]> git.sesse.net Git - vlc/blob - include/vlc_arrays.h
Helpers for var_Inherit()
[vlc] / include / vlc_arrays.h
1 /*****************************************************************************
2  * vlc_arrays.h : Arrays and data structures handling
3  *****************************************************************************
4  * Copyright (C) 1999-2004 the VideoLAN team
5  * $Id$
6  *
7  * Authors: Samuel Hocevar <sam@zoy.org>
8  *          ClĂ©ment 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
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 #if defined( _MSC_VER ) && _MSC_VER < 1300 && !defined( UNDER_CE )
44 #   define VLCCVP (void**) /* Work-around for broken compiler */
45 #else
46 #   define VLCCVP
47 #endif
48 #define INSERT_ELEM( p_ar, i_oldsize, i_pos, elem )                           \
49     do                                                                        \
50     {                                                                         \
51         if( !i_oldsize ) (p_ar) = NULL;                                       \
52         (p_ar) = VLCCVP realloc( p_ar, ((i_oldsize) + 1) * sizeof(*(p_ar)) ); \
53         if( !(p_ar) ) abort();                                                \
54         if( (i_oldsize) - (i_pos) )                                           \
55         {                                                                     \
56             memmove( (p_ar) + (i_pos) + 1, (p_ar) + (i_pos),                  \
57                      ((i_oldsize) - (i_pos)) * sizeof( *(p_ar) ) );           \
58         }                                                                     \
59         (p_ar)[i_pos] = elem;                                                 \
60         (i_oldsize)++;                                                        \
61     }                                                                         \
62     while( 0 )
63
64 #define REMOVE_ELEM( p_ar, i_size, i_pos )                                    \
65     do                                                                        \
66     {                                                                         \
67         if( (i_size) - (i_pos) - 1 )                                          \
68         {                                                                     \
69             memmove( (p_ar) + (i_pos),                                        \
70                      (p_ar) + (i_pos) + 1,                                    \
71                      ((i_size) - (i_pos) - 1) * sizeof( *(p_ar) ) );          \
72         }                                                                     \
73         if( i_size > 1 )                                                      \
74             (p_ar) = realloc_down( p_ar, ((i_size) - 1) * sizeof( *(p_ar) ) );\
75         else                                                                  \
76         {                                                                     \
77             free( p_ar );                                                     \
78             (p_ar) = NULL;                                                    \
79         }                                                                     \
80         (i_size)--;                                                           \
81     }                                                                         \
82     while( 0 )
83
84 #define TAB_INIT( count, tab )                  \
85   do {                                          \
86     (count) = 0;                                \
87     (tab) = NULL;                               \
88   } while(0)
89
90 #define TAB_CLEAN( count, tab )                 \
91   do {                                          \
92     free( tab );                                \
93     (count)= 0;                                 \
94     (tab)= NULL;                                \
95   } while(0)
96
97 #define TAB_APPEND_CAST( cast, count, tab, p )             \
98   do {                                          \
99     if( (count) > 0 )                           \
100         (tab) = cast realloc( tab, sizeof( void ** ) * ( (count) + 1 ) ); \
101     else                                        \
102         (tab) = cast malloc( sizeof( void ** ) );    \
103     if( !(tab) ) abort();                       \
104     (tab)[count] = (p);                         \
105     (count)++;                                  \
106   } while(0)
107
108 #define TAB_APPEND( count, tab, p )             \
109     TAB_APPEND_CAST( , count, tab, p )
110 #define TAB_APPEND_CPP( type, count, tab, p )   \
111     TAB_APPEND_CAST( (type**), count, tab, p )
112
113 #define TAB_FIND( count, tab, p, index )        \
114   do {                                          \
115         int _i_;                                \
116         (index) = -1;                           \
117         for( _i_ = 0; _i_ < (count); _i_++ )    \
118         {                                       \
119             if( (tab)[_i_] == (p) )             \
120             {                                   \
121                 (index) = _i_;                  \
122                 break;                          \
123             }                                   \
124         }                                       \
125   } while(0)
126
127
128 #define TAB_REMOVE( count, tab, p )             \
129   do {                                          \
130         int _i_index_;                          \
131         TAB_FIND( count, tab, p, _i_index_ );   \
132         if( _i_index_ >= 0 )                    \
133         {                                       \
134             if( (count) > 1 )                   \
135             {                                   \
136                 memmove( ((void**)(tab) + _i_index_),    \
137                          ((void**)(tab) + _i_index_+1),  \
138                          ( (count) - _i_index_ - 1 ) * sizeof( void* ) );\
139             }                                   \
140             (count)--;                          \
141             if( (count) == 0 )                  \
142             {                                   \
143                 free( tab );                    \
144                 (tab) = NULL;                   \
145             }                                   \
146         }                                       \
147   } while(0)
148
149 #define TAB_INSERT_CAST( cast, count, tab, p, index ) do { \
150     if( (count) > 0 )                           \
151         (tab) = cast realloc( tab, sizeof( void ** ) * ( (count) + 1 ) ); \
152     else                                        \
153         (tab) = cast malloc( sizeof( void ** ) );       \
154     if( !(tab) ) abort();                       \
155     if( (count) - (index) > 0 )                 \
156         memmove( (void**)(tab) + (index) + 1,   \
157                  (void**)(tab) + (index),       \
158                  ((count) - (index)) * sizeof(*(tab)) );\
159     (tab)[(index)] = (p);                       \
160     (count)++;                                  \
161 } while(0)
162
163 #define TAB_INSERT( count, tab, p, index )      \
164     TAB_INSERT_CAST( , count, tab, p, index )
165
166 /**
167  * Binary search in a sorted array. The key must be comparable by < and >
168  * \param entries array of entries
169  * \param count number of entries
170  * \param elem key to check within an entry (like .id, or ->i_id)
171  * \param zetype type of the key
172  * \param key value of the key
173  * \param answer index of answer within the array. -1 if not found
174  */
175 #define BSEARCH( entries, count, elem, zetype, key, answer ) \
176    do {  \
177     int low = 0, high = count - 1;   \
178     answer = -1; \
179     while( low <= high ) {\
180         int mid = (low + high ) / 2; /* Just don't care about 2^30 tables */ \
181         zetype mid_val = entries[mid] elem;\
182         if( mid_val < key ) \
183             low = mid + 1; \
184         else if ( mid_val > key ) \
185             high = mid -1;  \
186         else    \
187         {   \
188             answer = mid;  break;   \
189         }\
190     } \
191  } while(0)
192
193
194 /************************************************************************
195  * Dynamic arrays with progressive allocation
196  ************************************************************************/
197
198 /* Internal functions */
199 #define _ARRAY_ALLOC(array, newsize) {                                      \
200     (array).i_alloc = newsize;                                              \
201     (array).p_elems = VLCCVP realloc( (array).p_elems, (array).i_alloc *    \
202                                     sizeof(*(array).p_elems) );             \
203     if( !(array).p_elems ) abort();                                         \
204 }
205
206 #define _ARRAY_GROW1(array) {                                               \
207     if( (array).i_alloc < 10 )                                              \
208         _ARRAY_ALLOC(array, 10 )                                            \
209     else if( (array).i_alloc == (array).i_size )                            \
210         _ARRAY_ALLOC(array, (int)(array.i_alloc * 1.5) )                    \
211 }
212
213 #define _ARRAY_GROW(array,additional) {                                     \
214      int i_first = (array).i_alloc;                                         \
215      while( (array).i_alloc - i_first < additional )                        \
216      {                                                                      \
217          if( (array).i_alloc < 10 )                                         \
218             _ARRAY_ALLOC(array, 10 )                                        \
219         else if( (array).i_alloc == (array).i_size )                        \
220             _ARRAY_ALLOC(array, (int)((array).i_alloc * 1.5) )              \
221         else break;                                                         \
222      }                                                                      \
223 }
224
225 #define _ARRAY_SHRINK(array) {                                              \
226     if( (array).i_size > 10 && (array).i_size < (int)((array).i_alloc / 1.5) ) {  \
227         _ARRAY_ALLOC(array, (array).i_size + 5);                            \
228     }                                                                       \
229 }
230
231 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
232
233 /* API */
234 #define DECL_ARRAY(type) struct {                                           \
235     int i_alloc;                                                            \
236     int i_size;                                                             \
237     type *p_elems;                                                          \
238 }
239
240 #define TYPEDEF_ARRAY(type, name) typedef DECL_ARRAY(type) name;
241
242 #define ARRAY_INIT(array)                                                   \
243   do {                                                                      \
244     (array).i_alloc = 0;                                                    \
245     (array).i_size = 0;                                                     \
246     (array).p_elems = NULL;                                                 \
247   } while(0)
248
249 #define ARRAY_RESET(array)                                                  \
250   do {                                                                      \
251     (array).i_alloc = 0;                                                    \
252     (array).i_size = 0;                                                     \
253     free( (array).p_elems ); (array).p_elems = NULL;                        \
254   } while(0)
255
256 #define ARRAY_APPEND(array, elem)                                           \
257   do {                                                                      \
258     _ARRAY_GROW1(array);                                                    \
259     (array).p_elems[(array).i_size] = elem;                                 \
260     (array).i_size++;                                                       \
261   } while(0)
262
263 #define ARRAY_INSERT(array,elem,pos)                                        \
264   do {                                                                      \
265     _ARRAY_GROW1(array);                                                    \
266     if( (array).i_size - pos ) {                                            \
267         memmove( (array).p_elems + pos + 1, (array).p_elems + pos,          \
268                  ((array).i_size-pos) * sizeof(*(array).p_elems) );         \
269     }                                                                       \
270     (array).p_elems[pos] = elem;                                            \
271     (array).i_size++;                                                       \
272   } while(0)
273
274 #define ARRAY_REMOVE(array,pos)                                             \
275   do {                                                                      \
276     if( (array).i_size - (pos) - 1 )                                        \
277     {                                                                       \
278         memmove( (array).p_elems + pos, (array).p_elems + pos + 1,          \
279                  ( (array).i_size - pos - 1 ) *sizeof(*(array).p_elems) );  \
280     }                                                                       \
281     (array).i_size--;                                                       \
282     _ARRAY_SHRINK(array);                                                   \
283   } while(0)
284
285 #define ARRAY_VAL(array, pos) array.p_elems[pos]
286
287 #define ARRAY_BSEARCH(array, elem, zetype, key, answer) \
288     BSEARCH( (array).p_elems, (array).i_size, elem, zetype, key, answer)
289
290 #define FOREACH_ARRAY( item, array ) { \
291     int fe_idx; \
292     for( fe_idx = 0 ; fe_idx < (array).i_size ; fe_idx++ ) \
293     { \
294         item = (array).p_elems[fe_idx];
295
296 #define FOREACH_END() } }
297
298
299 /************************************************************************
300  * Dynamic arrays with progressive allocation (Preferred API)
301  ************************************************************************/
302 typedef struct vlc_array_t
303 {
304     int i_count;
305     void ** pp_elems;
306 } vlc_array_t;
307
308 static inline void vlc_array_init( vlc_array_t * p_array )
309 {
310     memset( p_array, 0, sizeof(vlc_array_t) );
311 }
312
313 static inline void vlc_array_clear( vlc_array_t * p_array )
314 {
315     free( p_array->pp_elems );
316     memset( p_array, 0, sizeof(vlc_array_t) );
317 }
318
319 static inline vlc_array_t * vlc_array_new( void )
320 {
321     vlc_array_t * ret = (vlc_array_t *)malloc( sizeof(vlc_array_t) );
322     if( ret ) vlc_array_init( ret );
323     return ret;
324 }
325
326 static inline void vlc_array_destroy( vlc_array_t * p_array )
327 {
328     if( !p_array )
329         return;
330     vlc_array_clear( p_array );
331     free( p_array );
332 }
333
334
335 /* Read */
336 static inline int
337 vlc_array_count( vlc_array_t * p_array )
338 {
339     return p_array->i_count;
340 }
341
342 static inline void *
343 vlc_array_item_at_index( vlc_array_t * p_array, int i_index )
344 {
345     return p_array->pp_elems[i_index];
346 }
347
348 static inline int
349 vlc_array_index_of_item( vlc_array_t * p_array, void * item )
350 {
351     int i;
352     for( i = 0; i < p_array->i_count; i++)
353     {
354         if( p_array->pp_elems[i] == item )
355             return i;
356     }
357     return -1;
358 }
359
360 /* Write */
361 static inline void
362 vlc_array_insert( vlc_array_t * p_array, void * p_elem, int i_index )
363 {
364     TAB_INSERT_CAST( (void **), p_array->i_count, p_array->pp_elems, p_elem, i_index );
365 }
366
367 static inline void
368 vlc_array_append( vlc_array_t * p_array, void * p_elem )
369 {
370     vlc_array_insert( p_array, p_elem, p_array->i_count );
371 }
372
373 static inline void
374 vlc_array_remove( vlc_array_t * p_array, int i_index )
375 {
376     if( i_index >= 0 )
377     {
378         if( p_array->i_count > 1 )
379         {
380             memmove( p_array->pp_elems + i_index,
381                      p_array->pp_elems + i_index+1,
382                      ( p_array->i_count - i_index - 1 ) * sizeof( void* ) );
383         }
384         p_array->i_count--;
385         if( p_array->i_count == 0 )
386         {
387             free( p_array->pp_elems );
388             p_array->pp_elems = NULL;
389         }
390     }
391 }
392
393
394 /************************************************************************
395  * Dictionaries
396  ************************************************************************/
397
398 /* This function is not intended to be crypto-secure, we only want it to be
399  * fast and not suck too much. This one is pretty fast and did 0 collisions
400  * in wenglish's dictionary.
401  */
402 static inline uint64_t DictHash( const char *psz_string, int hashsize )
403 {
404     uint64_t i_hash = 0;
405     if( psz_string )
406     {
407         while( *psz_string )
408         {
409             i_hash += *psz_string++;
410             i_hash += i_hash << 10;
411             i_hash ^= i_hash >> 8;
412         }
413     }
414     return i_hash % hashsize;
415 }
416
417 typedef struct vlc_dictionary_entry_t
418 {
419     char *   psz_key;
420     void *   p_value;
421     struct vlc_dictionary_entry_t * p_next;
422 } vlc_dictionary_entry_t;
423
424 typedef struct vlc_dictionary_t
425 {
426     int i_size;
427     vlc_dictionary_entry_t ** p_entries;
428 } vlc_dictionary_t;
429
430 static void * const kVLCDictionaryNotFound = NULL;
431
432 static inline void vlc_dictionary_init( vlc_dictionary_t * p_dict, int i_size )
433 {
434     p_dict->p_entries = NULL;
435
436     if( i_size > 0 )
437     {
438         p_dict->p_entries = (vlc_dictionary_entry_t **)calloc( i_size, sizeof(*p_dict->p_entries) );
439         if( !p_dict->p_entries )
440             i_size = 0;
441     }
442     p_dict->i_size = i_size;
443 }
444
445 static inline void vlc_dictionary_clear( vlc_dictionary_t * p_dict,
446                                          void ( * pf_free )( void * p_data, void * p_obj ),
447                                          void * p_obj )
448 {
449     if( p_dict->p_entries )
450     {
451         for( int i = 0; i < p_dict->i_size; i++ )
452         {
453             vlc_dictionary_entry_t * p_current, * p_next;
454             p_current = p_dict->p_entries[i];
455             while( p_current )
456             {
457                 p_next = p_current->p_next;
458                 if( pf_free != NULL )
459                     ( * pf_free )( p_current->p_value, p_obj );
460                 free( p_current->psz_key );
461                 free( p_current );
462                 p_current = p_next;
463             }
464         }
465         free( p_dict->p_entries );
466         p_dict->p_entries = NULL;
467     }
468     p_dict->i_size = 0;
469 }
470
471
472
473 static inline void *
474 vlc_dictionary_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
475 {
476     if( !p_dict->p_entries )
477         return kVLCDictionaryNotFound;
478
479     int i_pos = DictHash( psz_key, p_dict->i_size );
480     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
481
482     if( !p_entry )
483         return kVLCDictionaryNotFound;
484
485     /* Make sure we return the right item. (Hash collision) */
486     do {
487         if( !strcmp( psz_key, p_entry->psz_key ) )
488             return p_entry->p_value;
489         p_entry = p_entry->p_next;
490     } while( p_entry );
491
492     return kVLCDictionaryNotFound;
493 }
494
495 static inline int
496 vlc_dictionary_keys_count( const vlc_dictionary_t * p_dict )
497 {
498     vlc_dictionary_entry_t * p_entry;
499     int i, count = 0;
500
501     if( !p_dict->p_entries )
502         return 0;
503
504     for( i = 0; i < p_dict->i_size; i++ )
505     {
506         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next ) count++;
507     }
508     return count;
509 }
510
511 static inline char **
512 vlc_dictionary_all_keys( const vlc_dictionary_t * p_dict )
513 {
514     vlc_dictionary_entry_t * p_entry;
515     char ** ppsz_ret;
516     int i, count = vlc_dictionary_keys_count( p_dict );
517
518     ppsz_ret = (char**)malloc(sizeof(char *) * (count + 1));
519
520     count = 0;
521     for( i = 0; i < p_dict->i_size; i++ )
522     {
523         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next )
524             ppsz_ret[count++] = strdup( p_entry->psz_key );
525     }
526     ppsz_ret[count] = NULL;
527     return ppsz_ret;
528 }
529
530 static inline void
531 __vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key,
532                          void * p_value, bool rebuild )
533 {
534     if( !p_dict->p_entries )
535         vlc_dictionary_init( p_dict, 1 );
536
537     int i_pos = DictHash( psz_key, p_dict->i_size );
538     vlc_dictionary_entry_t * p_entry;
539
540     p_entry = (vlc_dictionary_entry_t *)malloc(sizeof(*p_entry));
541     p_entry->psz_key = strdup( psz_key );
542     p_entry->p_value = p_value;
543     p_entry->p_next = p_dict->p_entries[i_pos];
544     p_dict->p_entries[i_pos] = p_entry;
545     if( rebuild )
546     {
547         /* Count how many items there was */
548         int count;
549         for( count = 1; p_entry->p_next; count++ )
550             p_entry = p_entry->p_next;
551         if( count > 3 ) /* XXX: this need tuning */
552         {
553             /* Here it starts to be not good, rebuild a bigger dictionary */
554             struct vlc_dictionary_t new_dict;
555             int i_new_size = ( (p_dict->i_size+2) * 3) / 2; /* XXX: this need tuning */
556             int i;
557             vlc_dictionary_init( &new_dict, i_new_size );
558             for( i = 0; i < p_dict->i_size; i++ )
559             {
560                 p_entry = p_dict->p_entries[i];
561                 while( p_entry )
562                 {
563                     __vlc_dictionary_insert( &new_dict, p_entry->psz_key,
564                                              p_entry->p_value,
565                                              false /* To avoid multiple rebuild loop */);
566                     p_entry = p_entry->p_next;
567                 }
568             }
569
570             vlc_dictionary_clear( p_dict, NULL, NULL );
571             p_dict->i_size = new_dict.i_size;
572             p_dict->p_entries = new_dict.p_entries;
573         }
574     }
575 }
576
577 static inline void
578 vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key, void * p_value )
579 {
580     __vlc_dictionary_insert( p_dict, psz_key, p_value, true );
581 }
582
583 static inline void
584 vlc_dictionary_remove_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key,
585                                      void ( * pf_free )( void * p_data, void * p_obj ),
586                                      void * p_obj )
587 {
588     if( !p_dict->p_entries )
589         return;
590
591     int i_pos = DictHash( psz_key, p_dict->i_size );
592     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
593     vlc_dictionary_entry_t * p_prev;
594
595     if( !p_entry )
596         return; /* Not found, nothing to do */
597
598     /* Hash collision */
599     p_prev = NULL;
600     do {
601         if( !strcmp( psz_key, p_entry->psz_key ) )
602         {
603             if( pf_free != NULL )
604                 ( * pf_free )( p_entry->p_value, p_obj );
605             if( !p_prev )
606                 p_dict->p_entries[i_pos] = p_entry->p_next;
607             else
608                 p_prev->p_next = p_entry->p_next;
609             free( p_entry->psz_key );
610             free( p_entry );
611             return;
612         }
613         p_prev = p_entry;
614         p_entry = p_entry->p_next;
615     } while( p_entry );
616
617     /* No key was found */
618 }
619
620 #endif