ustream-fd.c

  1 /*
  2  * ustream - library for stream buffer management
  3  *
  4  * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
  5  *
  6  * Permission to use, copy, modify, and/or distribute this software for any
  7  * purpose with or without fee is hereby granted, provided that the above
  8  * copyright notice and this permission notice appear in all copies.
  9  *
 10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 17  */
 18 
 19 #include <unistd.h>
 20 #include <errno.h>
 21 #include <stdio.h>
 22 #include "ustream.h"
 23 
 24 static void ustream_fd_set_uloop(struct ustream *s, bool write)
 25 {
 26         struct ustream_fd *sf = container_of(s, struct ustream_fd, stream);
 27         struct ustream_buf *buf;
 28         unsigned int flags = ULOOP_EDGE_TRIGGER | ULOOP_ERROR_CB;
 29 
 30         if (!s->read_blocked && !s->eof)
 31                 flags |= ULOOP_READ;
 32 
 33         buf = s->w.head;
 34         if (write || (buf && s->w.data_bytes && !s->write_error))
 35                 flags |= ULOOP_WRITE;
 36 
 37         uloop_fd_add(&sf->fd, flags);
 38 }
 39 
 40 static void ustream_fd_set_read_blocked(struct ustream *s)
 41 {
 42         ustream_fd_set_uloop(s, false);
 43 }
 44 
 45 static void ustream_fd_read_pending(struct ustream_fd *sf, bool *more)
 46 {
 47         struct ustream *s = &sf->stream;
 48         int buflen = 0;
 49         ssize_t len;
 50         char *buf;
 51 
 52         do {
 53                 if (s->read_blocked)
 54                         break;
 55 
 56                 buf = ustream_reserve(s, 1, &buflen);
 57                 if (!buf)
 58                         break;
 59 
 60                 len = read(sf->fd.fd, buf, buflen);
 61                 if (len < 0) {
 62                         if (errno == EINTR)
 63                                 continue;
 64 
 65                         if (errno == EAGAIN || errno == ENOTCONN)
 66                                 return;
 67 
 68                         len = 0;
 69                 }
 70 
 71                 if (!len) {
 72                         if (!s->eof)
 73                                 ustream_state_change(s);
 74                         s->eof = true;
 75                         ustream_fd_set_uloop(s, false);
 76                         return;
 77                 }
 78 
 79                 ustream_fill_read(s, len);
 80                 *more = true;
 81         } while (1);
 82 }
 83 
 84 static int ustream_fd_write(struct ustream *s, const char *buf, int buflen, bool more)
 85 {
 86         struct ustream_fd *sf = container_of(s, struct ustream_fd, stream);
 87         ssize_t ret = 0, len;
 88 
 89         if (!buflen)
 90                 return 0;
 91 
 92         while (buflen) {
 93                 len = write(sf->fd.fd, buf, buflen);
 94 
 95                 if (len < 0) {
 96                         if (errno == EINTR)
 97                                 continue;
 98 
 99                         if (errno == EAGAIN || errno == EWOULDBLOCK || errno == ENOTCONN)
100                                 break;
101 
102                         return -1;
103                 }
104 
105                 ret += len;
106                 buf += len;
107                 buflen -= len;
108         }
109 
110         if (buflen)
111                 ustream_fd_set_uloop(s, true);
112 
113         return ret;
114 }
115 
116 static bool __ustream_fd_poll(struct ustream_fd *sf, unsigned int events)
117 {
118         struct ustream *s = &sf->stream;
119         bool more = false;
120 
121         if (events & ULOOP_READ)
122                 ustream_fd_read_pending(sf, &more);
123 
124         if (events & ULOOP_WRITE) {
125                 bool no_more = ustream_write_pending(s);
126                 if (no_more)
127                         ustream_fd_set_uloop(s, false);
128         }
129 
130         if (sf->fd.error && !s->write_error) {
131                 ustream_state_change(s);
132                 s->write_error = true;
133                 ustream_fd_set_uloop(s, false);
134         }
135 
136         return more;
137 }
138 
139 static bool ustream_fd_poll(struct ustream *s)
140 {
141         struct ustream_fd *sf = container_of(s, struct ustream_fd, stream);
142 
143         return __ustream_fd_poll(sf, ULOOP_READ | ULOOP_WRITE);
144 }
145 
146 static void ustream_uloop_cb(struct uloop_fd *fd, unsigned int events)
147 {
148         struct ustream_fd *sf = container_of(fd, struct ustream_fd, fd);
149 
150         __ustream_fd_poll(sf, events);
151 }
152 
153 static void ustream_fd_free(struct ustream *s)
154 {
155         struct ustream_fd *sf = container_of(s, struct ustream_fd, stream);
156 
157         uloop_fd_delete(&sf->fd);
158 }
159 
160 void ustream_fd_init(struct ustream_fd *sf, int fd)
161 {
162         struct ustream *s = &sf->stream;
163 
164         ustream_init_defaults(s);
165 
166         sf->fd.fd = fd;
167         sf->fd.cb = ustream_uloop_cb;
168         s->set_read_blocked = ustream_fd_set_read_blocked;
169         s->write = ustream_fd_write;
170         s->free = ustream_fd_free;
171         s->poll = ustream_fd_poll;
172         ustream_fd_set_uloop(s, false);
173 }
174
This page was automatically generated by LXR 0.3.1. • OpenWrt
OpenWrt.org Cross Reference

Sources/libubox/ustream-fd.c
