xref: /netbsd-src/external/bsd/libevent/dist/include/event2/buffer_compat.h (revision 657871a79c9a2060a6255a242fa1a1ef76b56ec6)
1 /*	$NetBSD: buffer_compat.h,v 1.1.1.4 2021/04/07 02:43:14 christos Exp $	*/
2 /*
3  * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. The name of the author may not be used to endorse or promote products
14  *    derived from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #ifndef EVENT2_BUFFER_COMPAT_H_INCLUDED_
29 #define EVENT2_BUFFER_COMPAT_H_INCLUDED_
30 
31 #include <event2/visibility.h>
32 
33 /** @file event2/buffer_compat.h
34 
35 	Obsolete and deprecated versions of the functions in buffer.h: provided
36 	only for backward compatibility.
37  */
38 
39 
40 /**
41    Obsolete alias for evbuffer_readln(buffer, NULL, EVBUFFER_EOL_ANY).
42 
43    @deprecated This function is deprecated because its behavior is not correct
44       for almost any protocol, and also because it's wholly subsumed by
45       evbuffer_readln().
46 
47    @param buffer the evbuffer to read from
48    @return pointer to a single line, or NULL if an error occurred
49 
50 */
51 EVENT2_EXPORT_SYMBOL
52 char *evbuffer_readline(struct evbuffer *buffer);
53 
54 /** Type definition for a callback that is invoked whenever data is added or
55     removed from an evbuffer.
56 
57     An evbuffer may have one or more callbacks set at a time.  The order
58     in which they are executed is undefined.
59 
60     A callback function may add more callbacks, or remove itself from the
61     list of callbacks, or add or remove data from the buffer.  It may not
62     remove another callback from the list.
63 
64     If a callback adds or removes data from the buffer or from another
65     buffer, this can cause a recursive invocation of your callback or
66     other callbacks.  If you ask for an infinite loop, you might just get
67     one: watch out!
68 
69     @param buffer the buffer whose size has changed
70     @param old_len the previous length of the buffer
71     @param new_len the current length of the buffer
72     @param arg a pointer to user data
73 */
74 typedef void (*evbuffer_cb)(struct evbuffer *buffer, size_t old_len, size_t new_len, void *arg);
75 
76 /**
77   Replace all callbacks on an evbuffer with a single new callback, or
78   remove them.
79 
80   Subsequent calls to evbuffer_setcb() replace callbacks set by previous
81   calls.  Setting the callback to NULL removes any previously set callback.
82 
83   @deprecated This function is deprecated because it clears all previous
84      callbacks set on the evbuffer, which can cause confusing behavior if
85      multiple parts of the code all want to add their own callbacks on a
86      buffer.  Instead, use evbuffer_add(), evbuffer_del(), and
87      evbuffer_setflags() to manage your own evbuffer callbacks without
88      interfering with callbacks set by others.
89 
90   @param buffer the evbuffer to be monitored
91   @param cb the callback function to invoke when the evbuffer is modified,
92 	 or NULL to remove all callbacks.
93   @param cbarg an argument to be provided to the callback function
94   @return 0 if successful, or -1 on error
95  */
96 EVENT2_EXPORT_SYMBOL
97 int evbuffer_setcb(struct evbuffer *buffer, evbuffer_cb cb, void *cbarg);
98 
99 
100 /**
101   Find a string within an evbuffer.
102 
103   @param buffer the evbuffer to be searched
104   @param what the string to be searched for
105   @param len the length of the search string
106   @return a pointer to the beginning of the search string, or NULL if the search failed.
107  */
108 EVENT2_EXPORT_SYMBOL
109 unsigned char *evbuffer_find(struct evbuffer *buffer, const unsigned char *what, size_t len);
110 
111 /** deprecated in favor of calling the functions directly */
112 #define EVBUFFER_LENGTH(x)	evbuffer_get_length(x)
113 /** deprecated in favor of calling the functions directly */
114 #define EVBUFFER_DATA(x)	evbuffer_pullup((x), -1)
115 
116 #endif
117 
118