glib/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 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.
*
* Author: Christian Kellner <gicmo@gnome.org>
*/
#include "config.h"
#include "gmemoryinputstream.h"
#include "ginputstream.h"
#include "gseekable.h"
#include "string.h"
#include "gsimpleasyncresult.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.
*
*/
typedef struct _Chunk Chunk;
struct _Chunk {
guint8 *data;
gsize len;
GDestroyNotify destroy;
};
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_read_async (GInputStream *stream,
void *buffer,
gsize count,
int io_priority,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data);
static gssize g_memory_input_stream_read_finish (GInputStream *stream,
GAsyncResult *result,
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_finalize (GObject *object);
G_DEFINE_TYPE_WITH_CODE (GMemoryInputStream, g_memory_input_stream, G_TYPE_INPUT_STREAM,
G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE,
g_memory_input_stream_seekable_iface_init))
static void
g_memory_input_stream_class_init (GMemoryInputStreamClass *klass)
{
GObjectClass *object_class;
GInputStreamClass *istream_class;
g_type_class_add_private (klass, sizeof (GMemoryInputStreamPrivate));
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->read_async = g_memory_input_stream_read_async;
istream_class->read_finish = g_memory_input_stream_read_finish;
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
free_chunk (gpointer data,
gpointer user_data)
{
Chunk *chunk = data;
if (chunk->destroy)
chunk->destroy (chunk->data);
g_slice_free (Chunk, chunk);
}
static void
g_memory_input_stream_finalize (GObject *object)
{
GMemoryInputStream *stream;
GMemoryInputStreamPrivate *priv;
stream = G_MEMORY_INPUT_STREAM (object);
priv = stream->priv;
g_slist_foreach (priv->chunks, free_chunk, NULL);
g_slist_free (priv->chunks);
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_init (GMemoryInputStream *stream)
{
stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (stream,
G_TYPE_MEMORY_INPUT_STREAM,
GMemoryInputStreamPrivate);
}
/**
* 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): input data
* @len: length of the data, may be -1 if @data is a nul-terminated string
* @destroy: (allow-none): 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_add_data:
* @stream: a #GMemoryInputStream
* @data: (array length=len) (element-type guint8): input data
* @len: length of the data, may be -1 if @data is a nul-terminated string
* @destroy: (allow-none): 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)
{
GMemoryInputStreamPrivate *priv;
Chunk *chunk;
g_return_if_fail (G_IS_MEMORY_INPUT_STREAM (stream));
g_return_if_fail (data != NULL);
priv = stream->priv;
if (len == -1)
len = strlen (data);
chunk = g_slice_new (Chunk);
chunk->data = (guint8 *)data;
chunk->len = len;
chunk->destroy = destroy;
priv->chunks = g_slist_append (priv->chunks, chunk);
priv->len += chunk->len;
}
static gssize
g_memory_input_stream_read (GInputStream *stream,
void *buffer,
gsize count,
GCancellable *cancellable,
GError **error)
{
GMemoryInputStream *memory_stream;
GMemoryInputStreamPrivate *priv;
GSList *l;
Chunk *chunk;
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 = (Chunk *)l->data;
if (offset + chunk->len > priv->pos)
break;
offset += chunk->len;
}
start = priv->pos - offset;
rest = count;
for (; l && rest > 0; l = l->next)
{
chunk = (Chunk *)l->data;
size = MIN (rest, chunk->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_read_async (GInputStream *stream,
void *buffer,
gsize count,
int io_priority,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
GSimpleAsyncResult *simple;
GError *error = NULL;
gssize nread;
nread = G_INPUT_STREAM_GET_CLASS (stream)->read_fn (stream,
buffer,
count,
cancellable,
&error);
simple = g_simple_async_result_new (G_OBJECT (stream),
callback,
user_data,
g_memory_input_stream_read_async);
if (error)
g_simple_async_result_take_error (simple, error);
else
g_simple_async_result_set_op_res_gssize (simple, nread);
g_simple_async_result_complete_in_idle (simple);
g_object_unref (simple);
}
static gssize
g_memory_input_stream_read_finish (GInputStream *stream,
GAsyncResult *result,
GError **error)
{
GSimpleAsyncResult *simple;
gssize nread;
simple = G_SIMPLE_ASYNC_RESULT (result);
g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_memory_input_stream_read_async);
nread = g_simple_async_result_get_op_res_gssize (simple);
return nread;
}
static void
g_memory_input_stream_skip_async (GInputStream *stream,
gsize count,
int io_priority,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
GSimpleAsyncResult *simple;
gssize nskipped;
nskipped = g_input_stream_skip (stream, count, cancellable, NULL);
simple = g_simple_async_result_new (G_OBJECT (stream),
callback,
user_data,
g_memory_input_stream_skip_async);
g_simple_async_result_set_op_res_gssize (simple, nskipped);
g_simple_async_result_complete_in_idle (simple);
g_object_unref (simple);
}
static gssize
g_memory_input_stream_skip_finish (GInputStream *stream,
GAsyncResult *result,
GError **error)
{
GSimpleAsyncResult *simple;
gssize nskipped;
simple = G_SIMPLE_ASYNC_RESULT (result);
g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_memory_input_stream_skip_async);
nskipped = g_simple_async_result_get_op_res_gssize (simple);
return nskipped;
}
static void
g_memory_input_stream_close_async (GInputStream *stream,
int io_priority,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
GSimpleAsyncResult *simple;
simple = g_simple_async_result_new (G_OBJECT (stream),
callback,
user_data,
g_memory_input_stream_close_async);
g_simple_async_result_complete_in_idle (simple);
g_object_unref (simple);
}
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;
}