code.delx.au - pulseaudio/blob - polyp/ioline.c

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of polypaudio.
   5
   6   polypaudio is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU Lesser General Public License as published
   8   by the Free Software Foundation; either version 2 of the License,
   9   or (at your option) any later version.
  10
  11   polypaudio is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with polypaudio; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <errno.h>
  27 #include <stdio.h>
  28 #include <assert.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31
  32 #include "ioline.h"
  33 #include "xmalloc.h"
  34 #include "log.h"
  35
  36 #define BUFFER_LIMIT (64*1024)
  37 #define READ_SIZE (1024)
  38
  39 struct pa_ioline {
  40     struct pa_iochannel *io;
  41     struct pa_defer_event *defer_event;
  42     struct pa_mainloop_api *mainloop;
  43     int ref;
  44     int dead;
  45
  46     char *wbuf;
  47     size_t wbuf_length, wbuf_index, wbuf_valid_length;
  48
  49     char *rbuf;
  50     size_t rbuf_length, rbuf_index, rbuf_valid_length;
  51
  52     void (*callback)(struct pa_ioline*io, const char *s, void *userdata);
  53     void *userdata;
  54 };
  55
  56 static void io_callback(struct pa_iochannel*io, void *userdata);
  57 static void defer_callback(struct pa_mainloop_api*m, struct pa_defer_event*e, void *userdata);
  58
  59 struct pa_ioline* pa_ioline_new(struct pa_iochannel *io) {
  60     struct pa_ioline *l;
  61     assert(io);
  62
  63     l = pa_xmalloc(sizeof(struct pa_ioline));
  64     l->io = io;
  65     l->dead = 0;
  66
  67     l->wbuf = NULL;
  68     l->wbuf_length = l->wbuf_index = l->wbuf_valid_length = 0;
  69
  70     l->rbuf = NULL;
  71     l->rbuf_length = l->rbuf_index = l->rbuf_valid_length = 0;
  72
  73     l->callback = NULL;
  74     l->userdata = NULL;
  75     l->ref = 1;
  76
  77     l->mainloop = pa_iochannel_get_mainloop_api(io);
  78
  79     l->defer_event = l->mainloop->defer_new(l->mainloop, defer_callback, l);
  80     l->mainloop->defer_enable(l->defer_event, 0);
  81
  82     pa_iochannel_set_callback(io, io_callback, l);
  83
  84     return l;
  85 }
  86
  87 static void ioline_free(struct pa_ioline *l) {
  88     assert(l);
  89
  90     if (l->io)
  91         pa_iochannel_free(l->io);
  92
  93     if (l->defer_event)
  94         l->mainloop->defer_free(l->defer_event);
  95
  96     pa_xfree(l->wbuf);
  97     pa_xfree(l->rbuf);
  98     pa_xfree(l);
  99 }
 100
 101 void pa_ioline_unref(struct pa_ioline *l) {
 102     assert(l && l->ref >= 1);
 103
 104     if ((--l->ref) <= 0)
 105         ioline_free(l);
 106 }
 107
 108 struct pa_ioline* pa_ioline_ref(struct pa_ioline *l) {
 109     assert(l && l->ref >= 1);
 110
 111     l->ref++;
 112     return l;
 113 }
 114
 115 void pa_ioline_close(struct pa_ioline *l) {
 116     assert(l && l->ref >= 1);
 117
 118     l->dead = 1;
 119     if (l->io) {
 120         pa_iochannel_free(l->io);
 121         l->io = NULL;
 122     }
 123
 124     if (l->defer_event) {
 125         l->mainloop->defer_free(l->defer_event);
 126         l->defer_event = NULL;
 127     }
 128 }
 129
 130 void pa_ioline_puts(struct pa_ioline *l, const char *c) {
 131     size_t len;
 132     assert(l && c && l->ref >= 1 && !l->dead);
 133
 134     pa_ioline_ref(l);
 135
 136     len = strlen(c);
 137     if (len > BUFFER_LIMIT - l->wbuf_valid_length)
 138         len = BUFFER_LIMIT - l->wbuf_valid_length;
 139
 140     if (len) {
 141         assert(l->wbuf_length >= l->wbuf_valid_length);
 142
 143         /* In case the allocated buffer is too small, enlarge it. */
 144         if (l->wbuf_valid_length + len > l->wbuf_length) {
 145             size_t n = l->wbuf_valid_length+len;
 146             char *new = pa_xmalloc(n);
 147             if (l->wbuf) {
 148                 memcpy(new, l->wbuf+l->wbuf_index, l->wbuf_valid_length);
 149                 pa_xfree(l->wbuf);
 150             }
 151             l->wbuf = new;
 152             l->wbuf_length = n;
 153             l->wbuf_index = 0;
 154         } else if (l->wbuf_index + l->wbuf_valid_length + len > l->wbuf_length) {
 155
 156             /* In case the allocated buffer fits, but the current index is too far from the start, move it to the front. */
 157             memmove(l->wbuf, l->wbuf+l->wbuf_index, l->wbuf_valid_length);
 158             l->wbuf_index = 0;
 159         }
 160
 161         assert(l->wbuf_index + l->wbuf_valid_length + len <= l->wbuf_length);
 162
 163         /* Append the new string */
 164         memcpy(l->wbuf + l->wbuf_index + l->wbuf_valid_length, c, len);
 165         l->wbuf_valid_length += len;
 166
 167         l->mainloop->defer_enable(l->defer_event, 1);
 168     }
 169
 170     pa_ioline_unref(l);
 171 }
 172
 173 void pa_ioline_set_callback(struct pa_ioline*l, void (*callback)(struct pa_ioline*io, const char *s, void *userdata), void *userdata) {
 174     assert(l && l->ref >= 1);
 175     l->callback = callback;
 176     l->userdata = userdata;
 177 }
 178
 179 static void failure(struct pa_ioline *l) {
 180     assert(l && l->ref >= 1 && !l->dead);
 181
 182     pa_ioline_close(l);
 183
 184     if (l->callback)
 185         l->callback(l, NULL, l->userdata);
 186 }
 187
 188 static void scan_for_lines(struct pa_ioline *l, size_t skip) {
 189     assert(l && l->ref >= 1 && skip < l->rbuf_valid_length);
 190
 191     while (!l->dead && l->rbuf_valid_length > skip) {
 192         char *e, *p;
 193         size_t m;
 194
 195         if (!(e = memchr(l->rbuf + l->rbuf_index + skip, '\n', l->rbuf_valid_length - skip)))
 196             break;
 197
 198         *e = 0;
 199
 200         p = l->rbuf + l->rbuf_index;
 201         m = strlen(p);
 202
 203         l->rbuf_index += m+1;
 204         l->rbuf_valid_length -= m+1;
 205
 206         /* A shortcut for the next time */
 207         if (l->rbuf_valid_length == 0)
 208             l->rbuf_index = 0;
 209
 210         if (l->callback)
 211             l->callback(l, p, l->userdata);
 212
 213         skip = 0;
 214     }
 215
 216     /* If the buffer became too large and still no newline was found, drop it. */
 217     if (l->rbuf_valid_length >= BUFFER_LIMIT)
 218         l->rbuf_index = l->rbuf_valid_length = 0;
 219 }
 220
 221 static int do_read(struct pa_ioline *l) {
 222     assert(l && l->ref >= 1);
 223
 224     while (!l->dead && pa_iochannel_is_readable(l->io)) {
 225         ssize_t r;
 226         size_t len;
 227
 228         len = l->rbuf_length - l->rbuf_index - l->rbuf_valid_length;
 229
 230         /* Check if we have to enlarge the read buffer */
 231         if (len < READ_SIZE) {
 232             size_t n = l->rbuf_valid_length+READ_SIZE;
 233
 234             if (n >= BUFFER_LIMIT)
 235                 n = BUFFER_LIMIT;
 236
 237             if (l->rbuf_length >= n) {
 238                 /* The current buffer is large enough, let's just move the data to the front */
 239                 if (l->rbuf_valid_length)
 240                     memmove(l->rbuf, l->rbuf+l->rbuf_index, l->rbuf_valid_length);
 241             } else {
 242                 /* Enlarge the buffer */
 243                 char *new = pa_xmalloc(n);
 244                 if (l->rbuf_valid_length)
 245                     memcpy(new, l->rbuf+l->rbuf_index, l->rbuf_valid_length);
 246                 pa_xfree(l->rbuf);
 247                 l->rbuf = new;
 248                 l->rbuf_length = n;
 249             }
 250
 251             l->rbuf_index = 0;
 252         }
 253
 254         len = l->rbuf_length - l->rbuf_index - l->rbuf_valid_length;
 255
 256         assert(len >= READ_SIZE);
 257
 258         /* Read some data */
 259         if ((r = pa_iochannel_read(l->io, l->rbuf+l->rbuf_index+l->rbuf_valid_length, len)) <= 0) {
 260             pa_log(__FILE__": read() failed: %s\n", r < 0 ? strerror(errno) : "EOF");
 261             failure(l);
 262             return -1;
 263         }
 264
 265         l->rbuf_valid_length += r;
 266
 267         /* Look if a line has been terminated in the newly read data */
 268         scan_for_lines(l, l->rbuf_valid_length - r);
 269     }
 270
 271     return 0;
 272 }
 273
 274 /* Try to flush the buffer */
 275 static int do_write(struct pa_ioline *l) {
 276     ssize_t r;
 277     assert(l && l->ref >= 1);
 278
 279     while (!l->dead && pa_iochannel_is_writable(l->io) && l->wbuf_valid_length) {
 280
 281         if ((r = pa_iochannel_write(l->io, l->wbuf+l->wbuf_index, l->wbuf_valid_length)) < 0) {
 282             pa_log(__FILE__": write() failed: %s\n", r < 0 ? strerror(errno) : "EOF");
 283             failure(l);
 284             return -1;
 285         }
 286
 287         l->wbuf_index += r;
 288         l->wbuf_valid_length -= r;
 289
 290         /* A shortcut for the next time */
 291         if (l->wbuf_valid_length == 0)
 292             l->wbuf_index = 0;
 293     }
 294
 295     return 0;
 296 }
 297
 298 /* Try to flush read/write data */
 299 static void do_work(struct pa_ioline *l) {
 300     assert(l && l->ref >= 1);
 301
 302     pa_ioline_ref(l);
 303
 304     l->mainloop->defer_enable(l->defer_event, 0);
 305
 306     if (!l->dead)
 307         do_write(l);
 308
 309     if (!l->dead)
 310         do_read(l);
 311
 312     pa_ioline_unref(l);
 313 }
 314
 315 static void io_callback(struct pa_iochannel*io, void *userdata) {
 316     struct pa_ioline *l = userdata;
 317     assert(io && l && l->ref >= 1);
 318
 319     do_work(l);
 320 }
 321
 322 static void defer_callback(struct pa_mainloop_api*m, struct pa_defer_event*e, void *userdata) {
 323     struct pa_ioline *l = userdata;
 324     assert(l && l->ref >= 1 && l->mainloop == m && l->defer_event == e);
 325
 326     do_work(l);
 327 }