xref: /freebsd/contrib/ntp/sntp/libevent/include/event2/buffer_compat.h (revision e8e8c939350bdf3c228a411caa9660c607c27a11)
1 /*
2  * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  * 3. The name of the author may not be used to endorse or promote products
13  *    derived from this software without specific prior written permission.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #ifndef EVENT2_BUFFER_COMPAT_H_INCLUDED_
28 #define EVENT2_BUFFER_COMPAT_H_INCLUDED_
29 
30 #include <event2/visibility.h>
31 
32 /** @file event2/buffer_compat.h
33 
34 	Obsolete and deprecated versions of the functions in buffer.h: provided
35 	only for backward compatibility.
36  */
37 
38 
39 /**
40    Obsolete alias for evbuffer_readln(buffer, NULL, EOL_STYLE_ANY).
41 
42    @deprecated This function is deprecated because its behavior is not correct
43       for almost any protocol, and also because it's wholly subsumed by
44       evbuffer_readln().
45 
46    @param buffer the evbuffer to read from
47    @return pointer to a single line, or NULL if an error occurred
48 
49 */
50 EVENT2_EXPORT_SYMBOL
51 char *evbuffer_readline(struct evbuffer *buffer);
52 
53 /** Type definition for a callback that is invoked whenever data is added or
54     removed from an evbuffer.
55 
56     An evbuffer may have one or more callbacks set at a time.  The order
57     in which they are executed is undefined.
58 
59     A callback function may add more callbacks, or remove itself from the
60     list of callbacks, or add or remove data from the buffer.  It may not
61     remove another callback from the list.
62 
63     If a callback adds or removes data from the buffer or from another
64     buffer, this can cause a recursive invocation of your callback or
65     other callbacks.  If you ask for an infinite loop, you might just get
66     one: watch out!
67 
68     @param buffer the buffer whose size has changed
69     @param old_len the previous length of the buffer
70     @param new_len the current length of the buffer
71     @param arg a pointer to user data
72 */
73 typedef void (*evbuffer_cb)(struct evbuffer *buffer, size_t old_len, size_t new_len, void *arg);
74 
75 /**
76   Replace all callbacks on an evbuffer with a single new callback, or
77   remove them.
78 
79   Subsequent calls to evbuffer_setcb() replace callbacks set by previous
80   calls.  Setting the callback to NULL removes any previously set callback.
81 
82   @deprecated This function is deprecated because it clears all previous
83      callbacks set on the evbuffer, which can cause confusing behavior if
84      multiple parts of the code all want to add their own callbacks on a
85      buffer.  Instead, use evbuffer_add(), evbuffer_del(), and
86      evbuffer_setflags() to manage your own evbuffer callbacks without
87      interfering with callbacks set by others.
88 
89   @param buffer the evbuffer to be monitored
90   @param cb the callback function to invoke when the evbuffer is modified,
91 	 or NULL to remove all callbacks.
92   @param cbarg an argument to be provided to the callback function
93  */
94 EVENT2_EXPORT_SYMBOL
95 void evbuffer_setcb(struct evbuffer *buffer, evbuffer_cb cb, void *cbarg);
96 
97 
98 /**
99   Find a string within an evbuffer.
100 
101   @param buffer the evbuffer to be searched
102   @param what the string to be searched for
103   @param len the length of the search string
104   @return a pointer to the beginning of the search string, or NULL if the search failed.
105  */
106 EVENT2_EXPORT_SYMBOL
107 unsigned char *evbuffer_find(struct evbuffer *buffer, const unsigned char *what, size_t len);
108 
109 /** deprecated in favor of calling the functions directly */
110 #define EVBUFFER_LENGTH(x)	evbuffer_get_length(x)
111 /** deprecated in favor of calling the functions directly */
112 #define EVBUFFER_DATA(x)	evbuffer_pullup((x), -1)
113 
114 #endif
115 
116