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#ifndef fooidxsethfoo
#define fooidxsethfoo

/* $Id$ */

/***
  This file is part of polypaudio.
 
  polypaudio 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.
 
  polypaudio 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 polypaudio; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  USA.
***/

#include <inttypes.h>

/* A combination of a set and a dynamic array. Entries are indexable
 * both through a numeric automatically generated index and the entry's
 * data pointer. As usual, memory management is the user's job. */

/* A special index value denoting the invalid index. */
#define PA_IDXSET_INVALID ((uint32_t) -1)

/* Generic implementations for hash and comparison functions. Just
 * compares the pointer or calculates the hash value directly from the
 * pointer value. */
unsigned pa_idxset_trivial_hash_func(const void *p);
int pa_idxset_trivial_compare_func(const void *a, const void *b);

/* Generic implementations for hash and comparison functions for strings. */
unsigned pa_idxset_string_hash_func(const void *p);
int pa_idxset_string_compare_func(const void *a, const void *b);

struct pa_idxset;

/* Instantiate a new idxset with the specified hash and comparison functions */
struct pa_idxset* pa_idxset_new(unsigned (*hash_func) (const void *p), int (*compare_func) (const void*a, const void*b));

/* Free the idxset. When the idxset is not empty the specified function is called for every entry contained */
void pa_idxset_free(struct pa_idxset *s, void (*free_func) (void *p, void *userdata), void *userdata);

/* Store a new item in the idxset. The index of the item is returned in *index */
int pa_idxset_put(struct pa_idxset*s, void *p, uint32_t *index);

/* Get the entry by its index */
void* pa_idxset_get_by_index(struct pa_idxset*s, uint32_t index);

/* Get the entry by its data. The index is returned in *index */
void* pa_idxset_get_by_data(struct pa_idxset*s, const void *p, uint32_t *index);

/* Similar to pa_idxset_get_by_index(), but removes the entry from the idxset. */
void* pa_idxset_remove_by_index(struct pa_idxset*s, uint32_t index);

/* Similar to pa_idxset_get_by_data(), but removes the entry from the idxset */
void* pa_idxset_remove_by_data(struct pa_idxset*s, const void *p, uint32_t *index);

/* This may be used to iterate through all entries. When called with
   an invalid index value it returns the first entry, otherwise the
   next following. The function is best called with *index =
   PA_IDXSET_VALID first. It is safe to manipulate the idxset between
   the calls. It is not guaranteed that all entries have already been
   returned before the an entry is returned the second time.*/
void* pa_idxset_rrobin(struct pa_idxset *s, uint32_t *index);

/* Return the oldest entry in the idxset. Fill in its index in *index. */
void* pa_idxset_first(struct pa_idxset *s, uint32_t *index);

/* Return the entry following the entry indexed by *index.  After the
 * call *index contains the index of the returned
 * object. pa_idxset_first() and pa_idxset_next() may be used to
 * iterate through the set.*/
void *pa_idxset_next(struct pa_idxset *s, uint32_t *index);

/* Call a function for every item in the set. If the callback function
   returns -1, the loop is terminated. If *del is set to non-zero that
   specific item is removed. It is not safe to call any other
   functions on the idxset while pa_idxset_foreach is executed. */
int pa_idxset_foreach(struct pa_idxset*s, int (*func)(void *p, uint32_t index, int *del, void*userdata), void *userdata);

unsigned pa_idxset_ncontents(struct pa_idxset*s);
int pa_idxset_isempty(struct pa_idxset *s);

#endif