/* GNU Mailutils -- a suite of utilities for electronic mail
   Copyright (C) 2008-2012, 2014-2015 Free Software Foundation, Inc.

   This library 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 3 of the License, or (at your option) any later version.

   This library 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 library.  If not, see 
   <http://www.gnu.org/licenses/>. */

#ifndef _MAILUTILS_OPOOL_H
#define _MAILUTILS_OPOOL_H

#include <mailutils/types.h>

#ifndef MU_OPOOL_BUCKET_SIZE
# define MU_OPOOL_BUCKET_SIZE 1024
#endif

/* Create an object pool.  If MEMERR is not 0, any operation of the
   resulting pool (including mu_opool_create itself) will abort on
   not enough memory condition, using mu_alloc_die. */
int mu_opool_create (mu_opool_t *pret, int memerr);
int mu_opool_set_bucket_size (mu_opool_t opool, size_t size);
int mu_opool_get_bucket_size (mu_opool_t opool, size_t *psize);

/* Merge all data from *SRC into *DST.  If the latter is NULL, create
   it.  On success, free *SRC and initialize it with NULL. */
int mu_opool_union (mu_opool_t *dst, mu_opool_t *src);

/* Clear all data from the pool, so next mu_opool_append* call will
   begin a new object. */
void mu_opool_clear (mu_opool_t opool);

/* Destroy the pool, reclaim any memory associated with it. */
void mu_opool_destroy (mu_opool_t *popool);

/* Allocate SIZE bytes in the pool. */
int mu_opool_alloc (mu_opool_t opool, size_t size);

/* Append to the current object N bytes pointed to by STR. */
int mu_opool_append (mu_opool_t opool, const void *str, size_t n);

/* Append to the current object a nul-terminated string STR. */
int mu_opool_appendz (mu_opool_t opool, const char *str);

/* Append a single byte C to the current object. */
int mu_opool_append_char (mu_opool_t opool, char c);

/* Return size of the current object in the pool. */
size_t mu_opool_size (mu_opool_t opool);

/* Coalesce all data collected so far (by using mu_opool_append* calls)
   into a single contiguous memory chunk.  Return the size of the resulting
   object in *PSIZE, unless PSIZE==NULL.  Return 0 on success, error code on
   failure (unless the pool was created with `memerr' option, see
   mu_opool_create, above). */
int mu_opool_coalesce (mu_opool_t opool, size_t *psize);

/* Copy at most SIZE bytes of collected data into BUF.  Return the
   actual number of bytes copied. */
size_t mu_opool_copy (mu_opool_t opool, void *buf, size_t size);

/* Return the pointer to the current object head chunk.  If mu_opool_coalesce 
   was called before, the returned value points to the entire object.
   If PSIZE is not NULL, store the size of the head chunk to *PSIZE. */     
void *mu_opool_head (mu_opool_t opool, size_t *psize);

/* Finish building the object.  Equivalent to:
   mu_opool_coalesce (opool, NULL);
   p = mu_opool_head (opool, psize);
   mu_opool_clear (opool);
   return p; */
void *mu_opool_finish (mu_opool_t opool, size_t *psize);

int mu_opool_get_iterator (mu_opool_t opool, mu_iterator_t *piterator);

#endif
