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glib2.0/gio/gmemoryinputstream.c

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/* GIO - GLib Input, Output and Streaming Library
*
* Copyright (C) 2006-2007 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 2.1 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, see <http://www.gnu.org/licenses/>.
*
* Author: Christian Kellner <gicmo@gnome.org>
*/
#include "config.h"
#include "gmemoryinputstream.h"
#include "gpollableinputstream.h"
#include "ginputstream.h"
#include "gseekable.h"
#include "string.h"
#include "gtask.h"
#include "gioerror.h"
#include "glibintl.h"
/**
* SECTION:gmemoryinputstream
* @short_description: Streaming input operations on memory chunks
* @include: gio/gio.h
* @see_also: #GMemoryOutputStream
*
* #GMemoryInputStream is a class for using arbitrary
* memory chunks as input for GIO streaming input operations.
*
* As of GLib 2.34, #GMemoryInputStream implements
* #GPollableInputStream.
*/
struct _GMemoryInputStreamPrivate {
GSList *chunks;
gsize len;
gsize pos;
};
static gssize g_memory_input_stream_read (GInputStream *stream,
void *buffer,
gsize count,
GCancellable *cancellable,
GError **error);
static gssize g_memory_input_stream_skip (GInputStream *stream,
gsize count,
GCancellable *cancellable,
GError **error);
static gboolean g_memory_input_stream_close (GInputStream *stream,
GCancellable *cancellable,
GError **error);
static void g_memory_input_stream_skip_async (GInputStream *stream,
gsize count,
int io_priority,
GCancellable *cancellabl,
GAsyncReadyCallback callback,
gpointer datae);
static gssize g_memory_input_stream_skip_finish (GInputStream *stream,
GAsyncResult *result,
GError **error);
static void g_memory_input_stream_close_async (GInputStream *stream,
int io_priority,
GCancellable *cancellabl,
GAsyncReadyCallback callback,
gpointer data);
static gboolean g_memory_input_stream_close_finish (GInputStream *stream,
GAsyncResult *result,
GError **error);
static void g_memory_input_stream_seekable_iface_init (GSeekableIface *iface);
static goffset g_memory_input_stream_tell (GSeekable *seekable);
static gboolean g_memory_input_stream_can_seek (GSeekable *seekable);
static gboolean g_memory_input_stream_seek (GSeekable *seekable,
goffset offset,
GSeekType type,
GCancellable *cancellable,
GError **error);
static gboolean g_memory_input_stream_can_truncate (GSeekable *seekable);
static gboolean g_memory_input_stream_truncate (GSeekable *seekable,
goffset offset,
GCancellable *cancellable,
GError **error);
static void g_memory_input_stream_pollable_iface_init (GPollableInputStreamInterface *iface);
static gboolean g_memory_input_stream_is_readable (GPollableInputStream *stream);
static GSource *g_memory_input_stream_create_source (GPollableInputStream *stream,
GCancellable *cancellable);
static void g_memory_input_stream_finalize (GObject *object);
G_DEFINE_TYPE_WITH_CODE (GMemoryInputStream, g_memory_input_stream, G_TYPE_INPUT_STREAM,
G_ADD_PRIVATE (GMemoryInputStream)
G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE,
g_memory_input_stream_seekable_iface_init);
G_IMPLEMENT_INTERFACE (G_TYPE_POLLABLE_INPUT_STREAM,
g_memory_input_stream_pollable_iface_init);
)
static void
g_memory_input_stream_class_init (GMemoryInputStreamClass *klass)
{
GObjectClass *object_class;
GInputStreamClass *istream_class;
object_class = G_OBJECT_CLASS (klass);
object_class->finalize = g_memory_input_stream_finalize;
istream_class = G_INPUT_STREAM_CLASS (klass);
istream_class->read_fn = g_memory_input_stream_read;
istream_class->skip = g_memory_input_stream_skip;
istream_class->close_fn = g_memory_input_stream_close;
istream_class->skip_async = g_memory_input_stream_skip_async;
istream_class->skip_finish = g_memory_input_stream_skip_finish;
istream_class->close_async = g_memory_input_stream_close_async;
istream_class->close_finish = g_memory_input_stream_close_finish;
}
static void
g_memory_input_stream_finalize (GObject *object)
{
GMemoryInputStream *stream;
GMemoryInputStreamPrivate *priv;
stream = G_MEMORY_INPUT_STREAM (object);
priv = stream->priv;
g_slist_free_full (priv->chunks, (GDestroyNotify)g_bytes_unref);
G_OBJECT_CLASS (g_memory_input_stream_parent_class)->finalize (object);
}
static void
g_memory_input_stream_seekable_iface_init (GSeekableIface *iface)
{
iface->tell = g_memory_input_stream_tell;
iface->can_seek = g_memory_input_stream_can_seek;
iface->seek = g_memory_input_stream_seek;
iface->can_truncate = g_memory_input_stream_can_truncate;
iface->truncate_fn = g_memory_input_stream_truncate;
}
static void
g_memory_input_stream_pollable_iface_init (GPollableInputStreamInterface *iface)
{
iface->is_readable = g_memory_input_stream_is_readable;
iface->create_source = g_memory_input_stream_create_source;
}
static void
g_memory_input_stream_init (GMemoryInputStream *stream)
{
stream->priv = g_memory_input_stream_get_instance_private (stream);
}
/**
* g_memory_input_stream_new:
*
* Creates a new empty #GMemoryInputStream.
*
* Returns: a new #GInputStream
*/
GInputStream *
g_memory_input_stream_new (void)
{
GInputStream *stream;
stream = g_object_new (G_TYPE_MEMORY_INPUT_STREAM, NULL);
return stream;
}
/**
* g_memory_input_stream_new_from_data:
* @data: (array length=len) (element-type guint8) (transfer full): input data
* @len: length of the data, may be -1 if @data is a nul-terminated string
* @destroy: (nullable): function that is called to free @data, or %NULL
*
* Creates a new #GMemoryInputStream with data in memory of a given size.
*
* Returns: new #GInputStream read from @data of @len bytes.
**/
GInputStream *
g_memory_input_stream_new_from_data (const void *data,
gssize len,
GDestroyNotify destroy)
{
GInputStream *stream;
stream = g_memory_input_stream_new ();
g_memory_input_stream_add_data (G_MEMORY_INPUT_STREAM (stream),
data, len, destroy);
return stream;
}
/**
* g_memory_input_stream_new_from_bytes:
* @bytes: a #GBytes
*
* Creates a new #GMemoryInputStream with data from the given @bytes.
*
* Returns: new #GInputStream read from @bytes
*
* Since: 2.34
**/
GInputStream *
g_memory_input_stream_new_from_bytes (GBytes *bytes)
{
GInputStream *stream;
stream = g_memory_input_stream_new ();
g_memory_input_stream_add_bytes (G_MEMORY_INPUT_STREAM (stream),
bytes);
return stream;
}
/**
* g_memory_input_stream_add_data:
* @stream: a #GMemoryInputStream
* @data: (array length=len) (element-type guint8) (transfer full): input data
* @len: length of the data, may be -1 if @data is a nul-terminated string
* @destroy: (nullable): function that is called to free @data, or %NULL
*
* Appends @data to data that can be read from the input stream
*/
void
g_memory_input_stream_add_data (GMemoryInputStream *stream,
const void *data,
gssize len,
GDestroyNotify destroy)
{
GBytes *bytes;
if (len == -1)
len = strlen (data);
/* It's safe to discard the const here because we're chaining the
* destroy callback.
*/
bytes = g_bytes_new_with_free_func (data, len, destroy, (void*)data);
g_memory_input_stream_add_bytes (stream, bytes);
g_bytes_unref (bytes);
}
/**
* g_memory_input_stream_add_bytes:
* @stream: a #GMemoryInputStream
* @bytes: input data
*
* Appends @bytes to data that can be read from the input stream.
*
* Since: 2.34
*/
void
g_memory_input_stream_add_bytes (GMemoryInputStream *stream,
GBytes *bytes)
{
GMemoryInputStreamPrivate *priv;
g_return_if_fail (G_IS_MEMORY_INPUT_STREAM (stream));
g_return_if_fail (bytes != NULL);
priv = stream->priv;
priv->chunks = g_slist_append (priv->chunks, g_bytes_ref (bytes));
priv->len += g_bytes_get_size (bytes);
}
static gssize
g_memory_input_stream_read (GInputStream *stream,
void *buffer,
gsize count,
GCancellable *cancellable,
GError **error)
{
GMemoryInputStream *memory_stream;
GMemoryInputStreamPrivate *priv;
GSList *l;
GBytes *chunk;
gsize len;
gsize offset, start, rest, size;
memory_stream = G_MEMORY_INPUT_STREAM (stream);
priv = memory_stream->priv;
count = MIN (count, priv->len - priv->pos);
offset = 0;
for (l = priv->chunks; l; l = l->next)
{
chunk = (GBytes *)l->data;
len = g_bytes_get_size (chunk);
if (offset + len > priv->pos)
break;
offset += len;
}
start = priv->pos - offset;
rest = count;
for (; l && rest > 0; l = l->next)
{
const guint8* chunk_data;
chunk = (GBytes *)l->data;
chunk_data = g_bytes_get_data (chunk, &len);
size = MIN (rest, len - start);
memcpy ((guint8 *)buffer + (count - rest), chunk_data + start, size);
rest -= size;
start = 0;
}
priv->pos += count;
return count;
}
static gssize
g_memory_input_stream_skip (GInputStream *stream,
gsize count,
GCancellable *cancellable,
GError **error)
{
GMemoryInputStream *memory_stream;
GMemoryInputStreamPrivate *priv;
memory_stream = G_MEMORY_INPUT_STREAM (stream);
priv = memory_stream->priv;
count = MIN (count, priv->len - priv->pos);
priv->pos += count;
return count;
}
static gboolean
g_memory_input_stream_close (GInputStream *stream,
GCancellable *cancellable,
GError **error)
{
return TRUE;
}
static void
g_memory_input_stream_skip_async (GInputStream *stream,
gsize count,
int io_priority,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
GTask *task;
gssize nskipped;
GError *error = NULL;
nskipped = G_INPUT_STREAM_GET_CLASS (stream)->skip (stream, count, cancellable, &error);
task = g_task_new (stream, cancellable, callback, user_data);
g_task_set_source_tag (task, g_memory_input_stream_skip_async);
if (error)
g_task_return_error (task, error);
else
g_task_return_int (task, nskipped);
g_object_unref (task);
}
static gssize
g_memory_input_stream_skip_finish (GInputStream *stream,
GAsyncResult *result,
GError **error)
{
g_return_val_if_fail (g_task_is_valid (result, stream), -1);
return g_task_propagate_int (G_TASK (result), error);
}
static void
g_memory_input_stream_close_async (GInputStream *stream,
int io_priority,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
GTask *task;
task = g_task_new (stream, cancellable, callback, user_data);
g_task_set_source_tag (task, g_memory_input_stream_close_async);
g_task_return_boolean (task, TRUE);
g_object_unref (task);
}
static gboolean
g_memory_input_stream_close_finish (GInputStream *stream,
GAsyncResult *result,
GError **error)
{
return TRUE;
}
static goffset
g_memory_input_stream_tell (GSeekable *seekable)
{
GMemoryInputStream *memory_stream;
GMemoryInputStreamPrivate *priv;
memory_stream = G_MEMORY_INPUT_STREAM (seekable);
priv = memory_stream->priv;
return priv->pos;
}
static
gboolean g_memory_input_stream_can_seek (GSeekable *seekable)
{
return TRUE;
}
static gboolean
g_memory_input_stream_seek (GSeekable *seekable,
goffset offset,
GSeekType type,
GCancellable *cancellable,
GError **error)
{
GMemoryInputStream *memory_stream;
GMemoryInputStreamPrivate *priv;
goffset absolute;
memory_stream = G_MEMORY_INPUT_STREAM (seekable);
priv = memory_stream->priv;
switch (type)
{
case G_SEEK_CUR:
absolute = priv->pos + offset;
break;
case G_SEEK_SET:
absolute = offset;
break;
case G_SEEK_END:
absolute = priv->len + offset;
break;
default:
g_set_error_literal (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Invalid GSeekType supplied"));
return FALSE;
}
if (absolute < 0 || absolute > priv->len)
{
g_set_error_literal (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Invalid seek request"));
return FALSE;
}
priv->pos = absolute;
return TRUE;
}
static gboolean
g_memory_input_stream_can_truncate (GSeekable *seekable)
{
return FALSE;
}
static gboolean
g_memory_input_stream_truncate (GSeekable *seekable,
goffset offset,
GCancellable *cancellable,
GError **error)
{
g_set_error_literal (error,
G_IO_ERROR,
G_IO_ERROR_NOT_SUPPORTED,
_("Cannot truncate GMemoryInputStream"));
return FALSE;
}
static gboolean
g_memory_input_stream_is_readable (GPollableInputStream *stream)
{
return TRUE;
}
static GSource *
g_memory_input_stream_create_source (GPollableInputStream *stream,
GCancellable *cancellable)
{
GSource *base_source, *pollable_source;
base_source = g_timeout_source_new (0);
pollable_source = g_pollable_source_new_full (stream, base_source,
cancellable);
g_source_unref (base_source);
return pollable_source;
}
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