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( *(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_REMOVE( count, tab, p )             \
 117   do {                                          \
 118         int i_index;                            \
 119         TAB_FIND( count, tab, p, i_index );     \
 120         if( i_index >= 0 )                      \
 121         {                                       \
 122             if( (count) > 1 )                   \
 123             {                                   \
 124                 memmove( ((void**)(tab) + i_index),    \
 125                          ((void**)(tab) + i_index+1),  \
 126                          ( (count) - i_index - 1 ) * sizeof( *(tab) ) );\
 127             }                                   \
 128             (count)--;                          \
 129             if( (count) == 0 )                  \
 130             {                                   \
 131                 free( tab );                    \
 132                 (tab) = NULL;                   \
 133             }                                   \
 134         }                                       \
 135   } while(0)
 136
 137 #define TAB_INSERT_CAST( cast, count, tab, p, index ) do { \
 138     if( (count) > 0 )                           \
 139         (tab) = cast realloc( tab, sizeof( *(tab) ) * ( (count) + 1 ) ); \
 140     else                                        \
 141         (tab) = cast malloc( sizeof( *(tab) ) );       \
 142     if( !(tab) ) abort();                       \
 143     if( (count) - (index) > 0 )                 \
 144         memmove( (void**)(tab) + (index) + 1,   \
 145                  (void**)(tab) + (index),       \
 146                  ((count) - (index)) * sizeof(*(tab)) );\
 147     (tab)[(index)] = (p);                       \
 148     (count)++;                                  \
 149 } while(0)
 150
 151 #define TAB_INSERT( count, tab, p, index )      \
 152     TAB_INSERT_CAST( , count, tab, p, index )
 153
 154 /**
 155  * Binary search in a sorted array. The key must be comparable by < and >
 156  * \param entries array of entries
 157  * \param count number of entries
 158  * \param elem key to check within an entry (like .id, or ->i_id)
 159  * \param zetype type of the key
 160  * \param key value of the key
 161  * \param answer index of answer within the array. -1 if not found
 162  */
 163 #define BSEARCH( entries, count, elem, zetype, key, answer ) \
 164    do {  \
 165     int low = 0, high = count - 1;   \
 166     answer = -1; \
 167     while( low <= high ) {\
 168         int mid = (low + high ) / 2; /* Just don't care about 2^30 tables */ \
 169         zetype mid_val = entries[mid] elem;\
 170         if( mid_val < key ) \
 171             low = mid + 1; \
 172         else if ( mid_val > key ) \
 173             high = mid -1;  \
 174         else    \
 175         {   \
 176             answer = mid;  break;   \
 177         }\
 178     } \
 179  } while(0)
 180
 181
 182 /************************************************************************
 183  * Dynamic arrays with progressive allocation
 184  ************************************************************************/
 185
 186 /* Internal functions */
 187 #define _ARRAY_ALLOC(array, newsize) {                                      \
 188     (array).i_alloc = newsize;                                              \
 189     (array).p_elems = realloc( (array).p_elems, (array).i_alloc *           \
 190                                sizeof(*(array).p_elems) );                  \
 191     if( !(array).p_elems ) abort();                                         \
 192 }
 193
 194 #define _ARRAY_GROW1(array) {                                               \
 195     if( (array).i_alloc < 10 )                                              \
 196         _ARRAY_ALLOC(array, 10 )                                            \
 197     else if( (array).i_alloc == (array).i_size )                            \
 198         _ARRAY_ALLOC(array, (int)(array.i_alloc * 1.5) )                    \
 199 }
 200
 201 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 202
 203 /* API */
 204 #define DECL_ARRAY(type) struct {                                           \
 205     int i_alloc;                                                            \
 206     int i_size;                                                             \
 207     type *p_elems;                                                          \
 208 }
 209
 210 #define TYPEDEF_ARRAY(type, name) typedef DECL_ARRAY(type) name;
 211
 212 #define ARRAY_INIT(array)                                                   \
 213   do {                                                                      \
 214     (array).i_alloc = 0;                                                    \
 215     (array).i_size = 0;                                                     \
 216     (array).p_elems = NULL;                                                 \
 217   } while(0)
 218
 219 #define ARRAY_RESET(array)                                                  \
 220   do {                                                                      \
 221     (array).i_alloc = 0;                                                    \
 222     (array).i_size = 0;                                                     \
 223     free( (array).p_elems ); (array).p_elems = NULL;                        \
 224   } while(0)
 225
 226 #define ARRAY_APPEND(array, elem)                                           \
 227   do {                                                                      \
 228     _ARRAY_GROW1(array);                                                    \
 229     (array).p_elems[(array).i_size] = elem;                                 \
 230     (array).i_size++;                                                       \
 231   } while(0)
 232
 233 #define ARRAY_INSERT(array,elem,pos)                                        \
 234   do {                                                                      \
 235     _ARRAY_GROW1(array);                                                    \
 236     if( (array).i_size - pos ) {                                            \
 237         memmove( (array).p_elems + pos + 1, (array).p_elems + pos,          \
 238                  ((array).i_size-pos) * sizeof(*(array).p_elems) );         \
 239     }                                                                       \
 240     (array).p_elems[pos] = elem;                                            \
 241     (array).i_size++;                                                       \
 242   } while(0)
 243
 244 #define _ARRAY_SHRINK(array) {                                              \
 245     if( (array).i_size > 10 && (array).i_size < (int)((array).i_alloc / 1.5) ) {  \
 246         _ARRAY_ALLOC(array, (array).i_size + 5);                            \
 247     }                                                                       \
 248 }
 249
 250 #define ARRAY_REMOVE(array,pos)                                             \
 251   do {                                                                      \
 252     if( (array).i_size - (pos) - 1 )                                        \
 253     {                                                                       \
 254         memmove( (array).p_elems + pos, (array).p_elems + pos + 1,          \
 255                  ( (array).i_size - pos - 1 ) *sizeof(*(array).p_elems) );  \
 256     }                                                                       \
 257     (array).i_size--;                                                       \
 258     _ARRAY_SHRINK(array);                                                   \
 259   } while(0)
 260
 261 #define ARRAY_VAL(array, pos) array.p_elems[pos]
 262
 263 #define ARRAY_BSEARCH(array, elem, zetype, key, answer) \
 264     BSEARCH( (array).p_elems, (array).i_size, elem, zetype, key, answer)
 265
 266 #define FOREACH_ARRAY( item, array ) { \
 267     int fe_idx; \
 268     for( fe_idx = 0 ; fe_idx < (array).i_size ; fe_idx++ ) \
 269     { \
 270         item = (array).p_elems[fe_idx];
 271
 272 #define FOREACH_END() } }
 273
 274
 275 /************************************************************************
 276  * Dynamic arrays with progressive allocation (Preferred API)
 277  ************************************************************************/
 278 typedef struct vlc_array_t
 279 {
 280     int i_count;
 281     void ** pp_elems;
 282 } vlc_array_t;
 283
 284 static inline void vlc_array_init( vlc_array_t * p_array )
 285 {
 286     memset( p_array, 0, sizeof(vlc_array_t) );
 287 }
 288
 289 static inline void vlc_array_clear( vlc_array_t * p_array )
 290 {
 291     free( p_array->pp_elems );
 292     memset( p_array, 0, sizeof(vlc_array_t) );
 293 }
 294
 295 static inline vlc_array_t * vlc_array_new( void )
 296 {
 297     vlc_array_t * ret = (vlc_array_t *)malloc( sizeof(vlc_array_t) );
 298     if( ret ) vlc_array_init( ret );
 299     return ret;
 300 }
 301
 302 static inline void vlc_array_destroy( vlc_array_t * p_array )
 303 {
 304     if( !p_array )
 305         return;
 306     vlc_array_clear( p_array );
 307     free( p_array );
 308 }
 309
 310
 311 /* Read */
 312 static inline int
 313 vlc_array_count( vlc_array_t * p_array )
 314 {
 315     return p_array->i_count;
 316 }
 317
 318 static inline void *
 319 vlc_array_item_at_index( vlc_array_t * p_array, int i_index )
 320 {
 321     return p_array->pp_elems[i_index];
 322 }
 323
 324 static inline int
 325 vlc_array_index_of_item( vlc_array_t * p_array, void * item )
 326 {
 327     int i;
 328     for( i = 0; i < p_array->i_count; i++)
 329     {
 330         if( p_array->pp_elems[i] == item )
 331             return i;
 332     }
 333     return -1;
 334 }
 335
 336 /* Write */
 337 static inline void
 338 vlc_array_insert( vlc_array_t * p_array, void * p_elem, int i_index )
 339 {
 340     TAB_INSERT_CAST( (void **), p_array->i_count, p_array->pp_elems, p_elem, i_index );
 341 }
 342
 343 static inline void
 344 vlc_array_append( vlc_array_t * p_array, void * p_elem )
 345 {
 346     vlc_array_insert( p_array, p_elem, p_array->i_count );
 347 }
 348
 349 static inline void
 350 vlc_array_remove( vlc_array_t * p_array, int i_index )
 351 {
 352     if( i_index >= 0 )
 353     {
 354         if( p_array->i_count > 1 )
 355         {
 356             memmove( p_array->pp_elems + i_index,
 357                      p_array->pp_elems + i_index+1,
 358                      ( p_array->i_count - i_index - 1 ) * sizeof( void* ) );
 359         }
 360         p_array->i_count--;
 361         if( p_array->i_count == 0 )
 362         {
 363             free( p_array->pp_elems );
 364             p_array->pp_elems = NULL;
 365         }
 366     }
 367 }
 368
 369
 370 /************************************************************************
 371  * Dictionaries
 372  ************************************************************************/
 373
 374 /* This function is not intended to be crypto-secure, we only want it to be
 375  * fast and not suck too much. This one is pretty fast and did 0 collisions
 376  * in wenglish's dictionary.
 377  */
 378 static inline uint64_t DictHash( const char *psz_string, int hashsize )
 379 {
 380     uint64_t i_hash = 0;
 381     if( psz_string )
 382     {
 383         while( *psz_string )
 384         {
 385             i_hash += *psz_string++;
 386             i_hash += i_hash << 10;
 387             i_hash ^= i_hash >> 8;
 388         }
 389     }
 390     return i_hash % hashsize;
 391 }
 392
 393 typedef struct vlc_dictionary_entry_t
 394 {
 395     char *   psz_key;
 396     void *   p_value;
 397     struct vlc_dictionary_entry_t * p_next;
 398 } vlc_dictionary_entry_t;
 399
 400 typedef struct vlc_dictionary_t
 401 {
 402     int i_size;
 403     vlc_dictionary_entry_t ** p_entries;
 404 } vlc_dictionary_t;
 405
 406 static void * const kVLCDictionaryNotFound = NULL;
 407
 408 static inline void vlc_dictionary_init( vlc_dictionary_t * p_dict, int i_size )
 409 {
 410     p_dict->p_entries = NULL;
 411
 412     if( i_size > 0 )
 413     {
 414         p_dict->p_entries = (vlc_dictionary_entry_t **)calloc( i_size, sizeof(*p_dict->p_entries) );
 415         if( !p_dict->p_entries )
 416             i_size = 0;
 417     }
 418     p_dict->i_size = i_size;
 419 }
 420
 421 static inline void vlc_dictionary_clear( vlc_dictionary_t * p_dict,
 422                                          void ( * pf_free )( void * p_data, void * p_obj ),
 423                                          void * p_obj )
 424 {
 425     if( p_dict->p_entries )
 426     {
 427         for( int i = 0; i < p_dict->i_size; i++ )
 428         {
 429             vlc_dictionary_entry_t * p_current, * p_next;
 430             p_current = p_dict->p_entries[i];
 431             while( p_current )
 432             {
 433                 p_next = p_current->p_next;
 434                 if( pf_free != NULL )
 435                     ( * pf_free )( p_current->p_value, p_obj );
 436                 free( p_current->psz_key );
 437                 free( p_current );
 438                 p_current = p_next;
 439             }
 440         }
 441         free( p_dict->p_entries );
 442         p_dict->p_entries = NULL;
 443     }
 444     p_dict->i_size = 0;
 445 }
 446
 447 static inline int
 448 vlc_dictionary_has_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 449 {
 450     if( !p_dict->p_entries )
 451         return 0;
 452
 453     int i_pos = DictHash( psz_key, p_dict->i_size );
 454     return p_dict->p_entries[i_pos] != NULL;
 455 }
 456
 457 static inline void *
 458 vlc_dictionary_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
 459 {
 460     if( !p_dict->p_entries )
 461         return kVLCDictionaryNotFound;
 462
 463     int i_pos = DictHash( psz_key, p_dict->i_size );
 464     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 465
 466     if( !p_entry )
 467         return kVLCDictionaryNotFound;
 468
 469     /* Make sure we return the right item. (Hash collision) */
 470     do {
 471         if( !strcmp( psz_key, p_entry->psz_key ) )
 472             return p_entry->p_value;
 473         p_entry = p_entry->p_next;
 474     } while( p_entry );
 475
 476     return kVLCDictionaryNotFound;
 477 }
 478
 479 static inline int
 480 vlc_dictionary_keys_count( const vlc_dictionary_t * p_dict )
 481 {
 482     vlc_dictionary_entry_t * p_entry;
 483     int i, count = 0;
 484
 485     if( !p_dict->p_entries )
 486         return 0;
 487
 488     for( i = 0; i < p_dict->i_size; i++ )
 489     {
 490         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next ) count++;
 491     }
 492     return count;
 493 }
 494
 495 static inline char **
 496 vlc_dictionary_all_keys( const vlc_dictionary_t * p_dict )
 497 {
 498     vlc_dictionary_entry_t * p_entry;
 499     char ** ppsz_ret;
 500     int i, count = vlc_dictionary_keys_count( p_dict );
 501
 502     ppsz_ret = (char**)malloc(sizeof(char *) * (count + 1));
 503     if( unlikely(!ppsz_ret) )
 504         return NULL;
 505
 506     count = 0;
 507     for( i = 0; i < p_dict->i_size; i++ )
 508     {
 509         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next )
 510             ppsz_ret[count++] = strdup( p_entry->psz_key );
 511     }
 512     ppsz_ret[count] = NULL;
 513     return ppsz_ret;
 514 }
 515
 516 static inline void
 517 __vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key,
 518                          void * p_value, bool rebuild )
 519 {
 520     if( !p_dict->p_entries )
 521         vlc_dictionary_init( p_dict, 1 );
 522
 523     int i_pos = DictHash( psz_key, p_dict->i_size );
 524     vlc_dictionary_entry_t * p_entry;
 525
 526     p_entry = (vlc_dictionary_entry_t *)malloc(sizeof(*p_entry));
 527     p_entry->psz_key = strdup( psz_key );
 528     p_entry->p_value = p_value;
 529     p_entry->p_next = p_dict->p_entries[i_pos];
 530     p_dict->p_entries[i_pos] = p_entry;
 531     if( rebuild )
 532     {
 533         /* Count how many items there was */
 534         int count;
 535         for( count = 1; p_entry->p_next; count++ )
 536             p_entry = p_entry->p_next;
 537         if( count > 3 ) /* XXX: this need tuning */
 538         {
 539             /* Here it starts to be not good, rebuild a bigger dictionary */
 540             struct vlc_dictionary_t new_dict;
 541             int i_new_size = ( (p_dict->i_size+2) * 3) / 2; /* XXX: this need tuning */
 542             int i;
 543             vlc_dictionary_init( &new_dict, i_new_size );
 544             for( i = 0; i < p_dict->i_size; i++ )
 545             {
 546                 p_entry = p_dict->p_entries[i];
 547                 while( p_entry )
 548                 {
 549                     __vlc_dictionary_insert( &new_dict, p_entry->psz_key,
 550                                              p_entry->p_value,
 551                                              false /* To avoid multiple rebuild loop */);
 552                     p_entry = p_entry->p_next;
 553                 }
 554             }
 555
 556             vlc_dictionary_clear( p_dict, NULL, NULL );
 557             p_dict->i_size = new_dict.i_size;
 558             p_dict->p_entries = new_dict.p_entries;
 559         }
 560     }
 561 }
 562
 563 static inline void
 564 vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key, void * p_value )
 565 {
 566     __vlc_dictionary_insert( p_dict, psz_key, p_value, true );
 567 }
 568
 569 static inline void
 570 vlc_dictionary_remove_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key,
 571                                      void ( * pf_free )( void * p_data, void * p_obj ),
 572                                      void * p_obj )
 573 {
 574     if( !p_dict->p_entries )
 575         return;
 576
 577     int i_pos = DictHash( psz_key, p_dict->i_size );
 578     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
 579     vlc_dictionary_entry_t * p_prev;
 580
 581     if( !p_entry )
 582         return; /* Not found, nothing to do */
 583
 584     /* Hash collision */
 585     p_prev = NULL;
 586     do {
 587         if( !strcmp( psz_key, p_entry->psz_key ) )
 588         {
 589             if( pf_free != NULL )
 590                 ( * pf_free )( p_entry->p_value, p_obj );
 591             if( !p_prev )
 592                 p_dict->p_entries[i_pos] = p_entry->p_next;
 593             else
 594                 p_prev->p_next = p_entry->p_next;
 595             free( p_entry->psz_key );
 596             free( p_entry );
 597             return;
 598         }
 599         p_prev = p_entry;
 600         p_entry = p_entry->p_next;
 601     } while( p_entry );
 602
 603     /* No key was found */
 604 }
 605
 606 #ifdef __cplusplus
 607 // C++ helpers
 608 template <typename T>
 609 void vlc_delete_all( T &container )
 610 {
 611     typename T::iterator it = container.begin();
 612     while ( it != container.end() )
 613     {
 614         delete *it;
 615         ++it;
 616     }
 617     container.clear();
 618 }
 619
 620 #endif
 621
 622 #endif