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vlc/include/vlc_arrays.h

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/*****************************************************************************
* vlc_arrays.h : Arrays and data structures handling
*****************************************************************************
* Copyright (C) 1999-2004 VLC authors and VideoLAN
*
* Authors: Samuel Hocevar <sam@zoy.org>
* Clément Stenac <zorglub@videolan.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
*****************************************************************************/
#ifndef VLC_ARRAYS_H_
#define VLC_ARRAYS_H_
#include <vlc_common.h>
/**
* \file
* This file defines functions, structures and macros for handling arrays in vlc
*/
/* realloc() that never fails *if* downsizing */
static inline void *realloc_down( void *ptr, size_t size )
{
void *ret = realloc( ptr, size );
return ret ? ret : ptr;
}
/**
* This wrapper around realloc() will free the input pointer when
* realloc() returns NULL. The use case ptr = realloc(ptr, newsize) will
* cause a memory leak when ptr pointed to a heap allocation before,
* leaving the buffer allocated but unreferenced. vlc_realloc() is a
* drop-in replacement for that use case (and only that use case).
*/
static inline void *realloc_or_free( void *p, size_t sz )
{
void *n = realloc(p,sz);
if( !n )
free(p);
return n;
}
#define TAB_INIT( count, tab ) \
do { \
(count) = 0; \
(tab) = NULL; \
} while(0)
#define TAB_CLEAN( count, tab ) \
do { \
free( tab ); \
(count)= 0; \
(tab)= NULL; \
} while(0)
#define TAB_APPEND_CAST( cast, count, tab, p ) \
do { \
if( (count) > 0 ) \
(tab) = cast realloc( tab, sizeof( *(tab) ) * ( (count) + 1 ) ); \
else \
(tab) = cast malloc( sizeof( *(tab) ) ); \
if( !(tab) ) abort(); \
(tab)[count] = (p); \
(count)++; \
} while(0)
#define TAB_APPEND( count, tab, p ) \
TAB_APPEND_CAST( , count, tab, p )
#define TAB_FIND( count, tab, p, idx ) \
do { \
for( (idx) = 0; (idx) < (count); (idx)++ ) \
if( (tab)[(idx)] == (p) ) \
break; \
if( (idx) >= (count) ) \
(idx) = -1; \
} while(0)
#define TAB_ERASE( count, tab, index ) \
do { \
if( (count) > 1 ) \
memmove( (tab) + (index), \
(tab) + (index) + 1, \
((count) - (index) - 1 ) * sizeof( *(tab) ) );\
(count)--; \
if( (count) == 0 ) \
{ \
free( tab ); \
(tab) = NULL; \
} \
} while(0)
#define TAB_REMOVE( count, tab, p ) \
do { \
int i_index; \
TAB_FIND( count, tab, p, i_index ); \
if( i_index >= 0 ) \
TAB_ERASE( count, tab, i_index ); \
} while(0)
#define TAB_INSERT_CAST( cast, count, tab, p, index ) do { \
if( (count) > 0 ) \
(tab) = cast realloc( tab, sizeof( *(tab) ) * ( (count) + 1 ) ); \
else \
(tab) = cast malloc( sizeof( *(tab) ) ); \
if( !(tab) ) abort(); \
if( (count) - (index) > 0 ) \
memmove( (tab) + (index) + 1, \
(tab) + (index), \
((count) - (index)) * sizeof( *(tab) ) );\
(tab)[(index)] = (p); \
(count)++; \
} while(0)
#define TAB_INSERT( count, tab, p, index ) \
TAB_INSERT_CAST( , count, tab, p, index )
/**
* Binary search in a sorted array. The key must be comparable by < and >
* \param entries array of entries
* \param count number of entries
* \param elem key to check within an entry (like .id, or ->i_id)
* \param zetype type of the key
* \param key value of the key
* \param answer index of answer within the array. -1 if not found
*/
#define BSEARCH( entries, count, elem, zetype, key, answer ) \
do { \
int low = 0, high = count - 1; \
answer = -1; \
while( low <= high ) {\
int mid = ((unsigned int)low + (unsigned int)high) >> 1;\
zetype mid_val = entries[mid] elem;\
if( mid_val < key ) \
low = mid + 1; \
else if ( mid_val > key ) \
high = mid -1; \
else \
{ \
answer = mid; break; \
}\
} \
} while(0)
/************************************************************************
* Dynamic arrays with progressive allocation
************************************************************************/
/* Internal functions */
#define _ARRAY_ALLOC(array, newsize) { \
(array).i_alloc = newsize; \
(array).p_elems = vlc_reallocarray( (array).p_elems, (array).i_alloc, \
sizeof(*(array).p_elems) ); \
if( !(array).p_elems ) abort(); \
}
#define _ARRAY_GROW1(array) { \
if( (array).i_alloc < 10 ) \
_ARRAY_ALLOC(array, 10 ) \
else if( (array).i_alloc == (array).i_size ) \
_ARRAY_ALLOC(array, (int)((array).i_alloc * 1.5) ) \
}
/* API */
#define DECL_ARRAY(type) struct { \
int i_alloc; \
int i_size; \
type *p_elems; \
}
#define TYPEDEF_ARRAY(type, name) typedef DECL_ARRAY(type) name;
#define ARRAY_INIT(array) \
do { \
(array).i_alloc = 0; \
(array).i_size = 0; \
(array).p_elems = NULL; \
} while(0)
#define ARRAY_RESET(array) \
do { \
(array).i_alloc = 0; \
(array).i_size = 0; \
free( (array).p_elems ); (array).p_elems = NULL; \
} while(0)
#define ARRAY_APPEND(array, elem) \
do { \
_ARRAY_GROW1(array); \
(array).p_elems[(array).i_size] = elem; \
(array).i_size++; \
} while(0)
#define ARRAY_INSERT(array,elem,pos) \
do { \
_ARRAY_GROW1(array); \
if( (array).i_size - (pos) ) { \
memmove( (array).p_elems + (pos) + 1, (array).p_elems + (pos), \
((array).i_size-(pos)) * sizeof(*(array).p_elems) ); \
} \
(array).p_elems[pos] = elem; \
(array).i_size++; \
} while(0)
#define _ARRAY_SHRINK(array) { \
if( (array).i_size > 10 && (array).i_size < (int)((array).i_alloc / 1.5) ) { \
_ARRAY_ALLOC(array, (array).i_size + 5); \
} \
}
#define ARRAY_FIND(array, p, idx) \
TAB_FIND((array).i_size, (array).p_elems, p, idx)
#define ARRAY_REMOVE(array,pos) \
do { \
if( (array).i_size - (pos) - 1 ) \
{ \
memmove( (array).p_elems + (pos), (array).p_elems + (pos) + 1, \
( (array).i_size - (pos) - 1 ) *sizeof(*(array).p_elems) );\
} \
(array).i_size--; \
_ARRAY_SHRINK(array); \
} while(0)
#define ARRAY_VAL(array, pos) array.p_elems[pos]
#define ARRAY_BSEARCH(array, elem, zetype, key, answer) \
BSEARCH( (array).p_elems, (array).i_size, elem, zetype, key, answer)
/* append ##item to index variable name to avoid variable shadowing warnings for
* nested loops */
#define ARRAY_FOREACH(item, array) \
for (int array_index_##item = 0; \
array_index_##item < (array).i_size && \
((item) = (array).p_elems[array_index_##item], 1); \
++array_index_##item)
/************************************************************************
* Dynamic arrays with progressive allocation (Preferred API)
************************************************************************/
typedef struct vlc_array_t
{
size_t i_count;
void ** pp_elems;
} vlc_array_t;
static inline void vlc_array_init( vlc_array_t * p_array )
{
p_array->i_count = 0;
p_array->pp_elems = NULL;
}
static inline void vlc_array_clear( vlc_array_t * p_array )
{
free( p_array->pp_elems );
vlc_array_init( p_array );
}
/* Read */
static inline size_t vlc_array_count( const vlc_array_t * p_array )
{
return p_array->i_count;
}
#ifndef __cplusplus
# define vlc_array_item_at_index(ar, idx) \
_Generic((ar), \
const vlc_array_t *: ((ar)->pp_elems[idx]), \
vlc_array_t *: ((ar)->pp_elems[idx]))
#else
static inline void *vlc_array_item_at_index( vlc_array_t *ar, size_t idx )
{
return ar->pp_elems[idx];
}
static inline const void *vlc_array_item_at_index( const vlc_array_t *ar,
size_t idx )
{
return ar->pp_elems[idx];
}
#endif
static inline ssize_t vlc_array_index_of_item( const vlc_array_t *ar,
const void *elem )
{
for( size_t i = 0; i < ar->i_count; i++ )
{
if( ar->pp_elems[i] == elem )
return i;
}
return -1;
}
/* Write */
static inline int vlc_array_insert( vlc_array_t *ar, void *elem, int idx )
{
void **pp = (void **)realloc( ar->pp_elems,
sizeof( void * ) * (ar->i_count + 1) );
if( unlikely(pp == NULL) )
return -1;
size_t tail = ar->i_count - idx;
if( tail > 0 )
memmove( pp + idx + 1, pp + idx, sizeof( void * ) * tail );
pp[idx] = elem;
ar->i_count++;
ar->pp_elems = pp;
return 0;
}
static inline void vlc_array_insert_or_abort( vlc_array_t *ar, void *elem, int idx )
{
if( vlc_array_insert( ar, elem, idx ) )
abort();
}
static inline int vlc_array_append( vlc_array_t *ar, void *elem )
{
void **pp = (void **)realloc( ar->pp_elems,
sizeof( void * ) * (ar->i_count + 1) );
if( unlikely(pp == NULL) )
return -1;
pp[ar->i_count++] = elem;
ar->pp_elems = pp;
return 0;
}
static inline void vlc_array_append_or_abort( vlc_array_t *ar, void *elem )
{
if( vlc_array_append( ar, elem ) != 0 )
abort();
}
static inline void vlc_array_remove( vlc_array_t *ar, size_t idx )
{
void **pp = ar->pp_elems;
size_t tail = ar->i_count - idx - 1;
if( tail > 0 )
memmove( pp + idx, pp + idx + 1, sizeof( void * ) * tail );
ar->i_count--;
if( ar->i_count > 0 )
{
pp = (void **)realloc( pp, sizeof( void * ) * ar->i_count );
if( likely(pp != NULL) )
ar->pp_elems = pp;
}
else
{
free( pp );
ar->pp_elems = NULL;
}
}
/************************************************************************
* Dictionaries
************************************************************************/
/* This function is not intended to be crypto-secure, we only want it to be
* fast and not suck too much. This one is pretty fast and did 0 collisions
* in wenglish's dictionary.
*/
static inline uint64_t DictHash( const char *psz_string, int hashsize )
{
uint64_t i_hash = 0;
if( psz_string )
{
while( *psz_string )
{
i_hash += *psz_string++;
i_hash += i_hash << 10;
i_hash ^= i_hash >> 8;
}
}
return i_hash % hashsize;
}
typedef struct vlc_dictionary_entry_t
{
char * psz_key;
void * p_value;
struct vlc_dictionary_entry_t * p_next;
} vlc_dictionary_entry_t;
typedef struct vlc_dictionary_t
{
int i_size;
vlc_dictionary_entry_t ** p_entries;
} vlc_dictionary_t;
static void * const kVLCDictionaryNotFound = NULL;
static inline void vlc_dictionary_init( vlc_dictionary_t * p_dict, int i_size )
{
p_dict->p_entries = NULL;
if( i_size > 0 )
{
p_dict->p_entries = (vlc_dictionary_entry_t **)calloc( i_size, sizeof(*p_dict->p_entries) );
if( !p_dict->p_entries )
i_size = 0;
}
p_dict->i_size = i_size;
}
static inline void vlc_dictionary_clear( vlc_dictionary_t * p_dict,
void ( * pf_free )( void * p_data, void * p_obj ),
void * p_obj )
{
if( p_dict->p_entries )
{
for( int i = 0; i < p_dict->i_size; i++ )
{
vlc_dictionary_entry_t * p_current, * p_next;
p_current = p_dict->p_entries[i];
while( p_current )
{
p_next = p_current->p_next;
if( pf_free != NULL )
( * pf_free )( p_current->p_value, p_obj );
free( p_current->psz_key );
free( p_current );
p_current = p_next;
}
}
free( p_dict->p_entries );
p_dict->p_entries = NULL;
}
p_dict->i_size = 0;
}
static inline int
vlc_dictionary_has_key( const vlc_dictionary_t * p_dict, const char * psz_key )
{
if( !p_dict->p_entries )
return 0;
int i_pos = DictHash( psz_key, p_dict->i_size );
const vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
for( ; p_entry != NULL; p_entry = p_entry->p_next )
{
if( !strcmp( psz_key, p_entry->psz_key ) )
break;
}
return p_entry != NULL;
}
static inline void *
vlc_dictionary_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key )
{
if( !p_dict->p_entries )
return kVLCDictionaryNotFound;
int i_pos = DictHash( psz_key, p_dict->i_size );
vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
if( !p_entry )
return kVLCDictionaryNotFound;
/* Make sure we return the right item. (Hash collision) */
do {
if( !strcmp( psz_key, p_entry->psz_key ) )
return p_entry->p_value;
p_entry = p_entry->p_next;
} while( p_entry );
return kVLCDictionaryNotFound;
}
static inline int
vlc_dictionary_keys_count( const vlc_dictionary_t * p_dict )
{
vlc_dictionary_entry_t * p_entry;
int i, count = 0;
if( !p_dict->p_entries )
return 0;
for( i = 0; i < p_dict->i_size; i++ )
{
for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next ) count++;
}
return count;
}
static inline bool
vlc_dictionary_is_empty( const vlc_dictionary_t * p_dict )
{
if( p_dict->p_entries )
for( int i = 0; i < p_dict->i_size; i++ )
if( p_dict->p_entries[i] )
return false;
return true;
}
static inline char **
vlc_dictionary_all_keys( const vlc_dictionary_t * p_dict )
{
vlc_dictionary_entry_t * p_entry;
char ** ppsz_ret;
int i, count = vlc_dictionary_keys_count( p_dict );
ppsz_ret = (char**)malloc(sizeof(char *) * (count + 1));
if( unlikely(!ppsz_ret) )
return NULL;
count = 0;
for( i = 0; i < p_dict->i_size; i++ )
{
for( p_entry = p_dict->p_entries[i]; p_entry; p_entry = p_entry->p_next )
ppsz_ret[count++] = strdup( p_entry->psz_key );
}
ppsz_ret[count] = NULL;
return ppsz_ret;
}
static inline void
vlc_dictionary_insert_impl_( vlc_dictionary_t * p_dict, const char * psz_key,
void * p_value, bool rebuild )
{
if( !p_dict->p_entries )
vlc_dictionary_init( p_dict, 1 );
int i_pos = DictHash( psz_key, p_dict->i_size );
vlc_dictionary_entry_t * p_entry;
p_entry = (vlc_dictionary_entry_t *)malloc(sizeof(*p_entry));
p_entry->psz_key = strdup( psz_key );
p_entry->p_value = p_value;
p_entry->p_next = p_dict->p_entries[i_pos];
p_dict->p_entries[i_pos] = p_entry;
if( rebuild )
{
/* Count how many items there was */
int count;
for( count = 1; p_entry->p_next; count++ )
p_entry = p_entry->p_next;
if( count > 3 ) /* XXX: this need tuning */
{
/* Here it starts to be not good, rebuild a bigger dictionary */
struct vlc_dictionary_t new_dict;
int i_new_size = ( (p_dict->i_size+2) * 3) / 2; /* XXX: this need tuning */
int i;
vlc_dictionary_init( &new_dict, i_new_size );
for( i = 0; i < p_dict->i_size; i++ )
{
p_entry = p_dict->p_entries[i];
while( p_entry )
{
vlc_dictionary_insert_impl_( &new_dict, p_entry->psz_key,
p_entry->p_value,
false /* To avoid multiple rebuild loop */);
p_entry = p_entry->p_next;
}
}
vlc_dictionary_clear( p_dict, NULL, NULL );
p_dict->i_size = new_dict.i_size;
p_dict->p_entries = new_dict.p_entries;
}
}
}
static inline void
vlc_dictionary_insert( vlc_dictionary_t * p_dict, const char * psz_key, void * p_value )
{
vlc_dictionary_insert_impl_( p_dict, psz_key, p_value, true );
}
static inline void
vlc_dictionary_remove_value_for_key( const vlc_dictionary_t * p_dict, const char * psz_key,
void ( * pf_free )( void * p_data, void * p_obj ),
void * p_obj )
{
if( !p_dict->p_entries )
return;
int i_pos = DictHash( psz_key, p_dict->i_size );
vlc_dictionary_entry_t * p_entry = p_dict->p_entries[i_pos];
vlc_dictionary_entry_t * p_prev;
if( !p_entry )
return; /* Not found, nothing to do */
/* Hash collision */
p_prev = NULL;
do {
if( !strcmp( psz_key, p_entry->psz_key ) )
{
if( pf_free != NULL )
( * pf_free )( p_entry->p_value, p_obj );
if( !p_prev )
p_dict->p_entries[i_pos] = p_entry->p_next;
else
p_prev->p_next = p_entry->p_next;
free( p_entry->psz_key );
free( p_entry );
return;
}
p_prev = p_entry;
p_entry = p_entry->p_next;
} while( p_entry );
/* No key was found */
}
#ifdef __cplusplus
// C++ helpers
template <typename T>
void vlc_delete_all( T &container )
{
typename T::iterator it = container.begin();
while ( it != container.end() )
{
delete *it;
++it;
}
container.clear();
}
#endif
#endif
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