1 /* GIO - GLib Input, Output and Streaming Library
3 * Copyright (C) 2009 Red Hat, Inc.
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General
16 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
18 * Author: Alexander Larsson <alexl@redhat.com>
25 #include "gconverterinputstream.h"
26 #include "gpollableinputstream.h"
27 #include "gcancellable.h"
28 #include "gioenumtypes.h"
34 * SECTION:gconverterinputstream
35 * @short_description: Converter Input Stream
37 * @see_also: #GInputStream, #GConverter
39 * Converter input stream implements #GInputStream and allows
40 * conversion of data of various types during reading.
42 * As of GLib 2.34, #GConverterInputStream implements
43 * #GPollableInputStream.
46 #define INITIAL_BUFFER_SIZE 4096
55 struct _GConverterInputStreamPrivate {
56 gboolean at_input_end;
59 GConverter *converter;
61 Buffer converted_buffer;
69 static void g_converter_input_stream_set_property (GObject *object,
73 static void g_converter_input_stream_get_property (GObject *object,
77 static void g_converter_input_stream_finalize (GObject *object);
78 static gssize g_converter_input_stream_read (GInputStream *stream,
81 GCancellable *cancellable,
84 static gboolean g_converter_input_stream_can_poll (GPollableInputStream *stream);
85 static gboolean g_converter_input_stream_is_readable (GPollableInputStream *stream);
86 static gssize g_converter_input_stream_read_nonblocking (GPollableInputStream *stream,
91 static GSource *g_converter_input_stream_create_source (GPollableInputStream *stream,
92 GCancellable *cancellable);
94 static void g_converter_input_stream_pollable_iface_init (GPollableInputStreamInterface *iface);
96 G_DEFINE_TYPE_WITH_CODE (GConverterInputStream,
97 g_converter_input_stream,
98 G_TYPE_FILTER_INPUT_STREAM,
99 G_ADD_PRIVATE (GConverterInputStream)
100 G_IMPLEMENT_INTERFACE (G_TYPE_POLLABLE_INPUT_STREAM,
101 g_converter_input_stream_pollable_iface_init))
104 g_converter_input_stream_class_init (GConverterInputStreamClass *klass)
106 GObjectClass *object_class;
107 GInputStreamClass *istream_class;
109 object_class = G_OBJECT_CLASS (klass);
110 object_class->get_property = g_converter_input_stream_get_property;
111 object_class->set_property = g_converter_input_stream_set_property;
112 object_class->finalize = g_converter_input_stream_finalize;
114 istream_class = G_INPUT_STREAM_CLASS (klass);
115 istream_class->read_fn = g_converter_input_stream_read;
117 g_object_class_install_property (object_class,
119 g_param_spec_object ("converter",
121 P_("The converter object"),
124 G_PARAM_CONSTRUCT_ONLY|
125 G_PARAM_STATIC_STRINGS));
130 g_converter_input_stream_pollable_iface_init (GPollableInputStreamInterface *iface)
132 iface->can_poll = g_converter_input_stream_can_poll;
133 iface->is_readable = g_converter_input_stream_is_readable;
134 iface->read_nonblocking = g_converter_input_stream_read_nonblocking;
135 iface->create_source = g_converter_input_stream_create_source;
139 g_converter_input_stream_finalize (GObject *object)
141 GConverterInputStreamPrivate *priv;
142 GConverterInputStream *stream;
144 stream = G_CONVERTER_INPUT_STREAM (object);
147 g_free (priv->input_buffer.data);
148 g_free (priv->converted_buffer.data);
150 g_object_unref (priv->converter);
152 G_OBJECT_CLASS (g_converter_input_stream_parent_class)->finalize (object);
156 g_converter_input_stream_set_property (GObject *object,
161 GConverterInputStream *cstream;
163 cstream = G_CONVERTER_INPUT_STREAM (object);
168 cstream->priv->converter = g_value_dup_object (value);
172 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
179 g_converter_input_stream_get_property (GObject *object,
184 GConverterInputStreamPrivate *priv;
185 GConverterInputStream *cstream;
187 cstream = G_CONVERTER_INPUT_STREAM (object);
188 priv = cstream->priv;
193 g_value_set_object (value, priv->converter);
197 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
203 g_converter_input_stream_init (GConverterInputStream *stream)
205 stream->priv = g_converter_input_stream_get_instance_private (stream);
209 * g_converter_input_stream_new:
210 * @base_stream: a #GInputStream
211 * @converter: a #GConverter
213 * Creates a new converter input stream for the @base_stream.
215 * Returns: a new #GInputStream.
218 g_converter_input_stream_new (GInputStream *base_stream,
219 GConverter *converter)
221 GInputStream *stream;
223 g_return_val_if_fail (G_IS_INPUT_STREAM (base_stream), NULL);
225 stream = g_object_new (G_TYPE_CONVERTER_INPUT_STREAM,
226 "base-stream", base_stream,
227 "converter", converter,
234 buffer_data_size (Buffer *buffer)
236 return buffer->end - buffer->start;
240 buffer_tailspace (Buffer *buffer)
242 return buffer->size - buffer->end;
246 buffer_data (Buffer *buffer)
248 return buffer->data + buffer->start;
252 buffer_consumed (Buffer *buffer,
255 buffer->start += count;
256 if (buffer->start == buffer->end)
257 buffer->start = buffer->end = 0;
261 buffer_read (Buffer *buffer,
266 memcpy (dest, buffer->data + buffer->start, count);
268 buffer_consumed (buffer, count);
272 compact_buffer (Buffer *buffer)
276 in_buffer = buffer_data_size (buffer);
277 memmove (buffer->data,
278 buffer->data + buffer->start,
280 buffer->end -= buffer->start;
285 grow_buffer (Buffer *buffer)
288 gsize size, in_buffer;
290 if (buffer->size == 0)
291 size = INITIAL_BUFFER_SIZE;
293 size = buffer->size * 2;
295 data = g_malloc (size);
296 in_buffer = buffer_data_size (buffer);
300 buffer->data + buffer->start,
303 g_free (buffer->data);
305 buffer->end -= buffer->start;
310 /* Ensures that the buffer can fit at_least_size bytes,
311 * *including* the current in-buffer data */
313 buffer_ensure_space (Buffer *buffer,
316 gsize in_buffer, left_to_fill;
318 in_buffer = buffer_data_size (buffer);
320 if (in_buffer >= at_least_size)
323 left_to_fill = buffer_tailspace (buffer);
325 if (in_buffer + left_to_fill >= at_least_size)
327 /* We fit in remaining space at end */
328 /* If the copy is small, compact now anyway so we can fill more */
330 compact_buffer (buffer);
332 else if (buffer->size >= at_least_size)
334 /* We fit, but only if we compact */
335 compact_buffer (buffer);
339 /* Need to grow buffer */
340 while (buffer->size < at_least_size)
341 grow_buffer (buffer);
346 fill_input_buffer (GConverterInputStream *stream,
349 GCancellable *cancellable,
352 GConverterInputStreamPrivate *priv;
353 GInputStream *base_stream;
358 buffer_ensure_space (&priv->input_buffer, at_least_size);
360 base_stream = G_FILTER_INPUT_STREAM (stream)->base_stream;
361 nread = g_pollable_stream_read (base_stream,
362 priv->input_buffer.data + priv->input_buffer.end,
363 buffer_tailspace (&priv->input_buffer),
370 priv->input_buffer.end += nread;
371 priv->need_input = FALSE;
379 read_internal (GInputStream *stream,
383 GCancellable *cancellable,
386 GConverterInputStream *cstream;
387 GConverterInputStreamPrivate *priv;
388 gsize available, total_bytes_read;
390 GConverterResult res;
396 cstream = G_CONVERTER_INPUT_STREAM (stream);
397 priv = cstream->priv;
399 available = buffer_data_size (&priv->converted_buffer);
404 /* Converted data available, return that */
405 buffer_read (&priv->converted_buffer, buffer, count);
409 /* Full request not available, read all currently available and request
410 refill/conversion for more */
412 buffer_read (&priv->converted_buffer, buffer, available);
414 total_bytes_read = available;
415 buffer = (char *) buffer + available;
418 /* If there is no data to convert, and no pre-converted data,
419 do some i/o for more input */
420 if (buffer_data_size (&priv->input_buffer) == 0 &&
421 total_bytes_read == 0 &&
424 nread = fill_input_buffer (cstream, count, blocking, cancellable, error);
428 priv->at_input_end = TRUE;
431 /* First try to convert any available data (or state) directly to the user buffer: */
435 res = g_converter_convert (priv->converter,
436 buffer_data (&priv->input_buffer),
437 buffer_data_size (&priv->input_buffer),
439 priv->at_input_end ? G_CONVERTER_INPUT_AT_END : 0,
443 if (res != G_CONVERTER_ERROR)
445 total_bytes_read += bytes_written;
446 buffer_consumed (&priv->input_buffer, bytes_read);
447 if (res == G_CONVERTER_FINISHED)
448 priv->finished = TRUE; /* We're done converting */
450 else if (total_bytes_read == 0 &&
451 !g_error_matches (my_error,
453 G_IO_ERROR_PARTIAL_INPUT) &&
454 !g_error_matches (my_error,
456 G_IO_ERROR_NO_SPACE))
458 /* No previously read data and no "special" error, return error */
459 g_propagate_error (error, my_error);
463 g_error_free (my_error);
466 /* We had some pre-converted data and/or we converted directly to the
468 if (total_bytes_read > 0)
469 return total_bytes_read;
471 /* If there is no more to convert, return EOF */
474 g_assert (buffer_data_size (&priv->converted_buffer) == 0);
478 /* There was "complexity" in the straight-to-buffer conversion,
479 * convert to our own buffer and write from that.
480 * At this point we didn't produce any data into @buffer.
483 /* Ensure we have *some* initial target space */
484 buffer_ensure_space (&priv->converted_buffer, count);
488 g_assert (!priv->finished);
490 /* Try to convert to our buffer */
492 res = g_converter_convert (priv->converter,
493 buffer_data (&priv->input_buffer),
494 buffer_data_size (&priv->input_buffer),
495 buffer_data (&priv->converted_buffer),
496 buffer_tailspace (&priv->converted_buffer),
497 priv->at_input_end ? G_CONVERTER_INPUT_AT_END : 0,
501 if (res != G_CONVERTER_ERROR)
503 priv->converted_buffer.end += bytes_written;
504 buffer_consumed (&priv->input_buffer, bytes_read);
506 /* Maybe we consumed without producing any output */
507 if (buffer_data_size (&priv->converted_buffer) == 0 && res != G_CONVERTER_FINISHED)
508 continue; /* Convert more */
510 if (res == G_CONVERTER_FINISHED)
511 priv->finished = TRUE;
513 total_bytes_read = MIN (count, buffer_data_size (&priv->converted_buffer));
514 buffer_read (&priv->converted_buffer, buffer, total_bytes_read);
516 g_assert (priv->finished || total_bytes_read > 0);
518 return total_bytes_read;
521 /* There was some kind of error filling our buffer */
523 if (g_error_matches (my_error,
525 G_IO_ERROR_PARTIAL_INPUT) &&
530 nread = fill_input_buffer (cstream,
531 buffer_data_size (&priv->input_buffer) + 4096,
537 /* Can't read any more data, return that error */
538 g_error_free (my_error);
539 g_propagate_error (error, my_error2);
540 priv->need_input = TRUE;
545 /* End of file, try INPUT_AT_END */
546 priv->at_input_end = TRUE;
548 g_error_free (my_error);
552 if (g_error_matches (my_error,
554 G_IO_ERROR_NO_SPACE))
556 /* Need more destination space, grow it
557 * Note: if we actually grow the buffer (as opposed to compacting it),
558 * this will double the size, not just add one byte. */
559 buffer_ensure_space (&priv->converted_buffer,
560 priv->converted_buffer.size + 1);
561 g_error_free (my_error);
565 /* Any other random error, return it */
566 g_propagate_error (error, my_error);
570 g_assert_not_reached ();
574 g_converter_input_stream_read (GInputStream *stream,
577 GCancellable *cancellable,
580 return read_internal (stream, buffer, count, TRUE, cancellable, error);
584 g_converter_input_stream_can_poll (GPollableInputStream *stream)
586 GInputStream *base_stream = G_FILTER_INPUT_STREAM (stream)->base_stream;
588 return (G_IS_POLLABLE_INPUT_STREAM (base_stream) &&
589 g_pollable_input_stream_can_poll (G_POLLABLE_INPUT_STREAM (base_stream)));
593 g_converter_input_stream_is_readable (GPollableInputStream *stream)
595 GInputStream *base_stream = G_FILTER_INPUT_STREAM (stream)->base_stream;
596 GConverterInputStream *cstream = G_CONVERTER_INPUT_STREAM (stream);
598 if (buffer_data_size (&cstream->priv->converted_buffer))
600 else if (buffer_data_size (&cstream->priv->input_buffer) &&
601 !cstream->priv->need_input)
604 return g_pollable_input_stream_is_readable (G_POLLABLE_INPUT_STREAM (base_stream));
608 g_converter_input_stream_read_nonblocking (GPollableInputStream *stream,
613 return read_internal (G_INPUT_STREAM (stream), buffer, count,
618 g_converter_input_stream_create_source (GPollableInputStream *stream,
619 GCancellable *cancellable)
621 GInputStream *base_stream = G_FILTER_INPUT_STREAM (stream)->base_stream;
622 GSource *base_source, *pollable_source;
624 if (g_pollable_input_stream_is_readable (stream))
625 base_source = g_timeout_source_new (0);
627 base_source = g_pollable_input_stream_create_source (G_POLLABLE_INPUT_STREAM (base_stream), NULL);
629 pollable_source = g_pollable_source_new_full (stream, base_source,
631 g_source_unref (base_source);
633 return pollable_source;
638 * g_converter_input_stream_get_converter:
639 * @converter_stream: a #GConverterInputStream
641 * Gets the #GConverter that is used by @converter_stream.
643 * Returns: (transfer none): the converter of the converter input stream
648 g_converter_input_stream_get_converter (GConverterInputStream *converter_stream)
650 return converter_stream->priv->converter;