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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: selbuf.c,v 1.2 1999/05/17 20:36:50 mdw Exp $ |
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4 | * |
5 | * Line-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: selbuf.c,v $ |
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33 | * Revision 1.2 1999/05/17 20:36:50 mdw |
34 | * Make the magical constants for the buffer flags uppercase. |
35 | * |
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36 | * Revision 1.1 1999/05/14 21:01:15 mdw |
37 | * Integrated `select' handling bits from the background resolver project. |
38 | * |
39 | */ |
40 | |
41 | /*----- Header files ------------------------------------------------------*/ |
42 | |
43 | #include <errno.h> |
44 | #include <stdio.h> |
45 | #include <stdlib.h> |
46 | #include <string.h> |
47 | |
48 | #include <sys/types.h> |
49 | #include <sys/time.h> |
50 | #include <unistd.h> |
51 | |
52 | #include "lbuf.h" |
53 | #include "sel.h" |
54 | #include "selbuf.h" |
55 | |
56 | /*----- Main code ---------------------------------------------------------*/ |
57 | |
58 | /* --- @selbuf_enable@ --- * |
59 | * |
60 | * Arguments: @selbuf *b@ = pointer to buffer block |
61 | * |
62 | * Returns: --- |
63 | * |
64 | * Use: Enables a buffer for reading, and emits any queued lines |
65 | * to the buffer's owner. |
66 | */ |
67 | |
68 | void selbuf_enable(selbuf *b) |
69 | { |
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70 | if (!(b->b.f & LBUF_ENABLE)) { |
71 | b->b.f |= LBUF_ENABLE; |
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72 | sel_addfile(&b->reader); |
73 | lbuf_flush(&b->b, 0, 0); |
74 | } |
75 | } |
76 | |
77 | /* --- @selbuf_disable@ --- * |
78 | * |
79 | * Arguments: @selbuf *b@ = pointer to a buffer block |
80 | * |
81 | * Returns: --- |
82 | * |
83 | * Use: Disables a buffer. It won't be read from until it's |
84 | * enabled again. |
85 | */ |
86 | |
87 | void selbuf_disable(selbuf *b) |
88 | { |
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89 | if (b->b.f & LBUF_ENABLE) { |
90 | b->b.f &= ~LBUF_ENABLE; |
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91 | sel_rmfile(&b->reader); |
92 | } |
93 | } |
94 | |
95 | /* --- @selbuf_read@ --- * |
96 | * |
97 | * Arguments: @int fd@ = file descriptor to read from |
98 | * @int mode@ = what we can do to the file |
99 | * @void *vp@ = pointer to buffer context |
100 | * |
101 | * Returns: --- |
102 | * |
103 | * Use: Acts on the result of a @select@ call. |
104 | */ |
105 | |
106 | static void selbuf_read(int fd, unsigned mode, void *vp) |
107 | { |
108 | selbuf *b = vp; |
109 | char *p; |
110 | size_t sz; |
111 | int n; |
112 | |
113 | sz = lbuf_free(&b->b, &p); |
114 | again: |
115 | n = read(fd, p, sz); |
116 | if (n <= 0) { |
117 | switch (errno) { |
118 | case EINTR: |
119 | goto again; |
120 | case EAGAIN: |
121 | #if EAGAIN != EWOULDBLOCK |
122 | case EWOULDBLOCK: |
123 | #endif |
124 | return; |
125 | default: |
126 | lbuf_close(&b->b); |
127 | } |
128 | } |
129 | else |
130 | lbuf_flush(&b->b, p, n); |
131 | } |
132 | |
133 | /* --- @selbuf_init@ --- * |
134 | * |
135 | * Arguments: @selbuf *b@ = pointer to buffer block |
136 | * @sel_state *s@ = pointer to select state to attach to |
137 | * @int fd@ = file descriptor to listen to |
138 | * @void (*func)(char *s, void *p)@ = function to call |
139 | * @void *p@ = argument for function |
140 | * |
141 | * Returns: --- |
142 | * |
143 | * Use: Initializes a buffer block. |
144 | */ |
145 | |
146 | void selbuf_init(selbuf *b, |
147 | sel_state *s, |
148 | int fd, |
149 | void (*func)(char */*s*/, void */*p*/), |
150 | void *p) |
151 | { |
152 | lbuf_init(&b->b, func, p); |
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153 | b->b.f &= ~LBUF_ENABLE; |
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154 | sel_initfile(s, &b->reader, fd, SEL_READ, selbuf_read, b); |
155 | selbuf_enable(b); |
156 | } |
157 | |
158 | /*----- That's all, folks -------------------------------------------------*/ |