p, index ) do { \
 141     if( (count) > 0 )                           \
 142         (tab) = cast realloc( tab, sizeof( *(tab) ) * ( (count) + 1 ) ); \
 143     else                                        \
 144         (tab) = cast malloc( sizeof( *(tab) ) );       \
 145     if( !(tab) ) abort();                       \
 146     if( (count) - (index) > 0 )                 \
 147         memmove( (void**)(tab) + (index) + 1,   \
 148                  (void**)(tab) + (index),       \
 149                  ((count) - (index)) * sizeof(*(tab)) );\
 150     (tab)[(index)] = (p);                       \
 151     (count)++;                                  \
 152 } while(0)
 153
 154 #define TAB_INSERT( count, tab, p, index )      \
 155     TAB_INSERT_CAST( , count, tab, p, index )
 156
 157 /**
 158  * Binary search in a sorted array. The key must be comparable by < and >
 159  * \param entries array of entries
 160  * \param count number of entries
 161  * \param elem key to check within an entry (like .id, or ->i_id)
 162  * \param zetype type of the key
 163  * \param key value of the key
 164  * \param answer index of answer within the array. -1 if not found
 165  */
 166 #define BSEARCH( entries, count, elem, zetype, key, answer ) \
 167    do {  \
 168     int low = 0, high = count - 1;   \
 169     answer = -1; \
 170     while( low <= high ) {\
 171         int mid = ((unsigned int)low + (unsigned int)high) >> 1;\
 172         zetype mid_val = entries[mid] elem;\
 173         if( mid_val < key ) \
 174             low = mid + 1; \
 175         else if ( mid_val > key ) \
 176             high = mid -1;  \
 177         else    \
 178         {   \
 179             answer = mid;  break;   \
 180         }\
 181     } \
 182  } while(0)
 183
 184
 185 /************************************************************************
 186  * Dynamic arrays with progressive allocation
 187  ************************************************************************/
 188
 189 /* Internal functions */
 190 #define _ARRAY_ALLOC(array, newsize) {                                      \
 191     (array).i_alloc = newsize;                                              \
 192     (array).p_elems = realloc( (array).p_elems, (array).i_alloc *           \
 193                                sizeof(*(array).p_elems) );                  \
 194     if( !(array).p_elems ) abort();                                         \
 195 }
 196
 197 #define _ARRAY_GROW1(array) {                                               \
 198     if( (array).i_alloc < 10 )                                              \
 199         _ARRAY_ALLOC(array, 10 )                                            \
 200     else if( (array).i_alloc == (array).i_size )                            \
 201         _ARRAY_ALLOC(array, (int)(array.i_alloc * 1.5) )                    \
 202 }
 203
 204 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 205
 206 /* API */
 207 #define DECL_ARRAY(type) struct {                                           \
 208     int i_alloc;                                                            \
 209     int i_size;                                                             \
 210     type *p_elems;                                                          \
 211 }
 212
 213 #define TYPEDEF_ARRAY(type, name) typedef DECL_ARRAY(type) name;
 214
 215 #define ARRAY_INIT(array)                                                   \
 216   do {                                                                      \
 217     (array).i_alloc = 0;                                                    \
 218     (array).i_size = 0;                                                     \
 219     (array).p_elems = NULL;                                                 \
 220   } while(0)
 221
 222 #define ARRAY_RESET(array)                                                  \
 223   do {                                                                      \
 224     (array).i_alloc = 0;                                                    \
 225     (array).i_size = 0;                                                     \
 226     free( (array).p_elems ); (array).p_elems = NULL;                        \
 227   } while(0)
 228
 229 #define ARRAY_APPEND(array, elem)                                           \
 230   do {                                                                      \
 231     _ARRAY_GROW1(array);                                                    \
 232     (array).p_elems[(array).i_size] = elem;                                 \
 233     (array).i_size++;                                                       \
 234   } while(0)
 235
 236 #define ARRAY_INSERT(array,elem,pos)                                        \
 237   do {                                                                      \
 238     _ARRAY_GROW1(array);                                                    \
 239     if( (array).i_size - pos ) {                                            \
 240         memmove( (array).p_elems + pos + 1, (array).p_elems + pos,          \
 241                  ((array).i_size-pos) * sizeof(*(array).p_elems) );         \
 242     }                                                                       \
 243     (array).p_elems[pos] = elem;                                            \
 244     (array).i_size++;                                                       \
 245   } while(0)
 246
 247 #define _ARRAY_SHRINK(array) {                                              \
 248     if( (array).i_size > 10 && (array).i_size < (int)((array).i_alloc / 1.5) ) {  \
 249         _ARRAY_ALLOC(array, (array).i_size + 5);                            \
 250     }                                                                       \
 251 }
 252
 253 #define ARRAY_REMOVE(array,pos)                                             \
 254   do {                                                                      \
 255     if( (array).i_size - (pos) - 1 )                                        \
 256     {                                                                       \
 257         memmove( (array).p_elems + pos, (array).p_elems + pos + 1,          \
 258                  ( (array).i_size - pos - 1 ) *sizeof(*(array).p_elems) );  \
 259     }                                                                       \
 260     (array).i_size--;                                                       \
 261     _ARRAY_SHRINK(array);                                                   \
 262   } while(0)
 263
 264 #define ARRAY_VAL(array, pos) array.p_elems[pos]
 265
 266 #define ARRAY_BSEARCH(array, elem, zetype, key, answer) \
 267     BSEARCH( (array).p_elems, (array).i_size, elem, zetype, key, answer)
 268
 269 #define FOREACH_ARRAY( item, array ) { \
 270     int fe_idx; \
 271     for( fe_idx = 0 ; fe_idx < (array).i_size ; fe_idx++ ) \
 272     { \
 273         item = (array).p_elems[fe_idx];
 274
 275 #define FOREACH_END() } }
 276
 277
 278 /************************************************************************
 279  * Dynamic arrays with progressive allocation (Preferred API)
 280  ************************************************************************/
 281 typedef struct vlc_array_t
 282 {
 283     int i_count;
 284     void ** pp_elems;
 285 } vlc_array_t;
 286
 287 static inline void vlc_array_init( vlc_array_t * p_array )
 288 {
 289     memset( p_array, 0, sizeof(vlc_array_t) );
 290 }
 291
 292 static inline void vlc_array_clear( vlc_array_t * p_array )
 293 {
 294     free( p_array->pp_elems );
 295     memset( p_array, 0, sizeof(vlc_array_t) );
 296 }
 297
 298 static inline vlc_array_t * vlc_array_new( void )
 299 {
 300     vlc_array_t * ret = (vlc_array_t *)malloc( sizeof(vlc_array_t) );
 301     if( ret ) vlc_array_init( ret );
 302     return ret;
 303 }
 304
 305 static inline void vlc_array_destroy( vlc_array_t * p_array )
 306 {
 307     if( !p_array )
 308         return;
 309     vlc_array_clear( p_array );
 310     free( p_array );
 311 }
 312
 313
 314 /* Read */
 315 static inline int
 316 vlc_array_count( vlc_array_t * p_array )
 317 {
 318     return p_array->i_count;
 319 }
 320
 321 static inline void *
 322 vlc_array_item_at_index( vlc_array_t * p_array, int i_index )
 323 {
 324     return p_array->pp_elems[i_index];
 325 }
 326
 327 static inline int
 328 vlc_array_index_of_item( vlc_array_t * p_array, void * item )
 329 {
 330     int i;
 331     for( i = 0; i < p_array->i_count; i++)
 332     {
 333         if( p_array->pp_elems[i] == item )
 334             return i;
 335     }
 336     return -1;
 337 }
 338
 339 /* Write */
 340 static inline void
 341 vlc_array_insert( vlc_array_t * p_array, void * p_elem, int i_index )
 342 {
 343     TAB_INSERT_CAST( (void **), p_array->i_count, p_array->pp_elems, p_elem, i_index );
 344 }
 345
 346 static inline void
 347 vlc_array_append( vlc_array_t * p_array, void * p_elem )
 348 {
 349     vlc_array_insert( p_array, p_elem, p_array->i_count );
 350 }
 351
 352 static inline void
 353 vlc_array_remove( vlc_array_t * p_array, int i_index )
 354 {
 355     if( i_index >= 0 )
 356     {
 357         if( p_array->i_count > 1 )
 358         {
 359             memmove( p_array->pp_elems + i_index,
 360                      p_array->pp_elems + i_index+1,
 361                      ( p_array->i_count - i_index - 1 ) * sizeof( void* ) );
 362         }
 363         p_array->i_count--;
 364         if( p_array->i_count == 0 )
 365         {
 366             free( p_array->pp_elems );
 367             p_array->pp_elems = NULL;
 368         }
 369     }
 370 }
 371
 372
 373 /************************************************************************
 374  * Dictionaries
 375  ************************************************************************/
 376
 377 /* This function is not intended to be crypto-secure, we only want it to be
 378  * fast and not suck too much. This one is pretty fast and did 0 collisions
 379  * in wenglish's dictionary.
 380  */
 381 static inline uint64_t DictHash( const char *psz_string, int hashsize )
 382 {
 383     uint64_t i_hash = 0;
 384     if( psz_string )
 385     {
 386         while( *psz_string )
 387         {
 388             i_hash += *psz_string++;
 389             i_hash += i_hash << 10;
 390             i_hash ^= i_hash >> 8;
 391         }
 392     }
 393     return i_hash % hashsize;
 394 }
 395
 396 typedef struct vlc_dictionary_entry_t
 397 {
 398     char *   psz_key;
 399     void *   p_value;
 400     struct vlc_dictionary_entry_t * p_next;
 401 } vlc_dictionary_entry_t;
 402
 403 typedef struct vlc_dictionary_t
 404 {
 405     int i_size;
 406     vlc_dictionary_entry_t ** p_entries;
 407 } vlc_dictionary_t;
 408
 409 static void * const kVLCDictionaryNotFound = NULL;
 410
 411 static inline void vlc_dictionary_init( vlc_dictionary_t * p_dict, int i_size )
 412 {
 413     p_dict->p_entries = NULL;
 414
 415     if( i_size > 0 )
 416     {
 417         p_dict->p_entries = (vlc_dictionary_entry_t **)calloc( i_size, sizeof(*p_dict->p_entries) );
 418         if( !p_dict->p_entries )
 419             i_size = 0;
 420     }
 421     p_dict->i_size = i_size;
 422 }
 423
 424 static inline void vlc_dictionary_clear( vlc_dictionary_t * p_dict,
 425                                          void ( * pf_free )( void * p_data, void * p_obj ),
 426                                          void * p_obj )
 427 {
 428     if( p_dict->p_entries )
 429     {
 430         for( int i = 0; i < p_dict->i_size; i++ )
 431         {
 432             vlc_dictionary_entry_t * p_current, * p_next;
 433             p_current = p_dict->p_entries[i];
 434             while( p_current )
 435             {
 436                 p_next = p_current->p_next;
 437                 if( pf_free != NULL )
 438                     ( * pf_free )( p_current->p_value, p_obj );
 439                 free( p_current->psz_key );
 440                 free( p_current );
 441                 p_current = p_next;
 442             }
 443         }
 444         free( p_dict->p_entries );
 445         p_dict->p_entries = NULL;
 446     }
 447     p_dict->i_size = 0;
 448 }
 449
 450 static inline int
 451 vlc_dictionary_has_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 452 {
 453     if( !p_dict->p_entries )
 454         return 0;
 455
 456     int i_pos = DictHash( psz_key, p_dict->i_size );
 457     return p_dict->p_entries[i_pos] != NULL;
 458 }
 459
 460 static inline void *
 461 vlc_dictionary_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 462 {
 463     if( !p_dict->p_entries )
 464         return kVLCDictionaryNotFound;
 465
 466     int i_pos = DictHash( psz_key, p_dict->i_size );
 467     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 468
 469     if( !p_entry )
 470         return kVLCDictionaryNotFound;
 471
 472     /* Make sure we return the right item. (Hash collision) */
 473     do {
 474         if( !strcmp( psz_key, p_entry->psz_key ) )
 475             return p_entry->p_value;
 476         p_entry = p_entry->p_next;
 477     } while( p_entry );
 478
 479     return kVLCDictionaryNotFound;
 480 }
 481
 482 static inline int
 483 vlc_dictionary_keys_count( const vlc_dictionary_t * p_dict )
 484 {
 485     vlc_dictionary_entry_t * p_entry;
 486     int i, count = 0;
 487
 488     if( !p_dict->p_entries )
 489         return 0;
 490
 491     for( i = 0; i < p_dict->i_size; i++ )
 492     {
 493         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next ) count++;
 494     }
 495     return count;
 496 }
 497
 498 static inline char **
 499 vlc_dictionary_all_keys( const vlc_dictionary_t * p_dict )
 500 {
 501     vlc_dictionary_entry_t * p_entry;
 502     char ** ppsz_ret;
 503     int i, count = vlc_dictionary_keys_count( p_dict );
 504
 505     ppsz_ret = (char**)malloc(sizeof(char *) * (count + 1));
 506     if( unlikely(!ppsz_ret) )
 507         return NULL;
 508
 509     count = 0;
 510     for( i = 0; i < p_dict->i_size; i++ )
 511     {
 512         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next )
 513             ppsz_ret[count++] = strdup( p_entry->psz_key );
 514     }
 515     ppsz_ret[count] = NULL;
 516     return ppsz_ret;
 517 }
 518
 519 static inline void
 520 __vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key,
 521                          void * p_value, bool rebuild )
 522 {
 523     if( !p_dict->p_entries )
 524         vlc_dictionary_init( p_dict, 1 );
 525
 526     int i_pos = DictHash( psz_key, p_dict->i_size );
 527     vlc_dictionary_entry_t * p_entry;
 528
 529     p_entry = (vlc_dictionary_entry_t *)malloc(sizeof(*p_entry));
 530     p_entry->psz_key = strdup( psz_key );
 531     p_entry->p_value = p_value;
 532     p_entry->p_next = p_dict->p_entries[i_pos];
 533     p_dict->p_entries[i_pos] = p_entry;
 534     if( rebuild )
 535     {
 536         /* Count how many items there was */
 537         int count;
 538         for( count = 1; p_entry->p_next; count++ )
 539             p_entry = p_entry->p_next;
 540         if( count > 3 ) /* XXX: this need tuning */
 541         {
 542             /* Here it starts to be not good, rebuild a bigger dictionary */
 543             struct vlc_dictionary_t new_dict;
 544             int i_new_size = ( (p_dict->i_size+2) * 3) / 2; /* XXX: this need tuning */
 545             int i;
 546             vlc_dictionary_init( &new_dict, i_new_size );
 547             for( i = 0; i < p_dict->i_size; i++ )
 548             {
 549                 p_entry = p_dict->p_entries[i];
 550                 while( p_entry )
 551                 {
 552                     __vlc_dictionary_insert( &new_dict, p_entry->psz_key,
 553                                              p_entry->p_value,
 554                                              false /* To avoid multiple rebuild loop */);
 555                     p_entry = p_entry->p_next;
 556                 }
 557             }
 558
 559             vlc_dictionary_clear( p_dict, NULL, NULL );
 560             p_dict->i_size = new_dict.i_size;
 561             p_dict->p_entries = new_dict.p_entries;
 562         }
 563     }
 564 }
 565
 566 static inline void
 567 vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key, void * p_value )
 568 {
 569     __vlc_dictionary_insert( p_dict, psz_key, p_value, true );
 570 }
 571
 572 static inline void
 573 vlc_dictionary_remove_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key,
 574                                      void ( * pf_free )( void * p_data, void * p_obj ),
 575                                      void * p_obj )
 576 {
 577     if( !p_dict->p_entries )
 578         return;
 579
 580     int i_pos = DictHash( psz_key, p_dict->i_size );
 581     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 582     vlc_dictionary_entry_t * p_prev;
 583
 584     if( !p_entry )
 585         return; /* Not found, nothing to do */
 586
 587     /* Hash collision */
 588     p_prev = NULL;
 589     do {
 590         if( !strcmp( psz_key, p_entry->psz_key ) )
 591         {
 592             if( pf_free != NULL )
 593                 ( * pf_free )( p_entry->p_value, p_obj );
 594             if( !p_prev )
 595                 p_dict->p_entries[i_pos] = p_entry->p_next;
 596             else
 597                 p_prev->p_next = p_entry->p_next;
 598             free( p_entry->psz_key );
 599             free( p_entry );
 600             return;
 601         }
 602         p_prev = p_entry;
 603         p_entry = p_entry->p_next;
 604     } while( p_entry );
 605
 606     /* No key was found */
 607 }
 608
 609 #ifdef __cplusplus
 610 // C++ helpers
 611 template <typename T>
 612 void vlc_delete_all( T &container )
 613 {
 614     typename T::iterator it = container.begin();
 615     while ( it != container.end() )
 616     {
 617         delete *it;
 618         ++it;
 619     }
 620     container.clear();
 621 }
 622
 623 #endif
 624
 625 #endif