/* Copyright (C) 1999 Aladdin Enterprises.  All rights reserved.
  
  This software is provided AS-IS with no warranty, either express or
  implied.
  
  This software is distributed under license and may not be copied,
  modified or distributed except as expressly authorized under the terms
  of the license contained in the file LICENSE in this distribution.
  
  For more information about licensing, please refer to
  http://www.ghostscript.com/licensing/. For information on
  commercial licensing, go to http://www.artifex.com/licensing/ or
  contact Artifex Software, Inc., 101 Lucas Valley Road #110,
  San Rafael, CA  94903, U.S.A., +1(415)492-9861.
*/

/* $Id: gsmemret.h,v 1.5 2002/06/16 08:45:42 lpd Exp $ */
/* Interface to retrying memory allocator */

#if !defined(gsmemret_INCLUDED)
#  define gsmemret_INCLUDED

#include "gsmemory.h"

/*
 * This allocator encapsulates another allocator with a closure that is
 * called to attempt to free up memory if an allocation fails.
 * Note that it does not keep track of memory that it acquires:
 * thus free_all with FREE_ALL_DATA is a no-op.
 */
typedef struct gs_memory_retrying_s gs_memory_retrying_t;

/*
 * Define the procedure type for the recovery closure.
 */
typedef enum {
    RECOVER_STATUS_NO_RETRY,
    RECOVER_STATUS_RETRY_OK
} gs_memory_recover_status_t;
typedef gs_memory_recover_status_t (*gs_memory_recover_proc_t)
     (gs_memory_retrying_t *rmem, void *proc_data);

struct gs_memory_retrying_s {
    gs_memory_common;		/* interface outside world sees */
    gs_memory_t *target;	/* allocator to front */
    gs_memory_recover_proc_t recover_proc;
    void *recover_proc_data;
};

/* ---------- Public constructors/destructors ---------- */

/* Initialize a retrying memory manager. */
int gs_memory_retrying_init(
			    gs_memory_retrying_t * rmem, /* allocator to init */
			    gs_memory_t * target	/* allocator to wrap */
			    );

/* Release a retrying memory manager. */
/* Note that this has no effect on the target. */
void gs_memory_retrying_release(gs_memory_retrying_t *rmem);

/* Set the recovery closure of a retrying memory manager. */
void gs_memory_retrying_set_recover(gs_memory_retrying_t *rmem,
				    gs_memory_recover_proc_t recover_proc,
				    void *recover_proc_data);

/* Get the target of a retrying memory manager. */
gs_memory_t * gs_memory_retrying_target(const gs_memory_retrying_t *rmem);

#endif /*!defined(gsmemret_INCLUDED) */