97f65b00 |
1 | /* -*-c-*- |
2 | * |
b342b114 |
3 | * $Id: selbuf.c,v 1.5 2002/01/13 13:33:15 mdw Exp $ |
97f65b00 |
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 $ |
b342b114 |
33 | * Revision 1.5 2002/01/13 13:33:15 mdw |
34 | * Track interface change for @lbuf@. |
35 | * |
e03be5f4 |
36 | * Revision 1.4 2000/06/17 10:38:14 mdw |
37 | * Add support for variable buffer sizes. |
38 | * |
693c44ef |
39 | * Revision 1.3 1999/05/22 13:41:00 mdw |
40 | * Fix end-of-file detection and error handling. |
41 | * |
1ef7279c |
42 | * Revision 1.2 1999/05/17 20:36:50 mdw |
43 | * Make the magical constants for the buffer flags uppercase. |
44 | * |
97f65b00 |
45 | * Revision 1.1 1999/05/14 21:01:15 mdw |
46 | * Integrated `select' handling bits from the background resolver project. |
47 | * |
48 | */ |
49 | |
50 | /*----- Header files ------------------------------------------------------*/ |
51 | |
52 | #include <errno.h> |
53 | #include <stdio.h> |
54 | #include <stdlib.h> |
55 | #include <string.h> |
56 | |
57 | #include <sys/types.h> |
58 | #include <sys/time.h> |
59 | #include <unistd.h> |
60 | |
61 | #include "lbuf.h" |
62 | #include "sel.h" |
63 | #include "selbuf.h" |
64 | |
65 | /*----- Main code ---------------------------------------------------------*/ |
66 | |
67 | /* --- @selbuf_enable@ --- * |
68 | * |
69 | * Arguments: @selbuf *b@ = pointer to buffer block |
70 | * |
71 | * Returns: --- |
72 | * |
73 | * Use: Enables a buffer for reading, and emits any queued lines |
74 | * to the buffer's owner. |
75 | */ |
76 | |
77 | void selbuf_enable(selbuf *b) |
78 | { |
1ef7279c |
79 | if (!(b->b.f & LBUF_ENABLE)) { |
80 | b->b.f |= LBUF_ENABLE; |
97f65b00 |
81 | sel_addfile(&b->reader); |
82 | lbuf_flush(&b->b, 0, 0); |
83 | } |
84 | } |
85 | |
86 | /* --- @selbuf_disable@ --- * |
87 | * |
88 | * Arguments: @selbuf *b@ = pointer to a buffer block |
89 | * |
90 | * Returns: --- |
91 | * |
92 | * Use: Disables a buffer. It won't be read from until it's |
93 | * enabled again. |
94 | */ |
95 | |
96 | void selbuf_disable(selbuf *b) |
97 | { |
1ef7279c |
98 | if (b->b.f & LBUF_ENABLE) { |
99 | b->b.f &= ~LBUF_ENABLE; |
97f65b00 |
100 | sel_rmfile(&b->reader); |
101 | } |
102 | } |
103 | |
104 | /* --- @selbuf_read@ --- * |
105 | * |
106 | * Arguments: @int fd@ = file descriptor to read from |
107 | * @int mode@ = what we can do to the file |
108 | * @void *vp@ = pointer to buffer context |
109 | * |
110 | * Returns: --- |
111 | * |
112 | * Use: Acts on the result of a @select@ call. |
113 | */ |
114 | |
115 | static void selbuf_read(int fd, unsigned mode, void *vp) |
116 | { |
117 | selbuf *b = vp; |
118 | char *p; |
119 | size_t sz; |
120 | int n; |
121 | |
122 | sz = lbuf_free(&b->b, &p); |
97f65b00 |
123 | n = read(fd, p, sz); |
693c44ef |
124 | if (n == 0) |
125 | lbuf_close(&b->b); |
126 | else if (n > 0) |
127 | lbuf_flush(&b->b, p, n); |
128 | else switch (errno) { |
129 | case EINTR: |
130 | case EAGAIN: |
97f65b00 |
131 | #if EAGAIN != EWOULDBLOCK |
693c44ef |
132 | case EWOULDBLOCK: |
97f65b00 |
133 | #endif |
693c44ef |
134 | return; |
135 | default: |
136 | lbuf_close(&b->b); |
97f65b00 |
137 | } |
97f65b00 |
138 | } |
139 | |
e03be5f4 |
140 | /* --- @selbuf_setsize@ --- * |
141 | * |
142 | * Arguments: @selbuf *b@ = pointer to buffer block |
143 | * @size_t sz@ = size of buffer |
144 | * |
145 | * Returns: --- |
146 | * |
147 | * Use: Sets the size of the buffer used for reading lines. |
148 | */ |
149 | |
150 | void selbuf_setsize(selbuf *b, size_t sz) |
151 | { |
152 | lbuf_setsize(&b->b, sz); |
153 | } |
154 | |
97f65b00 |
155 | /* --- @selbuf_init@ --- * |
156 | * |
157 | * Arguments: @selbuf *b@ = pointer to buffer block |
158 | * @sel_state *s@ = pointer to select state to attach to |
159 | * @int fd@ = file descriptor to listen to |
b342b114 |
160 | * @lbuf_func *func@ = function to call |
97f65b00 |
161 | * @void *p@ = argument for function |
162 | * |
163 | * Returns: --- |
164 | * |
165 | * Use: Initializes a buffer block. |
166 | */ |
167 | |
b342b114 |
168 | void selbuf_init(selbuf *b, sel_state *s, int fd, lbuf_func *func, void *p) |
97f65b00 |
169 | { |
170 | lbuf_init(&b->b, func, p); |
1ef7279c |
171 | b->b.f &= ~LBUF_ENABLE; |
97f65b00 |
172 | sel_initfile(s, &b->reader, fd, SEL_READ, selbuf_read, b); |
173 | selbuf_enable(b); |
174 | } |
175 | |
e03be5f4 |
176 | /* --- @selbuf_destroy@ --- * |
177 | * |
178 | * Arguments: @selbuf *b@ = pointer to buffer block |
179 | * |
180 | * Returns: --- |
181 | * |
182 | * Use: Deallocates a line buffer and frees any resources it owned. |
183 | */ |
184 | |
185 | void selbuf_destroy(selbuf *b) |
186 | { |
187 | selbuf_disable(b); |
188 | lbuf_destroy(&b->b); |
189 | } |
190 | |
97f65b00 |
191 | /*----- That's all, folks -------------------------------------------------*/ |