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

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of PulseAudio.
   5
   6   Copyright 2004-2006 Lennart Poettering
   7
   8   PulseAudio is free software; you can redistribute it and/or modify
   9   it under the terms of the GNU Lesser General Public License as published
  10   by the Free Software Foundation; either version 2 of the License,
  11   or (at your option) any later version.
  12
  13   PulseAudio is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with PulseAudio; if not, write to the Free Software
  20   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  21   USA.
  22 ***/
  23
  24 #ifdef HAVE_CONFIG_H
  25 #include <config.h>
  26 #endif
  27
  28 #include <errno.h>
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32
  33 #include <pulse/xmalloc.h>
  34
  35 #include <pulsecore/winsock.h>
  36 #include <pulsecore/core-error.h>
  37 #include <pulsecore/log.h>
  38 #include <pulsecore/macro.h>
  39 #include <pulsecore/refcnt.h>
  40
  41 #include "ioline.h"
  42
  43 #define BUFFER_LIMIT (64*1024)
  44 #define READ_SIZE (1024)
  45
  46 struct pa_ioline {
  47     PA_REFCNT_DECLARE;
  48
  49     pa_iochannel *io;
  50     pa_defer_event *defer_event;
  51     pa_mainloop_api *mainloop;
  52     int dead;
  53
  54     char *wbuf;
  55     size_t wbuf_length, wbuf_index, wbuf_valid_length;
  56
  57     char *rbuf;
  58     size_t rbuf_length, rbuf_index, rbuf_valid_length;
  59
  60     void (*callback)(pa_ioline*io, const char *s, void *userdata);
  61     void *userdata;
  62
  63     int defer_close;
  64 };
  65
  66 static void io_callback(pa_iochannel*io, void *userdata);
  67 static void defer_callback(pa_mainloop_api*m, pa_defer_event*e, void *userdata);
  68
  69 pa_ioline* pa_ioline_new(pa_iochannel *io) {
  70     pa_ioline *l;
  71     pa_assert(io);
  72
  73     l = pa_xnew(pa_ioline, 1);
  74     PA_REFCNT_INIT(l);
  75     l->io = io;
  76     l->dead = 0;
  77
  78     l->wbuf = NULL;
  79     l->wbuf_length = l->wbuf_index = l->wbuf_valid_length = 0;
  80
  81     l->rbuf = NULL;
  82     l->rbuf_length = l->rbuf_index = l->rbuf_valid_length = 0;
  83
  84     l->callback = NULL;
  85     l->userdata = NULL;
  86
  87     l->mainloop = pa_iochannel_get_mainloop_api(io);
  88
  89     l->defer_event = l->mainloop->defer_new(l->mainloop, defer_callback, l);
  90     l->mainloop->defer_enable(l->defer_event, 0);
  91
  92     l->defer_close = 0;
  93
  94     pa_iochannel_set_callback(io, io_callback, l);
  95
  96     return l;
  97 }
  98
  99 static void ioline_free(pa_ioline *l) {
 100     pa_assert(l);
 101
 102     if (l->io)
 103         pa_iochannel_free(l->io);
 104
 105     if (l->defer_event)
 106         l->mainloop->defer_free(l->defer_event);
 107
 108     pa_xfree(l->wbuf);
 109     pa_xfree(l->rbuf);
 110     pa_xfree(l);
 111 }
 112
 113 void pa_ioline_unref(pa_ioline *l) {
 114     pa_assert(l);
 115     pa_assert(PA_REFCNT_VALUE(l) >= 1);
 116
 117     if (PA_REFCNT_DEC(l) <= 0)
 118         ioline_free(l);
 119 }
 120
 121 pa_ioline* pa_ioline_ref(pa_ioline *l) {
 122     pa_assert(l);
 123     pa_assert(PA_REFCNT_VALUE(l) >= 1);
 124
 125     PA_REFCNT_INC(l);
 126     return l;
 127 }
 128
 129 void pa_ioline_close(pa_ioline *l) {
 130     pa_assert(l);
 131     pa_assert(PA_REFCNT_VALUE(l) >= 1);
 132
 133     l->dead = 1;
 134
 135     if (l->io) {
 136         pa_iochannel_free(l->io);
 137         l->io = NULL;
 138     }
 139
 140     if (l->defer_event) {
 141         l->mainloop->defer_free(l->defer_event);
 142         l->defer_event = NULL;
 143     }
 144
 145     if (l->callback)
 146         l->callback = NULL;
 147 }
 148
 149 void pa_ioline_puts(pa_ioline *l, const char *c) {
 150     size_t len;
 151
 152     pa_assert(l);
 153     pa_assert(PA_REFCNT_VALUE(l) >= 1);
 154     pa_assert(c);
 155
 156     if (l->dead)
 157         return;
 158
 159     len = strlen(c);
 160     if (len > BUFFER_LIMIT - l->wbuf_valid_length)
 161         len = BUFFER_LIMIT - l->wbuf_valid_length;
 162
 163     if (len) {
 164         pa_assert(l->wbuf_length >= l->wbuf_valid_length);
 165
 166         /* In case the allocated buffer is too small, enlarge it. */
 167         if (l->wbuf_valid_length + len > l->wbuf_length) {
 168             size_t n = l->wbuf_valid_length+len;
 169             char *new = pa_xmalloc(n);
 170             if (l->wbuf) {
 171                 memcpy(new, l->wbuf+l->wbuf_index, l->wbuf_valid_length);
 172                 pa_xfree(l->wbuf);
 173             }
 174             l->wbuf = new;
 175             l->wbuf_length = n;
 176             l->wbuf_index = 0;
 177         } else if (l->wbuf_index + l->wbuf_valid_length + len > l->wbuf_length) {
 178
 179             /* In case the allocated buffer fits, but the current index is too far from the start, move it to the front. */
 180             memmove(l->wbuf, l->wbuf+l->wbuf_index, l->wbuf_valid_length);
 181             l->wbuf_index = 0;
 182         }
 183
 184         pa_assert(l->wbuf_index + l->wbuf_valid_length + len <= l->wbuf_length);
 185
 186         /* Append the new string */
 187         memcpy(l->wbuf + l->wbuf_index + l->wbuf_valid_length, c, len);
 188         l->wbuf_valid_length += len;
 189
 190         l->mainloop->defer_enable(l->defer_event, 1);
 191     }
 192 }
 193
 194 void pa_ioline_set_callback(pa_ioline*l, void (*callback)(pa_ioline*io, const char *s, void *userdata), void *userdata) {
 195     pa_assert(l);
 196     pa_assert(PA_REFCNT_VALUE(l) >= 1);
 197
 198     l->callback = callback;
 199     l->userdata = userdata;
 200 }
 201
 202 static void failure(pa_ioline *l, int process_leftover) {
 203     pa_assert(l);
 204     pa_assert(PA_REFCNT_VALUE(l) >= 1);
 205     pa_assert(!l->dead);
 206
 207     if (process_leftover && l->rbuf_valid_length > 0) {
 208         /* Pass the last missing bit to the client */
 209
 210         if (l->callback) {
 211             char *p = pa_xstrndup(l->rbuf+l->rbuf_index, l->rbuf_valid_length);
 212             l->callback(l, p, l->userdata);
 213             pa_xfree(p);
 214         }
 215     }
 216
 217     if (l->callback) {
 218         l->callback(l, NULL, l->userdata);
 219         l->callback = NULL;
 220     }
 221
 222     pa_ioline_close(l);
 223 }
 224
 225 static void scan_for_lines(pa_ioline *l, size_t skip) {
 226     pa_assert(l);
 227     pa_assert(PA_REFCNT_VALUE(l) >= 1);
 228     pa_assert(skip < l->rbuf_valid_length);
 229
 230     while (!l->dead && l->rbuf_valid_length > skip) {
 231         char *e, *p;
 232         size_t m;
 233
 234         if (!(e = memchr(l->rbuf + l->rbuf_index + skip, '\n', l->rbuf_valid_length - skip)))
 235             break;
 236
 237         *e = 0;
 238
 239         p = l->rbuf + l->rbuf_index;
 240         m = strlen(p);
 241
 242         l->rbuf_index += m+1;
 243         l->rbuf_valid_length -= m+1;
 244
 245         /* A shortcut for the next time */
 246         if (l->rbuf_valid_length == 0)
 247             l->rbuf_index = 0;
 248
 249         if (l->callback)
 250             l->callback(l, p, l->userdata);
 251
 252         skip = 0;
 253     }
 254
 255     /* If the buffer became too large and still no newline was found, drop it. */
 256     if (l->rbuf_valid_length >= BUFFER_LIMIT)
 257         l->rbuf_index = l->rbuf_valid_length = 0;
 258 }
 259
 260 static int do_write(pa_ioline *l);
 261
 262 static int do_read(pa_ioline *l) {
 263     pa_assert(l);
 264     pa_assert(PA_REFCNT_VALUE(l) >= 1);
 265
 266     while (!l->dead && pa_iochannel_is_readable(l->io)) {
 267         ssize_t r;
 268         size_t len;
 269
 270         len = l->rbuf_length - l->rbuf_index - l->rbuf_valid_length;
 271
 272         /* Check if we have to enlarge the read buffer */
 273         if (len < READ_SIZE) {
 274             size_t n = l->rbuf_valid_length+READ_SIZE;
 275
 276             if (n >= BUFFER_LIMIT)
 277                 n = BUFFER_LIMIT;
 278
 279             if (l->rbuf_length >= n) {
 280                 /* The current buffer is large enough, let's just move the data to the front */
 281                 if (l->rbuf_valid_length)
 282                     memmove(l->rbuf, l->rbuf+l->rbuf_index, l->rbuf_valid_length);
 283             } else {
 284                 /* Enlarge the buffer */
 285                 char *new = pa_xmalloc(n);
 286                 if (l->rbuf_valid_length)
 287                     memcpy(new, l->rbuf+l->rbuf_index, l->rbuf_valid_length);
 288                 pa_xfree(l->rbuf);
 289                 l->rbuf = new;
 290                 l->rbuf_length = n;
 291             }
 292
 293             l->rbuf_index = 0;
 294         }
 295
 296         len = l->rbuf_length - l->rbuf_index - l->rbuf_valid_length;
 297
 298         pa_assert(len >= READ_SIZE);
 299
 300         /* Read some data */
 301         if ((r = pa_iochannel_read(l->io, l->rbuf+l->rbuf_index+l->rbuf_valid_length, len)) <= 0) {
 302             if (r < 0 && errno != ECONNRESET) {
 303                 pa_log("read(): %s", pa_cstrerror(errno));
 304                 failure(l, 0);
 305             } else
 306                 failure(l, 1);
 307
 308             return -1;
 309         }
 310
 311         l->rbuf_valid_length += r;
 312
 313         /* Look if a line has been terminated in the newly read data */
 314         scan_for_lines(l, l->rbuf_valid_length - r);
 315     }
 316
 317     return 0;
 318 }
 319
 320 /* Try to flush the buffer */
 321 static int do_write(pa_ioline *l) {
 322     ssize_t r;
 323
 324     pa_assert(l);
 325     pa_assert(PA_REFCNT_VALUE(l) >= 1);
 326
 327     while (!l->dead && pa_iochannel_is_writable(l->io) && l->wbuf_valid_length) {
 328
 329         if ((r = pa_iochannel_write(l->io, l->wbuf+l->wbuf_index, l->wbuf_valid_length)) <= 0) {
 330
 331             if (r < 0 && errno != EPIPE)
 332                 pa_log("write(): %s", pa_cstrerror(errno));
 333
 334             failure(l, 0);
 335
 336             return -1;
 337         }
 338
 339         l->wbuf_index += r;
 340         l->wbuf_valid_length -= r;
 341
 342         /* A shortcut for the next time */
 343         if (l->wbuf_valid_length == 0)
 344             l->wbuf_index = 0;
 345     }
 346
 347     return 0;
 348 }
 349
 350 /* Try to flush read/write data */
 351 static void do_work(pa_ioline *l) {
 352     pa_assert(l);
 353     pa_assert(PA_REFCNT_VALUE(l) >= 1);
 354
 355     pa_ioline_ref(l);
 356
 357     l->mainloop->defer_enable(l->defer_event, 0);
 358
 359     if (!l->dead)
 360         do_read(l);
 361
 362     if (!l->dead)
 363         do_write(l);
 364
 365     if (l->defer_close && !l->wbuf_valid_length)
 366         failure(l, 1);
 367
 368     pa_ioline_unref(l);
 369 }
 370
 371 static void io_callback(pa_iochannel*io, void *userdata) {
 372     pa_ioline *l = userdata;
 373
 374     pa_assert(io);
 375     pa_assert(l);
 376     pa_assert(PA_REFCNT_VALUE(l) >= 1);
 377
 378     do_work(l);
 379 }
 380
 381 static void defer_callback(pa_mainloop_api*m, pa_defer_event*e, void *userdata) {
 382     pa_ioline *l = userdata;
 383
 384     pa_assert(l);
 385     pa_assert(PA_REFCNT_VALUE(l) >= 1);
 386     pa_assert(l->mainloop == m);
 387     pa_assert(l->defer_event == e);
 388
 389     do_work(l);
 390 }
 391
 392 void pa_ioline_defer_close(pa_ioline *l) {
 393     pa_assert(l);
 394     pa_assert(PA_REFCNT_VALUE(l) >= 1);
 395
 396     l->defer_close = 1;
 397
 398     if (!l->wbuf_valid_length)
 399         l->mainloop->defer_enable(l->defer_event, 1);
 400 }
 401
 402 void pa_ioline_printf(pa_ioline *l, const char *format, ...) {
 403     char *t;
 404     va_list ap;
 405
 406     pa_assert(l);
 407     pa_assert(PA_REFCNT_VALUE(l) >= 1);
 408
 409     va_start(ap, format);
 410     t = pa_vsprintf_malloc(format, ap);
 411     va_end(ap);
 412
 413     pa_ioline_puts(l, t);
 414     pa_xfree(t);
 415 }