qpb/qpb_allocator.h

/*
 * qpb_allocator.h
 *
 * @copyright Copyright (C) 2016 Sproute Networks, Inc.
 *
 * @author Avneesh Sachdev <avneesh@sproute.com>
 *
 * This file is part of Quagga.
 *
 * Quagga is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * Quagga 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
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Quagga; see the file COPYING.  If not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 */

/*
 * Header file for quagga protobuf memory management code.
 */

#ifndef _QPB_ALLOCATOR_H_
#define _QPB_ALLOCATOR_H_

#include <google/protobuf-c/protobuf-c.h>

struct linear_allocator_t_;

/*
 * Alias for ProtobufCAllocator that is easier on the fingers.
 */
typedef ProtobufCAllocator qpb_allocator_t;

/*
 * qpb_alloc
 */
static inline void *
qpb_alloc (qpb_allocator_t *allocator, size_t size)
{
  return allocator->alloc (allocator->allocator_data, size);
}

/*
 * qpb_alloc_ptr_array
 *
 * Allocate space for the specified number of pointers.
 */
static inline void *
qpb_alloc_ptr_array (qpb_allocator_t *allocator, size_t num_ptrs)
{
  return qpb_alloc (allocator, num_ptrs * sizeof (void *));
}

/*
 * qpb_free
 */
static inline void
qpb_free (qpb_allocator_t *allocator, void *ptr)
{
  allocator->free (allocator->allocator_data, ptr);
}

/*
 * QPB_ALLOC
 *
 * Convenience macro to reduce the probability of allocating memory of
 * incorrect size. It returns enough memory to store the given type,
 * and evaluates to an appropriately typed pointer.
 */
#define QPB_ALLOC(allocator, type)		\
  (type *) qpb_alloc(allocator, sizeof(type))


/*
 * Externs.
 */
extern void qpb_allocator_init_linear (qpb_allocator_t *,
				       struct linear_allocator_t_ *);

/*
 * The following macros are for the common case where a qpb allocator
 * is being used alongside a linear allocator that allocates memory
 * off of the stack.
 */
#define QPB_DECLARE_STACK_ALLOCATOR(allocator, size)	\
    qpb_allocator_t allocator;				\
    linear_allocator_t lin_ ## allocator;		\
    char lin_ ## allocator ## _buf[size]

#define QPB_INIT_STACK_ALLOCATOR(allocator)				\
  do									\
    {									\
      linear_allocator_init(&(lin_ ## allocator),			\
			    lin_ ## allocator ## _buf,			\
			    sizeof(lin_ ## allocator ## _buf));		\
      qpb_allocator_init_linear(&allocator, &(lin_ ## allocator));	\
    } while (0)

#define QPB_RESET_STACK_ALLOCATOR(allocator)		\
  do							\
    {							\
      linear_allocator_reset (&(lin_ ## allocator));	\
    } while (0)

#endif /* _QPB_ALLOCATOR_H_ */