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third-party-mirror/glib/refs/heads/main/./gio/gbufferedoutputstream.c
blob: aab308c67086ba9433fe00470205b9f73685dd00 [file] [edit]
/* GIO - GLib Input, Output and Streaming Library
*
* Copyright (C) 2006-2007 Red Hat, Inc.
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*
* 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 "gbufferedoutputstream.h"
#include "goutputstream.h"
#include "gseekable.h"
#include "gtask.h"
#include "string.h"
#include "gioerror.h"
#include "glibintl.h"
/**
* GBufferedOutputStream:
*
* Buffered output stream implements [class@Gio.FilterOutputStream] and provides
* for buffered writes.
*
* By default, `GBufferedOutputStream`'s buffer size is set at 4 kilobytes.
*
* To create a buffered output stream, use [ctor@Gio.BufferedOutputStream.new],
* or [ctor@Gio.BufferedOutputStream.new_sized] to specify the buffer's size
* at construction.
*
* To get the size of a buffer within a buffered input stream, use
* [method@Gio.BufferedOutputStream.get_buffer_size]. To change the size of a
* buffered output stream's buffer, use [method@Gio.BufferedOutputStream.set_buffer_size].
* Note that the buffer's size cannot be reduced below the size of the data within the buffer.
*/
#define DEFAULT_BUFFER_SIZE 4096
struct _GBufferedOutputStreamPrivate {
guint8 *buffer;
gsize len;
goffset pos;
gboolean auto_grow;
};
enum {
PROP_0,
PROP_BUFSIZE,
PROP_AUTO_GROW
};
static void g_buffered_output_stream_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec);
static void g_buffered_output_stream_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec);
static void g_buffered_output_stream_finalize (GObject *object);
static gssize g_buffered_output_stream_write (GOutputStream *stream,
const void *buffer,
gsize count,
GCancellable *cancellable,
GError **error);
static gboolean g_buffered_output_stream_flush (GOutputStream *stream,
GCancellable *cancellable,
GError **error);
static gboolean g_buffered_output_stream_close (GOutputStream *stream,
GCancellable *cancellable,
GError **error);
static void g_buffered_output_stream_flush_async (GOutputStream *stream,
int io_priority,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer data);
static gboolean g_buffered_output_stream_flush_finish (GOutputStream *stream,
GAsyncResult *result,
GError **error);
static void g_buffered_output_stream_close_async (GOutputStream *stream,
int io_priority,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer data);
static gboolean g_buffered_output_stream_close_finish (GOutputStream *stream,
GAsyncResult *result,
GError **error);
static void g_buffered_output_stream_seekable_iface_init (GSeekableIface *iface);
static goffset g_buffered_output_stream_tell (GSeekable *seekable);
static gboolean g_buffered_output_stream_can_seek (GSeekable *seekable);
static gboolean g_buffered_output_stream_seek (GSeekable *seekable,
goffset offset,
GSeekType type,
GCancellable *cancellable,
GError **error);
static gboolean g_buffered_output_stream_can_truncate (GSeekable *seekable);
static gboolean g_buffered_output_stream_truncate (GSeekable *seekable,
goffset offset,
GCancellable *cancellable,
GError **error);
G_DEFINE_TYPE_WITH_CODE (GBufferedOutputStream,
g_buffered_output_stream,
G_TYPE_FILTER_OUTPUT_STREAM,
G_ADD_PRIVATE (GBufferedOutputStream)
G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE,
g_buffered_output_stream_seekable_iface_init))
static void
g_buffered_output_stream_class_init (GBufferedOutputStreamClass *klass)
{
GObjectClass *object_class;
GOutputStreamClass *ostream_class;
object_class = G_OBJECT_CLASS (klass);
object_class->get_property = g_buffered_output_stream_get_property;
object_class->set_property = g_buffered_output_stream_set_property;
object_class->finalize = g_buffered_output_stream_finalize;
ostream_class = G_OUTPUT_STREAM_CLASS (klass);
ostream_class->write_fn = g_buffered_output_stream_write;
ostream_class->flush = g_buffered_output_stream_flush;
ostream_class->close_fn = g_buffered_output_stream_close;
ostream_class->flush_async = g_buffered_output_stream_flush_async;
ostream_class->flush_finish = g_buffered_output_stream_flush_finish;
ostream_class->close_async = g_buffered_output_stream_close_async;
ostream_class->close_finish = g_buffered_output_stream_close_finish;
/**
* GBufferedOutputStream:buffer-size:
*
* The size of the backend buffer, in bytes.
*/
g_object_class_install_property (object_class,
PROP_BUFSIZE,
g_param_spec_uint ("buffer-size", NULL, NULL,
1,
G_MAXUINT,
DEFAULT_BUFFER_SIZE,
G_PARAM_READWRITE|G_PARAM_CONSTRUCT|
G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
/**
* GBufferedOutputStream:auto-grow:
*
* Whether the buffer should automatically grow.
*/
g_object_class_install_property (object_class,
PROP_AUTO_GROW,
g_param_spec_boolean ("auto-grow", NULL, NULL,
FALSE,
G_PARAM_READWRITE|
G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
}
/**
* g_buffered_output_stream_get_buffer_size:
* @stream: a [class@Gio.BufferedOutputStream].
*
* Gets the size of the buffer in the @stream.
*
* Returns: the current size of the buffer.
**/
gsize
g_buffered_output_stream_get_buffer_size (GBufferedOutputStream *stream)
{
g_return_val_if_fail (G_IS_BUFFERED_OUTPUT_STREAM (stream), -1);
return stream->priv->len;
}
/**
* g_buffered_output_stream_set_buffer_size:
* @stream: a [class@Gio.BufferedOutputStream].
* @size: a #gsize.
*
* Sets the size of the internal buffer to @size.
**/
void
g_buffered_output_stream_set_buffer_size (GBufferedOutputStream *stream,
gsize size)
{
GBufferedOutputStreamPrivate *priv;
guint8 *buffer;
g_return_if_fail (G_IS_BUFFERED_OUTPUT_STREAM (stream));
priv = stream->priv;
if (size == priv->len)
return;
if (priv->buffer)
{
size = (priv->pos > 0) ? MAX (size, (gsize) priv->pos) : size;
buffer = g_malloc (size);
memcpy (buffer, priv->buffer, priv->pos);
g_free (priv->buffer);
priv->buffer = buffer;
priv->len = size;
/* Keep old pos */
}
else
{
priv->buffer = g_malloc (size);
priv->len = size;
priv->pos = 0;
}
g_object_notify (G_OBJECT (stream), "buffer-size");
}
/**
* g_buffered_output_stream_get_auto_grow:
* @stream: a [class@Gio.BufferedOutputStream].
*
* Checks if the buffer automatically grows as data is added.
*
* Returns: `TRUE` if the @stream's buffer automatically grows,
* `FALSE` otherwise.
**/
gboolean
g_buffered_output_stream_get_auto_grow (GBufferedOutputStream *stream)
{
g_return_val_if_fail (G_IS_BUFFERED_OUTPUT_STREAM (stream), FALSE);
return stream->priv->auto_grow;
}
/**
* g_buffered_output_stream_set_auto_grow:
* @stream: a [class@Gio.BufferedOutputStream].
* @auto_grow: a #gboolean.
*
* Sets whether or not the @stream's buffer should automatically grow.
* If @auto_grow is true, then each write will just make the buffer
* larger, and you must manually flush the buffer to actually write out
* the data to the underlying stream.
**/
void
g_buffered_output_stream_set_auto_grow (GBufferedOutputStream *stream,
gboolean auto_grow)
{
GBufferedOutputStreamPrivate *priv;
g_return_if_fail (G_IS_BUFFERED_OUTPUT_STREAM (stream));
priv = stream->priv;
auto_grow = auto_grow != FALSE;
if (priv->auto_grow != auto_grow)
{
priv->auto_grow = auto_grow;
g_object_notify (G_OBJECT (stream), "auto-grow");
}
}
static void
g_buffered_output_stream_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GBufferedOutputStream *stream;
stream = G_BUFFERED_OUTPUT_STREAM (object);
switch (prop_id)
{
case PROP_BUFSIZE:
g_buffered_output_stream_set_buffer_size (stream, g_value_get_uint (value));
break;
case PROP_AUTO_GROW:
g_buffered_output_stream_set_auto_grow (stream, g_value_get_boolean (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
g_buffered_output_stream_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GBufferedOutputStream *buffered_stream;
GBufferedOutputStreamPrivate *priv;
buffered_stream = G_BUFFERED_OUTPUT_STREAM (object);
priv = buffered_stream->priv;
switch (prop_id)
{
case PROP_BUFSIZE:
g_value_set_uint (value, priv->len);
break;
case PROP_AUTO_GROW:
g_value_set_boolean (value, priv->auto_grow);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
g_buffered_output_stream_finalize (GObject *object)
{
GBufferedOutputStream *stream;
GBufferedOutputStreamPrivate *priv;
stream = G_BUFFERED_OUTPUT_STREAM (object);
priv = stream->priv;
g_free (priv->buffer);
G_OBJECT_CLASS (g_buffered_output_stream_parent_class)->finalize (object);
}
static void
g_buffered_output_stream_init (GBufferedOutputStream *stream)
{
stream->priv = g_buffered_output_stream_get_instance_private (stream);
}
static void
g_buffered_output_stream_seekable_iface_init (GSeekableIface *iface)
{
iface->tell = g_buffered_output_stream_tell;
iface->can_seek = g_buffered_output_stream_can_seek;
iface->seek = g_buffered_output_stream_seek;
iface->can_truncate = g_buffered_output_stream_can_truncate;
iface->truncate_fn = g_buffered_output_stream_truncate;
}
/**
* g_buffered_output_stream_new:
* @base_stream: a [class@Gio.OutputStream].
*
* Creates a new buffered output stream for a base stream.
*
* Returns: a [class@Gio.OutputStream] for the given @base_stream.
**/
GOutputStream *
g_buffered_output_stream_new (GOutputStream *base_stream)
{
GOutputStream *stream;
g_return_val_if_fail (G_IS_OUTPUT_STREAM (base_stream), NULL);
stream = g_object_new (G_TYPE_BUFFERED_OUTPUT_STREAM,
"base-stream", base_stream,
NULL);
return stream;
}
/**
* g_buffered_output_stream_new_sized:
* @base_stream: a [class@Gio.OutputStream].
* @size: a #gsize.
*
* Creates a new buffered output stream with a given buffer size.
*
* Returns: a [class@Gio.OutputStream] with an internal buffer set to @size.
**/
GOutputStream *
g_buffered_output_stream_new_sized (GOutputStream *base_stream,
gsize size)
{
GOutputStream *stream;
g_return_val_if_fail (G_IS_OUTPUT_STREAM (base_stream), NULL);
stream = g_object_new (G_TYPE_BUFFERED_OUTPUT_STREAM,
"base-stream", base_stream,
"buffer-size", size,
NULL);
return stream;
}
static gboolean
flush_buffer (GBufferedOutputStream *stream,
GCancellable *cancellable,
GError **error)
{
GBufferedOutputStreamPrivate *priv;
GOutputStream *base_stream;
gboolean res;
gsize bytes_written;
gsize count;
priv = stream->priv;
bytes_written = 0;
base_stream = G_FILTER_OUTPUT_STREAM (stream)->base_stream;
g_return_val_if_fail (G_IS_OUTPUT_STREAM (base_stream), FALSE);
res = g_output_stream_write_all (base_stream,
priv->buffer,
priv->pos,
&bytes_written,
cancellable,
error);
count = priv->pos - bytes_written;
if (count > 0)
memmove (priv->buffer, priv->buffer + bytes_written, count);
priv->pos -= bytes_written;
return res;
}
static gssize
g_buffered_output_stream_write (GOutputStream *stream,
const void *buffer,
gsize count,
GCancellable *cancellable,
GError **error)
{
GBufferedOutputStream *bstream;
GBufferedOutputStreamPrivate *priv;
gboolean res;
gsize n;
gsize new_size;
bstream = G_BUFFERED_OUTPUT_STREAM (stream);
priv = bstream->priv;
n = priv->len - priv->pos;
if (priv->auto_grow && n < count)
{
new_size = MAX (priv->len * 2, priv->len + count);
g_buffered_output_stream_set_buffer_size (bstream, new_size);
}
else if (n == 0)
{
res = flush_buffer (bstream, cancellable, error);
if (res == FALSE)
return -1;
}
n = priv->len - priv->pos;
count = MIN (count, n);
memcpy (priv->buffer + priv->pos, buffer, count);
priv->pos += count;
return count;
}
static gboolean
g_buffered_output_stream_flush (GOutputStream *stream,
GCancellable *cancellable,
GError **error)
{
GBufferedOutputStream *bstream;
GOutputStream *base_stream;
gboolean res;
bstream = G_BUFFERED_OUTPUT_STREAM (stream);
base_stream = G_FILTER_OUTPUT_STREAM (stream)->base_stream;
res = flush_buffer (bstream, cancellable, error);
if (res == FALSE)
return FALSE;
res = g_output_stream_flush (base_stream, cancellable, error);
return res;
}
static gboolean
g_buffered_output_stream_close (GOutputStream *stream,
GCancellable *cancellable,
GError **error)
{
GBufferedOutputStream *bstream;
GOutputStream *base_stream;
gboolean res;
bstream = G_BUFFERED_OUTPUT_STREAM (stream);
base_stream = G_FILTER_OUTPUT_STREAM (bstream)->base_stream;
res = flush_buffer (bstream, cancellable, error);
if (g_filter_output_stream_get_close_base_stream (G_FILTER_OUTPUT_STREAM (stream)))
{
/* report the first error but still close the stream */
if (res)
res = g_output_stream_close (base_stream, cancellable, error);
else
g_output_stream_close (base_stream, cancellable, NULL);
}
return res;
}
static goffset
g_buffered_output_stream_tell (GSeekable *seekable)
{
GBufferedOutputStream *bstream;
GBufferedOutputStreamPrivate *priv;
GOutputStream *base_stream;
GSeekable *base_stream_seekable;
goffset base_offset;
bstream = G_BUFFERED_OUTPUT_STREAM (seekable);
priv = bstream->priv;
base_stream = G_FILTER_OUTPUT_STREAM (seekable)->base_stream;
if (!G_IS_SEEKABLE (base_stream))
return 0;
base_stream_seekable = G_SEEKABLE (base_stream);
base_offset = g_seekable_tell (base_stream_seekable);
return base_offset + priv->pos;
}
static gboolean
g_buffered_output_stream_can_seek (GSeekable *seekable)
{
GOutputStream *base_stream;
base_stream = G_FILTER_OUTPUT_STREAM (seekable)->base_stream;
return G_IS_SEEKABLE (base_stream) && g_seekable_can_seek (G_SEEKABLE (base_stream));
}
static gboolean
g_buffered_output_stream_seek (GSeekable *seekable,
goffset offset,
GSeekType type,
GCancellable *cancellable,
GError **error)
{
GBufferedOutputStream *bstream;
GOutputStream *base_stream;
GSeekable *base_stream_seekable;
gboolean flushed;
bstream = G_BUFFERED_OUTPUT_STREAM (seekable);
base_stream = G_FILTER_OUTPUT_STREAM (seekable)->base_stream;
if (!G_IS_SEEKABLE (base_stream))
{
g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
_("Seek not supported on base stream"));
return FALSE;
}
base_stream_seekable = G_SEEKABLE (base_stream);
flushed = flush_buffer (bstream, cancellable, error);
if (!flushed)
return FALSE;
return g_seekable_seek (base_stream_seekable, offset, type, cancellable, error);
}
static gboolean
g_buffered_output_stream_can_truncate (GSeekable *seekable)
{
GOutputStream *base_stream;
base_stream = G_FILTER_OUTPUT_STREAM (seekable)->base_stream;
return G_IS_SEEKABLE (base_stream) && g_seekable_can_truncate (G_SEEKABLE (base_stream));
}
static gboolean
g_buffered_output_stream_truncate (GSeekable *seekable,
goffset offset,
GCancellable *cancellable,
GError **error)
{
GBufferedOutputStream *bstream;
GOutputStream *base_stream;
GSeekable *base_stream_seekable;
gboolean flushed;
bstream = G_BUFFERED_OUTPUT_STREAM (seekable);
base_stream = G_FILTER_OUTPUT_STREAM (seekable)->base_stream;
if (!G_IS_SEEKABLE (base_stream))
{
g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
_("Truncate not supported on base stream"));
return FALSE;
}
base_stream_seekable = G_SEEKABLE (base_stream);
flushed = flush_buffer (bstream, cancellable, error);
if (!flushed)
return FALSE;
return g_seekable_truncate (base_stream_seekable, offset, cancellable, error);
}
/* ************************** */
/* Async stuff implementation */
/* ************************** */
/* TODO: This should be using the base class async ops, not threads */
typedef struct {
guint flush_stream : 1;
guint close_stream : 1;
} FlushData;
static void
free_flush_data (gpointer data)
{
g_slice_free (FlushData, data);
}
/* This function is used by all three (i.e.
* _write, _flush, _close) functions since
* all of them will need to flush the buffer
* and so closing and writing is just a special
* case of flushing + some addition stuff */
static void
flush_buffer_thread (GTask *task,
gpointer object,
gpointer task_data,
GCancellable *cancellable)
{
GBufferedOutputStream *stream;
GOutputStream *base_stream;
FlushData *fdata;
gboolean res;
GError *error = NULL;
stream = G_BUFFERED_OUTPUT_STREAM (object);
fdata = task_data;
base_stream = G_FILTER_OUTPUT_STREAM (stream)->base_stream;
res = flush_buffer (stream, cancellable, &error);
/* if flushing the buffer didn't work don't even bother
* to flush the stream but just report that error */
if (res && fdata->flush_stream)
res = g_output_stream_flush (base_stream, cancellable, &error);
if (fdata->close_stream)
{
/* if flushing the buffer or the stream returned
* an error report that first error but still try
* close the stream */
if (g_filter_output_stream_get_close_base_stream (G_FILTER_OUTPUT_STREAM (stream)))
{
if (res == FALSE)
g_output_stream_close (base_stream, cancellable, NULL);
else
res = g_output_stream_close (base_stream, cancellable, &error);
}
}
if (res == FALSE)
g_task_return_error (task, error);
else
g_task_return_boolean (task, TRUE);
}
static void
g_buffered_output_stream_flush_async (GOutputStream *stream,
int io_priority,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer data)
{
GTask *task;
FlushData *fdata;
fdata = g_slice_new0 (FlushData);
fdata->flush_stream = TRUE;
fdata->close_stream = FALSE;
task = g_task_new (stream, cancellable, callback, data);
g_task_set_source_tag (task, g_buffered_output_stream_flush_async);
g_task_set_task_data (task, fdata, free_flush_data);
g_task_set_priority (task, io_priority);
g_task_run_in_thread (task, flush_buffer_thread);
g_object_unref (task);
}
static gboolean
g_buffered_output_stream_flush_finish (GOutputStream *stream,
GAsyncResult *result,
GError **error)
{
g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
return g_task_propagate_boolean (G_TASK (result), error);
}
static void
g_buffered_output_stream_close_async (GOutputStream *stream,
int io_priority,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer data)
{
GTask *task;
FlushData *fdata;
fdata = g_slice_new0 (FlushData);
fdata->close_stream = TRUE;
task = g_task_new (stream, cancellable, callback, data);
g_task_set_source_tag (task, g_buffered_output_stream_close_async);
g_task_set_task_data (task, fdata, free_flush_data);
g_task_set_priority (task, io_priority);
g_task_run_in_thread (task, flush_buffer_thread);
g_object_unref (task);
}
static gboolean
g_buffered_output_stream_close_finish (GOutputStream *stream,
GAsyncResult *result,
GError **error)
{
g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
return g_task_propagate_boolean (G_TASK (result), error);
}