glib/gio/gpollableutils.c

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/* GIO - GLib Input, Output and Streaming Library
*
* Copyright (C) 2010 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "config.h"
#include <errno.h>
#include "gpollableinputstream.h"
#include "gasynchelper.h"
#include "glibintl.h"
/**
* SECTION:gpollableutils
* @short_description: #GPollableInputStream / #GPollableOutputStream utilities
* @include: gio/gio.h
*
* Utility functions for #GPollableInputStream and
* #GPollableOutputStream implementations.
*/
typedef struct {
GSource source;
GObject *stream;
} GPollableSource;
static gboolean
pollable_source_prepare (GSource *source,
gint *timeout)
{
*timeout = -1;
return FALSE;
}
static gboolean
pollable_source_check (GSource *source)
{
return FALSE;
}
static gboolean
pollable_source_dispatch (GSource *source,
GSourceFunc callback,
gpointer user_data)
{
GPollableSourceFunc func = (GPollableSourceFunc)callback;
GPollableSource *pollable_source = (GPollableSource *)source;
return (*func) (pollable_source->stream, user_data);
}
static void
pollable_source_finalize (GSource *source)
{
GPollableSource *pollable_source = (GPollableSource *)source;
g_object_unref (pollable_source->stream);
}
static gboolean
pollable_source_closure_callback (GObject *stream,
gpointer data)
{
GClosure *closure = data;
GValue param = G_VALUE_INIT;
GValue result_value = G_VALUE_INIT;
gboolean result;
g_value_init (&result_value, G_TYPE_BOOLEAN);
g_value_init (&param, G_TYPE_OBJECT);
g_value_set_object (&param, stream);
g_closure_invoke (closure, &result_value, 1, &param, NULL);
result = g_value_get_boolean (&result_value);
g_value_unset (&result_value);
g_value_unset (&param);
return result;
}
static GSourceFuncs pollable_source_funcs =
{
pollable_source_prepare,
pollable_source_check,
pollable_source_dispatch,
pollable_source_finalize,
(GSourceFunc)pollable_source_closure_callback,
(GSourceDummyMarshal)g_cclosure_marshal_generic,
};
/**
* g_pollable_source_new:
* @pollable_stream: the stream associated with the new source
*
* Utility method for #GPollableInputStream and #GPollableOutputStream
* implementations. Creates a new #GSource that expects a callback of
* type #GPollableSourceFunc. The new source does not actually do
* anything on its own; use g_source_add_child_source() to add other
* sources to it to cause it to trigger.
*
* Return value: (transfer full): the new #GSource.
*
* Since: 2.28
*/
GSource *
g_pollable_source_new (GObject *pollable_stream)
{
GSource *source;
GPollableSource *pollable_source;
g_return_val_if_fail (G_IS_POLLABLE_INPUT_STREAM (pollable_stream) ||
G_IS_POLLABLE_OUTPUT_STREAM (pollable_stream), NULL);
source = g_source_new (&pollable_source_funcs, sizeof (GPollableSource));
g_source_set_name (source, "GPollableSource");
pollable_source = (GPollableSource *)source;
pollable_source->stream = g_object_ref (pollable_stream);
return source;
}
/**
* g_pollable_source_new_full:
* @pollable_stream: (type GObject): the stream associated with the
* new source
* @child_source: (allow-none): optional child source to attach
* @cancellable: (allow-none): optional #GCancellable to attach
*
* Utility method for #GPollableInputStream and #GPollableOutputStream
* implementations. Creates a new #GSource, as with
* g_pollable_source_new(), but also attaching @child_source (with a
* dummy callback), and @cancellable, if they are non-%NULL.
*
* Return value: (transfer full): the new #GSource.
*
* Since: 2.34
*/
GSource *
g_pollable_source_new_full (gpointer pollable_stream,
GSource *child_source,
GCancellable *cancellable)
{
GSource *source;
g_return_val_if_fail (G_IS_POLLABLE_INPUT_STREAM (pollable_stream) ||
G_IS_POLLABLE_OUTPUT_STREAM (pollable_stream), NULL);
source = g_pollable_source_new (pollable_stream);
if (child_source)
{
g_source_set_dummy_callback (child_source);
g_source_add_child_source (source, child_source);
}
if (cancellable)
{
GSource *cancellable_source = g_cancellable_source_new (cancellable);
g_source_set_dummy_callback (cancellable_source);
g_source_add_child_source (source, cancellable_source);
g_source_unref (cancellable_source);
}
return source;
}
/**
* g_pollable_stream_read:
* @stream: a #GInputStream
* @buffer: a buffer to read data into
* @count: the number of bytes to read
* @blocking: whether to do blocking I/O
* @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
* @error: location to store the error occurring, or %NULL to ignore
*
* Tries to read from @stream, as with g_input_stream_read() (if
* @blocking is %TRUE) or g_pollable_input_stream_read_nonblocking()
* (if @blocking is %FALSE). This can be used to more easily share
* code between blocking and non-blocking implementations of a method.
*
* If @blocking is %FALSE, then @stream must be a
* #GPollableInputStream for which g_pollable_input_stream_can_poll()
* returns %TRUE, or else the behavior is undefined. If @blocking is
* %TRUE, then @stream does not need to be a #GPollableInputStream.
*
* Returns: the number of bytes read, or -1 on error.
*
* Since: 2.34
*/
gssize
g_pollable_stream_read (GInputStream *stream,
void *buffer,
gsize count,
gboolean blocking,
GCancellable *cancellable,
GError **error)
{
if (blocking)
{
return g_input_stream_read (stream,
buffer, count,
cancellable, error);
}
else
{
return g_pollable_input_stream_read_nonblocking (G_POLLABLE_INPUT_STREAM (stream),
buffer, count,
cancellable, error);
}
}
/**
* g_pollable_stream_write:
* @stream: a #GOutputStream.
* @buffer: (array length=count) (element-type guint8): the buffer
* containing the data to write.
* @count: the number of bytes to write
* @blocking: whether to do blocking I/O
* @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
* @error: location to store the error occurring, or %NULL to ignore
*
* Tries to write to @stream, as with g_output_stream_write() (if
* @blocking is %TRUE) or g_pollable_output_stream_write_nonblocking()
* (if @blocking is %FALSE). This can be used to more easily share
* code between blocking and non-blocking implementations of a method.
*
* If @blocking is %FALSE, then @stream must be a
* #GPollableOutputStream for which
* g_pollable_output_stream_can_poll() returns %TRUE or else the
* behavior is undefined. If @blocking is %TRUE, then @stream does not
* need to be a #GPollableOutputStream.
*
* Returns: the number of bytes written, or -1 on error.
*
* Since: 2.34
*/
gssize
g_pollable_stream_write (GOutputStream *stream,
const void *buffer,
gsize count,
gboolean blocking,
GCancellable *cancellable,
GError **error)
{
if (blocking)
{
return g_output_stream_write (stream,
buffer, count,
cancellable, error);
}
else
{
return g_pollable_output_stream_write_nonblocking (G_POLLABLE_OUTPUT_STREAM (stream),
buffer, count,
cancellable, error);
}
}
/**
* g_pollable_stream_write_all:
* @stream: a #GOutputStream.
* @buffer: (array length=count) (element-type guint8): the buffer
* containing the data to write.
* @count: the number of bytes to write
* @blocking: whether to do blocking I/O
* @bytes_written: (out): location to store the number of bytes that was
* written to the stream
* @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
* @error: location to store the error occurring, or %NULL to ignore
*
* Tries to write @count bytes to @stream, as with
* g_output_stream_write_all(), but using g_pollable_stream_write()
* rather than g_output_stream_write().
*
* On a successful write of @count bytes, %TRUE is returned, and
* @bytes_written is set to @count.
*
* If there is an error during the operation (including
* %G_IO_ERROR_WOULD_BLOCK in the non-blocking case), %FALSE is
* returned and @error is set to indicate the error status,
* @bytes_written is updated to contain the number of bytes written
* into the stream before the error occurred.
*
* As with g_pollable_stream_write(), if @blocking is %FALSE, then
* @stream must be a #GPollableOutputStream for which
* g_pollable_output_stream_can_poll() returns %TRUE or else the
* behavior is undefined. If @blocking is %TRUE, then @stream does not
* need to be a #GPollableOutputStream.
*
* Return value: %TRUE on success, %FALSE if there was an error
*
* Since: 2.34
*/
gboolean
g_pollable_stream_write_all (GOutputStream *stream,
const void *buffer,
gsize count,
gboolean blocking,
gsize *bytes_written,
GCancellable *cancellable,
GError **error)
{
gsize _bytes_written;
gssize res;
_bytes_written = 0;
while (_bytes_written < count)
{
res = g_pollable_stream_write (stream,
(char *)buffer + _bytes_written,
count - _bytes_written,
blocking,
cancellable, error);
if (res == -1)
{
if (bytes_written)
*bytes_written = _bytes_written;
return FALSE;
}
if (res == 0)
g_warning ("Write returned zero without error");
_bytes_written += res;
}
if (bytes_written)
*bytes_written = _bytes_written;
return TRUE;
}