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