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
  21  * along with Quagga; see the file COPYING.  If not, write to the Free
  22  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  23  * 02111-1307, USA.
  24  */
  25
  26 /*
  27  * Header file for Quagga/FRR protobuf memory management code.
  28  */
  29
  30 #ifndef _QPB_ALLOCATOR_H_
  31 #define _QPB_ALLOCATOR_H_
  32
  33 #include <google/protobuf-c/protobuf-c.h>
  34
  35 struct linear_allocator_t_;
  36
  37 /*
  38  * Alias for ProtobufCAllocator that is easier on the fingers.
  39  */
  40 typedef ProtobufCAllocator qpb_allocator_t;
  41
  42 /*
  43  * qpb_alloc
  44  */
  45 static inline void *
  46 qpb_alloc (qpb_allocator_t *allocator, size_t size)
  47 {
  48   return allocator->alloc (allocator->allocator_data, size);
  49 }
  50
  51 /*
  52  * qpb_alloc_ptr_array
  53  *
  54  * Allocate space for the specified number of pointers.
  55  */
  56 static inline void *
  57 qpb_alloc_ptr_array (qpb_allocator_t *allocator, size_t num_ptrs)
  58 {
  59   return qpb_alloc (allocator, num_ptrs * sizeof (void *));
  60 }
  61
  62 /*
  63  * qpb_free
  64  */
  65 static inline void
  66 qpb_free (qpb_allocator_t *allocator, void *ptr)
  67 {
  68   allocator->free (allocator->allocator_data, ptr);
  69 }
  70
  71 /*
  72  * QPB_ALLOC
  73  *
  74  * Convenience macro to reduce the probability of allocating memory of
  75  * incorrect size. It returns enough memory to store the given type,
  76  * and evaluates to an appropriately typed pointer.
  77  */
  78 #define QPB_ALLOC(allocator, type)              \
  79   (type *) qpb_alloc(allocator, sizeof(type))
  80
  81
  82 /*
  83  * Externs.
  84  */
  85 extern void qpb_allocator_init_linear (qpb_allocator_t *,
  86                                        struct linear_allocator_t_ *);
  87
  88 /*
  89  * The following macros are for the common case where a qpb allocator
  90  * is being used alongside a linear allocator that allocates memory
  91  * off of the stack.
  92  */
  93 #define QPB_DECLARE_STACK_ALLOCATOR(allocator, size)    \
  94     qpb_allocator_t allocator;                          \
  95     linear_allocator_t lin_ ## allocator;               \
  96     char lin_ ## allocator ## _buf[size]
  97
  98 #define QPB_INIT_STACK_ALLOCATOR(allocator)                             \
  99   do                                                                    \
 100     {                                                                   \
 101       linear_allocator_init(&(lin_ ## allocator),                       \
 102                             lin_ ## allocator ## _buf,                  \
 103                             sizeof(lin_ ## allocator ## _buf));         \
 104       qpb_allocator_init_linear(&allocator, &(lin_ ## allocator));      \
 105     } while (0)
 106
 107 #define QPB_RESET_STACK_ALLOCATOR(allocator)            \
 108   do                                                    \
 109     {                                                   \
 110       linear_allocator_reset (&(lin_ ## allocator));    \
 111     } while (0)
 112
 113 #endif /* _QPB_ALLOCATOR_H_ */