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 *qpb_alloc(qpb_allocator_t *allocator, size_t size)
  45 {
  46         return allocator->alloc(allocator->allocator_data, size);
  47 }
  48
  49 /*
  50  * qpb_alloc_ptr_array
  51  *
  52  * Allocate space for the specified number of pointers.
  53  */
  54 static inline void *qpb_alloc_ptr_array(qpb_allocator_t *allocator,
  55                                         size_t num_ptrs)
  56 {
  57         return qpb_alloc(allocator, num_ptrs * sizeof(void *));
  58 }
  59
  60 /*
  61  * qpb_free
  62  */
  63 static inline void qpb_free(qpb_allocator_t *allocator, void *ptr)
  64 {
  65         allocator->free(allocator->allocator_data, ptr);
  66 }
  67
  68 /*
  69  * QPB_ALLOC
  70  *
  71  * Convenience macro to reduce the probability of allocating memory of
  72  * incorrect size. It returns enough memory to store the given type,
  73  * and evaluates to an appropriately typed pointer.
  74  */
  75 #define QPB_ALLOC(allocator, type) (type *)qpb_alloc(allocator, sizeof(type))
  76
  77
  78 /*
  79  * Externs.
  80  */
  81 extern void qpb_allocator_init_linear(qpb_allocator_t *,
  82                                       struct linear_allocator_t_ *);
  83
  84 /*
  85  * The following macros are for the common case where a qpb allocator
  86  * is being used alongside a linear allocator that allocates memory
  87  * off of the stack.
  88  */
  89 #define QPB_DECLARE_STACK_ALLOCATOR(allocator, size)                           \
  90         qpb_allocator_t allocator;                                             \
  91         linear_allocator_t lin_##allocator;                                    \
  92         char lin_##allocator##_buf[size]
  93
  94 #define QPB_INIT_STACK_ALLOCATOR(allocator)                                    \
  95         do {                                                                   \
  96                 linear_allocator_init(&(lin_##allocator),                      \
  97                                       lin_##allocator##_buf,                   \
  98                                       sizeof(lin_##allocator##_buf));          \
  99                 qpb_allocator_init_linear(&allocator, &(lin_##allocator));     \
 100         } while (0)
 101
 102 #define QPB_RESET_STACK_ALLOCATOR(allocator)                                   \
 103         do {                                                                   \
 104                 linear_allocator_reset(&(lin_##allocator));                    \
 105         } while (0)
 106
 107 #endif /* _QPB_ALLOCATOR_H_ */