chiark / gitweb /
Test universal hashing and fix bugs.
[mLib] / selbuf.c
CommitLineData
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
77void 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
96void 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
115static 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
150void 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 168void 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
185void selbuf_destroy(selbuf *b)
186{
187 selbuf_disable(b);
188 lbuf_destroy(&b->b);
189}
190
97f65b00 191/*----- That's all, folks -------------------------------------------------*/