5e5ef4545825523b8d218d0f1db539283eaeac5c
[vlc.git] / 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  *          ClĂ©ment 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 #define TAB_INIT( count, tab )                  \
41   do {                                          \
42     (count) = 0;                                \
43     (tab) = NULL;                               \
44   } while(0)
45
46 #define TAB_CLEAN( count, tab )                 \
47   do {                                          \
48     free( tab );                                \
49     (count)= 0;                                 \
50     (tab)= NULL;                                \
51   } while(0)
52
53 #define TAB_APPEND_CAST( cast, count, tab, p )             \
54   do {                                          \
55     if( (count) > 0 )                           \
56         (tab) = cast realloc( tab, sizeof( *(tab) ) * ( (count) + 1 ) ); \
57     else                                        \
58         (tab) = cast malloc( sizeof( *(tab) ) );    \
59     if( !(tab) ) abort();                       \
60     (tab)[count] = (p);                         \
61     (count)++;                                  \
62   } while(0)
63
64 #define TAB_APPEND( count, tab, p )             \
65     TAB_APPEND_CAST( , count, tab, p )
66
67 #define TAB_FIND( count, tab, p, idx )          \
68   do {                                          \
69     for( (idx) = 0; (idx) < (count); (idx)++ )  \
70         if( (tab)[(idx)] == (p) )               \
71             break;                              \
72     if( (idx) >= (count) )                      \
73         (idx) = -1;                             \
74   } while(0)
75
76
77 #define TAB_ERASE( count, tab, index )      \
78   do {                                      \
79         if( (count) > 1 )                   \
80             memmove( (tab) + (index),       \
81                      (tab) + (index) + 1,   \
82                      ((count) - (index) - 1 ) * sizeof( *(tab) ) );\
83         (count)--;                          \
84         if( (count) == 0 )                  \
85         {                                   \
86             free( tab );                    \
87             (tab) = NULL;                   \
88         }                                   \
89   } while(0)
90
91 #define TAB_REMOVE( count, tab, p )             \
92   do {                                          \
93         int i_index;                            \
94         TAB_FIND( count, tab, p, i_index );     \
95         if( i_index >= 0 )                      \
96             TAB_ERASE( count, tab, i_index );   \
97   } while(0)
98
99 #define TAB_INSERT_CAST( cast, count, tab, p, index ) do { \
100     if( (count) > 0 )                           \
101         (tab) = cast realloc( tab, sizeof( *(tab) ) * ( (count) + 1 ) ); \
102     else                                        \
103         (tab) = cast malloc( sizeof( *(tab) ) );       \
104     if( !(tab) ) abort();                       \
105     if( (count) - (index) > 0 )                 \
106         memmove( (tab) + (index) + 1,           \
107                  (tab) + (index),               \
108                  ((count) - (index)) * sizeof( *(tab) ) );\
109     (tab)[(index)] = (p);                       \
110     (count)++;                                  \
111 } while(0)
112
113 #define TAB_INSERT( count, tab, p, index )      \
114     TAB_INSERT_CAST( , count, tab, p, index )
115
116 /**
117  * Binary search in a sorted array. The key must be comparable by < and >
118  * \param entries array of entries
119  * \param count number of entries
120  * \param elem key to check within an entry (like .id, or ->i_id)
121  * \param zetype type of the key
122  * \param key value of the key
123  * \param answer index of answer within the array. -1 if not found
124  */
125 #define BSEARCH( entries, count, elem, zetype, key, answer ) \
126    do {  \
127     int low = 0, high = count - 1;   \
128     answer = -1; \
129     while( low <= high ) {\
130         int mid = ((unsigned int)low + (unsigned int)high) >> 1;\
131         zetype mid_val = entries[mid] elem;\
132         if( mid_val < key ) \
133             low = mid + 1; \
134         else if ( mid_val > key ) \
135             high = mid -1;  \
136         else    \
137         {   \
138             answer = mid;  break;   \
139         }\
140     } \
141  } while(0)
142
143
144 /************************************************************************
145  * Dynamic arrays with progressive allocation
146  ************************************************************************/
147
148 /* Internal functions */
149 #define _ARRAY_ALLOC(array, newsize) {                                      \
150     (array).i_alloc = newsize;                                              \
151     (array).p_elems = realloc( (array).p_elems, (array).i_alloc *           \
152                                sizeof(*(array).p_elems) );                  \
153     if( !(array).p_elems ) abort();                                         \
154 }
155
156 #define _ARRAY_GROW1(array) {                                               \
157     if( (array).i_alloc < 10 )                                              \
158         _ARRAY_ALLOC(array, 10 )                                            \
159     else if( (array).i_alloc == (array).i_size )                            \
160         _ARRAY_ALLOC(array, (int)((array).i_alloc * 1.5) )                    \
161 }
162
163 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
164
165 /* API */
166 #define DECL_ARRAY(type) struct {                                           \
167     int i_alloc;                                                            \
168     int i_size;                                                             \
169     type *p_elems;                                                          \
170 }
171
172 #define TYPEDEF_ARRAY(type, name) typedef DECL_ARRAY(type) name;
173
174 #define ARRAY_INIT(array)                                                   \
175   do {                                                                      \
176     (array).i_alloc = 0;                                                    \
177     (array).i_size = 0;                                                     \
178     (array).p_elems = NULL;                                                 \
179   } while(0)
180
181 #define ARRAY_RESET(array)                                                  \
182   do {                                                                      \
183     (array).i_alloc = 0;                                                    \
184     (array).i_size = 0;                                                     \
185     free( (array).p_elems ); (array).p_elems = NULL;                        \
186   } while(0)
187
188 #define ARRAY_APPEND(array, elem)                                           \
189   do {                                                                      \
190     _ARRAY_GROW1(array);                                                    \
191     (array).p_elems[(array).i_size] = elem;                                 \
192     (array).i_size++;                                                       \
193   } while(0)
194
195 #define ARRAY_INSERT(array,elem,pos)                                        \
196   do {                                                                      \
197     _ARRAY_GROW1(array);                                                    \
198     if( (array).i_size - pos ) {                                            \
199         memmove( (array).p_elems + pos + 1, (array).p_elems + pos,          \
200                  ((array).i_size-pos) * sizeof(*(array).p_elems) );         \
201     }                                                                       \
202     (array).p_elems[pos] = elem;                                            \
203     (array).i_size++;                                                       \
204   } while(0)
205
206 #define _ARRAY_SHRINK(array) {                                              \
207     if( (array).i_size > 10 && (array).i_size < (int)((array).i_alloc / 1.5) ) {  \
208         _ARRAY_ALLOC(array, (array).i_size + 5);                            \
209     }                                                                       \
210 }
211
212 #define ARRAY_REMOVE(array,pos)                                             \
213   do {                                                                      \
214     if( (array).i_size - (pos) - 1 )                                        \
215     {                                                                       \
216         memmove( (array).p_elems + pos, (array).p_elems + pos + 1,          \
217                  ( (array).i_size - pos - 1 ) *sizeof(*(array).p_elems) );  \
218     }                                                                       \
219     (array).i_size--;                                                       \
220     _ARRAY_SHRINK(array);                                                   \
221   } while(0)
222
223 #define ARRAY_VAL(array, pos) array.p_elems[pos]
224
225 #define ARRAY_BSEARCH(array, elem, zetype, key, answer) \
226     BSEARCH( (array).p_elems, (array).i_size, elem, zetype, key, answer)
227
228 #define FOREACH_ARRAY( item, array ) { \
229     int fe_idx; \
230     for( fe_idx = 0 ; fe_idx < (array).i_size ; fe_idx++ ) \
231     { \
232         item = (array).p_elems[fe_idx];
233
234 #define FOREACH_END() } }
235
236
237 /************************************************************************
238  * Dynamic arrays with progressive allocation (Preferred API)
239  ************************************************************************/
240 typedef struct vlc_array_t
241 {
242     size_t i_count;
243     void ** pp_elems;
244 } vlc_array_t;
245
246 static inline void vlc_array_init( vlc_array_t * p_array )
247 {
248     p_array->i_count = 0;
249     p_array->pp_elems = NULL;
250 }
251
252 static inline void vlc_array_clear( vlc_array_t * p_array )
253 {
254     free( p_array->pp_elems );
255     vlc_array_init( p_array );
256 }
257
258 /* Read */
259 static inline size_t vlc_array_count( vlc_array_t * p_array )
260 {
261     return p_array->i_count;
262 }
263
264 #if defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L)
265 # define vlc_array_item_at_index(ar, idx) \
266     _Generic((ar), \
267         const vlc_array_t *: ((ar)->pp_elems[idx]), \
268         vlc_array_t *: ((ar)->pp_elems[idx]))
269 #elif defined (__cplusplus)
270 static inline void *vlc_array_item_at_index( vlc_array_t *ar, size_t idx )
271 {
272     return ar->pp_elems[idx];
273 }
274
275 static inline const void *vlc_array_item_at_index( const vlc_array_t *ar,
276                                                    size_t idx )
277 {
278     return ar->pp_elems[idx];
279 }
280 #endif
281
282 static inline ssize_t vlc_array_index_of_item( const vlc_array_t *ar,
283                                                const void *elem )
284 {
285     for( size_t i = 0; i < ar->i_count; i++ )
286     {
287         if( ar->pp_elems[i] == elem )
288             return i;
289     }
290     return -1;
291 }
292
293 /* Write */
294 static inline void vlc_array_insert( vlc_array_t *ar, void *elem, int idx )
295 {
296     void **pp = (void **)realloc( ar->pp_elems,
297                                   sizeof( void * ) * (ar->i_count + 1) );
298     if( unlikely(pp == NULL) )
299         abort();
300
301     size_t tail = ar->i_count - idx;
302     if( tail > 0 )
303         memmove( pp + idx + 1, pp + idx, sizeof( void * ) * tail );
304
305     pp[idx] = elem;
306     ar->i_count++;
307     ar->pp_elems = pp;
308 }
309
310 static inline void vlc_array_append( vlc_array_t *ar, void *elem )
311 {
312     void **pp = (void **)realloc( ar->pp_elems,
313                                   sizeof( void * ) * (ar->i_count + 1) );
314     if( unlikely(pp == NULL) )
315         abort();
316
317     pp[ar->i_count++] = elem;
318     ar->pp_elems = pp;
319 }
320
321 static inline void vlc_array_remove( vlc_array_t *ar, size_t idx )
322 {
323     void **pp = ar->pp_elems;
324     size_t tail = ar->i_count - idx - 1;
325
326     if( tail > 0 )
327         memmove( pp + idx, pp + idx + 1, sizeof( void * ) * tail );
328
329     ar->i_count--;
330
331     if( ar->i_count > 0 )
332     {
333         pp = (void **)realloc( pp, sizeof( void * ) * ar->i_count );
334         if( likely(pp != NULL) )
335             ar->pp_elems = pp;
336     }
337     else
338     {
339         free( pp );
340         ar->pp_elems = NULL;
341     }
342 }
343
344
345 /************************************************************************
346  * Dictionaries
347  ************************************************************************/
348
349 /* This function is not intended to be crypto-secure, we only want it to be
350  * fast and not suck too much. This one is pretty fast and did 0 collisions
351  * in wenglish's dictionary.
352  */
353 static inline uint64_t DictHash( const char *psz_string, int hashsize )
354 {
355     uint64_t i_hash = 0;
356     if( psz_string )
357     {
358         while( *psz_string )
359         {
360             i_hash += *psz_string++;
361             i_hash += i_hash << 10;
362             i_hash ^= i_hash >> 8;
363         }
364     }
365     return i_hash % hashsize;
366 }
367
368 typedef struct vlc_dictionary_entry_t
369 {
370     char *   psz_key;
371     void *   p_value;
372     struct vlc_dictionary_entry_t * p_next;
373 } vlc_dictionary_entry_t;
374
375 typedef struct vlc_dictionary_t
376 {
377     int i_size;
378     vlc_dictionary_entry_t ** p_entries;
379 } vlc_dictionary_t;
380
381 static void * const kVLCDictionaryNotFound = NULL;
382
383 static inline void vlc_dictionary_init( vlc_dictionary_t * p_dict, int i_size )
384 {
385     p_dict->p_entries = NULL;
386
387     if( i_size > 0 )
388     {
389         p_dict->p_entries = (vlc_dictionary_entry_t **)calloc( i_size, sizeof(*p_dict->p_entries) );
390         if( !p_dict->p_entries )
391             i_size = 0;
392     }
393     p_dict->i_size = i_size;
394 }
395
396 static inline void vlc_dictionary_clear( vlc_dictionary_t * p_dict,
397                                          void ( * pf_free )( void * p_data, void * p_obj ),
398                                          void * p_obj )
399 {
400     if( p_dict->p_entries )
401     {
402         for( int i = 0; i < p_dict->i_size; i++ )
403         {
404             vlc_dictionary_entry_t * p_current, * p_next;
405             p_current = p_dict->p_entries[i];
406             while( p_current )
407             {
408                 p_next = p_current->p_next;
409                 if( pf_free != NULL )
410                     ( * pf_free )( p_current->p_value, p_obj );
411                 free( p_current->psz_key );
412                 free( p_current );
413                 p_current = p_next;
414             }
415         }
416         free( p_dict->p_entries );
417         p_dict->p_entries = NULL;
418     }
419     p_dict->i_size = 0;
420 }
421
422 static inline int
423 vlc_dictionary_has_key( const vlc_dictionary_t * p_dict, const char * psz_key )
424 {
425     if( !p_dict->p_entries )
426         return 0;
427
428     int i_pos = DictHash( psz_key, p_dict->i_size );
429     const vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
430     for( ; p_entry != NULL; p_entry = p_entry->p_next )
431     {
432         if( !strcmp( psz_key, p_entry->psz_key ) )
433             break;
434     }
435     return p_entry != NULL;
436 }
437
438 static inline void *
439 vlc_dictionary_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
440 {
441     if( !p_dict->p_entries )
442         return kVLCDictionaryNotFound;
443
444     int i_pos = DictHash( psz_key, p_dict->i_size );
445     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
446
447     if( !p_entry )
448         return kVLCDictionaryNotFound;
449
450     /* Make sure we return the right item. (Hash collision) */
451     do {
452         if( !strcmp( psz_key, p_entry->psz_key ) )
453             return p_entry->p_value;
454         p_entry = p_entry->p_next;
455     } while( p_entry );
456
457     return kVLCDictionaryNotFound;
458 }
459
460 static inline int
461 vlc_dictionary_keys_count( const vlc_dictionary_t * p_dict )
462 {
463     vlc_dictionary_entry_t * p_entry;
464     int i, count = 0;
465
466     if( !p_dict->p_entries )
467         return 0;
468
469     for( i = 0; i < p_dict->i_size; i++ )
470     {
471         for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next ) count++;
472     }
473     return count;
474 }
475
476 static inline char **
477 vlc_dictionary_all_keys( const vlc_dictionary_t * p_dict )
478 {
479     vlc_dictionary_entry_t * p_entry;
480     char ** ppsz_ret;
481     int i, count = vlc_dictionary_keys_count( p_dict );
482
483     ppsz_ret = (char**)malloc(sizeof(char *) * (count + 1));
484     if( unlikely(!ppsz_ret) )
485         return NULL;
486
487     count = 0;
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 )
491             ppsz_ret[count++] = strdup( p_entry->psz_key );
492     }
493     ppsz_ret[count] = NULL;
494     return ppsz_ret;
495 }
496
497 static inline void
498 vlc_dictionary_insert_impl_( vlc_dictionary_t * p_dict, const char * psz_key,
499                              void * p_value, bool rebuild )
500 {
501     if( !p_dict->p_entries )
502         vlc_dictionary_init( p_dict, 1 );
503
504     int i_pos = DictHash( psz_key, p_dict->i_size );
505     vlc_dictionary_entry_t * p_entry;
506
507     p_entry = (vlc_dictionary_entry_t *)malloc(sizeof(*p_entry));
508     p_entry->psz_key = strdup( psz_key );
509     p_entry->p_value = p_value;
510     p_entry->p_next = p_dict->p_entries[i_pos];
511     p_dict->p_entries[i_pos] = p_entry;
512     if( rebuild )
513     {
514         /* Count how many items there was */
515         int count;
516         for( count = 1; p_entry->p_next; count++ )
517             p_entry = p_entry->p_next;
518         if( count > 3 ) /* XXX: this need tuning */
519         {
520             /* Here it starts to be not good, rebuild a bigger dictionary */
521             struct vlc_dictionary_t new_dict;
522             int i_new_size = ( (p_dict->i_size+2) * 3) / 2; /* XXX: this need tuning */
523             int i;
524             vlc_dictionary_init( &new_dict, i_new_size );
525             for( i = 0; i < p_dict->i_size; i++ )
526             {
527                 p_entry = p_dict->p_entries[i];
528                 while( p_entry )
529                 {
530                     vlc_dictionary_insert_impl_( &new_dict, p_entry->psz_key,
531                                              p_entry->p_value,
532                                              false /* To avoid multiple rebuild loop */);
533                     p_entry = p_entry->p_next;
534                 }
535             }
536
537             vlc_dictionary_clear( p_dict, NULL, NULL );
538             p_dict->i_size = new_dict.i_size;
539             p_dict->p_entries = new_dict.p_entries;
540         }
541     }
542 }
543
544 static inline void
545 vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key, void * p_value )
546 {
547     vlc_dictionary_insert_impl_( p_dict, psz_key, p_value, true );
548 }
549
550 static inline void
551 vlc_dictionary_remove_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key,
552                                      void ( * pf_free )( void * p_data, void * p_obj ),
553                                      void * p_obj )
554 {
555     if( !p_dict->p_entries )
556         return;
557
558     int i_pos = DictHash( psz_key, p_dict->i_size );
559     vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
560     vlc_dictionary_entry_t * p_prev;
561
562     if( !p_entry )
563         return; /* Not found, nothing to do */
564
565     /* Hash collision */
566     p_prev = NULL;
567     do {
568         if( !strcmp( psz_key, p_entry->psz_key ) )
569         {
570             if( pf_free != NULL )
571                 ( * pf_free )( p_entry->p_value, p_obj );
572             if( !p_prev )
573                 p_dict->p_entries[i_pos] = p_entry->p_next;
574             else
575                 p_prev->p_next = p_entry->p_next;
576             free( p_entry->psz_key );
577             free( p_entry );
578             return;
579         }
580         p_prev = p_entry;
581         p_entry = p_entry->p_next;
582     } while( p_entry );
583
584     /* No key was found */
585 }
586
587 #ifdef __cplusplus
588 // C++ helpers
589 template <typename T>
590 void vlc_delete_all( T &container )
591 {
592     typename T::iterator it = container.begin();
593     while ( it != container.end() )
594     {
595         delete *it;
596         ++it;
597     }
598     container.clear();
599 }
600
601 #endif
602
603 #endif