code.delx.au - pulseaudio/blob - src/polypcore/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 <polyp/error.h>
  33 #include <polyp/xmalloc.h>
  34
  35 #include <polypcore/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_xmalloc(sizeof(pa_ioline));
  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 && l->ref >= 1);
 110
 111     if ((--l->ref) <= 0)
 112         ioline_free(l);
 113 }
 114
 115 pa_ioline* pa_ioline_ref(pa_ioline *l) {
 116     assert(l && l->ref >= 1);
 117
 118     l->ref++;
 119     return l;
 120 }
 121
 122 void pa_ioline_close(pa_ioline *l) {
 123     assert(l && l->ref >= 1);
 124
 125     l->dead = 1;
 126     if (l->io) {
 127         pa_iochannel_free(l->io);
 128         l->io = NULL;
 129     }
 130
 131     if (l->defer_event) {
 132         l->mainloop->defer_free(l->defer_event);
 133         l->defer_event = NULL;
 134     }
 135 }
 136
 137 void pa_ioline_puts(pa_ioline *l, const char *c) {
 138     size_t len;
 139     assert(l && c && l->ref >= 1 && !l->dead);
 140
 141     pa_ioline_ref(l);
 142
 143     len = strlen(c);
 144     if (len > BUFFER_LIMIT - l->wbuf_valid_length)
 145         len = BUFFER_LIMIT - l->wbuf_valid_length;
 146
 147     if (len) {
 148         assert(l->wbuf_length >= l->wbuf_valid_length);
 149
 150         /* In case the allocated buffer is too small, enlarge it. */
 151         if (l->wbuf_valid_length + len > l->wbuf_length) {
 152             size_t n = l->wbuf_valid_length+len;
 153             char *new = pa_xmalloc(n);
 154             if (l->wbuf) {
 155                 memcpy(new, l->wbuf+l->wbuf_index, l->wbuf_valid_length);
 156                 pa_xfree(l->wbuf);
 157             }
 158             l->wbuf = new;
 159             l->wbuf_length = n;
 160             l->wbuf_index = 0;
 161         } else if (l->wbuf_index + l->wbuf_valid_length + len > l->wbuf_length) {
 162
 163             /* In case the allocated buffer fits, but the current index is too far from the start, move it to the front. */
 164             memmove(l->wbuf, l->wbuf+l->wbuf_index, l->wbuf_valid_length);
 165             l->wbuf_index = 0;
 166         }
 167
 168         assert(l->wbuf_index + l->wbuf_valid_length + len <= l->wbuf_length);
 169
 170         /* Append the new string */
 171         memcpy(l->wbuf + l->wbuf_index + l->wbuf_valid_length, c, len);
 172         l->wbuf_valid_length += len;
 173
 174         l->mainloop->defer_enable(l->defer_event, 1);
 175     }
 176
 177     pa_ioline_unref(l);
 178 }
 179
 180 void pa_ioline_set_callback(pa_ioline*l, void (*callback)(pa_ioline*io, const char *s, void *userdata), void *userdata) {
 181     assert(l && l->ref >= 1);
 182     l->callback = callback;
 183     l->userdata = userdata;
 184 }
 185
 186 static void failure(pa_ioline *l) {
 187     assert(l && l->ref >= 1 && !l->dead);
 188
 189     pa_ioline_close(l);
 190
 191     if (l->callback) {
 192         l->callback(l, NULL, l->userdata);
 193         l->callback = NULL;
 194     }
 195 }
 196
 197 static void scan_for_lines(pa_ioline *l, size_t skip) {
 198     assert(l && l->ref >= 1 && skip < l->rbuf_valid_length);
 199
 200     while (!l->dead && l->rbuf_valid_length > skip) {
 201         char *e, *p;
 202         size_t m;
 203
 204         if (!(e = memchr(l->rbuf + l->rbuf_index + skip, '\n', l->rbuf_valid_length - skip)))
 205             break;
 206
 207         *e = 0;
 208
 209         p = l->rbuf + l->rbuf_index;
 210         m = strlen(p);
 211
 212         l->rbuf_index += m+1;
 213         l->rbuf_valid_length -= m+1;
 214
 215         /* A shortcut for the next time */
 216         if (l->rbuf_valid_length == 0)
 217             l->rbuf_index = 0;
 218
 219         if (l->callback)
 220             l->callback(l, p, l->userdata);
 221
 222         skip = 0;
 223     }
 224
 225     /* If the buffer became too large and still no newline was found, drop it. */
 226     if (l->rbuf_valid_length >= BUFFER_LIMIT)
 227         l->rbuf_index = l->rbuf_valid_length = 0;
 228 }
 229
 230 static int do_write(pa_ioline *l);
 231
 232 static int do_read(pa_ioline *l) {
 233     assert(l && l->ref >= 1);
 234
 235     while (!l->dead && pa_iochannel_is_readable(l->io)) {
 236         ssize_t r;
 237         size_t len;
 238
 239         len = l->rbuf_length - l->rbuf_index - l->rbuf_valid_length;
 240
 241         /* Check if we have to enlarge the read buffer */
 242         if (len < READ_SIZE) {
 243             size_t n = l->rbuf_valid_length+READ_SIZE;
 244
 245             if (n >= BUFFER_LIMIT)
 246                 n = BUFFER_LIMIT;
 247
 248             if (l->rbuf_length >= n) {
 249                 /* The current buffer is large enough, let's just move the data to the front */
 250                 if (l->rbuf_valid_length)
 251                     memmove(l->rbuf, l->rbuf+l->rbuf_index, l->rbuf_valid_length);
 252             } else {
 253                 /* Enlarge the buffer */
 254                 char *new = pa_xmalloc(n);
 255                 if (l->rbuf_valid_length)
 256                     memcpy(new, l->rbuf+l->rbuf_index, l->rbuf_valid_length);
 257                 pa_xfree(l->rbuf);
 258                 l->rbuf = new;
 259                 l->rbuf_length = n;
 260             }
 261
 262             l->rbuf_index = 0;
 263         }
 264
 265         len = l->rbuf_length - l->rbuf_index - l->rbuf_valid_length;
 266
 267         assert(len >= READ_SIZE);
 268
 269         /* Read some data */
 270         r = pa_iochannel_read(l->io, l->rbuf+l->rbuf_index+l->rbuf_valid_length, len);
 271         if (r == 0) {
 272             /* Got an EOF, so fake an exit command. */
 273             l->rbuf_index = 0;
 274             snprintf (l->rbuf, l->rbuf_length, "exit\n");
 275             r = 5;
 276             pa_ioline_puts(l, "\nExiting.\n");
 277             do_write(l);
 278         } else if (r < 0) {
 279             pa_log(__FILE__": read(): %s", pa_cstrerror(errno));
 280             failure(l);
 281             return -1;
 282         }
 283
 284         l->rbuf_valid_length += r;
 285
 286         /* Look if a line has been terminated in the newly read data */
 287         scan_for_lines(l, l->rbuf_valid_length - r);
 288     }
 289
 290     return 0;
 291 }
 292
 293 /* Try to flush the buffer */
 294 static int do_write(pa_ioline *l) {
 295     ssize_t r;
 296     assert(l && l->ref >= 1);
 297
 298     while (!l->dead && pa_iochannel_is_writable(l->io) && l->wbuf_valid_length) {
 299
 300         if ((r = pa_iochannel_write(l->io, l->wbuf+l->wbuf_index, l->wbuf_valid_length)) < 0) {
 301             pa_log(__FILE__": write(): %s", r < 0 ? pa_cstrerror(errno) : "EOF");
 302             failure(l);
 303             return -1;
 304         }
 305
 306         l->wbuf_index += r;
 307         l->wbuf_valid_length -= r;
 308
 309         /* A shortcut for the next time */
 310         if (l->wbuf_valid_length == 0)
 311             l->wbuf_index = 0;
 312     }
 313
 314     return 0;
 315 }
 316
 317 /* Try to flush read/write data */
 318 static void do_work(pa_ioline *l) {
 319     assert(l && l->ref >= 1);
 320
 321     pa_ioline_ref(l);
 322
 323     l->mainloop->defer_enable(l->defer_event, 0);
 324
 325     if (!l->dead)
 326         do_write(l);
 327
 328     if (!l->dead)
 329         do_read(l);
 330
 331     if (l->defer_close && !l->wbuf_valid_length)
 332         failure(l);
 333
 334     pa_ioline_unref(l);
 335 }
 336
 337 static void io_callback(pa_iochannel*io, void *userdata) {
 338     pa_ioline *l = userdata;
 339     assert(io && l && l->ref >= 1);
 340
 341     do_work(l);
 342 }
 343
 344 static void defer_callback(pa_mainloop_api*m, pa_defer_event*e, void *userdata) {
 345     pa_ioline *l = userdata;
 346     assert(l && l->ref >= 1 && l->mainloop == m && l->defer_event == e);
 347
 348     do_work(l);
 349 }
 350
 351 void pa_ioline_defer_close(pa_ioline *l) {
 352     assert(l);
 353
 354     l->defer_close = 1;
 355
 356     if (!l->wbuf_valid_length)
 357         l->mainloop->defer_enable(l->defer_event, 1);
 358 }
 359
 360 void pa_ioline_printf(pa_ioline *s, const char *format, ...) {
 361     char *t;
 362     va_list ap;
 363
 364
 365     va_start(ap, format);
 366     t = pa_vsprintf_malloc(format, ap);
 367     va_end(ap);
 368
 369     pa_ioline_puts(s, t);
 370     pa_xfree(t);
 371 }