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
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