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