qpb/qpb_allocator.h

   1 /*
   2  * qpb_allocator.h
   3  *
   4  * @copyright Copyright (C) 2016 Sproute Networks, Inc.
   5  *
   6  * @author Avneesh Sachdev <avneesh@sproute.com>
   7  *
   8  * This file is part of Quagga.
   9  *
  10  * Quagga is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU General Public License as published by the
  12  * Free Software Foundation; either version 2, or (at your option) any
  13  * later version.
  14  *
  15  * Quagga is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License along
  21  * with this program; see the file COPYING; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  23  */
  24
  25 /*
  26  * Header file for Quagga/FRR protobuf memory management code.
  27  */
  28
  29 #ifndef _QPB_ALLOCATOR_H_
  30 #define _QPB_ALLOCATOR_H_
  31
  32 #include <google/protobuf-c/protobuf-c.h>
  33
  34 struct linear_allocator_t_;
  35
  36 /*
  37  * Alias for ProtobufCAllocator that is easier on the fingers.
  38  */
  39 typedef ProtobufCAllocator qpb_allocator_t;
  40
  41 /*
  42  * qpb_alloc
  43  */
  44 static inline void *
  45 qpb_alloc (qpb_allocator_t *allocator, size_t size)
  46 {
  47   return allocator->alloc (allocator->allocator_data, size);
  48 }
  49
  50 /*
  51  * qpb_alloc_ptr_array
  52  *
  53  * Allocate space for the specified number of pointers.
  54  */
  55 static inline void *
  56 qpb_alloc_ptr_array (qpb_allocator_t *allocator, size_t num_ptrs)
  57 {
  58   return qpb_alloc (allocator, num_ptrs * sizeof (void *));
  59 }
  60
  61 /*
  62  * qpb_free
  63  */
  64 static inline void
  65 qpb_free (qpb_allocator_t *allocator, void *ptr)
  66 {
  67   allocator->free (allocator->allocator_data, ptr);
  68 }
  69
  70 /*
  71  * QPB_ALLOC
  72  *
  73  * Convenience macro to reduce the probability of allocating memory of
  74  * incorrect size. It returns enough memory to store the given type,
  75  * and evaluates to an appropriately typed pointer.
  76  */
  77 #define QPB_ALLOC(allocator, type)              \
  78   (type *) qpb_alloc(allocator, sizeof(type))
  79
  80
  81 /*
  82  * Externs.
  83  */
  84 extern void qpb_allocator_init_linear (qpb_allocator_t *,
  85                                        struct linear_allocator_t_ *);
  86
  87 /*
  88  * The following macros are for the common case where a qpb allocator
  89  * is being used alongside a linear allocator that allocates memory
  90  * off of the stack.
  91  */
  92 #define QPB_DECLARE_STACK_ALLOCATOR(allocator, size)    \
  93     qpb_allocator_t allocator;                          \
  94     linear_allocator_t lin_ ## allocator;               \
  95     char lin_ ## allocator ## _buf[size]
  96
  97 #define QPB_INIT_STACK_ALLOCATOR(allocator)                             \
  98   do                                                                    \
  99     {                                                                   \
 100       linear_allocator_init(&(lin_ ## allocator),                       \
 101                             lin_ ## allocator ## _buf,                  \
 102                             sizeof(lin_ ## allocator ## _buf));         \
 103       qpb_allocator_init_linear(&allocator, &(lin_ ## allocator));      \
 104     } while (0)
 105
 106 #define QPB_RESET_STACK_ALLOCATOR(allocator)            \
 107   do                                                    \
 108     {                                                   \
 109       linear_allocator_reset (&(lin_ ## allocator));    \
 110     } while (0)
 111
 112 #endif /* _QPB_ALLOCATOR_H_ */