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Infrastructure: Split the files into subdirectories.
[mLib] / buf / pkbuf.h
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436fddaa 1/* -*-c-*-
2 *
436fddaa 3 * Simple packet buffering
4 *
5 * (c) 2000 Straylight/Edgeware
6 */
7
d4efbcd9 8/*----- Licensing notice --------------------------------------------------*
436fddaa 9 *
10 * This file is part of the mLib utilities library.
11 *
12 * mLib is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU Library General Public License as
14 * published by the Free Software Foundation; either version 2 of the
15 * License, or (at your option) any later version.
d4efbcd9 16 *
436fddaa 17 * mLib is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU Library General Public License for more details.
d4efbcd9 21 *
436fddaa 22 * You should have received a copy of the GNU Library General Public
23 * License along with mLib; if not, write to the Free
24 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
25 * MA 02111-1307, USA.
26 */
27
436fddaa 28#ifndef MLIB_PKBUF_H
29#define MLIB_PKBUF_H
30
31#ifdef __cplusplus
32 extern "C" {
33#endif
34
35/*----- Header files ------------------------------------------------------*/
36
37#include <stddef.h>
38
39#ifndef MLIB_ARENA_H
40# include "arena.h"
41#endif
42
43#ifndef MLIB_BITS_H
44# include "bits.h"
45#endif
46
47/*----- Data structures ---------------------------------------------------*/
48
0daaeb18 49struct pkbuf;
50
51typedef void pkbuf_func(octet */*b*/, size_t /*sz*/,
52 struct pkbuf */*pk*/, size_t */*keep*/,
53 void */*p*/);
54
436fddaa 55typedef struct pkbuf {
56 size_t sz; /* Size of current buffer */
57 size_t len; /* Length of data in the buffer */
58 size_t want; /* Want this many bytes for packet */
59 unsigned f; /* Various state flags */
0daaeb18 60 pkbuf_func *func; /* Handler function */
436fddaa 61 void *p; /* Argument for handler */
62 arena *a; /* Memory allocation arena */
63 octet *buf; /* Actual buffer space */
64} pkbuf;
65
393cf1d9 66#define PKBUF_ENABLE 1u /* Buffer is currently enabled */
3fd896a4 67#define PKBUF_CLOSE 2u /* Buffer is now closed */
436fddaa 68
69/*----- Functions provided ------------------------------------------------*/
70
71/* --- @pkbuf_flush@ --- *
72 *
73 * Arguments: @pkbuf *pk@ = pointer to buffer block
74 * @octet *p@ = pointer to where to start searching
75 * @size_t len@ = length of new material added
76 *
77 * Returns: ---
78 *
79 * Use: Flushes any complete packets in a packet buffer. New
80 * material is assumed to have been added starting at @p@. If
81 * @p@ is null, then the scan starts at the beginning of the
82 * buffer, and the size of data already in the buffer is used in
83 * place of @len@.
84 *
85 * It is assumed that the buffer is initially enabled. You
86 * shouldn't be contributing data to a disabled buffer anyway.
87 * However, the buffer handler may at some point disable itself,
88 * and @pkbuf_flush@ can cope with this eventuality. Any
89 * pending data is left at the start of the buffer and can be
90 * flushed out by calling @pkbuf_flush(b, 0, 0)@ if the buffer
91 * is ever re-enabled.
92 */
93
94extern void pkbuf_flush(pkbuf */*pk*/, octet */*p*/, size_t /*len*/);
95
96/* --- @pkbuf_close@ --- *
97 *
98 * Arguments: @pkbuf *pk@ = pointer to buffer block
99 *
100 * Returns: ---
101 *
102 * Use: Informs the client that no more data is likely to arrive. If
103 * there is a partial packet in the buffer, it is discarded.
104 */
105
106extern void pkbuf_close(pkbuf */*pk*/);
107
108/* --- @pkbuf_free@ --- *
109 *
110 * Arguments: @pkbuf *pk@ = pointer to buffer block
111 * @octet **p@ = output pointer to free space
112 *
113 * Returns: Free buffer size.
114 *
115 * Use: Returns the free portion of a packet buffer. Data can then
116 * be written to this portion, and split out into packets by
117 * calling @pkbuf_flush@.
118 */
119
120extern size_t pkbuf_free(pkbuf */*pk*/, octet **/*p*/);
121
122/* --- @pkbuf_snarf@ --- *
123 *
124 * Arguments: @pkbuf *pk@ = pointer to buffer block
125 * @const void *p@ = pointer to input data buffer
126 * @size_t sz@ = size of data in input buffer
127 *
128 * Returns: ---
129 *
130 * Use: Snarfs the data from the input buffer and spits it out as
131 * packets. This interface ignores the complexities of dealing
132 * with disablement: you should be using @pkbuf_free@ to
133 * contribute data if you want to cope with that.
134 */
135
136extern void pkbuf_snarf(pkbuf */*pk*/, const void */*p*/, size_t /*sz*/);
137
138/* --- @pkbuf_want@ --- *
139 *
140 * Arguments: @pkbuf *pk@ = pointer to buffer block
141 * @size_t want@ = how many octets wanted for next packet
142 *
143 * Returns: ---
144 *
145 * Use: Sets the desired size for the next packet to be read. If
146 * it's larger than the current buffer, the buffer is extended.
147 */
148
149extern void pkbuf_want(pkbuf */*pk*/, size_t /*want*/);
150
151/* --- @pkbuf_init@ --- *
152 *
153 * Arguments: @pkbuf *pk@ = pointer to buffer block
0daaeb18 154 * @pkbuf_func *func@ = handler function
436fddaa 155 * @void *p@ = argument pointer for @func@
156 *
157 * Returns: ---
158 *
159 * Use: Initializes a packet buffer block. Any packets are passed to
160 * the provided function for handling.
161 */
162
0daaeb18 163extern void pkbuf_init(pkbuf */*pk*/, pkbuf_func */*func*/, void */*p*/);
436fddaa 164
165/* --- @pkbuf_destroy@ --- *
166 *
167 * Arguments: @pkbuf *pk@ = pointer to buffer block
168 *
169 * Returns: ---
170 *
171 * Use: Deallocates a packet buffer and frees any resources it owned.
172 */
173
174extern void pkbuf_destroy(pkbuf */*pk*/);
175
176/*----- That's all, folks -------------------------------------------------*/
177
178#ifdef __cplusplus
179 }
180#endif
181
182#endif