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     int defer_close;
  56 };
  57
  58 static void io_callback(struct pa_iochannel*io, void *userdata);
  59 static void defer_callback(struct pa_mainloop_api*m, struct pa_defer_event*e, void *userdata);
  60
  61 struct pa_ioline* pa_ioline_new(struct pa_iochannel *io) {
  62     struct pa_ioline *l;
  63     assert(io);
  64
  65     l = pa_xmalloc(sizeof(struct pa_ioline));
  66     l->io = io;
  67     l->dead = 0;
  68
  69     l->wbuf = NULL;
  70     l->wbuf_length = l->wbuf_index = l->wbuf_valid_length = 0;
  71
  72     l->rbuf = NULL;
  73     l->rbuf_length = l->rbuf_index = l->rbuf_valid_length = 0;
  74
  75     l->callback = NULL;
  76     l->userdata = NULL;
  77     l->ref = 1;
  78
  79     l->mainloop = pa_iochannel_get_mainloop_api(io);
  80
  81     l->defer_event = l->mainloop->defer_new(l->mainloop, defer_callback, l);
  82     l->mainloop->defer_enable(l->defer_event, 0);
  83
  84     l->defer_close = 0;
  85
  86     pa_iochannel_set_callback(io, io_callback, l);
  87
  88     return l;
  89 }
  90
  91 static void ioline_free(struct pa_ioline *l) {
  92     assert(l);
  93
  94     if (l->io)
  95         pa_iochannel_free(l->io);
  96
  97     if (l->defer_event)
  98         l->mainloop->defer_free(l->defer_event);
  99
 100     pa_xfree(l->wbuf);
 101     pa_xfree(l->rbuf);
 102     pa_xfree(l);
 103 }
 104
 105 void pa_ioline_unref(struct pa_ioline *l) {
 106     assert(l && l->ref >= 1);
 107
 108     if ((--l->ref) <= 0)
 109         ioline_free(l);
 110 }
 111
 112 struct pa_ioline* pa_ioline_ref(struct pa_ioline *l) {
 113     assert(l && l->ref >= 1);
 114
 115     l->ref++;
 116     return l;
 117 }
 118
 119 void pa_ioline_close(struct pa_ioline *l) {
 120     assert(l && l->ref >= 1);
 121
 122     l->dead = 1;
 123     if (l->io) {
 124         pa_iochannel_free(l->io);
 125         l->io = NULL;
 126     }
 127
 128     if (l->defer_event) {
 129         l->mainloop->defer_free(l->defer_event);
 130         l->defer_event = NULL;
 131     }
 132 }
 133
 134 void pa_ioline_puts(struct pa_ioline *l, const char *c) {
 135     size_t len;
 136     assert(l && c && l->ref >= 1 && !l->dead);
 137
 138     pa_ioline_ref(l);
 139
 140     len = strlen(c);
 141     if (len > BUFFER_LIMIT - l->wbuf_valid_length)
 142         len = BUFFER_LIMIT - l->wbuf_valid_length;
 143
 144     if (len) {
 145         assert(l->wbuf_length >= l->wbuf_valid_length);
 146
 147         /* In case the allocated buffer is too small, enlarge it. */
 148         if (l->wbuf_valid_length + len > l->wbuf_length) {
 149             size_t n = l->wbuf_valid_length+len;
 150             char *new = pa_xmalloc(n);
 151             if (l->wbuf) {
 152                 memcpy(new, l->wbuf+l->wbuf_index, l->wbuf_valid_length);
 153                 pa_xfree(l->wbuf);
 154             }
 155             l->wbuf = new;
 156             l->wbuf_length = n;
 157             l->wbuf_index = 0;
 158         } else if (l->wbuf_index + l->wbuf_valid_length + len > l->wbuf_length) {
 159
 160             /* In case the allocated buffer fits, but the current index is too far from the start, move it to the front. */
 161             memmove(l->wbuf, l->wbuf+l->wbuf_index, l->wbuf_valid_length);
 162             l->wbuf_index = 0;
 163         }
 164
 165         assert(l->wbuf_index + l->wbuf_valid_length + len <= l->wbuf_length);
 166
 167         /* Append the new string */
 168         memcpy(l->wbuf + l->wbuf_index + l->wbuf_valid_length, c, len);
 169         l->wbuf_valid_length += len;
 170
 171         l->mainloop->defer_enable(l->defer_event, 1);
 172     }
 173
 174     pa_ioline_unref(l);
 175 }
 176
 177 void pa_ioline_set_callback(struct pa_ioline*l, void (*callback)(struct pa_ioline*io, const char *s, void *userdata), void *userdata) {
 178     assert(l && l->ref >= 1);
 179     l->callback = callback;
 180     l->userdata = userdata;
 181 }
 182
 183 static void failure(struct pa_ioline *l) {
 184     assert(l && l->ref >= 1 && !l->dead);
 185
 186     pa_ioline_close(l);
 187
 188     if (l->callback) {
 189         l->callback(l, NULL, l->userdata);
 190         l->callback = NULL;
 191     }
 192 }
 193
 194 static void scan_for_lines(struct pa_ioline *l, size_t skip) {
 195     assert(l && l->ref >= 1 && skip < l->rbuf_valid_length);
 196
 197     while (!l->dead && l->rbuf_valid_length > skip) {
 198         char *e, *p;
 199         size_t m;
 200
 201         if (!(e = memchr(l->rbuf + l->rbuf_index + skip, '\n', l->rbuf_valid_length - skip)))
 202             break;
 203
 204         *e = 0;
 205
 206         p = l->rbuf + l->rbuf_index;
 207         m = strlen(p);
 208
 209         l->rbuf_index += m+1;
 210         l->rbuf_valid_length -= m+1;
 211
 212         /* A shortcut for the next time */
 213         if (l->rbuf_valid_length == 0)
 214             l->rbuf_index = 0;
 215
 216         if (l->callback)
 217             l->callback(l, p, l->userdata);
 218
 219         skip = 0;
 220     }
 221
 222     /* If the buffer became too large and still no newline was found, drop it. */
 223     if (l->rbuf_valid_length >= BUFFER_LIMIT)
 224         l->rbuf_index = l->rbuf_valid_length = 0;
 225 }
 226
 227 static int do_read(struct pa_ioline *l) {
 228     assert(l && l->ref >= 1);
 229
 230     while (!l->dead && pa_iochannel_is_readable(l->io)) {
 231         ssize_t r;
 232         size_t len;
 233
 234         len = l->rbuf_length - l->rbuf_index - l->rbuf_valid_length;
 235
 236         /* Check if we have to enlarge the read buffer */
 237         if (len < READ_SIZE) {
 238             size_t n = l->rbuf_valid_length+READ_SIZE;
 239
 240             if (n >= BUFFER_LIMIT)
 241                 n = BUFFER_LIMIT;
 242
 243             if (l->rbuf_length >= n) {
 244                 /* The current buffer is large enough, let's just move the data to the front */
 245                 if (l->rbuf_valid_length)
 246                     memmove(l->rbuf, l->rbuf+l->rbuf_index, l->rbuf_valid_length);
 247             } else {
 248                 /* Enlarge the buffer */
 249                 char *new = pa_xmalloc(n);
 250                 if (l->rbuf_valid_length)
 251                     memcpy(new, l->rbuf+l->rbuf_index, l->rbuf_valid_length);
 252                 pa_xfree(l->rbuf);
 253                 l->rbuf = new;
 254                 l->rbuf_length = n;
 255             }
 256
 257             l->rbuf_index = 0;
 258         }
 259
 260         len = l->rbuf_length - l->rbuf_index - l->rbuf_valid_length;
 261
 262         assert(len >= READ_SIZE);
 263
 264         /* Read some data */
 265         if ((r = pa_iochannel_read(l->io, l->rbuf+l->rbuf_index+l->rbuf_valid_length, len)) <= 0) {
 266             pa_log(__FILE__": read() failed: %s\n", r < 0 ? strerror(errno) : "EOF");
 267             failure(l);
 268             return -1;
 269         }
 270
 271         l->rbuf_valid_length += r;
 272
 273         /* Look if a line has been terminated in the newly read data */
 274         scan_for_lines(l, l->rbuf_valid_length - r);
 275     }
 276
 277     return 0;
 278 }
 279
 280 /* Try to flush the buffer */
 281 static int do_write(struct pa_ioline *l) {
 282     ssize_t r;
 283     assert(l && l->ref >= 1);
 284
 285     while (!l->dead && pa_iochannel_is_writable(l->io) && l->wbuf_valid_length) {
 286
 287         if ((r = pa_iochannel_write(l->io, l->wbuf+l->wbuf_index, l->wbuf_valid_length)) < 0) {
 288             pa_log(__FILE__": write() failed: %s\n", r < 0 ? strerror(errno) : "EOF");
 289             failure(l);
 290             return -1;
 291         }
 292
 293         l->wbuf_index += r;
 294         l->wbuf_valid_length -= r;
 295
 296         /* A shortcut for the next time */
 297         if (l->wbuf_valid_length == 0)
 298             l->wbuf_index = 0;
 299     }
 300
 301     return 0;
 302 }
 303
 304 /* Try to flush read/write data */
 305 static void do_work(struct pa_ioline *l) {
 306     assert(l && l->ref >= 1);
 307
 308     pa_ioline_ref(l);
 309
 310     l->mainloop->defer_enable(l->defer_event, 0);
 311
 312     if (!l->dead)
 313         do_write(l);
 314
 315     if (!l->dead)
 316         do_read(l);
 317
 318     if (l->defer_close && !l->wbuf_valid_length)
 319         failure(l);
 320
 321     pa_ioline_unref(l);
 322 }
 323
 324 static void io_callback(struct pa_iochannel*io, void *userdata) {
 325     struct pa_ioline *l = userdata;
 326     assert(io && l && l->ref >= 1);
 327
 328     do_work(l);
 329 }
 330
 331 static void defer_callback(struct pa_mainloop_api*m, struct pa_defer_event*e, void *userdata) {
 332     struct pa_ioline *l = userdata;
 333     assert(l && l->ref >= 1 && l->mainloop == m && l->defer_event == e);
 334
 335     do_work(l);
 336 }
 337
 338 void pa_ioline_defer_close(struct pa_ioline *l) {
 339     assert(l);
 340
 341     l->defer_close = 1;
 342
 343     if (!l->wbuf_valid_length)
 344         l->mainloop->defer_enable(l->defer_event, 1);
 345 }
 346
 347 void pa_ioline_printf(struct pa_ioline *s, const char *format, ...) {
 348     char *t;
 349     va_list ap;
 350
 351
 352     va_start(ap, format);
 353     t = pa_vsprintf_malloc(format, ap);
 354     va_end(ap);
 355
 356     pa_ioline_puts(s, t);
 357     pa_xfree(t);
 358 }