code.delx.au - pulseaudio/blob - src/pulsecore/ioline.c

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of PulseAudio.
   5
   6   PulseAudio 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   PulseAudio 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 PulseAudio; 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 <pulse/xmalloc.h>
  33
  34 #include <pulsecore/core-error.h>
  35 #include <pulsecore/log.h>
  36
  37 #include "ioline.h"
  38
  39 #define BUFFER_LIMIT (64*1024)
  40 #define READ_SIZE (1024)
  41
  42 struct pa_ioline {
  43     pa_iochannel *io;
  44     pa_defer_event *defer_event;
  45     pa_mainloop_api *mainloop;
  46     int ref;
  47     int dead;
  48
  49     char *wbuf;
  50     size_t wbuf_length, wbuf_index, wbuf_valid_length;
  51
  52     char *rbuf;
  53     size_t rbuf_length, rbuf_index, rbuf_valid_length;
  54
  55     void (*callback)(pa_ioline*io, const char *s, void *userdata);
  56     void *userdata;
  57
  58     int defer_close;
  59 };
  60
  61 static void io_callback(pa_iochannel*io, void *userdata);
  62 static void defer_callback(pa_mainloop_api*m, pa_defer_event*e, void *userdata);
  63
  64 pa_ioline* pa_ioline_new(pa_iochannel *io) {
  65     pa_ioline *l;
  66     assert(io);
  67
  68     l = pa_xnew(pa_ioline, 1);
  69     l->io = io;
  70     l->dead = 0;
  71
  72     l->wbuf = NULL;
  73     l->wbuf_length = l->wbuf_index = l->wbuf_valid_length = 0;
  74
  75     l->rbuf = NULL;
  76     l->rbuf_length = l->rbuf_index = l->rbuf_valid_length = 0;
  77
  78     l->callback = NULL;
  79     l->userdata = NULL;
  80     l->ref = 1;
  81
  82     l->mainloop = pa_iochannel_get_mainloop_api(io);
  83
  84     l->defer_event = l->mainloop->defer_new(l->mainloop, defer_callback, l);
  85     l->mainloop->defer_enable(l->defer_event, 0);
  86
  87     l->defer_close = 0;
  88
  89     pa_iochannel_set_callback(io, io_callback, l);
  90
  91     return l;
  92 }
  93
  94 static void ioline_free(pa_ioline *l) {
  95     assert(l);
  96
  97     if (l->io)
  98         pa_iochannel_free(l->io);
  99
 100     if (l->defer_event)
 101         l->mainloop->defer_free(l->defer_event);
 102
 103     pa_xfree(l->wbuf);
 104     pa_xfree(l->rbuf);
 105     pa_xfree(l);
 106 }
 107
 108 void pa_ioline_unref(pa_ioline *l) {
 109     assert(l);
 110     assert(l->ref >= 1);
 111
 112     if ((--l->ref) <= 0)
 113         ioline_free(l);
 114 }
 115
 116 pa_ioline* pa_ioline_ref(pa_ioline *l) {
 117     assert(l);
 118     assert(l->ref >= 1);
 119
 120     l->ref++;
 121     return l;
 122 }
 123
 124 void pa_ioline_close(pa_ioline *l) {
 125     assert(l);
 126     assert(l->ref >= 1);
 127
 128     l->dead = 1;
 129
 130     if (l->io) {
 131         pa_iochannel_free(l->io);
 132         l->io = NULL;
 133     }
 134
 135     if (l->defer_event) {
 136         l->mainloop->defer_free(l->defer_event);
 137         l->defer_event = NULL;
 138     }
 139
 140     if (l->callback)
 141         l->callback = NULL;
 142 }
 143
 144 void pa_ioline_puts(pa_ioline *l, const char *c) {
 145     size_t len;
 146
 147     assert(l);
 148     assert(l->ref >= 1);
 149     assert(c);
 150
 151     if (l->dead)
 152         return;
 153
 154     len = strlen(c);
 155     if (len > BUFFER_LIMIT - l->wbuf_valid_length)
 156         len = BUFFER_LIMIT - l->wbuf_valid_length;
 157
 158     if (len) {
 159         assert(l->wbuf_length >= l->wbuf_valid_length);
 160
 161         /* In case the allocated buffer is too small, enlarge it. */
 162         if (l->wbuf_valid_length + len > l->wbuf_length) {
 163             size_t n = l->wbuf_valid_length+len;
 164             char *new = pa_xmalloc(n);
 165             if (l->wbuf) {
 166                 memcpy(new, l->wbuf+l->wbuf_index, l->wbuf_valid_length);
 167                 pa_xfree(l->wbuf);
 168             }
 169             l->wbuf = new;
 170             l->wbuf_length = n;
 171             l->wbuf_index = 0;
 172         } else if (l->wbuf_index + l->wbuf_valid_length + len > l->wbuf_length) {
 173
 174             /* In case the allocated buffer fits, but the current index is too far from the start, move it to the front. */
 175             memmove(l->wbuf, l->wbuf+l->wbuf_index, l->wbuf_valid_length);
 176             l->wbuf_index = 0;
 177         }
 178
 179         assert(l->wbuf_index + l->wbuf_valid_length + len <= l->wbuf_length);
 180
 181         /* Append the new string */
 182         memcpy(l->wbuf + l->wbuf_index + l->wbuf_valid_length, c, len);
 183         l->wbuf_valid_length += len;
 184
 185         l->mainloop->defer_enable(l->defer_event, 1);
 186     }
 187 }
 188
 189 void pa_ioline_set_callback(pa_ioline*l, void (*callback)(pa_ioline*io, const char *s, void *userdata), void *userdata) {
 190     assert(l);
 191     assert(l->ref >= 1);
 192
 193     l->callback = callback;
 194     l->userdata = userdata;
 195 }
 196
 197 static void failure(pa_ioline *l, int process_leftover) {
 198     assert(l);
 199     assert(l->ref >= 1);
 200     assert(!l->dead);
 201
 202     if (process_leftover && l->rbuf_valid_length > 0) {
 203         /* Pass the last missing bit to the client */
 204
 205         if (l->callback) {
 206             char *p = pa_xstrndup(l->rbuf+l->rbuf_index, l->rbuf_valid_length);
 207             l->callback(l, p, l->userdata);
 208             pa_xfree(p);
 209         }
 210     }
 211
 212     if (l->callback) {
 213         l->callback(l, NULL, l->userdata);
 214         l->callback = NULL;
 215     }
 216
 217     pa_ioline_close(l);
 218 }
 219
 220 static void scan_for_lines(pa_ioline *l, size_t skip) {
 221     assert(l && l->ref >= 1 && skip < l->rbuf_valid_length);
 222
 223     while (!l->dead && l->rbuf_valid_length > skip) {
 224         char *e, *p;
 225         size_t m;
 226
 227         if (!(e = memchr(l->rbuf + l->rbuf_index + skip, '\n', l->rbuf_valid_length - skip)))
 228             break;
 229
 230         *e = 0;
 231
 232         p = l->rbuf + l->rbuf_index;
 233         m = strlen(p);
 234
 235         l->rbuf_index += m+1;
 236         l->rbuf_valid_length -= m+1;
 237
 238         /* A shortcut for the next time */
 239         if (l->rbuf_valid_length == 0)
 240             l->rbuf_index = 0;
 241
 242         if (l->callback)
 243             l->callback(l, p, l->userdata);
 244
 245         skip = 0;
 246     }
 247
 248     /* If the buffer became too large and still no newline was found, drop it. */
 249     if (l->rbuf_valid_length >= BUFFER_LIMIT)
 250         l->rbuf_index = l->rbuf_valid_length = 0;
 251 }
 252
 253 static int do_write(pa_ioline *l);
 254
 255 static int do_read(pa_ioline *l) {
 256     assert(l && l->ref >= 1);
 257
 258     while (!l->dead && pa_iochannel_is_readable(l->io)) {
 259         ssize_t r;
 260         size_t len;
 261
 262         len = l->rbuf_length - l->rbuf_index - l->rbuf_valid_length;
 263
 264         /* Check if we have to enlarge the read buffer */
 265         if (len < READ_SIZE) {
 266             size_t n = l->rbuf_valid_length+READ_SIZE;
 267
 268             if (n >= BUFFER_LIMIT)
 269                 n = BUFFER_LIMIT;
 270
 271             if (l->rbuf_length >= n) {
 272                 /* The current buffer is large enough, let's just move the data to the front */
 273                 if (l->rbuf_valid_length)
 274                     memmove(l->rbuf, l->rbuf+l->rbuf_index, l->rbuf_valid_length);
 275             } else {
 276                 /* Enlarge the buffer */
 277                 char *new = pa_xmalloc(n);
 278                 if (l->rbuf_valid_length)
 279                     memcpy(new, l->rbuf+l->rbuf_index, l->rbuf_valid_length);
 280                 pa_xfree(l->rbuf);
 281                 l->rbuf = new;
 282                 l->rbuf_length = n;
 283             }
 284
 285             l->rbuf_index = 0;
 286         }
 287
 288         len = l->rbuf_length - l->rbuf_index - l->rbuf_valid_length;
 289
 290         assert(len >= READ_SIZE);
 291
 292         /* Read some data */
 293         if ((r = pa_iochannel_read(l->io, l->rbuf+l->rbuf_index+l->rbuf_valid_length, len)) <= 0) {
 294             if (r < 0) {
 295                 pa_log(__FILE__": read(): %s", pa_cstrerror(errno));
 296                 failure(l, 0);
 297             } else
 298                 failure(l, 1);
 299
 300             return -1;
 301         }
 302
 303         l->rbuf_valid_length += r;
 304
 305         /* Look if a line has been terminated in the newly read data */
 306         scan_for_lines(l, l->rbuf_valid_length - r);
 307     }
 308
 309     return 0;
 310 }
 311
 312 /* Try to flush the buffer */
 313 static int do_write(pa_ioline *l) {
 314     ssize_t r;
 315     assert(l && l->ref >= 1);
 316
 317     while (!l->dead && pa_iochannel_is_writable(l->io) && l->wbuf_valid_length) {
 318
 319         if ((r = pa_iochannel_write(l->io, l->wbuf+l->wbuf_index, l->wbuf_valid_length)) < 0) {
 320             pa_log(__FILE__": write(): %s", r < 0 ? pa_cstrerror(errno) : "EOF");
 321             failure(l, 0);
 322             return -1;
 323         }
 324
 325         l->wbuf_index += r;
 326         l->wbuf_valid_length -= r;
 327
 328         /* A shortcut for the next time */
 329         if (l->wbuf_valid_length == 0)
 330             l->wbuf_index = 0;
 331     }
 332
 333     return 0;
 334 }
 335
 336 /* Try to flush read/write data */
 337 static void do_work(pa_ioline *l) {
 338     assert(l);
 339     assert(l->ref >= 1);
 340
 341     pa_ioline_ref(l);
 342
 343     l->mainloop->defer_enable(l->defer_event, 0);
 344
 345     if (!l->dead)
 346         do_read(l);
 347
 348     if (!l->dead)
 349         do_write(l);
 350
 351     if (l->defer_close && !l->wbuf_valid_length)
 352         failure(l, 1);
 353
 354     pa_ioline_unref(l);
 355 }
 356
 357 static void io_callback(pa_iochannel*io, void *userdata) {
 358     pa_ioline *l = userdata;
 359     assert(io && l && l->ref >= 1);
 360
 361     do_work(l);
 362 }
 363
 364 static void defer_callback(pa_mainloop_api*m, pa_defer_event*e, void *userdata) {
 365     pa_ioline *l = userdata;
 366     assert(l && l->ref >= 1 && l->mainloop == m && l->defer_event == e);
 367
 368     do_work(l);
 369 }
 370
 371 void pa_ioline_defer_close(pa_ioline *l) {
 372     assert(l);
 373     assert(l->ref >= 1);
 374
 375     l->defer_close = 1;
 376
 377     if (!l->wbuf_valid_length)
 378         l->mainloop->defer_enable(l->defer_event, 1);
 379 }
 380
 381 void pa_ioline_printf(pa_ioline *l, const char *format, ...) {
 382     char *t;
 383     va_list ap;
 384
 385     assert(l);
 386     assert(l->ref >= 1);
 387
 388     va_start(ap, format);
 389     t = pa_vsprintf_malloc(format, ap);
 390     va_end(ap);
 391
 392     pa_ioline_puts(l, t);
 393     pa_xfree(t);
 394 }