xref: /netbsd-src/external/bsd/ntp/dist/sntp/libevent/include/event2/buffer_compat.h (revision eabc0478de71e4e011a5b4e0392741e01d491794)
1 /*	$NetBSD: buffer_compat.h,v 1.6 2024/08/18 20:47:22 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #ifndef EVENT2_BUFFER_COMPAT_H_INCLUDED_
30 #define EVENT2_BUFFER_COMPAT_H_INCLUDED_
31 
32 #include <event2/visibility.h>
33 
34 /** @file event2/buffer_compat.h
35 
36 	Obsolete and deprecated versions of the functions in buffer.h: provided
37 	only for backward compatibility.
38  */
39 
40 
41 /**
42    Obsolete alias for evbuffer_readln(buffer, NULL, EVBUFFER_EOL_ANY).
43 
44    @deprecated This function is deprecated because its behavior is not correct
45       for almost any protocol, and also because it's wholly subsumed by
46       evbuffer_readln().
47 
48    @param buffer the evbuffer to read from
49    @return pointer to a single line, or NULL if an error occurred
50 
51 */
52 EVENT2_EXPORT_SYMBOL
53 char *evbuffer_readline(struct evbuffer *buffer);
54 
55 /** Type definition for a callback that is invoked whenever data is added or
56     removed from an evbuffer.
57 
58     An evbuffer may have one or more callbacks set at a time.  The order
59     in which they are executed is undefined.
60 
61     A callback function may add more callbacks, or remove itself from the
62     list of callbacks, or add or remove data from the buffer.  It may not
63     remove another callback from the list.
64 
65     If a callback adds or removes data from the buffer or from another
66     buffer, this can cause a recursive invocation of your callback or
67     other callbacks.  If you ask for an infinite loop, you might just get
68     one: watch out!
69 
70     @param buffer the buffer whose size has changed
71     @param old_len the previous length of the buffer
72     @param new_len the current length of the buffer
73     @param arg a pointer to user data
74 */
75 typedef void (*evbuffer_cb)(struct evbuffer *buffer, size_t old_len, size_t new_len, void *arg);
76 
77 /**
78   Replace all callbacks on an evbuffer with a single new callback, or
79   remove them.
80 
81   Subsequent calls to evbuffer_setcb() replace callbacks set by previous
82   calls.  Setting the callback to NULL removes any previously set callback.
83 
84   @deprecated This function is deprecated because it clears all previous
85      callbacks set on the evbuffer, which can cause confusing behavior if
86      multiple parts of the code all want to add their own callbacks on a
87      buffer.  Instead, use evbuffer_add(), evbuffer_del(), and
88      evbuffer_setflags() to manage your own evbuffer callbacks without
89      interfering with callbacks set by others.
90 
91   @param buffer the evbuffer to be monitored
92   @param cb the callback function to invoke when the evbuffer is modified,
93 	 or NULL to remove all callbacks.
94   @param cbarg an argument to be provided to the callback function
95   @return 0 if successful, or -1 on error
96  */
97 EVENT2_EXPORT_SYMBOL
98 int evbuffer_setcb(struct evbuffer *buffer, evbuffer_cb cb, void *cbarg);
99 
100 
101 /**
102   Find a string within an evbuffer.
103 
104   @param buffer the evbuffer to be searched
105   @param what the string to be searched for
106   @param len the length of the search string
107   @return a pointer to the beginning of the search string, or NULL if the search failed.
108  */
109 EVENT2_EXPORT_SYMBOL
110 unsigned char *evbuffer_find(struct evbuffer *buffer, const unsigned char *what, size_t len);
111 
112 /** deprecated in favor of calling the functions directly */
113 #define EVBUFFER_LENGTH(x)	evbuffer_get_length(x)
114 /** deprecated in favor of calling the functions directly */
115 #define EVBUFFER_DATA(x)	evbuffer_pullup((x), -1)
116 
117 #endif
118 
119