436fddaa |
1 | /* -*-c-*- |
2 | * |
3 | * $Id: selpk.c,v 1.1 2000/06/17 10:39:19 mdw Exp $ |
4 | * |
5 | * Packet-buffering select handler |
6 | * |
7 | * (c) 1999 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of the mLib utilities library. |
13 | * |
14 | * mLib is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU Library General Public License as |
16 | * published by the Free Software Foundation; either version 2 of the |
17 | * License, or (at your option) any later version. |
18 | * |
19 | * mLib is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
22 | * GNU Library General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU Library General Public |
25 | * License along with mLib; if not, write to the Free |
26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
27 | * MA 02111-1307, USA. |
28 | */ |
29 | |
30 | /*----- Revision history --------------------------------------------------* |
31 | * |
32 | * $Log: selpk.c,v $ |
33 | * Revision 1.1 2000/06/17 10:39:19 mdw |
34 | * Experimental new support for packet buffering. |
35 | * |
36 | */ |
37 | |
38 | /*----- Header files ------------------------------------------------------*/ |
39 | |
40 | #include <errno.h> |
41 | #include <stdio.h> |
42 | #include <stdlib.h> |
43 | #include <string.h> |
44 | |
45 | #include <sys/types.h> |
46 | #include <sys/time.h> |
47 | #include <unistd.h> |
48 | |
49 | #include "pkbuf.h" |
50 | #include "sel.h" |
51 | #include "selpk.h" |
52 | |
53 | /*----- Main code ---------------------------------------------------------*/ |
54 | |
55 | /* --- @selpk_enable@ --- * |
56 | * |
57 | * Arguments: @selpk *pk@ = pointer to buffer block |
58 | * |
59 | * Returns: --- |
60 | * |
61 | * Use: Enables a buffer for reading, and emits any queued packets |
62 | * to the buffer's owner. |
63 | */ |
64 | |
65 | void selpk_enable(selpk *pk) |
66 | { |
67 | if (!(pk->pk.f & PKBUF_ENABLE)) { |
68 | pk->pk.f |= PKBUF_ENABLE; |
69 | sel_addfile(&pk->reader); |
70 | pkbuf_flush(&pk->pk, 0, 0); |
71 | } |
72 | } |
73 | |
74 | /* --- @selpk_disable@ --- * |
75 | * |
76 | * Arguments: @selpk *pk@ = pointer to a buffer block |
77 | * |
78 | * Returns: --- |
79 | * |
80 | * Use: Disables a buffer. It won't be read from until it's |
81 | * enabled again. |
82 | */ |
83 | |
84 | void selpk_disable(selpk *pk) |
85 | { |
86 | if (pk->pk.f & PKBUF_ENABLE) { |
87 | pk->pk.f &= ~PKBUF_ENABLE; |
88 | sel_rmfile(&pk->reader); |
89 | } |
90 | } |
91 | |
92 | /* --- @selpk_read@ --- * |
93 | * |
94 | * Arguments: @int fd@ = file descriptor to read from |
95 | * @int mode@ = what we can do to the file |
96 | * @void *vp@ = pointer to buffer context |
97 | * |
98 | * Returns: --- |
99 | * |
100 | * Use: Acts on the result of a @select@ call. |
101 | */ |
102 | |
103 | static void selpk_read(int fd, unsigned mode, void *vp) |
104 | { |
105 | selpk *pk = vp; |
106 | octet *p; |
107 | size_t sz; |
108 | int n; |
109 | |
110 | sz = pkbuf_free(&pk->pk, &p); |
111 | n = read(fd, p, sz); |
112 | if (n == 0) |
113 | pkbuf_close(&pk->pk); |
114 | else if (n > 0) |
115 | pkbuf_flush(&pk->pk, p, n); |
116 | else switch (errno) { |
117 | case EINTR: |
118 | case EAGAIN: |
119 | #if EAGAIN != EWOULDBLOCK |
120 | case EWOULDBLOCK: |
121 | #endif |
122 | return; |
123 | default: |
124 | pkbuf_close(&pk->pk); |
125 | } |
126 | } |
127 | |
128 | /* --- @selpk_want@ --- * |
129 | * |
130 | * Arguments: @selpk *pk@ = pointer to buffer block |
131 | * @size_t sz@ = size of buffer |
132 | * |
133 | * Returns: --- |
134 | * |
135 | * Use: Sets the size of the packet to be read next. |
136 | */ |
137 | |
138 | void selpk_want(selpk *pk, size_t sz) |
139 | { |
140 | pkbuf_want(&pk->pk, sz); |
141 | } |
142 | |
143 | /* --- @selpk_init@ --- * |
144 | * |
145 | * Arguments: @selpk *pk@ = pointer to buffer block |
146 | * @sel_state *s@ = pointer to select state to attach to |
147 | * @int fd@ = file descriptor to listen to |
148 | * @void (*func)(char *s, void *p)@ = function to call |
149 | * @void *p@ = argument for function |
150 | * |
151 | * Returns: --- |
152 | * |
153 | * Use: Initializes a buffer block. |
154 | */ |
155 | |
156 | void selpk_init(selpk *pk, |
157 | sel_state *s, |
158 | int fd, |
159 | void (*func)(octet */*b*/, size_t /*sz*/, pkbuf */*pk*/, |
160 | size_t */*keep*/, void */*p*/), |
161 | void *p) |
162 | { |
163 | pkbuf_init(&pk->pk, func, p); |
164 | pk->pk.f &= ~PKBUF_ENABLE; |
165 | sel_initfile(s, &pk->reader, fd, SEL_READ, selpk_read, pk); |
166 | selpk_enable(pk); |
167 | } |
168 | |
169 | /* --- @selpk_destroy@ --- * |
170 | * |
171 | * Arguments: @selpk *pk@ = pointer to buffer block |
172 | * |
173 | * Returns: --- |
174 | * |
175 | * Use: Deallocates a packet buffer and frees any resources it owned. |
176 | */ |
177 | |
178 | void selpk_destroy(selpk *pk) |
179 | { |
180 | selpk_disable(pk); |
181 | pkbuf_destroy(&pk->pk); |
182 | } |
183 | |
184 | /*----- That's all, folks -------------------------------------------------*/ |