qpb/qpb_allocator.h

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * qpb_allocator.h
   4  *
   5  * @copyright Copyright (C) 2016 Sproute Networks, Inc.
   6  *
   7  * @author Avneesh Sachdev <avneesh@sproute.com>
   8  */
   9
  10 /*
  11  * Header file for Quagga/FRR protobuf memory management code.
  12  */
  13
  14 #ifndef _QPB_ALLOCATOR_H_
  15 #define _QPB_ALLOCATOR_H_
  16
  17 #include <google/protobuf-c/protobuf-c.h>
  18
  19 struct linear_allocator_t_;
  20
  21 /*
  22  * Alias for ProtobufCAllocator that is easier on the fingers.
  23  */
  24 typedef ProtobufCAllocator qpb_allocator_t;
  25
  26 /*
  27  * qpb_alloc
  28  */
  29 static inline void *qpb_alloc(qpb_allocator_t *allocator, size_t size)
  30 {
  31         return allocator->alloc(allocator->allocator_data, size);
  32 }
  33
  34 /*
  35  * qpb_alloc_ptr_array
  36  *
  37  * Allocate space for the specified number of pointers.
  38  */
  39 static inline void *qpb_alloc_ptr_array(qpb_allocator_t *allocator,
  40                                         size_t num_ptrs)
  41 {
  42         return qpb_alloc(allocator, num_ptrs * sizeof(void *));
  43 }
  44
  45 /*
  46  * qpb_free
  47  */
  48 static inline void qpb_free(qpb_allocator_t *allocator, void *ptr)
  49 {
  50         allocator->free(allocator->allocator_data, ptr);
  51 }
  52
  53 /*
  54  * QPB_ALLOC
  55  *
  56  * Convenience macro to reduce the probability of allocating memory of
  57  * incorrect size. It returns enough memory to store the given type,
  58  * and evaluates to an appropriately typed pointer.
  59  */
  60 #define QPB_ALLOC(allocator, type) (type *)qpb_alloc(allocator, sizeof(type))
  61
  62 /*
  63  * Externs.
  64  */
  65 extern void qpb_allocator_init_linear(qpb_allocator_t *,
  66                                       struct linear_allocator_t_ *);
  67
  68 /*
  69  * The following macros are for the common case where a qpb allocator
  70  * is being used alongside a linear allocator that allocates memory
  71  * off of the stack.
  72  */
  73 #define QPB_DECLARE_STACK_ALLOCATOR(allocator, size)                           \
  74         qpb_allocator_t allocator;                                             \
  75         linear_allocator_t lin_##allocator;                                    \
  76         char lin_##allocator##_buf[size]
  77
  78 #define QPB_INIT_STACK_ALLOCATOR(allocator)                                    \
  79         do {                                                                   \
  80                 linear_allocator_init(&(lin_##allocator),                      \
  81                                       lin_##allocator##_buf,                   \
  82                                       sizeof(lin_##allocator##_buf));          \
  83                 qpb_allocator_init_linear(&allocator, &(lin_##allocator));     \
  84         } while (0)
  85
  86 #define QPB_RESET_STACK_ALLOCATOR(allocator)                                   \
  87         do {                                                                   \
  88                 linear_allocator_reset(&(lin_##allocator));                    \
  89         } while (0)
  90
  91 #endif /* _QPB_ALLOCATOR_H_ */