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git.proxmox.com Git - mirror_frr.git/blob - lib/qobj.h
2 * Copyright (c) 2015-16 David Lamparter, for NetDEF, Inc.
4 * Permission to use, copy, modify, and 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.
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.
24 /* reserve a specific amount of bytes for a struct, which can grow up to
25 * that size (or be dummy'd out if not needed)
27 * note the padding's array size will be an error if it gets negative or zero;
28 * this is intentional to prevent the struct from growing beyond the allocated
31 #define RESERVED_SPACE_STRUCT(name, fieldname, size) \
33 struct name fieldname; \
34 char padding ## fieldname[size - sizeof(struct name)]; \
37 /* don't need struct definitions for these here. code actually using
38 * these needs to define the struct *before* including this header.
39 * HAVE_QOBJ_xxx should be defined to +1 in that case, like this:
41 * #if defined(HAVE_QOBJ_NODETYPE_CLI) && HAVE_QOBJ_NODETYPE_CLI < 0
42 * #error include files are in wrong order
44 * #define HAVE_QOBJ_NODETYPE_CLI 1
45 * struct qobj_nodetype_cli { ... }
48 #ifndef HAVE_QOBJ_NODETYPE_CLI
49 #define HAVE_QOBJ_NODETYPE_CLI -1
50 struct qobj_nodetype_cli
{ int dummy
; };
53 #ifndef HAVE_QOBJ_NODETYPE_CAPNP
54 #define HAVE_QOBJ_NODETYPE_CAPNP -1
55 struct qobj_nodetype_capnp
{ int dummy
; };
58 /* each different kind of object will have a global variable of this type,
59 * which can be used by various other pieces to store type-related bits.
60 * type equality can be tested as pointer equality. (cf. QOBJ_GET_TYPESAFE)
62 struct qobj_nodetype
{
63 ptrdiff_t node_member_offset
;
64 RESERVED_SPACE_STRUCT(qobj_nodetype_cli
, cli
, 256)
65 RESERVED_SPACE_STRUCT(qobj_nodetype_capnp
, capnp
, 256)
68 /* anchor to be embedded somewhere in the object's struct */
71 struct qobj_nodetype
*type
;
75 struct qobj_node qobj_node;
77 /* call these at the end of any _create function (QOBJ_REG)
78 * and beginning of any _destroy function (QOBJ_UNREG) */
79 #define QOBJ_REG(n, structname) \
80 qobj_reg(&n->qobj_node, &qobj_t_ ## structname)
81 #define QOBJ_UNREG(n) \
82 qobj_unreg(&n->qobj_node)
84 /* internals - should not be directly used without a good reason*/
85 void qobj_reg(struct qobj_node
*node
, struct qobj_nodetype
*type
);
86 void qobj_unreg(struct qobj_node
*node
);
87 struct qobj_node
*qobj_get(uint64_t id
);
88 void *qobj_get_typed(uint64_t id
, struct qobj_nodetype
*type
);
90 /* type declarations */
91 #define DECLARE_QOBJ_TYPE(structname) \
92 extern struct qobj_nodetype qobj_t_ ## structname;
93 #define DEFINE_QOBJ_TYPE(structname) \
94 struct qobj_nodetype qobj_t_ ## structname = { \
95 .node_member_offset = \
96 (ptrdiff_t)offsetof(struct structname, qobj_node) \
98 #define DEFINE_QOBJ_TYPE_INIT(structname, ...) \
99 struct qobj_nodetype qobj_t_ ## structname = { \
100 .node_member_offset = \
101 (ptrdiff_t)offsetof(struct structname, qobj_node), \
105 /* ID dereference with typecheck.
106 * will return NULL if id not found or wrong type. */
107 #define QOBJ_GET_TYPESAFE(id, structname) \
108 ((struct structname *)qobj_get_typed((id), &qobj_t_ ## structname))
110 #define QOBJ_ID(ptr) \
111 ((ptr)->qobj_node.nid)
113 void qobj_init(void);
114 void qobj_finish(void);