src/marshal.h

   1 /*
   2  * Copyright (c) 2012 Vincent Bernat <bernat@luffy.cx>
   3  *
   4  * Permission to use, copy, modify, and/or distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #ifndef _MARSHAL_H
  18 #define _MARSHAL_H
  19
  20 struct marshal_info;
  21 enum marshal_subinfo_kind {
  22         pointer,
  23         substruct,
  24         string,
  25 };
  26 #define MARSHAL_INFO_POINTER 1
  27 #define MARSHAL_INFO_SUB     2
  28 struct marshal_subinfo {
  29         size_t offset;       /* Offset compared to parent structure */
  30         enum marshal_subinfo_kind kind; /* Kind of substructure */
  31         struct  marshal_info *mi;
  32 };
  33 struct marshal_info {
  34         char   *name;           /* Name of structure */
  35         size_t  size;           /* Size of the structure */
  36         struct marshal_subinfo pointers[]; /* Pointer to other structures */
  37 };
  38 /* Special case for strings */
  39 extern struct marshal_info marshal_info__string;
  40
  41 /* Declare a new marshal_info struct named after the type we want to
  42    marshal. The marshalled type has to be a structure. */
  43 #define MARSHAL_BEGIN(type) struct marshal_info marshal_info_##type = \
  44         {                                                               \
  45                 .name = #type,                                          \
  46                 .size = sizeof(struct type),                            \
  47                 .pointers = {
  48 #define MARSHAL_ADD(_kind, type, subtype, member)       \
  49         { .offset = offsetof(struct type, member),      \
  50           .kind = _kind,                                \
  51           .mi = &marshal_info_##subtype },
  52 #define MARSHAL_POINTER(...) MARSHAL_ADD(pointer, ##__VA_ARGS__)
  53 #define MARSHAL_SUBSTRUCT(...) MARSHAL_ADD(substruct, ##__VA_ARGS__)
  54 #define MARSHAL_STR(type, member) MARSHAL_ADD(pointer, type, _string, member)
  55 #define MARSHAL_TQE(type, field)                         \
  56         MARSHAL_POINTER(type, type, field.tqe_next)      \
  57         MARSHAL_POINTER(type, type, field.tqe_prev)
  58 #define MARSHAL_TQH(type, subtype)                       \
  59         MARSHAL_POINTER(type, subtype, tqh_first)        \
  60         MARSHAL_POINTER(type, subtype, tqh_last)
  61 #define MARSHAL_SUBTQ(type, subtype, field)              \
  62         MARSHAL_POINTER(type, subtype, field.tqh_first)  \
  63         MARSHAL_POINTER(type, subtype, field.tqh_last)
  64 #define MARSHAL_END { .mi = NULL } } }
  65 /* Shortcuts */
  66 #define MARSHAL(type)                   \
  67         MARSHAL_BEGIN(type)             \
  68         MARSHAL_END
  69 #define MARSHAL_TQ(type, subtype)       \
  70         MARSHAL_BEGIN(type)             \
  71         MARSHAL_TQH(type, subtype)      \
  72         MARSHAL_END
  73
  74 /* Serialization */
  75 size_t  _marshal_serialize(struct marshal_info *, void *, void **, int, void *);
  76 #define marshal_serialize(type, o, output) _marshal_serialize(&marshal_info_##type, o, output, 0, NULL)
  77
  78 /* Unserialization */
  79 size_t  _marshal_unserialize(struct marshal_info *, void *, size_t, void **, void*, int);
  80 #define marshal_unserialize(type, o, l, input) \
  81         _marshal_unserialize(&marshal_info_##type, o, l, (void **)input, NULL, 0)
  82
  83 #endif