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vlc_arrays.h
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1 /*****************************************************************************
2  * vlc_arrays.h : Arrays and data structures handling
3  *****************************************************************************
4  * Copyright (C) 1999-2004 VLC authors and VideoLAN
5  * $Id: 7749140f10f5ce76339559b166d041854bb4a7da $
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 
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 
43 #define INSERT_ELEM( p_ar, i_oldsize, i_pos, elem ) \
44  do \
45  { \
46  if( !(i_oldsize) ) (p_ar) = NULL; \
47  (p_ar) = realloc( p_ar, ((i_oldsize) + 1) * sizeof(*(p_ar)) ); \
48  if( !(p_ar) ) abort(); \
49  if( (i_oldsize) - (i_pos) ) \
50  { \
51  memmove( (p_ar) + (i_pos) + 1, (p_ar) + (i_pos), \
52  ((i_oldsize) - (i_pos)) * sizeof( *(p_ar) ) ); \
53  } \
54  (p_ar)[(i_pos)] = elem; \
55  (i_oldsize)++; \
56  } \
57  while( 0 )
58 
59 #define REMOVE_ELEM( p_ar, i_size, i_pos ) \
60  do \
61  { \
62  if( (i_size) - (i_pos) - 1 ) \
63  { \
64  memmove( (p_ar) + (i_pos), \
65  (p_ar) + (i_pos) + 1, \
66  ((i_size) - (i_pos) - 1) * sizeof( *(p_ar) ) ); \
67  } \
68  if( i_size > 1 ) \
69  (p_ar) = realloc_down( p_ar, ((i_size) - 1) * sizeof( *(p_ar) ) );\
70  else \
71  { \
72  free( p_ar ); \
73  (p_ar) = NULL; \
74  } \
75  (i_size)--; \
76  } \
77  while( 0 )
78 
79 #define TAB_INIT( count, tab ) \
80  do { \
81  (count) = 0; \
82  (tab) = NULL; \
83  } while(0)
84 
85 #define TAB_CLEAN( count, tab ) \
86  do { \
87  free( tab ); \
88  (count)= 0; \
89  (tab)= NULL; \
90  } while(0)
91 
92 #define TAB_APPEND_CAST( cast, count, tab, p ) \
93  do { \
94  if( (count) > 0 ) \
95  (tab) = cast realloc( tab, sizeof( void ** ) * ( (count) + 1 ) ); \
96  else \
97  (tab) = cast malloc( sizeof( void ** ) ); \
98  if( !(tab) ) abort(); \
99  (tab)[count] = (p); \
100  (count)++; \
101  } while(0)
102 
103 #define TAB_APPEND( count, tab, p ) \
104  TAB_APPEND_CAST( , count, tab, p )
105 
106 #define TAB_FIND( count, tab, p, 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( void* ) );\
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( void ** ) * ( (count) + 1 ) ); \
140  else \
141  (tab) = cast malloc( sizeof( void ** ) ); \
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 
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
vlc_array_t
Definition: vlc_arrays.h:278
vlc_dictionary_entry_t
Definition: vlc_arrays.h:393
vlc_dictionary_t
Definition: vlc_arrays.h:400