xref: /minix3/external/bsd/libevent/dist/include/event2/tag.h (revision 0a6a1f1d05b60e214de2f05a7310ddd1f0e590e7)
1 /*	$NetBSD: tag.h,v 1.1.1.2 2015/01/29 06:38:26 spz Exp $	*/
2 /*	$NetBSD: tag.h,v 1.1.1.2 2015/01/29 06:38:26 spz Exp $	*/
3 /*
4  * Copyright (c) 2000-2007 Niels Provos <provos@citi.umich.edu>
5  * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 #ifndef _EVENT2_TAG_H_
30 #define _EVENT2_TAG_H_
31 
32 /** @file event2/tag.h
33 
34   Helper functions for reading and writing tagged data onto buffers.
35 
36  */
37 
38 #ifdef __cplusplus
39 extern "C" {
40 #endif
41 
42 #include <event2/event-config.h>
43 #ifdef _EVENT_HAVE_SYS_TYPES_H
44 #include <sys/types.h>
45 #endif
46 #ifdef _EVENT_HAVE_SYS_TIME_H
47 #include <sys/time.h>
48 #endif
49 
50 /* For int types. */
51 #include <event2/util.h>
52 
53 struct evbuffer;
54 
55 /*
56  * Marshaling tagged data - We assume that all tags are inserted in their
57  * numeric order - so that unknown tags will always be higher than the
58  * known ones - and we can just ignore the end of an event buffer.
59  */
60 
61 void evtag_init(void);
62 
63 /**
64    Unmarshals the header and returns the length of the payload
65 
66    @param evbuf the buffer from which to unmarshal data
67    @param ptag a pointer in which the tag id is being stored
68    @returns -1 on failure or the number of bytes in the remaining payload.
69 */
70 int evtag_unmarshal_header(struct evbuffer *evbuf, ev_uint32_t *ptag);
71 
72 void evtag_marshal(struct evbuffer *evbuf, ev_uint32_t tag, const void *data,
73     ev_uint32_t len);
74 void evtag_marshal_buffer(struct evbuffer *evbuf, ev_uint32_t tag,
75     struct evbuffer *data);
76 
77 /**
78   Encode an integer and store it in an evbuffer.
79 
80   We encode integers by nybbles; the first nibble contains the number
81   of significant nibbles - 1;  this allows us to encode up to 64-bit
82   integers.  This function is byte-order independent.
83 
84   @param evbuf evbuffer to store the encoded number
85   @param number a 32-bit integer
86  */
87 void evtag_encode_int(struct evbuffer *evbuf, ev_uint32_t number);
88 void evtag_encode_int64(struct evbuffer *evbuf, ev_uint64_t number);
89 
90 void evtag_marshal_int(struct evbuffer *evbuf, ev_uint32_t tag,
91     ev_uint32_t integer);
92 void evtag_marshal_int64(struct evbuffer *evbuf, ev_uint32_t tag,
93     ev_uint64_t integer);
94 
95 void evtag_marshal_string(struct evbuffer *buf, ev_uint32_t tag,
96     const char *string);
97 
98 void evtag_marshal_timeval(struct evbuffer *evbuf, ev_uint32_t tag,
99     struct timeval *tv);
100 
101 int evtag_unmarshal(struct evbuffer *src, ev_uint32_t *ptag,
102     struct evbuffer *dst);
103 int evtag_peek(struct evbuffer *evbuf, ev_uint32_t *ptag);
104 int evtag_peek_length(struct evbuffer *evbuf, ev_uint32_t *plength);
105 int evtag_payload_length(struct evbuffer *evbuf, ev_uint32_t *plength);
106 int evtag_consume(struct evbuffer *evbuf);
107 
108 int evtag_unmarshal_int(struct evbuffer *evbuf, ev_uint32_t need_tag,
109     ev_uint32_t *pinteger);
110 int evtag_unmarshal_int64(struct evbuffer *evbuf, ev_uint32_t need_tag,
111     ev_uint64_t *pinteger);
112 
113 int evtag_unmarshal_fixed(struct evbuffer *src, ev_uint32_t need_tag,
114     void *data, size_t len);
115 
116 int evtag_unmarshal_string(struct evbuffer *evbuf, ev_uint32_t need_tag,
117     char **pstring);
118 
119 int evtag_unmarshal_timeval(struct evbuffer *evbuf, ev_uint32_t need_tag,
120     struct timeval *ptv);
121 
122 #ifdef __cplusplus
123 }
124 #endif
125 
126 #endif /* _EVENT2_TAG_H_ */
127