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1 /* GLIB - Library of useful routines for C programming
2  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
3  *
4  * giochannel.c: IO Channel abstraction
5  * Copyright 1998 Owen Taylor
6  *
7  * This library is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2 of the License, or (at your option) any later version.
11  *
12  * This library is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with this library; if not, write to the
19  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20  * Boston, MA 02111-1307, USA.
21  */
22 
23 /*
24  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
25  * file for a list of people on the GLib Team.  See the ChangeLog
26  * files for a list of changes.  These files are distributed with
27  * GLib at ftp://ftp.gtk.org/pub/gtk/.
28  */
29 
30 /*
31  * MT safe
32  */
33 
34 #include "config.h"
35 
36 #include <string.h>
37 #include <errno.h>
38 
39 #ifdef HAVE_UNISTD_H
40 #include <unistd.h>
41 #endif
42 
43 #undef G_DISABLE_DEPRECATED
44 
45 #include "glib.h"
46 
47 #include "giochannel.h"
48 
49 #include "glibintl.h"
50 
51 #include "galias.h"
52 
53 #define G_IO_NICE_BUF_SIZE	1024
54 
55 /* This needs to be as wide as the largest character in any possible encoding */
56 #define MAX_CHAR_SIZE		10
57 
58 /* Some simplifying macros, which reduce the need to worry whether the
59  * buffers have been allocated. These also make USE_BUF () an lvalue,
60  * which is used in g_io_channel_read_to_end ().
61  */
62 #define USE_BUF(channel)	((channel)->encoding ? (channel)->encoded_read_buf \
63 				 : (channel)->read_buf)
64 #define BUF_LEN(string)		((string) ? (string)->len : 0)
65 
66 static GIOError		g_io_error_get_from_g_error	(GIOStatus    status,
67 							 GError      *err);
68 static void		g_io_channel_purge		(GIOChannel  *channel);
69 static GIOStatus	g_io_channel_fill_buffer	(GIOChannel  *channel,
70 							 GError     **err);
71 static GIOStatus	g_io_channel_read_line_backend	(GIOChannel  *channel,
72 							 gsize       *length,
73 							 gsize       *terminator_pos,
74 							 GError     **error);
75 
76 /**
77  * g_io_channel_init:
78  * @channel: a #GIOChannel
79  *
80  * Initializes a #GIOChannel struct.
81  *
82  * This is called by each of the above functions when creating a
83  * #GIOChannel, and so is not often needed by the application
84  * programmer (unless you are creating a new type of #GIOChannel).
85  */
86 void
g_io_channel_init(GIOChannel * channel)87 g_io_channel_init (GIOChannel *channel)
88 {
89   channel->ref_count = 1;
90   channel->encoding = g_strdup ("UTF-8");
91   channel->line_term = NULL;
92   channel->line_term_len = 0;
93   channel->buf_size = G_IO_NICE_BUF_SIZE;
94   channel->read_cd = (GIConv) -1;
95   channel->write_cd = (GIConv) -1;
96   channel->read_buf = NULL; /* Lazy allocate buffers */
97   channel->encoded_read_buf = NULL;
98   channel->write_buf = NULL;
99   channel->partial_write_buf[0] = '\0';
100   channel->use_buffer = TRUE;
101   channel->do_encode = FALSE;
102   channel->close_on_unref = FALSE;
103 }
104 
105 /**
106  * g_io_channel_ref:
107  * @channel: a #GIOChannel
108  *
109  * Increments the reference count of a #GIOChannel.
110  *
111  * Returns: the @channel that was passed in (since 2.6)
112  */
113 GIOChannel *
g_io_channel_ref(GIOChannel * channel)114 g_io_channel_ref (GIOChannel *channel)
115 {
116   g_return_val_if_fail (channel != NULL, NULL);
117 
118   g_atomic_int_inc (&channel->ref_count);
119 
120   return channel;
121 }
122 
123 /**
124  * g_io_channel_unref:
125  * @channel: a #GIOChannel
126  *
127  * Decrements the reference count of a #GIOChannel.
128  */
129 void
g_io_channel_unref(GIOChannel * channel)130 g_io_channel_unref (GIOChannel *channel)
131 {
132   gboolean is_zero;
133 
134   g_return_if_fail (channel != NULL);
135 
136   is_zero = g_atomic_int_dec_and_test (&channel->ref_count);
137 
138   if (G_UNLIKELY (is_zero))
139     {
140       if (channel->close_on_unref)
141         g_io_channel_shutdown (channel, TRUE, NULL);
142       else
143         g_io_channel_purge (channel);
144       g_free (channel->encoding);
145       if (channel->read_cd != (GIConv) -1)
146         g_iconv_close (channel->read_cd);
147       if (channel->write_cd != (GIConv) -1)
148         g_iconv_close (channel->write_cd);
149       g_free (channel->line_term);
150       if (channel->read_buf)
151         g_string_free (channel->read_buf, TRUE);
152       if (channel->write_buf)
153         g_string_free (channel->write_buf, TRUE);
154       if (channel->encoded_read_buf)
155         g_string_free (channel->encoded_read_buf, TRUE);
156       channel->funcs->io_free (channel);
157     }
158 }
159 
160 static GIOError
g_io_error_get_from_g_error(GIOStatus status,GError * err)161 g_io_error_get_from_g_error (GIOStatus  status,
162 			     GError    *err)
163 {
164   switch (status)
165     {
166       case G_IO_STATUS_NORMAL:
167       case G_IO_STATUS_EOF:
168         return G_IO_ERROR_NONE;
169       case G_IO_STATUS_AGAIN:
170         return G_IO_ERROR_AGAIN;
171       case G_IO_STATUS_ERROR:
172 	g_return_val_if_fail (err != NULL, G_IO_ERROR_UNKNOWN);
173 
174         if (err->domain != G_IO_CHANNEL_ERROR)
175           return G_IO_ERROR_UNKNOWN;
176         switch (err->code)
177           {
178             case G_IO_CHANNEL_ERROR_INVAL:
179               return G_IO_ERROR_INVAL;
180             default:
181               return G_IO_ERROR_UNKNOWN;
182           }
183       default:
184         g_assert_not_reached ();
185     }
186 }
187 
188 /**
189  * g_io_channel_read:
190  * @channel: a #GIOChannel
191  * @buf: a buffer to read the data into (which should be at least
192  *       count bytes long)
193  * @count: the number of bytes to read from the #GIOChannel
194  * @bytes_read: returns the number of bytes actually read
195  *
196  * Reads data from a #GIOChannel.
197  *
198  * Return value: %G_IO_ERROR_NONE if the operation was successful.
199  *
200  * Deprecated:2.2: Use g_io_channel_read_chars() instead.
201  **/
202 GIOError
g_io_channel_read(GIOChannel * channel,gchar * buf,gsize count,gsize * bytes_read)203 g_io_channel_read (GIOChannel *channel,
204 		   gchar      *buf,
205 		   gsize       count,
206 		   gsize      *bytes_read)
207 {
208   GError *err = NULL;
209   GIOError error;
210   GIOStatus status;
211 
212   g_return_val_if_fail (channel != NULL, G_IO_ERROR_UNKNOWN);
213   g_return_val_if_fail (bytes_read != NULL, G_IO_ERROR_UNKNOWN);
214 
215   if (count == 0)
216     {
217       if (bytes_read)
218         *bytes_read = 0;
219       return G_IO_ERROR_NONE;
220     }
221 
222   g_return_val_if_fail (buf != NULL, G_IO_ERROR_UNKNOWN);
223 
224   status = channel->funcs->io_read (channel, buf, count, bytes_read, &err);
225 
226   error = g_io_error_get_from_g_error (status, err);
227 
228   if (err)
229     g_error_free (err);
230 
231   return error;
232 }
233 
234 /**
235  * g_io_channel_write:
236  * @channel:  a #GIOChannel
237  * @buf: the buffer containing the data to write
238  * @count: the number of bytes to write
239  * @bytes_written: the number of bytes actually written
240  *
241  * Writes data to a #GIOChannel.
242  *
243  * Return value:  %G_IO_ERROR_NONE if the operation was successful.
244  *
245  * Deprecated:2.2: Use g_io_channel_write_chars() instead.
246  **/
247 GIOError
g_io_channel_write(GIOChannel * channel,const gchar * buf,gsize count,gsize * bytes_written)248 g_io_channel_write (GIOChannel  *channel,
249 		    const gchar *buf,
250 		    gsize        count,
251 		    gsize       *bytes_written)
252 {
253   GError *err = NULL;
254   GIOError error;
255   GIOStatus status;
256 
257   g_return_val_if_fail (channel != NULL, G_IO_ERROR_UNKNOWN);
258   g_return_val_if_fail (bytes_written != NULL, G_IO_ERROR_UNKNOWN);
259 
260   status = channel->funcs->io_write (channel, buf, count, bytes_written, &err);
261 
262   error = g_io_error_get_from_g_error (status, err);
263 
264   if (err)
265     g_error_free (err);
266 
267   return error;
268 }
269 
270 /**
271  * g_io_channel_seek:
272  * @channel: a #GIOChannel
273  * @offset: an offset, in bytes, which is added to the position specified
274  *          by @type
275  * @type: the position in the file, which can be %G_SEEK_CUR (the current
276  *        position), %G_SEEK_SET (the start of the file), or %G_SEEK_END
277  *        (the end of the file)
278  *
279  * Sets the current position in the #GIOChannel, similar to the standard
280  * library function fseek().
281  *
282  * Return value: %G_IO_ERROR_NONE if the operation was successful.
283  *
284  * Deprecated:2.2: Use g_io_channel_seek_position() instead.
285  **/
286 GIOError
g_io_channel_seek(GIOChannel * channel,gint64 offset,GSeekType type)287 g_io_channel_seek (GIOChannel *channel,
288 		   gint64      offset,
289 		   GSeekType   type)
290 {
291   GError *err = NULL;
292   GIOError error;
293   GIOStatus status;
294 
295   g_return_val_if_fail (channel != NULL, G_IO_ERROR_UNKNOWN);
296   g_return_val_if_fail (channel->is_seekable, G_IO_ERROR_UNKNOWN);
297 
298   switch (type)
299     {
300       case G_SEEK_CUR:
301       case G_SEEK_SET:
302       case G_SEEK_END:
303         break;
304       default:
305         g_warning ("g_io_channel_seek: unknown seek type");
306         return G_IO_ERROR_UNKNOWN;
307     }
308 
309   status = channel->funcs->io_seek (channel, offset, type, &err);
310 
311   error = g_io_error_get_from_g_error (status, err);
312 
313   if (err)
314     g_error_free (err);
315 
316   return error;
317 }
318 
319 /* The function g_io_channel_new_file() is prototyped in both
320  * giounix.c and giowin32.c, so we stick its documentation here.
321  */
322 
323 /**
324  * g_io_channel_new_file:
325  * @filename: A string containing the name of a file
326  * @mode: One of "r", "w", "a", "r+", "w+", "a+". These have
327  *        the same meaning as in fopen()
328  * @error: A location to return an error of type %G_FILE_ERROR
329  *
330  * Open a file @filename as a #GIOChannel using mode @mode. This
331  * channel will be closed when the last reference to it is dropped,
332  * so there is no need to call g_io_channel_close() (though doing
333  * so will not cause problems, as long as no attempt is made to
334  * access the channel after it is closed).
335  *
336  * Return value: A #GIOChannel on success, %NULL on failure.
337  **/
338 
339 /**
340  * g_io_channel_close:
341  * @channel: A #GIOChannel
342  *
343  * Close an IO channel. Any pending data to be written will be
344  * flushed, ignoring errors. The channel will not be freed until the
345  * last reference is dropped using g_io_channel_unref().
346  *
347  * Deprecated:2.2: Use g_io_channel_shutdown() instead.
348  **/
349 void
g_io_channel_close(GIOChannel * channel)350 g_io_channel_close (GIOChannel *channel)
351 {
352   GError *err = NULL;
353 
354   g_return_if_fail (channel != NULL);
355 
356   g_io_channel_purge (channel);
357 
358   channel->funcs->io_close (channel, &err);
359 
360   if (err)
361     { /* No way to return the error */
362       g_warning ("Error closing channel: %s", err->message);
363       g_error_free (err);
364     }
365 
366   channel->close_on_unref = FALSE; /* Because we already did */
367   channel->is_readable = FALSE;
368   channel->is_writeable = FALSE;
369   channel->is_seekable = FALSE;
370 }
371 
372 /**
373  * g_io_channel_shutdown:
374  * @channel: a #GIOChannel
375  * @flush: if %TRUE, flush pending
376  * @err: location to store a #GIOChannelError
377  *
378  * Close an IO channel. Any pending data to be written will be
379  * flushed if @flush is %TRUE. The channel will not be freed until the
380  * last reference is dropped using g_io_channel_unref().
381  *
382  * Return value: the status of the operation.
383  **/
384 GIOStatus
g_io_channel_shutdown(GIOChannel * channel,gboolean flush,GError ** err)385 g_io_channel_shutdown (GIOChannel  *channel,
386 		       gboolean     flush,
387 		       GError     **err)
388 {
389   GIOStatus status, result;
390   GError *tmperr = NULL;
391 
392   g_return_val_if_fail (channel != NULL, G_IO_STATUS_ERROR);
393   g_return_val_if_fail (err == NULL || *err == NULL, G_IO_STATUS_ERROR);
394 
395   if (channel->write_buf && channel->write_buf->len > 0)
396     {
397       if (flush)
398         {
399           GIOFlags flags;
400 
401           /* Set the channel to blocking, to avoid a busy loop
402            */
403           flags = g_io_channel_get_flags (channel);
404           /* Ignore any errors here, they're irrelevant */
405           g_io_channel_set_flags (channel, flags & ~G_IO_FLAG_NONBLOCK, NULL);
406 
407           result = g_io_channel_flush (channel, &tmperr);
408         }
409       else
410         result = G_IO_STATUS_NORMAL;
411 
412       g_string_truncate(channel->write_buf, 0);
413     }
414   else
415     result = G_IO_STATUS_NORMAL;
416 
417   if (channel->partial_write_buf[0] != '\0')
418     {
419       if (flush)
420         g_warning ("Partial character at end of write buffer not flushed.\n");
421       channel->partial_write_buf[0] = '\0';
422     }
423 
424   status = channel->funcs->io_close (channel, err);
425 
426   channel->close_on_unref = FALSE; /* Because we already did */
427   channel->is_readable = FALSE;
428   channel->is_writeable = FALSE;
429   channel->is_seekable = FALSE;
430 
431   if (status != G_IO_STATUS_NORMAL)
432     {
433       g_clear_error (&tmperr);
434       return status;
435     }
436   else if (result != G_IO_STATUS_NORMAL)
437     {
438       g_propagate_error (err, tmperr);
439       return result;
440     }
441   else
442     return G_IO_STATUS_NORMAL;
443 }
444 
445 /* This function is used for the final flush on close or unref */
446 static void
g_io_channel_purge(GIOChannel * channel)447 g_io_channel_purge (GIOChannel *channel)
448 {
449   GError *err = NULL;
450   GIOStatus status;
451 
452   g_return_if_fail (channel != NULL);
453 
454   if (channel->write_buf && channel->write_buf->len > 0)
455     {
456       GIOFlags flags;
457 
458       /* Set the channel to blocking, to avoid a busy loop
459        */
460       flags = g_io_channel_get_flags (channel);
461       g_io_channel_set_flags (channel, flags & ~G_IO_FLAG_NONBLOCK, NULL);
462 
463       status = g_io_channel_flush (channel, &err);
464 
465       if (err)
466 	{ /* No way to return the error */
467 	  g_warning ("Error flushing string: %s", err->message);
468 	  g_error_free (err);
469 	}
470     }
471 
472   /* Flush these in case anyone tries to close without unrefing */
473 
474   if (channel->read_buf)
475     g_string_truncate (channel->read_buf, 0);
476   if (channel->write_buf)
477     g_string_truncate (channel->write_buf, 0);
478   if (channel->encoding)
479     {
480       if (channel->encoded_read_buf)
481         g_string_truncate (channel->encoded_read_buf, 0);
482 
483       if (channel->partial_write_buf[0] != '\0')
484         {
485           g_warning ("Partial character at end of write buffer not flushed.\n");
486           channel->partial_write_buf[0] = '\0';
487         }
488     }
489 }
490 
491 /**
492  * g_io_create_watch:
493  * @channel: a #GIOChannel to watch
494  * @condition: conditions to watch for
495  *
496  * Creates a #GSource that's dispatched when @condition is met for the
497  * given @channel. For example, if condition is #G_IO_IN, the source will
498  * be dispatched when there's data available for reading.
499  *
500  * g_io_add_watch() is a simpler interface to this same functionality, for
501  * the case where you want to add the source to the default main loop context
502  * at the default priority.
503  *
504  * On Windows, polling a #GSource created to watch a channel for a socket
505  * puts the socket in non-blocking mode. This is a side-effect of the
506  * implementation and unavoidable.
507  *
508  * Returns: a new #GSource
509  */
510 GSource *
g_io_create_watch(GIOChannel * channel,GIOCondition condition)511 g_io_create_watch (GIOChannel   *channel,
512 		   GIOCondition  condition)
513 {
514   g_return_val_if_fail (channel != NULL, NULL);
515 
516   return channel->funcs->io_create_watch (channel, condition);
517 }
518 
519 /**
520  * g_io_add_watch_full:
521  * @channel: a #GIOChannel
522  * @priority: the priority of the #GIOChannel source
523  * @condition: the condition to watch for
524  * @func: the function to call when the condition is satisfied
525  * @user_data: user data to pass to @func
526  * @notify: the function to call when the source is removed
527  *
528  * Adds the #GIOChannel into the default main loop context
529  * with the given priority.
530  *
531  * This internally creates a main loop source using g_io_create_watch()
532  * and attaches it to the main loop context with g_source_attach().
533  * You can do these steps manuallt if you need greater control.
534  *
535  * Returns: the event source id
536  */
537 guint
g_io_add_watch_full(GIOChannel * channel,gint priority,GIOCondition condition,GIOFunc func,gpointer user_data,GDestroyNotify notify)538 g_io_add_watch_full (GIOChannel    *channel,
539 		     gint           priority,
540 		     GIOCondition   condition,
541 		     GIOFunc        func,
542 		     gpointer       user_data,
543 		     GDestroyNotify notify)
544 {
545   GSource *source;
546   guint id;
547 
548   g_return_val_if_fail (channel != NULL, 0);
549 
550   source = g_io_create_watch (channel, condition);
551 
552   if (priority != G_PRIORITY_DEFAULT)
553     g_source_set_priority (source, priority);
554   g_source_set_callback (source, (GSourceFunc)func, user_data, notify);
555 
556   id = g_source_attach (source, NULL);
557   g_source_unref (source);
558 
559   return id;
560 }
561 
562 /**
563  * g_io_add_watch:
564  * @channel: a #GIOChannel
565  * @condition: the condition to watch for
566  * @func: the function to call when the condition is satisfied
567  * @user_data: user data to pass to @func
568  *
569  * Adds the #GIOChannel into the default main loop context
570  * with the default priority.
571  *
572  * Returns: the event source id
573  */
574 guint
g_io_add_watch(GIOChannel * channel,GIOCondition condition,GIOFunc func,gpointer user_data)575 g_io_add_watch (GIOChannel   *channel,
576 		GIOCondition  condition,
577 		GIOFunc       func,
578 		gpointer      user_data)
579 {
580   return g_io_add_watch_full (channel, G_PRIORITY_DEFAULT, condition, func, user_data, NULL);
581 }
582 
583 /**
584  * g_io_channel_get_buffer_condition:
585  * @channel: A #GIOChannel
586  *
587  * This function returns a #GIOCondition depending on whether there
588  * is data to be read/space to write data in the internal buffers in
589  * the #GIOChannel. Only the flags %G_IO_IN and %G_IO_OUT may be set.
590  *
591  * Return value: A #GIOCondition
592  **/
593 GIOCondition
g_io_channel_get_buffer_condition(GIOChannel * channel)594 g_io_channel_get_buffer_condition (GIOChannel *channel)
595 {
596   GIOCondition condition = 0;
597 
598   if (channel->encoding)
599     {
600       if (channel->encoded_read_buf && (channel->encoded_read_buf->len > 0))
601         condition |= G_IO_IN; /* Only return if we have full characters */
602     }
603   else
604     {
605       if (channel->read_buf && (channel->read_buf->len > 0))
606         condition |= G_IO_IN;
607     }
608 
609   if (channel->write_buf && (channel->write_buf->len < channel->buf_size))
610     condition |= G_IO_OUT;
611 
612   return condition;
613 }
614 
615 /**
616  * g_io_channel_error_from_errno:
617  * @en: an <literal>errno</literal> error number, e.g. %EINVAL
618  *
619  * Converts an <literal>errno</literal> error number to a #GIOChannelError.
620  *
621  * Return value: a #GIOChannelError error number, e.g.
622  *      %G_IO_CHANNEL_ERROR_INVAL.
623  **/
624 GIOChannelError
g_io_channel_error_from_errno(gint en)625 g_io_channel_error_from_errno (gint en)
626 {
627 #ifdef EAGAIN
628   g_return_val_if_fail (en != EAGAIN, G_IO_CHANNEL_ERROR_FAILED);
629 #endif
630 
631   switch (en)
632     {
633 #ifdef EBADF
634     case EBADF:
635       g_warning("Invalid file descriptor.\n");
636       return G_IO_CHANNEL_ERROR_FAILED;
637 #endif
638 
639 #ifdef EFAULT
640     case EFAULT:
641       g_warning("Buffer outside valid address space.\n");
642       return G_IO_CHANNEL_ERROR_FAILED;
643 #endif
644 
645 #ifdef EFBIG
646     case EFBIG:
647       return G_IO_CHANNEL_ERROR_FBIG;
648 #endif
649 
650 #ifdef EINTR
651     /* In general, we should catch EINTR before we get here,
652      * but close() is allowed to return EINTR by POSIX, so
653      * we need to catch it here; EINTR from close() is
654      * unrecoverable, because it's undefined whether
655      * the fd was actually closed or not, so we just return
656      * a generic error code.
657      */
658     case EINTR:
659       return G_IO_CHANNEL_ERROR_FAILED;
660 #endif
661 
662 #ifdef EINVAL
663     case EINVAL:
664       return G_IO_CHANNEL_ERROR_INVAL;
665 #endif
666 
667 #ifdef EIO
668     case EIO:
669       return G_IO_CHANNEL_ERROR_IO;
670 #endif
671 
672 #ifdef EISDIR
673     case EISDIR:
674       return G_IO_CHANNEL_ERROR_ISDIR;
675 #endif
676 
677 #ifdef ENOSPC
678     case ENOSPC:
679       return G_IO_CHANNEL_ERROR_NOSPC;
680 #endif
681 
682 #ifdef ENXIO
683     case ENXIO:
684       return G_IO_CHANNEL_ERROR_NXIO;
685 #endif
686 
687 #ifdef EOVERFLOW
688     case EOVERFLOW:
689       return G_IO_CHANNEL_ERROR_OVERFLOW;
690 #endif
691 
692 #ifdef EPIPE
693     case EPIPE:
694       return G_IO_CHANNEL_ERROR_PIPE;
695 #endif
696 
697     default:
698       return G_IO_CHANNEL_ERROR_FAILED;
699     }
700 }
701 
702 /**
703  * g_io_channel_set_buffer_size:
704  * @channel: a #GIOChannel
705  * @size: the size of the buffer, or 0 to let GLib pick a good size
706  *
707  * Sets the buffer size.
708  **/
709 void
g_io_channel_set_buffer_size(GIOChannel * channel,gsize size)710 g_io_channel_set_buffer_size (GIOChannel *channel,
711                               gsize       size)
712 {
713   g_return_if_fail (channel != NULL);
714 
715   if (size == 0)
716     size = G_IO_NICE_BUF_SIZE;
717 
718   if (size < MAX_CHAR_SIZE)
719     size = MAX_CHAR_SIZE;
720 
721   channel->buf_size = size;
722 }
723 
724 /**
725  * g_io_channel_get_buffer_size:
726  * @channel: a #GIOChannel
727  *
728  * Gets the buffer size.
729  *
730  * Return value: the size of the buffer.
731  **/
732 gsize
g_io_channel_get_buffer_size(GIOChannel * channel)733 g_io_channel_get_buffer_size (GIOChannel *channel)
734 {
735   g_return_val_if_fail (channel != NULL, 0);
736 
737   return channel->buf_size;
738 }
739 
740 /**
741  * g_io_channel_set_line_term:
742  * @channel: a #GIOChannel
743  * @line_term: The line termination string. Use %NULL for autodetect.
744  *             Autodetection breaks on "\n", "\r\n", "\r", "\0", and
745  *             the Unicode paragraph separator. Autodetection should
746  *             not be used for anything other than file-based channels.
747  * @length: The length of the termination string. If -1 is passed, the
748  *          string is assumed to be nul-terminated. This option allows
749  *          termination strings with embedded nuls.
750  *
751  * This sets the string that #GIOChannel uses to determine
752  * where in the file a line break occurs.
753  **/
754 void
g_io_channel_set_line_term(GIOChannel * channel,const gchar * line_term,gint length)755 g_io_channel_set_line_term (GIOChannel	*channel,
756                             const gchar	*line_term,
757 			    gint         length)
758 {
759   g_return_if_fail (channel != NULL);
760   g_return_if_fail (line_term == NULL || length != 0); /* Disallow "" */
761 
762   if (line_term == NULL)
763     length = 0;
764   else if (length < 0)
765     length = strlen (line_term);
766 
767   g_free (channel->line_term);
768   channel->line_term = line_term ? g_memdup (line_term, length) : NULL;
769   channel->line_term_len = length;
770 }
771 
772 /**
773  * g_io_channel_get_line_term:
774  * @channel: a #GIOChannel
775  * @length: a location to return the length of the line terminator
776  *
777  * This returns the string that #GIOChannel uses to determine
778  * where in the file a line break occurs. A value of %NULL
779  * indicates autodetection.
780  *
781  * Return value: The line termination string. This value
782  *   is owned by GLib and must not be freed.
783  **/
784 G_CONST_RETURN gchar*
g_io_channel_get_line_term(GIOChannel * channel,gint * length)785 g_io_channel_get_line_term (GIOChannel *channel,
786 			    gint       *length)
787 {
788   g_return_val_if_fail (channel != NULL, NULL);
789 
790   if (length)
791     *length = channel->line_term_len;
792 
793   return channel->line_term;
794 }
795 
796 /**
797  * g_io_channel_set_flags:
798  * @channel: a #GIOChannel
799  * @flags: the flags to set on the IO channel
800  * @error: A location to return an error of type #GIOChannelError
801  *
802  * Sets the (writeable) flags in @channel to (@flags & %G_IO_CHANNEL_SET_MASK).
803  *
804  * Return value: the status of the operation.
805  **/
806 GIOStatus
g_io_channel_set_flags(GIOChannel * channel,GIOFlags flags,GError ** error)807 g_io_channel_set_flags (GIOChannel  *channel,
808                         GIOFlags     flags,
809                         GError     **error)
810 {
811   g_return_val_if_fail (channel != NULL, G_IO_STATUS_ERROR);
812   g_return_val_if_fail ((error == NULL) || (*error == NULL),
813 			G_IO_STATUS_ERROR);
814 
815   return (*channel->funcs->io_set_flags) (channel,
816 					  flags & G_IO_FLAG_SET_MASK,
817 					  error);
818 }
819 
820 /**
821  * g_io_channel_get_flags:
822  * @channel: a #GIOChannel
823  *
824  * Gets the current flags for a #GIOChannel, including read-only
825  * flags such as %G_IO_FLAG_IS_READABLE.
826  *
827  * The values of the flags %G_IO_FLAG_IS_READABLE and %G_IO_FLAG_IS_WRITEABLE
828  * are cached for internal use by the channel when it is created.
829  * If they should change at some later point (e.g. partial shutdown
830  * of a socket with the UNIX shutdown() function), the user
831  * should immediately call g_io_channel_get_flags() to update
832  * the internal values of these flags.
833  *
834  * Return value: the flags which are set on the channel
835  **/
836 GIOFlags
g_io_channel_get_flags(GIOChannel * channel)837 g_io_channel_get_flags (GIOChannel *channel)
838 {
839   GIOFlags flags;
840 
841   g_return_val_if_fail (channel != NULL, 0);
842 
843   flags = (* channel->funcs->io_get_flags) (channel);
844 
845   /* Cross implementation code */
846 
847   if (channel->is_seekable)
848     flags |= G_IO_FLAG_IS_SEEKABLE;
849   if (channel->is_readable)
850     flags |= G_IO_FLAG_IS_READABLE;
851   if (channel->is_writeable)
852     flags |= G_IO_FLAG_IS_WRITEABLE;
853 
854   return flags;
855 }
856 
857 /**
858  * g_io_channel_set_close_on_unref:
859  * @channel: a #GIOChannel
860  * @do_close: Whether to close the channel on the final unref of
861  *            the GIOChannel data structure. The default value of
862  *            this is %TRUE for channels created by g_io_channel_new_file (),
863  *            and %FALSE for all other channels.
864  *
865  * Setting this flag to %TRUE for a channel you have already closed
866  * can cause problems.
867  **/
868 void
g_io_channel_set_close_on_unref(GIOChannel * channel,gboolean do_close)869 g_io_channel_set_close_on_unref	(GIOChannel *channel,
870 				 gboolean    do_close)
871 {
872   g_return_if_fail (channel != NULL);
873 
874   channel->close_on_unref = do_close;
875 }
876 
877 /**
878  * g_io_channel_get_close_on_unref:
879  * @channel: a #GIOChannel.
880  *
881  * Returns whether the file/socket/whatever associated with @channel
882  * will be closed when @channel receives its final unref and is
883  * destroyed. The default value of this is %TRUE for channels created
884  * by g_io_channel_new_file (), and %FALSE for all other channels.
885  *
886  * Return value: Whether the channel will be closed on the final unref of
887  *               the GIOChannel data structure.
888  **/
889 gboolean
g_io_channel_get_close_on_unref(GIOChannel * channel)890 g_io_channel_get_close_on_unref	(GIOChannel *channel)
891 {
892   g_return_val_if_fail (channel != NULL, FALSE);
893 
894   return channel->close_on_unref;
895 }
896 
897 /**
898  * g_io_channel_seek_position:
899  * @channel: a #GIOChannel
900  * @offset: The offset in bytes from the position specified by @type
901  * @type: a #GSeekType. The type %G_SEEK_CUR is only allowed in those
902  *                      cases where a call to g_io_channel_set_encoding ()
903  *                      is allowed. See the documentation for
904  *                      g_io_channel_set_encoding () for details.
905  * @error: A location to return an error of type #GIOChannelError
906  *
907  * Replacement for g_io_channel_seek() with the new API.
908  *
909  * Return value: the status of the operation.
910  **/
911 GIOStatus
g_io_channel_seek_position(GIOChannel * channel,gint64 offset,GSeekType type,GError ** error)912 g_io_channel_seek_position (GIOChannel  *channel,
913                             gint64       offset,
914                             GSeekType    type,
915                             GError     **error)
916 {
917   GIOStatus status;
918 
919   /* For files, only one of the read and write buffers can contain data.
920    * For sockets, both can contain data.
921    */
922 
923   g_return_val_if_fail (channel != NULL, G_IO_STATUS_ERROR);
924   g_return_val_if_fail ((error == NULL) || (*error == NULL),
925 			G_IO_STATUS_ERROR);
926   g_return_val_if_fail (channel->is_seekable, G_IO_STATUS_ERROR);
927 
928   switch (type)
929     {
930       case G_SEEK_CUR: /* The user is seeking relative to the head of the buffer */
931         if (channel->use_buffer)
932           {
933             if (channel->do_encode && channel->encoded_read_buf
934                 && channel->encoded_read_buf->len > 0)
935               {
936                 g_warning ("Seek type G_SEEK_CUR not allowed for this"
937                   " channel's encoding.\n");
938                 return G_IO_STATUS_ERROR;
939               }
940           if (channel->read_buf)
941             offset -= channel->read_buf->len;
942           if (channel->encoded_read_buf)
943             {
944               g_assert (channel->encoded_read_buf->len == 0 || !channel->do_encode);
945 
946               /* If there's anything here, it's because the encoding is UTF-8,
947                * so we can just subtract the buffer length, the same as for
948                * the unencoded data.
949                */
950 
951               offset -= channel->encoded_read_buf->len;
952             }
953           }
954         break;
955       case G_SEEK_SET:
956       case G_SEEK_END:
957         break;
958       default:
959         g_warning ("g_io_channel_seek_position: unknown seek type");
960         return G_IO_STATUS_ERROR;
961     }
962 
963   if (channel->use_buffer)
964     {
965       status = g_io_channel_flush (channel, error);
966       if (status != G_IO_STATUS_NORMAL)
967         return status;
968     }
969 
970   status = channel->funcs->io_seek (channel, offset, type, error);
971 
972   if ((status == G_IO_STATUS_NORMAL) && (channel->use_buffer))
973     {
974       if (channel->read_buf)
975         g_string_truncate (channel->read_buf, 0);
976 
977       /* Conversion state no longer matches position in file */
978       if (channel->read_cd != (GIConv) -1)
979         g_iconv (channel->read_cd, NULL, NULL, NULL, NULL);
980       if (channel->write_cd != (GIConv) -1)
981         g_iconv (channel->write_cd, NULL, NULL, NULL, NULL);
982 
983       if (channel->encoded_read_buf)
984         {
985           g_assert (channel->encoded_read_buf->len == 0 || !channel->do_encode);
986           g_string_truncate (channel->encoded_read_buf, 0);
987         }
988 
989       if (channel->partial_write_buf[0] != '\0')
990         {
991           g_warning ("Partial character at end of write buffer not flushed.\n");
992           channel->partial_write_buf[0] = '\0';
993         }
994     }
995 
996   return status;
997 }
998 
999 /**
1000  * g_io_channel_flush:
1001  * @channel: a #GIOChannel
1002  * @error: location to store an error of type #GIOChannelError
1003  *
1004  * Flushes the write buffer for the GIOChannel.
1005  *
1006  * Return value: the status of the operation: One of
1007  *   #G_IO_STATUS_NORMAL, #G_IO_STATUS_AGAIN, or
1008  *   #G_IO_STATUS_ERROR.
1009  **/
1010 GIOStatus
g_io_channel_flush(GIOChannel * channel,GError ** error)1011 g_io_channel_flush (GIOChannel	*channel,
1012 		    GError     **error)
1013 {
1014   GIOStatus status;
1015   gsize this_time = 1, bytes_written = 0;
1016 
1017   g_return_val_if_fail (channel != NULL, G_IO_STATUS_ERROR);
1018   g_return_val_if_fail ((error == NULL) || (*error == NULL), G_IO_STATUS_ERROR);
1019 
1020   if (channel->write_buf == NULL || channel->write_buf->len == 0)
1021     return G_IO_STATUS_NORMAL;
1022 
1023   do
1024     {
1025       g_assert (this_time > 0);
1026 
1027       status = channel->funcs->io_write (channel,
1028 					 channel->write_buf->str + bytes_written,
1029 					 channel->write_buf->len - bytes_written,
1030 					 &this_time, error);
1031       bytes_written += this_time;
1032     }
1033   while ((bytes_written < channel->write_buf->len)
1034          && (status == G_IO_STATUS_NORMAL));
1035 
1036   g_string_erase (channel->write_buf, 0, bytes_written);
1037 
1038   return status;
1039 }
1040 
1041 /**
1042  * g_io_channel_set_buffered:
1043  * @channel: a #GIOChannel
1044  * @buffered: whether to set the channel buffered or unbuffered
1045  *
1046  * The buffering state can only be set if the channel's encoding
1047  * is %NULL. For any other encoding, the channel must be buffered.
1048  *
1049  * A buffered channel can only be set unbuffered if the channel's
1050  * internal buffers have been flushed. Newly created channels or
1051  * channels which have returned %G_IO_STATUS_EOF
1052  * not require such a flush. For write-only channels, a call to
1053  * g_io_channel_flush () is sufficient. For all other channels,
1054  * the buffers may be flushed by a call to g_io_channel_seek_position ().
1055  * This includes the possibility of seeking with seek type %G_SEEK_CUR
1056  * and an offset of zero. Note that this means that socket-based
1057  * channels cannot be set unbuffered once they have had data
1058  * read from them.
1059  *
1060  * On unbuffered channels, it is safe to mix read and write
1061  * calls from the new and old APIs, if this is necessary for
1062  * maintaining old code.
1063  *
1064  * The default state of the channel is buffered.
1065  **/
1066 void
g_io_channel_set_buffered(GIOChannel * channel,gboolean buffered)1067 g_io_channel_set_buffered (GIOChannel *channel,
1068                            gboolean    buffered)
1069 {
1070   g_return_if_fail (channel != NULL);
1071 
1072   if (channel->encoding != NULL)
1073     {
1074       g_warning ("Need to have NULL encoding to set the buffering state of the "
1075                  "channel.\n");
1076       return;
1077     }
1078 
1079   g_return_if_fail (!channel->read_buf || channel->read_buf->len == 0);
1080   g_return_if_fail (!channel->write_buf || channel->write_buf->len == 0);
1081 
1082   channel->use_buffer = buffered;
1083 }
1084 
1085 /**
1086  * g_io_channel_get_buffered:
1087  * @channel: a #GIOChannel
1088  *
1089  * Returns whether @channel is buffered.
1090  *
1091  * Return Value: %TRUE if the @channel is buffered.
1092  **/
1093 gboolean
g_io_channel_get_buffered(GIOChannel * channel)1094 g_io_channel_get_buffered (GIOChannel *channel)
1095 {
1096   g_return_val_if_fail (channel != NULL, FALSE);
1097 
1098   return channel->use_buffer;
1099 }
1100 
1101 /**
1102  * g_io_channel_set_encoding:
1103  * @channel: a #GIOChannel
1104  * @encoding: the encoding type
1105  * @error: location to store an error of type #GConvertError
1106  *
1107  * Sets the encoding for the input/output of the channel.
1108  * The internal encoding is always UTF-8. The default encoding
1109  * for the external file is UTF-8.
1110  *
1111  * The encoding %NULL is safe to use with binary data.
1112  *
1113  * The encoding can only be set if one of the following conditions
1114  * is true:
1115  * <itemizedlist>
1116  * <listitem><para>
1117  *    The channel was just created, and has not been written to or read
1118  *    from yet.
1119  * </para></listitem>
1120  * <listitem><para>
1121  *    The channel is write-only.
1122  * </para></listitem>
1123  * <listitem><para>
1124  *    The channel is a file, and the file pointer was just
1125  *    repositioned by a call to g_io_channel_seek_position().
1126  *    (This flushes all the internal buffers.)
1127  * </para></listitem>
1128  * <listitem><para>
1129  *    The current encoding is %NULL or UTF-8.
1130  * </para></listitem>
1131  * <listitem><para>
1132  *    One of the (new API) read functions has just returned %G_IO_STATUS_EOF
1133  *    (or, in the case of g_io_channel_read_to_end(), %G_IO_STATUS_NORMAL).
1134  * </para></listitem>
1135  * <listitem><para>
1136  *    One of the functions g_io_channel_read_chars() or
1137  *    g_io_channel_read_unichar() has returned %G_IO_STATUS_AGAIN or
1138  *    %G_IO_STATUS_ERROR. This may be useful in the case of
1139  *    %G_CONVERT_ERROR_ILLEGAL_SEQUENCE.
1140  *    Returning one of these statuses from g_io_channel_read_line(),
1141  *    g_io_channel_read_line_string(), or g_io_channel_read_to_end()
1142  *    does <emphasis>not</emphasis> guarantee that the encoding can
1143  *    be changed.
1144  * </para></listitem>
1145  * </itemizedlist>
1146  * Channels which do not meet one of the above conditions cannot call
1147  * g_io_channel_seek_position() with an offset of %G_SEEK_CUR, and, if
1148  * they are "seekable", cannot call g_io_channel_write_chars() after
1149  * calling one of the API "read" functions.
1150  *
1151  * Return Value: %G_IO_STATUS_NORMAL if the encoding was successfully set.
1152  **/
1153 GIOStatus
g_io_channel_set_encoding(GIOChannel * channel,const gchar * encoding,GError ** error)1154 g_io_channel_set_encoding (GIOChannel	*channel,
1155                            const gchar	*encoding,
1156 			   GError      **error)
1157 {
1158   GIConv read_cd, write_cd;
1159   gboolean did_encode;
1160 
1161   g_return_val_if_fail (channel != NULL, G_IO_STATUS_ERROR);
1162   g_return_val_if_fail ((error == NULL) || (*error == NULL), G_IO_STATUS_ERROR);
1163 
1164   /* Make sure the encoded buffers are empty */
1165 
1166   g_return_val_if_fail (!channel->do_encode || !channel->encoded_read_buf ||
1167 			channel->encoded_read_buf->len == 0, G_IO_STATUS_ERROR);
1168 
1169   if (!channel->use_buffer)
1170     {
1171       g_warning ("Need to set the channel buffered before setting the encoding.\n");
1172       g_warning ("Assuming this is what you meant and acting accordingly.\n");
1173 
1174       channel->use_buffer = TRUE;
1175     }
1176 
1177   if (channel->partial_write_buf[0] != '\0')
1178     {
1179       g_warning ("Partial character at end of write buffer not flushed.\n");
1180       channel->partial_write_buf[0] = '\0';
1181     }
1182 
1183   did_encode = channel->do_encode;
1184 
1185   if (!encoding || strcmp (encoding, "UTF8") == 0 || strcmp (encoding, "UTF-8") == 0)
1186     {
1187       channel->do_encode = FALSE;
1188       read_cd = write_cd = (GIConv) -1;
1189     }
1190   else
1191     {
1192       gint err = 0;
1193       const gchar *from_enc = NULL, *to_enc = NULL;
1194 
1195       if (channel->is_readable)
1196         {
1197           read_cd = g_iconv_open ("UTF-8", encoding);
1198 
1199           if (read_cd == (GIConv) -1)
1200             {
1201               err = errno;
1202               from_enc = encoding;
1203               to_enc = "UTF-8";
1204             }
1205         }
1206       else
1207         read_cd = (GIConv) -1;
1208 
1209       if (channel->is_writeable && err == 0)
1210         {
1211           write_cd = g_iconv_open (encoding, "UTF-8");
1212 
1213           if (write_cd == (GIConv) -1)
1214             {
1215               err = errno;
1216               from_enc = "UTF-8";
1217               to_enc = encoding;
1218             }
1219         }
1220       else
1221         write_cd = (GIConv) -1;
1222 
1223       if (err != 0)
1224         {
1225           g_assert (from_enc);
1226           g_assert (to_enc);
1227 
1228           if (err == EINVAL)
1229             g_set_error (error, G_CONVERT_ERROR, G_CONVERT_ERROR_NO_CONVERSION,
1230                          _("Conversion from character set '%s' to '%s' is not supported"),
1231                          from_enc, to_enc);
1232           else
1233             g_set_error (error, G_CONVERT_ERROR, G_CONVERT_ERROR_FAILED,
1234                          _("Could not open converter from '%s' to '%s': %s"),
1235                          from_enc, to_enc, g_strerror (err));
1236 
1237           if (read_cd != (GIConv) -1)
1238             g_iconv_close (read_cd);
1239           if (write_cd != (GIConv) -1)
1240             g_iconv_close (write_cd);
1241 
1242           return G_IO_STATUS_ERROR;
1243         }
1244 
1245       channel->do_encode = TRUE;
1246     }
1247 
1248   /* The encoding is ok, so set the fields in channel */
1249 
1250   if (channel->read_cd != (GIConv) -1)
1251     g_iconv_close (channel->read_cd);
1252   if (channel->write_cd != (GIConv) -1)
1253     g_iconv_close (channel->write_cd);
1254 
1255   if (channel->encoded_read_buf && channel->encoded_read_buf->len > 0)
1256     {
1257       g_assert (!did_encode); /* Encoding UTF-8, NULL doesn't use encoded_read_buf */
1258 
1259       /* This is just validated UTF-8, so we can copy it back into read_buf
1260        * so it can be encoded in whatever the new encoding is.
1261        */
1262 
1263       g_string_prepend_len (channel->read_buf, channel->encoded_read_buf->str,
1264                             channel->encoded_read_buf->len);
1265       g_string_truncate (channel->encoded_read_buf, 0);
1266     }
1267 
1268   channel->read_cd = read_cd;
1269   channel->write_cd = write_cd;
1270 
1271   g_free (channel->encoding);
1272   channel->encoding = g_strdup (encoding);
1273 
1274   return G_IO_STATUS_NORMAL;
1275 }
1276 
1277 /**
1278  * g_io_channel_get_encoding:
1279  * @channel: a #GIOChannel
1280  *
1281  * Gets the encoding for the input/output of the channel.
1282  * The internal encoding is always UTF-8. The encoding %NULL
1283  * makes the channel safe for binary data.
1284  *
1285  * Return value: A string containing the encoding, this string is
1286  *   owned by GLib and must not be freed.
1287  **/
1288 G_CONST_RETURN gchar*
g_io_channel_get_encoding(GIOChannel * channel)1289 g_io_channel_get_encoding (GIOChannel *channel)
1290 {
1291   g_return_val_if_fail (channel != NULL, NULL);
1292 
1293   return channel->encoding;
1294 }
1295 
1296 static GIOStatus
g_io_channel_fill_buffer(GIOChannel * channel,GError ** err)1297 g_io_channel_fill_buffer (GIOChannel  *channel,
1298                           GError     **err)
1299 {
1300   gsize read_size, cur_len, oldlen;
1301   GIOStatus status;
1302 
1303   if (channel->is_seekable && channel->write_buf && channel->write_buf->len > 0)
1304     {
1305       status = g_io_channel_flush (channel, err);
1306       if (status != G_IO_STATUS_NORMAL)
1307         return status;
1308     }
1309   if (channel->is_seekable && channel->partial_write_buf[0] != '\0')
1310     {
1311       g_warning ("Partial character at end of write buffer not flushed.\n");
1312       channel->partial_write_buf[0] = '\0';
1313     }
1314 
1315   if (!channel->read_buf)
1316     channel->read_buf = g_string_sized_new (channel->buf_size);
1317 
1318   cur_len = channel->read_buf->len;
1319 
1320   g_string_set_size (channel->read_buf, channel->read_buf->len + channel->buf_size);
1321 
1322   status = channel->funcs->io_read (channel, channel->read_buf->str + cur_len,
1323                                     channel->buf_size, &read_size, err);
1324 
1325   g_assert ((status == G_IO_STATUS_NORMAL) || (read_size == 0));
1326 
1327   g_string_truncate (channel->read_buf, read_size + cur_len);
1328 
1329   if ((status != G_IO_STATUS_NORMAL) &&
1330       ((status != G_IO_STATUS_EOF) || (channel->read_buf->len == 0)))
1331     return status;
1332 
1333   g_assert (channel->read_buf->len > 0);
1334 
1335   if (channel->encoded_read_buf)
1336     oldlen = channel->encoded_read_buf->len;
1337   else
1338     {
1339       oldlen = 0;
1340       if (channel->encoding)
1341         channel->encoded_read_buf = g_string_sized_new (channel->buf_size);
1342     }
1343 
1344   if (channel->do_encode)
1345     {
1346       gsize errnum, inbytes_left, outbytes_left;
1347       gchar *inbuf, *outbuf;
1348       int errval;
1349 
1350       g_assert (channel->encoded_read_buf);
1351 
1352 reencode:
1353 
1354       inbytes_left = channel->read_buf->len;
1355       outbytes_left = MAX (channel->read_buf->len,
1356                            channel->encoded_read_buf->allocated_len
1357                            - channel->encoded_read_buf->len - 1); /* 1 for NULL */
1358       outbytes_left = MAX (outbytes_left, 6);
1359 
1360       inbuf = channel->read_buf->str;
1361       g_string_set_size (channel->encoded_read_buf,
1362                          channel->encoded_read_buf->len + outbytes_left);
1363       outbuf = channel->encoded_read_buf->str + channel->encoded_read_buf->len
1364                - outbytes_left;
1365 
1366       errnum = g_iconv (channel->read_cd, &inbuf, &inbytes_left,
1367 			&outbuf, &outbytes_left);
1368       errval = errno;
1369 
1370       g_assert (inbuf + inbytes_left == channel->read_buf->str
1371                 + channel->read_buf->len);
1372       g_assert (outbuf + outbytes_left == channel->encoded_read_buf->str
1373                 + channel->encoded_read_buf->len);
1374 
1375       g_string_erase (channel->read_buf, 0,
1376 		      channel->read_buf->len - inbytes_left);
1377       g_string_truncate (channel->encoded_read_buf,
1378 			 channel->encoded_read_buf->len - outbytes_left);
1379 
1380       if (errnum == (gsize) -1)
1381         {
1382           switch (errval)
1383             {
1384               case EINVAL:
1385                 if ((oldlen == channel->encoded_read_buf->len)
1386                   && (status == G_IO_STATUS_EOF))
1387                   status = G_IO_STATUS_EOF;
1388                 else
1389                   status = G_IO_STATUS_NORMAL;
1390                 break;
1391               case E2BIG:
1392                 /* Buffer size at least 6, wrote at least on character */
1393                 g_assert (inbuf != channel->read_buf->str);
1394                 goto reencode;
1395               case EILSEQ:
1396                 if (oldlen < channel->encoded_read_buf->len)
1397                   status = G_IO_STATUS_NORMAL;
1398                 else
1399                   {
1400                     g_set_error_literal (err, G_CONVERT_ERROR,
1401                       G_CONVERT_ERROR_ILLEGAL_SEQUENCE,
1402                       _("Invalid byte sequence in conversion input"));
1403                     return G_IO_STATUS_ERROR;
1404                   }
1405                 break;
1406               default:
1407                 g_assert (errval != EBADF); /* The converter should be open */
1408                 g_set_error (err, G_CONVERT_ERROR, G_CONVERT_ERROR_FAILED,
1409                   _("Error during conversion: %s"), g_strerror (errval));
1410                 return G_IO_STATUS_ERROR;
1411             }
1412         }
1413       g_assert ((status != G_IO_STATUS_NORMAL)
1414                || (channel->encoded_read_buf->len > 0));
1415     }
1416   else if (channel->encoding) /* UTF-8 */
1417     {
1418       gchar *nextchar, *lastchar;
1419 
1420       g_assert (channel->encoded_read_buf);
1421 
1422       nextchar = channel->read_buf->str;
1423       lastchar = channel->read_buf->str + channel->read_buf->len;
1424 
1425       while (nextchar < lastchar)
1426         {
1427           gunichar val_char;
1428 
1429           val_char = g_utf8_get_char_validated (nextchar, lastchar - nextchar);
1430 
1431           switch (val_char)
1432             {
1433               case -2:
1434                 /* stop, leave partial character in buffer */
1435                 lastchar = nextchar;
1436                 break;
1437               case -1:
1438                 if (oldlen < channel->encoded_read_buf->len)
1439                   status = G_IO_STATUS_NORMAL;
1440                 else
1441                   {
1442                     g_set_error_literal (err, G_CONVERT_ERROR,
1443                       G_CONVERT_ERROR_ILLEGAL_SEQUENCE,
1444                       _("Invalid byte sequence in conversion input"));
1445                     status = G_IO_STATUS_ERROR;
1446                   }
1447                 lastchar = nextchar;
1448                 break;
1449               default:
1450                 nextchar = g_utf8_next_char (nextchar);
1451                 break;
1452             }
1453         }
1454 
1455       if (lastchar > channel->read_buf->str)
1456         {
1457           gint copy_len = lastchar - channel->read_buf->str;
1458 
1459           g_string_append_len (channel->encoded_read_buf, channel->read_buf->str,
1460                                copy_len);
1461           g_string_erase (channel->read_buf, 0, copy_len);
1462         }
1463     }
1464 
1465   return status;
1466 }
1467 
1468 /**
1469  * g_io_channel_read_line:
1470  * @channel: a #GIOChannel
1471  * @str_return: The line read from the #GIOChannel, including the
1472  *              line terminator. This data should be freed with g_free()
1473  *              when no longer needed. This is a nul-terminated string.
1474  *              If a @length of zero is returned, this will be %NULL instead.
1475  * @length: location to store length of the read data, or %NULL
1476  * @terminator_pos: location to store position of line terminator, or %NULL
1477  * @error: A location to return an error of type #GConvertError
1478  *         or #GIOChannelError
1479  *
1480  * Reads a line, including the terminating character(s),
1481  * from a #GIOChannel into a newly-allocated string.
1482  * @str_return will contain allocated memory if the return
1483  * is %G_IO_STATUS_NORMAL.
1484  *
1485  * Return value: the status of the operation.
1486  **/
1487 GIOStatus
g_io_channel_read_line(GIOChannel * channel,gchar ** str_return,gsize * length,gsize * terminator_pos,GError ** error)1488 g_io_channel_read_line (GIOChannel  *channel,
1489                         gchar      **str_return,
1490                         gsize       *length,
1491 			gsize       *terminator_pos,
1492 		        GError     **error)
1493 {
1494   GIOStatus status;
1495   gsize got_length;
1496 
1497   g_return_val_if_fail (channel != NULL, G_IO_STATUS_ERROR);
1498   g_return_val_if_fail (str_return != NULL, G_IO_STATUS_ERROR);
1499   g_return_val_if_fail ((error == NULL) || (*error == NULL),
1500 			G_IO_STATUS_ERROR);
1501   g_return_val_if_fail (channel->is_readable, G_IO_STATUS_ERROR);
1502 
1503   status = g_io_channel_read_line_backend (channel, &got_length, terminator_pos, error);
1504 
1505   if (length)
1506     *length = got_length;
1507 
1508   if (status == G_IO_STATUS_NORMAL)
1509     {
1510       g_assert (USE_BUF (channel));
1511       *str_return = g_strndup (USE_BUF (channel)->str, got_length);
1512       g_string_erase (USE_BUF (channel), 0, got_length);
1513     }
1514   else
1515     *str_return = NULL;
1516 
1517   return status;
1518 }
1519 
1520 /**
1521  * g_io_channel_read_line_string:
1522  * @channel: a #GIOChannel
1523  * @buffer: a #GString into which the line will be written.
1524  *          If @buffer already contains data, the old data will
1525  *          be overwritten.
1526  * @terminator_pos: location to store position of line terminator, or %NULL
1527  * @error: a location to store an error of type #GConvertError
1528  *         or #GIOChannelError
1529  *
1530  * Reads a line from a #GIOChannel, using a #GString as a buffer.
1531  *
1532  * Return value: the status of the operation.
1533  **/
1534 GIOStatus
g_io_channel_read_line_string(GIOChannel * channel,GString * buffer,gsize * terminator_pos,GError ** error)1535 g_io_channel_read_line_string (GIOChannel  *channel,
1536                                GString	   *buffer,
1537 			       gsize       *terminator_pos,
1538                                GError	  **error)
1539 {
1540   gsize length;
1541   GIOStatus status;
1542 
1543   g_return_val_if_fail (channel != NULL, G_IO_STATUS_ERROR);
1544   g_return_val_if_fail (buffer != NULL, G_IO_STATUS_ERROR);
1545   g_return_val_if_fail ((error == NULL) || (*error == NULL),
1546 			G_IO_STATUS_ERROR);
1547   g_return_val_if_fail (channel->is_readable, G_IO_STATUS_ERROR);
1548 
1549   if (buffer->len > 0)
1550     g_string_truncate (buffer, 0); /* clear out the buffer */
1551 
1552   status = g_io_channel_read_line_backend (channel, &length, terminator_pos, error);
1553 
1554   if (status == G_IO_STATUS_NORMAL)
1555     {
1556       g_assert (USE_BUF (channel));
1557       g_string_append_len (buffer, USE_BUF (channel)->str, length);
1558       g_string_erase (USE_BUF (channel), 0, length);
1559     }
1560 
1561   return status;
1562 }
1563 
1564 
1565 static GIOStatus
g_io_channel_read_line_backend(GIOChannel * channel,gsize * length,gsize * terminator_pos,GError ** error)1566 g_io_channel_read_line_backend (GIOChannel  *channel,
1567                                 gsize       *length,
1568                                 gsize       *terminator_pos,
1569                                 GError     **error)
1570 {
1571   GIOStatus status;
1572   gsize checked_to, line_term_len, line_length, got_term_len;
1573   gboolean first_time = TRUE;
1574 
1575   if (!channel->use_buffer)
1576     {
1577       /* Can't do a raw read in read_line */
1578       g_set_error_literal (error, G_CONVERT_ERROR, G_CONVERT_ERROR_FAILED,
1579                            _("Can't do a raw read in g_io_channel_read_line_string"));
1580       return G_IO_STATUS_ERROR;
1581     }
1582 
1583   status = G_IO_STATUS_NORMAL;
1584 
1585   if (channel->line_term)
1586     line_term_len = channel->line_term_len;
1587   else
1588     line_term_len = 3;
1589     /* This value used for setting checked_to, it's the longest of the four
1590      * we autodetect for.
1591      */
1592 
1593   checked_to = 0;
1594 
1595   while (TRUE)
1596     {
1597       gchar *nextchar, *lastchar;
1598       GString *use_buf;
1599 
1600       if (!first_time || (BUF_LEN (USE_BUF (channel)) == 0))
1601         {
1602 read_again:
1603           status = g_io_channel_fill_buffer (channel, error);
1604           switch (status)
1605             {
1606               case G_IO_STATUS_NORMAL:
1607                 if (BUF_LEN (USE_BUF (channel)) == 0)
1608                   /* Can happen when using conversion and only read
1609                    * part of a character
1610                    */
1611                   {
1612                     first_time = FALSE;
1613                     continue;
1614                   }
1615                 break;
1616               case G_IO_STATUS_EOF:
1617                 if (BUF_LEN (USE_BUF (channel)) == 0)
1618                   {
1619                     if (length)
1620                       *length = 0;
1621 
1622                     if (channel->encoding && channel->read_buf->len != 0)
1623                       {
1624                         g_set_error_literal (error, G_CONVERT_ERROR,
1625                                              G_CONVERT_ERROR_PARTIAL_INPUT,
1626                                              _("Leftover unconverted data in "
1627                                                "read buffer"));
1628                         return G_IO_STATUS_ERROR;
1629                       }
1630                     else
1631                       return G_IO_STATUS_EOF;
1632                   }
1633                 break;
1634               default:
1635                 if (length)
1636                   *length = 0;
1637                 return status;
1638             }
1639         }
1640 
1641       g_assert (BUF_LEN (USE_BUF (channel)) != 0);
1642 
1643       use_buf = USE_BUF (channel); /* The buffer has been created by this point */
1644 
1645       first_time = FALSE;
1646 
1647       lastchar = use_buf->str + use_buf->len;
1648 
1649       for (nextchar = use_buf->str + checked_to; nextchar < lastchar;
1650            channel->encoding ? nextchar = g_utf8_next_char (nextchar) : nextchar++)
1651         {
1652           if (channel->line_term)
1653             {
1654               if (memcmp (channel->line_term, nextchar, line_term_len) == 0)
1655                 {
1656                   line_length = nextchar - use_buf->str;
1657                   got_term_len = line_term_len;
1658                   goto done;
1659                 }
1660             }
1661           else /* auto detect */
1662             {
1663               switch (*nextchar)
1664                 {
1665                   case '\n': /* unix */
1666                     line_length = nextchar - use_buf->str;
1667                     got_term_len = 1;
1668                     goto done;
1669                   case '\r': /* Warning: do not use with sockets */
1670                     line_length = nextchar - use_buf->str;
1671                     if ((nextchar == lastchar - 1) && (status != G_IO_STATUS_EOF)
1672                        && (lastchar == use_buf->str + use_buf->len))
1673                       goto read_again; /* Try to read more data */
1674                     if ((nextchar < lastchar - 1) && (*(nextchar + 1) == '\n')) /* dos */
1675                       got_term_len = 2;
1676                     else /* mac */
1677                       got_term_len = 1;
1678                     goto done;
1679                   case '\xe2': /* Unicode paragraph separator */
1680                     if (strncmp ("\xe2\x80\xa9", nextchar, 3) == 0)
1681                       {
1682                         line_length = nextchar - use_buf->str;
1683                         got_term_len = 3;
1684                         goto done;
1685                       }
1686                     break;
1687                   case '\0': /* Embeded null in input */
1688                     line_length = nextchar - use_buf->str;
1689                     got_term_len = 1;
1690                     goto done;
1691                   default: /* no match */
1692                     break;
1693                 }
1694             }
1695         }
1696 
1697       /* If encoding != NULL, valid UTF-8, didn't overshoot */
1698       g_assert (nextchar == lastchar);
1699 
1700       /* Check for EOF */
1701 
1702       if (status == G_IO_STATUS_EOF)
1703         {
1704           if (channel->encoding && channel->read_buf->len > 0)
1705             {
1706               g_set_error_literal (error, G_CONVERT_ERROR, G_CONVERT_ERROR_PARTIAL_INPUT,
1707                                    _("Channel terminates in a partial character"));
1708               return G_IO_STATUS_ERROR;
1709             }
1710           line_length = use_buf->len;
1711           got_term_len = 0;
1712           break;
1713         }
1714 
1715       if (use_buf->len > line_term_len - 1)
1716 	checked_to = use_buf->len - (line_term_len - 1);
1717       else
1718 	checked_to = 0;
1719     }
1720 
1721 done:
1722 
1723   if (terminator_pos)
1724     *terminator_pos = line_length;
1725 
1726   if (length)
1727     *length = line_length + got_term_len;
1728 
1729   return G_IO_STATUS_NORMAL;
1730 }
1731 
1732 /**
1733  * g_io_channel_read_to_end:
1734  * @channel: a #GIOChannel
1735  * @str_return: Location to store a pointer to a string holding
1736  *              the remaining data in the #GIOChannel. This data should
1737  *              be freed with g_free() when no longer needed. This
1738  *              data is terminated by an extra nul character, but there
1739  *              may be other nuls in the intervening data.
1740  * @length: location to store length of the data
1741  * @error: location to return an error of type #GConvertError
1742  *         or #GIOChannelError
1743  *
1744  * Reads all the remaining data from the file.
1745  *
1746  * Return value: %G_IO_STATUS_NORMAL on success.
1747  *     This function never returns %G_IO_STATUS_EOF.
1748  **/
1749 GIOStatus
g_io_channel_read_to_end(GIOChannel * channel,gchar ** str_return,gsize * length,GError ** error)1750 g_io_channel_read_to_end (GIOChannel  *channel,
1751                           gchar      **str_return,
1752                           gsize	      *length,
1753                           GError     **error)
1754 {
1755   GIOStatus status;
1756 
1757   g_return_val_if_fail (channel != NULL, G_IO_STATUS_ERROR);
1758   g_return_val_if_fail ((error == NULL) || (*error == NULL),
1759     G_IO_STATUS_ERROR);
1760   g_return_val_if_fail (channel->is_readable, G_IO_STATUS_ERROR);
1761 
1762   if (str_return)
1763     *str_return = NULL;
1764   if (length)
1765     *length = 0;
1766 
1767   if (!channel->use_buffer)
1768     {
1769       g_set_error_literal (error, G_CONVERT_ERROR, G_CONVERT_ERROR_FAILED,
1770                            _("Can't do a raw read in g_io_channel_read_to_end"));
1771       return G_IO_STATUS_ERROR;
1772     }
1773 
1774   do
1775     status = g_io_channel_fill_buffer (channel, error);
1776   while (status == G_IO_STATUS_NORMAL);
1777 
1778   if (status != G_IO_STATUS_EOF)
1779     return status;
1780 
1781   if (channel->encoding && channel->read_buf->len > 0)
1782     {
1783       g_set_error_literal (error, G_CONVERT_ERROR, G_CONVERT_ERROR_PARTIAL_INPUT,
1784                            _("Channel terminates in a partial character"));
1785       return G_IO_STATUS_ERROR;
1786     }
1787 
1788   if (USE_BUF (channel) == NULL)
1789     {
1790       /* length is already set to zero */
1791       if (str_return)
1792         *str_return = g_strdup ("");
1793     }
1794   else
1795     {
1796       if (length)
1797         *length = USE_BUF (channel)->len;
1798 
1799       if (str_return)
1800         *str_return = g_string_free (USE_BUF (channel), FALSE);
1801       else
1802         g_string_free (USE_BUF (channel), TRUE);
1803 
1804       if (channel->encoding)
1805 	channel->encoded_read_buf = NULL;
1806       else
1807 	channel->read_buf = NULL;
1808     }
1809 
1810   return G_IO_STATUS_NORMAL;
1811 }
1812 
1813 /**
1814  * g_io_channel_read_chars:
1815  * @channel: a #GIOChannel
1816  * @buf: a buffer to read data into
1817  * @count: the size of the buffer. Note that the buffer may
1818  *         not be complelely filled even if there is data
1819  *         in the buffer if the remaining data is not a
1820  *         complete character.
1821  * @bytes_read: The number of bytes read. This may be zero even on
1822  *              success if count < 6 and the channel's encoding is non-%NULL.
1823  *              This indicates that the next UTF-8 character is too wide for
1824  *              the buffer.
1825  * @error: a location to return an error of type #GConvertError
1826  *         or #GIOChannelError.
1827  *
1828  * Replacement for g_io_channel_read() with the new API.
1829  *
1830  * Return value: the status of the operation.
1831  **/
1832 GIOStatus
g_io_channel_read_chars(GIOChannel * channel,gchar * buf,gsize count,gsize * bytes_read,GError ** error)1833 g_io_channel_read_chars (GIOChannel  *channel,
1834                          gchar	     *buf,
1835                          gsize	      count,
1836 			 gsize       *bytes_read,
1837                          GError     **error)
1838 {
1839   GIOStatus status;
1840   gsize got_bytes;
1841 
1842   g_return_val_if_fail (channel != NULL, G_IO_STATUS_ERROR);
1843   g_return_val_if_fail ((error == NULL) || (*error == NULL),
1844 			G_IO_STATUS_ERROR);
1845   g_return_val_if_fail (channel->is_readable, G_IO_STATUS_ERROR);
1846 
1847   if (count == 0)
1848     {
1849       *bytes_read = 0;
1850       return G_IO_STATUS_NORMAL;
1851     }
1852   g_return_val_if_fail (buf != NULL, G_IO_STATUS_ERROR);
1853 
1854   if (!channel->use_buffer)
1855     {
1856       gsize tmp_bytes;
1857 
1858       g_assert (!channel->read_buf || channel->read_buf->len == 0);
1859 
1860       status = channel->funcs->io_read (channel, buf, count, &tmp_bytes, error);
1861 
1862       if (bytes_read)
1863 	*bytes_read = tmp_bytes;
1864 
1865       return status;
1866     }
1867 
1868   status = G_IO_STATUS_NORMAL;
1869 
1870   while (BUF_LEN (USE_BUF (channel)) < count && status == G_IO_STATUS_NORMAL)
1871     status = g_io_channel_fill_buffer (channel, error);
1872 
1873   /* Only return an error if we have no data */
1874 
1875   if (BUF_LEN (USE_BUF (channel)) == 0)
1876     {
1877       g_assert (status != G_IO_STATUS_NORMAL);
1878 
1879       if (status == G_IO_STATUS_EOF && channel->encoding
1880           && BUF_LEN (channel->read_buf) > 0)
1881         {
1882           g_set_error_literal (error, G_CONVERT_ERROR,
1883                                G_CONVERT_ERROR_PARTIAL_INPUT,
1884                                _("Leftover unconverted data in read buffer"));
1885           status = G_IO_STATUS_ERROR;
1886         }
1887 
1888       if (bytes_read)
1889         *bytes_read = 0;
1890 
1891       return status;
1892     }
1893 
1894   if (status == G_IO_STATUS_ERROR)
1895     g_clear_error (error);
1896 
1897   got_bytes = MIN (count, BUF_LEN (USE_BUF (channel)));
1898 
1899   g_assert (got_bytes > 0);
1900 
1901   if (channel->encoding)
1902     /* Don't validate for NULL encoding, binary safe */
1903     {
1904       gchar *nextchar, *prevchar;
1905 
1906       g_assert (USE_BUF (channel) == channel->encoded_read_buf);
1907 
1908       nextchar = channel->encoded_read_buf->str;
1909 
1910       do
1911         {
1912           prevchar = nextchar;
1913           nextchar = g_utf8_next_char (nextchar);
1914           g_assert (nextchar != prevchar); /* Possible for *prevchar of -1 or -2 */
1915         }
1916       while (nextchar < channel->encoded_read_buf->str + got_bytes);
1917 
1918       if (nextchar > channel->encoded_read_buf->str + got_bytes)
1919         got_bytes = prevchar - channel->encoded_read_buf->str;
1920 
1921       g_assert (got_bytes > 0 || count < 6);
1922     }
1923 
1924   memcpy (buf, USE_BUF (channel)->str, got_bytes);
1925   g_string_erase (USE_BUF (channel), 0, got_bytes);
1926 
1927   if (bytes_read)
1928     *bytes_read = got_bytes;
1929 
1930   return G_IO_STATUS_NORMAL;
1931 }
1932 
1933 /**
1934  * g_io_channel_read_unichar:
1935  * @channel: a #GIOChannel
1936  * @thechar: a location to return a character
1937  * @error: a location to return an error of type #GConvertError
1938  *         or #GIOChannelError
1939  *
1940  * Reads a Unicode character from @channel.
1941  * This function cannot be called on a channel with %NULL encoding.
1942  *
1943  * Return value: a #GIOStatus
1944  **/
1945 GIOStatus
g_io_channel_read_unichar(GIOChannel * channel,gunichar * thechar,GError ** error)1946 g_io_channel_read_unichar (GIOChannel  *channel,
1947 			   gunichar    *thechar,
1948 			   GError     **error)
1949 {
1950   GIOStatus status = G_IO_STATUS_NORMAL;
1951 
1952   g_return_val_if_fail (channel != NULL, G_IO_STATUS_ERROR);
1953   g_return_val_if_fail (channel->encoding != NULL, G_IO_STATUS_ERROR);
1954   g_return_val_if_fail ((error == NULL) || (*error == NULL),
1955 			G_IO_STATUS_ERROR);
1956   g_return_val_if_fail (channel->is_readable, G_IO_STATUS_ERROR);
1957 
1958   while (BUF_LEN (channel->encoded_read_buf) == 0 && status == G_IO_STATUS_NORMAL)
1959     status = g_io_channel_fill_buffer (channel, error);
1960 
1961   /* Only return an error if we have no data */
1962 
1963   if (BUF_LEN (USE_BUF (channel)) == 0)
1964     {
1965       g_assert (status != G_IO_STATUS_NORMAL);
1966 
1967       if (status == G_IO_STATUS_EOF && BUF_LEN (channel->read_buf) > 0)
1968         {
1969           g_set_error_literal (error, G_CONVERT_ERROR,
1970                                G_CONVERT_ERROR_PARTIAL_INPUT,
1971                                _("Leftover unconverted data in read buffer"));
1972           status = G_IO_STATUS_ERROR;
1973         }
1974 
1975       if (thechar)
1976         *thechar = (gunichar) -1;
1977 
1978       return status;
1979     }
1980 
1981   if (status == G_IO_STATUS_ERROR)
1982     g_clear_error (error);
1983 
1984   if (thechar)
1985     *thechar = g_utf8_get_char (channel->encoded_read_buf->str);
1986 
1987   g_string_erase (channel->encoded_read_buf, 0,
1988                   g_utf8_next_char (channel->encoded_read_buf->str)
1989                   - channel->encoded_read_buf->str);
1990 
1991   return G_IO_STATUS_NORMAL;
1992 }
1993 
1994 /**
1995  * g_io_channel_write_chars:
1996  * @channel: a #GIOChannel
1997  * @buf: a buffer to write data from
1998  * @count: the size of the buffer. If -1, the buffer
1999  *         is taken to be a nul-terminated string.
2000  * @bytes_written: The number of bytes written. This can be nonzero
2001  *                 even if the return value is not %G_IO_STATUS_NORMAL.
2002  *                 If the return value is %G_IO_STATUS_NORMAL and the
2003  *                 channel is blocking, this will always be equal
2004  *                 to @count if @count >= 0.
2005  * @error: a location to return an error of type #GConvertError
2006  *         or #GIOChannelError
2007  *
2008  * Replacement for g_io_channel_write() with the new API.
2009  *
2010  * On seekable channels with encodings other than %NULL or UTF-8, generic
2011  * mixing of reading and writing is not allowed. A call to g_io_channel_write_chars ()
2012  * may only be made on a channel from which data has been read in the
2013  * cases described in the documentation for g_io_channel_set_encoding ().
2014  *
2015  * Return value: the status of the operation.
2016  **/
2017 GIOStatus
g_io_channel_write_chars(GIOChannel * channel,const gchar * buf,gssize count,gsize * bytes_written,GError ** error)2018 g_io_channel_write_chars (GIOChannel   *channel,
2019                           const gchar  *buf,
2020                           gssize        count,
2021 			  gsize        *bytes_written,
2022                           GError      **error)
2023 {
2024   GIOStatus status;
2025   gssize wrote_bytes = 0;
2026 
2027   g_return_val_if_fail (channel != NULL, G_IO_STATUS_ERROR);
2028   g_return_val_if_fail ((error == NULL) || (*error == NULL),
2029 			G_IO_STATUS_ERROR);
2030   g_return_val_if_fail (channel->is_writeable, G_IO_STATUS_ERROR);
2031 
2032   if ((count < 0) && buf)
2033     count = strlen (buf);
2034 
2035   if (count == 0)
2036     {
2037       if (bytes_written)
2038         *bytes_written = 0;
2039       return G_IO_STATUS_NORMAL;
2040     }
2041 
2042   g_return_val_if_fail (buf != NULL, G_IO_STATUS_ERROR);
2043   g_return_val_if_fail (count > 0, G_IO_STATUS_ERROR);
2044 
2045   /* Raw write case */
2046 
2047   if (!channel->use_buffer)
2048     {
2049       gsize tmp_bytes;
2050 
2051       g_assert (!channel->write_buf || channel->write_buf->len == 0);
2052       g_assert (channel->partial_write_buf[0] == '\0');
2053 
2054       status = channel->funcs->io_write (channel, buf, count, &tmp_bytes, error);
2055 
2056       if (bytes_written)
2057 	*bytes_written = tmp_bytes;
2058 
2059       return status;
2060     }
2061 
2062   /* General case */
2063 
2064   if (channel->is_seekable && (( BUF_LEN (channel->read_buf) > 0)
2065     || (BUF_LEN (channel->encoded_read_buf) > 0)))
2066     {
2067       if (channel->do_encode && BUF_LEN (channel->encoded_read_buf) > 0)
2068         {
2069           g_warning("Mixed reading and writing not allowed on encoded files");
2070           return G_IO_STATUS_ERROR;
2071         }
2072       status = g_io_channel_seek_position (channel, 0, G_SEEK_CUR, error);
2073       if (status != G_IO_STATUS_NORMAL)
2074         {
2075           if (bytes_written)
2076             *bytes_written = 0;
2077           return status;
2078         }
2079     }
2080 
2081   if (!channel->write_buf)
2082     channel->write_buf = g_string_sized_new (channel->buf_size);
2083 
2084   while (wrote_bytes < count)
2085     {
2086       gsize space_in_buf;
2087 
2088       /* If the buffer is full, try a write immediately. In
2089        * the nonblocking case, this prevents the user from
2090        * writing just a little bit to the buffer every time
2091        * and never receiving an EAGAIN.
2092        */
2093 
2094       if (channel->write_buf->len >= channel->buf_size - MAX_CHAR_SIZE)
2095         {
2096           gsize did_write = 0, this_time;
2097 
2098           do
2099             {
2100               status = channel->funcs->io_write (channel, channel->write_buf->str
2101                                                  + did_write, channel->write_buf->len
2102                                                  - did_write, &this_time, error);
2103               did_write += this_time;
2104             }
2105           while (status == G_IO_STATUS_NORMAL &&
2106                  did_write < MIN (channel->write_buf->len, MAX_CHAR_SIZE));
2107 
2108           g_string_erase (channel->write_buf, 0, did_write);
2109 
2110           if (status != G_IO_STATUS_NORMAL)
2111             {
2112               if (status == G_IO_STATUS_AGAIN && wrote_bytes > 0)
2113                 status = G_IO_STATUS_NORMAL;
2114               if (bytes_written)
2115                 *bytes_written = wrote_bytes;
2116               return status;
2117             }
2118         }
2119 
2120       space_in_buf = MAX (channel->buf_size, channel->write_buf->allocated_len - 1)
2121                      - channel->write_buf->len; /* 1 for NULL */
2122 
2123       /* This is only true because g_io_channel_set_buffer_size ()
2124        * ensures that channel->buf_size >= MAX_CHAR_SIZE.
2125        */
2126       g_assert (space_in_buf >= MAX_CHAR_SIZE);
2127 
2128       if (!channel->encoding)
2129         {
2130           gssize write_this = MIN (space_in_buf, count - wrote_bytes);
2131 
2132           g_string_append_len (channel->write_buf, buf, write_this);
2133           buf += write_this;
2134           wrote_bytes += write_this;
2135         }
2136       else
2137         {
2138           const gchar *from_buf;
2139           gsize from_buf_len, from_buf_old_len, left_len;
2140           gsize err;
2141           gint errnum;
2142 
2143           if (channel->partial_write_buf[0] != '\0')
2144             {
2145               g_assert (wrote_bytes == 0);
2146 
2147               from_buf = channel->partial_write_buf;
2148               from_buf_old_len = strlen (channel->partial_write_buf);
2149               g_assert (from_buf_old_len > 0);
2150               from_buf_len = MIN (6, from_buf_old_len + count);
2151 
2152               memcpy (channel->partial_write_buf + from_buf_old_len, buf,
2153                       from_buf_len - from_buf_old_len);
2154             }
2155           else
2156             {
2157               from_buf = buf;
2158               from_buf_len = count - wrote_bytes;
2159               from_buf_old_len = 0;
2160             }
2161 
2162 reconvert:
2163 
2164           if (!channel->do_encode) /* UTF-8 encoding */
2165             {
2166               const gchar *badchar;
2167               gsize try_len = MIN (from_buf_len, space_in_buf);
2168 
2169               /* UTF-8, just validate, emulate g_iconv */
2170 
2171               if (!g_utf8_validate (from_buf, try_len, &badchar))
2172                 {
2173                   gunichar try_char;
2174                   gsize incomplete_len = from_buf + try_len - badchar;
2175 
2176                   left_len = from_buf + from_buf_len - badchar;
2177 
2178                   try_char = g_utf8_get_char_validated (badchar, incomplete_len);
2179 
2180                   switch (try_char)
2181                     {
2182                       case -2:
2183                         g_assert (incomplete_len < 6);
2184                         if (try_len == from_buf_len)
2185                           {
2186                             errnum = EINVAL;
2187                             err = (gsize) -1;
2188                           }
2189                         else
2190                           {
2191                             errnum = 0;
2192                             err = (gsize) 0;
2193                           }
2194                         break;
2195                       case -1:
2196                         g_warning ("Invalid UTF-8 passed to g_io_channel_write_chars().");
2197                         /* FIXME bail here? */
2198                         errnum = EILSEQ;
2199                         err = (gsize) -1;
2200                         break;
2201                       default:
2202                         g_assert_not_reached ();
2203                         err = (gsize) -1;
2204                         errnum = 0; /* Don't confunse the compiler */
2205                     }
2206                 }
2207               else
2208                 {
2209                   err = (gsize) 0;
2210                   errnum = 0;
2211                   left_len = from_buf_len - try_len;
2212                 }
2213 
2214               g_string_append_len (channel->write_buf, from_buf,
2215                                    from_buf_len - left_len);
2216               from_buf += from_buf_len - left_len;
2217             }
2218           else
2219             {
2220                gchar *outbuf;
2221 
2222                left_len = from_buf_len;
2223                g_string_set_size (channel->write_buf, channel->write_buf->len
2224                                   + space_in_buf);
2225                outbuf = channel->write_buf->str + channel->write_buf->len
2226                         - space_in_buf;
2227                err = g_iconv (channel->write_cd, (gchar **) &from_buf, &left_len,
2228                               &outbuf, &space_in_buf);
2229                errnum = errno;
2230                g_string_truncate (channel->write_buf, channel->write_buf->len
2231                                   - space_in_buf);
2232             }
2233 
2234           if (err == (gsize) -1)
2235             {
2236               switch (errnum)
2237         	{
2238                   case EINVAL:
2239                     g_assert (left_len < 6);
2240 
2241                     if (from_buf_old_len == 0)
2242                       {
2243                         /* Not from partial_write_buf */
2244 
2245                         memcpy (channel->partial_write_buf, from_buf, left_len);
2246                         channel->partial_write_buf[left_len] = '\0';
2247                         if (bytes_written)
2248                           *bytes_written = count;
2249                         return G_IO_STATUS_NORMAL;
2250                       }
2251 
2252                     /* Working in partial_write_buf */
2253 
2254                     if (left_len == from_buf_len)
2255                       {
2256                         /* Didn't convert anything, must still have
2257                          * less than a full character
2258                          */
2259 
2260                         g_assert (count == from_buf_len - from_buf_old_len);
2261 
2262                         channel->partial_write_buf[from_buf_len] = '\0';
2263 
2264                         if (bytes_written)
2265                           *bytes_written = count;
2266 
2267                         return G_IO_STATUS_NORMAL;
2268                       }
2269 
2270                     g_assert (from_buf_len - left_len >= from_buf_old_len);
2271 
2272                     /* We converted all the old data. This is fine */
2273 
2274                     break;
2275                   case E2BIG:
2276                     if (from_buf_len == left_len)
2277                       {
2278                         /* Nothing was written, add enough space for
2279                          * at least one character.
2280                          */
2281                         space_in_buf += MAX_CHAR_SIZE;
2282                         goto reconvert;
2283                       }
2284                     break;
2285                   case EILSEQ:
2286                     g_set_error_literal (error, G_CONVERT_ERROR,
2287                       G_CONVERT_ERROR_ILLEGAL_SEQUENCE,
2288                       _("Invalid byte sequence in conversion input"));
2289                     if (from_buf_old_len > 0 && from_buf_len == left_len)
2290                       g_warning ("Illegal sequence due to partial character "
2291                                  "at the end of a previous write.\n");
2292                     else
2293                       wrote_bytes += from_buf_len - left_len - from_buf_old_len;
2294                     if (bytes_written)
2295                       *bytes_written = wrote_bytes;
2296                     channel->partial_write_buf[0] = '\0';
2297                     return G_IO_STATUS_ERROR;
2298                   default:
2299                     g_set_error (error, G_CONVERT_ERROR, G_CONVERT_ERROR_FAILED,
2300                       _("Error during conversion: %s"), g_strerror (errnum));
2301                     if (from_buf_len >= left_len + from_buf_old_len)
2302                       wrote_bytes += from_buf_len - left_len - from_buf_old_len;
2303                     if (bytes_written)
2304                       *bytes_written = wrote_bytes;
2305                     channel->partial_write_buf[0] = '\0';
2306                     return G_IO_STATUS_ERROR;
2307                 }
2308             }
2309 
2310           g_assert (from_buf_len - left_len >= from_buf_old_len);
2311 
2312           wrote_bytes += from_buf_len - left_len - from_buf_old_len;
2313 
2314           if (from_buf_old_len > 0)
2315             {
2316               /* We were working in partial_write_buf */
2317 
2318               buf += from_buf_len - left_len - from_buf_old_len;
2319               channel->partial_write_buf[0] = '\0';
2320             }
2321           else
2322             buf = from_buf;
2323         }
2324     }
2325 
2326   if (bytes_written)
2327     *bytes_written = count;
2328 
2329   return G_IO_STATUS_NORMAL;
2330 }
2331 
2332 /**
2333  * g_io_channel_write_unichar:
2334  * @channel: a #GIOChannel
2335  * @thechar: a character
2336  * @error: location to return an error of type #GConvertError
2337  *         or #GIOChannelError
2338  *
2339  * Writes a Unicode character to @channel.
2340  * This function cannot be called on a channel with %NULL encoding.
2341  *
2342  * Return value: a #GIOStatus
2343  **/
2344 GIOStatus
g_io_channel_write_unichar(GIOChannel * channel,gunichar thechar,GError ** error)2345 g_io_channel_write_unichar (GIOChannel  *channel,
2346 			    gunichar     thechar,
2347 			    GError     **error)
2348 {
2349   GIOStatus status;
2350   gchar static_buf[6];
2351   gsize char_len, wrote_len;
2352 
2353   g_return_val_if_fail (channel != NULL, G_IO_STATUS_ERROR);
2354   g_return_val_if_fail (channel->encoding != NULL, G_IO_STATUS_ERROR);
2355   g_return_val_if_fail ((error == NULL) || (*error == NULL),
2356 			G_IO_STATUS_ERROR);
2357   g_return_val_if_fail (channel->is_writeable, G_IO_STATUS_ERROR);
2358 
2359   char_len = g_unichar_to_utf8 (thechar, static_buf);
2360 
2361   if (channel->partial_write_buf[0] != '\0')
2362     {
2363       g_warning ("Partial charater written before writing unichar.\n");
2364       channel->partial_write_buf[0] = '\0';
2365     }
2366 
2367   status = g_io_channel_write_chars (channel, static_buf,
2368                                      char_len, &wrote_len, error);
2369 
2370   /* We validate UTF-8, so we can't get a partial write */
2371 
2372   g_assert (wrote_len == char_len || status != G_IO_STATUS_NORMAL);
2373 
2374   return status;
2375 }
2376 
2377 /**
2378  * g_io_channel_error_quark:
2379  *
2380  * Return value: the quark used as %G_IO_CHANNEL_ERROR
2381  **/
2382 GQuark
g_io_channel_error_quark(void)2383 g_io_channel_error_quark (void)
2384 {
2385   return g_quark_from_static_string ("g-io-channel-error-quark");
2386 }
2387 
2388 #define __G_IOCHANNEL_C__
2389 #include "galiasdef.c"
2390