gio/gmemoryoutputstream.c - third_party/glib - Git at Google

 /* 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 "gmemoryoutputstream.h"
 #include "goutputstream.h"
 #include "gseekable.h"
 #include "gsimpleasyncresult.h"
 #include "string.h"
 #include "glibintl.h"

 #include "gioalias.h"

 /**
  * SECTION:gmemoryoutputstream
  * @short_description: Streaming output operations on memory chunks
  * @include: gio.h
  * @see_also: #GMemoryInputStream
  *
  * #GMemoryOutputStream is a class for using arbitrary
  * memory chunks as output for GIO streaming output operations.
  *
  */

 #define MIN_ARRAY_SIZE  16

 struct _GMemoryOutputStreamPrivate {

   gpointer       data;
   gsize          len;

   goffset        pos;

   GReallocFunc   realloc_fn;
   GDestroyNotify destroy;
 };

 static void     g_memory_output_stream_finalize     (GObject      *object);

 static gssize   g_memory_output_stream_write       (GOutputStream *stream,
                                                     const void    *buffer,
                                                     gsize          count,
                                                     GCancellable  *cancellable,
                                                     GError       **error);

 static gboolean g_memory_output_stream_close       (GOutputStream  *stream,
                                                     GCancellable   *cancellable,
                                                     GError        **error);

 static void     g_memory_output_stream_write_async  (GOutputStream        *stream,
                                                      const void           *buffer,
                                                      gsize                 count,
                                                      int                   io_priority,
                                                      GCancellable         *cancellable,
                                                      GAsyncReadyCallback   callback,
                                                      gpointer              data);
 static gssize   g_memory_output_stream_write_finish (GOutputStream        *stream,
                                                      GAsyncResult         *result,
                                                      GError              **error);
 static void     g_memory_output_stream_close_async  (GOutputStream        *stream,
                                                      int                   io_priority,
                                                      GCancellable         *cancellable,
                                                      GAsyncReadyCallback   callback,
                                                      gpointer              data);
 static gboolean g_memory_output_stream_close_finish (GOutputStream        *stream,
                                                      GAsyncResult         *result,
                                                      GError              **error);

 static void     g_memory_output_stream_seekable_iface_init (GSeekableIface  *iface);
 static goffset  g_memory_output_stream_tell                (GSeekable       *seekable);
 static gboolean g_memory_output_stream_can_seek            (GSeekable       *seekable);
 static gboolean g_memory_output_stream_seek                (GSeekable       *seekable,
                                                            goffset          offset,
                                                            GSeekType        type,
                                                            GCancellable    *cancellable,
                                                            GError         **error);
 static gboolean g_memory_output_stream_can_truncate        (GSeekable       *seekable);
 static gboolean g_memory_output_stream_truncate            (GSeekable       *seekable,
                                                            goffset          offset,
                                                            GCancellable    *cancellable,
                                                            GError         **error);

 G_DEFINE_TYPE_WITH_CODE (GMemoryOutputStream, g_memory_output_stream, G_TYPE_OUTPUT_STREAM,
                          G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE,
                                                 g_memory_output_stream_seekable_iface_init))


 static void
 g_memory_output_stream_class_init (GMemoryOutputStreamClass *klass)
 {
   GOutputStreamClass *ostream_class;
   GObjectClass *gobject_class;

   g_type_class_add_private (klass, sizeof (GMemoryOutputStreamPrivate));

   gobject_class = G_OBJECT_CLASS (klass);
   gobject_class->finalize = g_memory_output_stream_finalize;

   ostream_class = G_OUTPUT_STREAM_CLASS (klass);

   ostream_class->write_fn = g_memory_output_stream_write;
   ostream_class->close_fn = g_memory_output_stream_close;
   ostream_class->write_async  = g_memory_output_stream_write_async;
   ostream_class->write_finish = g_memory_output_stream_write_finish;
   ostream_class->close_async  = g_memory_output_stream_close_async;
   ostream_class->close_finish = g_memory_output_stream_close_finish;
 }

 static void
 g_memory_output_stream_finalize (GObject *object)
 {
   GMemoryOutputStream        *stream;
   GMemoryOutputStreamPrivate *priv;

   stream = G_MEMORY_OUTPUT_STREAM (object);
   priv = stream->priv;

   if (priv->destroy)
     priv->destroy (priv->data);

   if (G_OBJECT_CLASS (g_memory_output_stream_parent_class)->finalize)
     (*G_OBJECT_CLASS (g_memory_output_stream_parent_class)->finalize) (object);
 }

 static void
 g_memory_output_stream_seekable_iface_init (GSeekableIface *iface)
 {
   iface->tell         = g_memory_output_stream_tell;
   iface->can_seek     = g_memory_output_stream_can_seek;
   iface->seek         = g_memory_output_stream_seek;
   iface->can_truncate = g_memory_output_stream_can_truncate;
   iface->truncate_fn  = g_memory_output_stream_truncate;
 }


 static void
 g_memory_output_stream_init (GMemoryOutputStream *stream)
 {
   stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (stream,
                                               G_TYPE_MEMORY_OUTPUT_STREAM,
                                               GMemoryOutputStreamPrivate);
 }

 /**
  * g_memory_output_stream_new:
  * @data: pointer to a chunk of memory to use, or %NULL
  * @len: the size of @data
  * @realloc_fn: a function with realloc() semantics to be called when
  *     @data needs to be grown, or %NULL
  * @destroy: a function to be called on @data when the stream is finalized,
  *     or %NULL
  *
  * Creates a new #GMemoryOutputStream.
  *
  * If @data is non-%NULL, the stream  will use that for its internal storage.
  * If @realloc_fn is non-%NULL, it will be used for resizing the internal
  * storage when necessary. To construct a fixed-size output stream,
  * pass %NULL as @realloc_fn.
  * |[
  * /&ast; a stream that can grow &ast;/
  * stream = g_memory_output_stream_new (NULL, 0, realloc, free);
  *
  * /&ast; a fixed-size stream &ast;/
  * data = malloc (200);
  * stream2 = g_memory_output_stream_new (data, 200, NULL, free);
  * ]|
  *
  * Return value: A newly created #GMemoryOutputStream object.
  **/
 GOutputStream *
 g_memory_output_stream_new (gpointer       data,
                             gsize          len,
                             GReallocFunc   realloc_fn,
                             GDestroyNotify destroy)
 {
   GOutputStream *stream;
   GMemoryOutputStreamPrivate *priv;

   stream = g_object_new (G_TYPE_MEMORY_OUTPUT_STREAM, NULL);

   priv = G_MEMORY_OUTPUT_STREAM (stream)->priv;

   priv->data = data;
   priv->len = len;
   priv->realloc_fn = realloc_fn;
   priv->destroy = destroy;

   priv->pos = 0;

   return stream;
 }

 /**
  * g_memory_output_stream_get_data:
  * @ostream: a #GMemoryOutputStream
  *
  * Gets any loaded data from the @ostream.
  *
  * Note that the returned pointer may become invalid on the next
  * write or truncate operation on the stream.
  *
  * Returns: pointer to the stream's data
  **/
 gpointer
 g_memory_output_stream_get_data (GMemoryOutputStream *ostream)
 {
   g_return_val_if_fail (G_IS_MEMORY_OUTPUT_STREAM (ostream), NULL);

   return ostream->priv->data;
 }

 /**
  * g_memory_output_stream_get_size:
  * @ostream: a #GMemoryOutputStream
  *
  * Gets the size of the loaded data from the @ostream.
  *
  * Note that the returned size may become invalid on the next
  * write or truncate operation on the stream.
  *
  * Returns: the size of the stream's data
  */
 gsize
 g_memory_output_stream_get_size (GMemoryOutputStream *ostream)
 {
   g_return_val_if_fail (G_IS_MEMORY_OUTPUT_STREAM (ostream), 0);

   return ostream->priv->len;
 }

 static gboolean
 array_check_boundary (GMemoryOutputStream  *stream,
                       goffset               size,
                       GError              **error)
 {
   if (size > G_MAXUINT)
     {
       g_set_error (error,
                    G_IO_ERROR,
                    G_IO_ERROR_FAILED,
                    _("Reached maximum data array limit"));

       return FALSE;
     }

   return TRUE;
 }

 static gboolean
 array_resize (GMemoryOutputStream  *ostream,
               gsize                 size,
 	      gboolean              allow_partial,
               GError              **error)
 {
   GMemoryOutputStreamPrivate *priv;
   gpointer data;
   gsize len;

   priv = ostream->priv;

   if (!array_check_boundary (ostream, size, error))
     return FALSE;

   if (priv->len == size)
     return TRUE;

   if (!priv->realloc_fn)
     {
       if (allow_partial &&
 	  priv->pos < priv->len)
 	return TRUE; /* Short write */

       g_set_error (error,
                    G_IO_ERROR,
                    G_IO_ERROR_NO_SPACE,
                    _("Memory output stream not resizable"));
       return FALSE;
     }

   len = priv->len;
   data = priv->realloc_fn (priv->data, size);

   if (!data)
     {
       if (allow_partial &&
 	  priv->pos < priv->len)
 	return TRUE; /* Short write */

       g_set_error (error,
                    G_IO_ERROR,
                    G_IO_ERROR_NO_SPACE,
                    _("Failed to resize memory output stream"));
       return FALSE;
     }

   if (size > len)
     memset ((guint8 *)data + len, 0, size - len);

   priv->data = data;
   priv->len = size;

   return TRUE;
 }

 static gint
 g_nearest_pow (gint num)
 {
   gint n = 1;

   while (n < num)
     n <<= 1;

   return n;
 }

 static gssize
 g_memory_output_stream_write (GOutputStream  *stream,
                               const void     *buffer,
                               gsize           count,
                               GCancellable   *cancellable,
                               GError        **error)
 {
   GMemoryOutputStream        *ostream;
   GMemoryOutputStreamPrivate *priv;
   guint8   *dest;
   gsize new_size;

   ostream = G_MEMORY_OUTPUT_STREAM (stream);
   priv = ostream->priv;

   if (count == 0)
     return 0;

   if (priv->pos + count > priv->len)
     {
       /* At least enought to fit the write, rounded up
 	 for greater than linear growth */
       new_size = g_nearest_pow (priv->pos + count);
       new_size = MAX (new_size, MIN_ARRAY_SIZE);

       if (!array_resize (ostream, new_size, TRUE, error))
 	return -1;
     }

   /* Make sure we handle short writes if the array_resize
      only added part of the required memory */
   count = MIN (count, priv->len - priv->pos);

   dest = (guint8 *)priv->data + priv->pos;
   memcpy (dest, buffer, count);
   priv->pos += count;

   return count;
 }

 static gboolean
 g_memory_output_stream_close (GOutputStream  *stream,
                               GCancellable   *cancellable,
                               GError        **error)
 {
   return TRUE;
 }

 static void
 g_memory_output_stream_write_async (GOutputStream       *stream,
                                     const void          *buffer,
                                     gsize                count,
                                     int                  io_priority,
                                     GCancellable        *cancellable,
                                     GAsyncReadyCallback  callback,
                                     gpointer             data)
 {
   GSimpleAsyncResult *simple;
   gssize nwritten;

   nwritten = g_memory_output_stream_write (stream,
                                            buffer,
                                            count,
                                            cancellable,
                                            NULL);


   simple = g_simple_async_result_new (G_OBJECT (stream),
                                       callback,
                                       data,
                                       g_memory_output_stream_write_async);

   g_simple_async_result_set_op_res_gssize (simple, nwritten);
   g_simple_async_result_complete_in_idle (simple);
   g_object_unref (simple);
 }

 static gssize
 g_memory_output_stream_write_finish (GOutputStream  *stream,
                                      GAsyncResult   *result,
                                      GError        **error)
 {
   GSimpleAsyncResult *simple;
   gssize nwritten;

   simple = G_SIMPLE_ASYNC_RESULT (result);

   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) ==
                   g_memory_output_stream_write_async);

   nwritten = g_simple_async_result_get_op_res_gssize (simple);

   return nwritten;
 }

 static void
 g_memory_output_stream_close_async (GOutputStream       *stream,
                                     int                  io_priority,
                                     GCancellable        *cancellable,
                                     GAsyncReadyCallback  callback,
                                     gpointer             data)
 {
   GSimpleAsyncResult *simple;

   simple = g_simple_async_result_new (G_OBJECT (stream),
                                       callback,
                                       data,
                                       g_memory_output_stream_close_async);


   /* will always return TRUE */
   g_memory_output_stream_close (stream, cancellable, NULL);

   g_simple_async_result_complete_in_idle (simple);
   g_object_unref (simple);
 }

 static gboolean
 g_memory_output_stream_close_finish (GOutputStream  *stream,
                                      GAsyncResult   *result,
                                      GError        **error)
 {
   GSimpleAsyncResult *simple;

   simple = G_SIMPLE_ASYNC_RESULT (result);

   g_warn_if_fail (g_simple_async_result_get_source_tag (simple) ==
                   g_memory_output_stream_close_async);

   return TRUE;
 }

 static goffset
 g_memory_output_stream_tell (GSeekable *seekable)
 {
   GMemoryOutputStream *stream;
   GMemoryOutputStreamPrivate *priv;

   stream = G_MEMORY_OUTPUT_STREAM (seekable);
   priv = stream->priv;

   return priv->pos;
 }

 static gboolean
 g_memory_output_stream_can_seek (GSeekable *seekable)
 {
   return TRUE;
 }

 static gboolean
 g_memory_output_stream_seek (GSeekable    *seekable,
                             goffset        offset,
                             GSeekType      type,
                             GCancellable  *cancellable,
                             GError       **error)
 {
   GMemoryOutputStream        *stream;
   GMemoryOutputStreamPrivate *priv;
   goffset absolute;

   stream = G_MEMORY_OUTPUT_STREAM (seekable);
   priv = 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 (error,
                    G_IO_ERROR,
                    G_IO_ERROR_INVALID_ARGUMENT,
                    _("Invalid GSeekType supplied"));

       return FALSE;
     }

   if (absolute < 0)
     {
       g_set_error (error,
                    G_IO_ERROR,
                    G_IO_ERROR_INVALID_ARGUMENT,
                    _("Invalid seek request"));
       return FALSE;
     }

   if (!array_check_boundary (stream, absolute, error))
     return FALSE;

   priv->pos = absolute;

   return TRUE;
 }

 static gboolean
 g_memory_output_stream_can_truncate (GSeekable *seekable)
 {
   GMemoryOutputStream *ostream;
   GMemoryOutputStreamPrivate *priv;

   ostream = G_MEMORY_OUTPUT_STREAM (seekable);
   priv = ostream->priv;

   return priv->realloc_fn != NULL;
 }

 static gboolean
 g_memory_output_stream_truncate (GSeekable     *seekable,
                                  goffset        offset,
                                  GCancellable  *cancellable,
                                  GError       **error)
 {
   GMemoryOutputStream *ostream;
   GMemoryOutputStreamPrivate *priv;

   ostream = G_MEMORY_OUTPUT_STREAM (seekable);
   priv = ostream->priv;

   if (!array_resize (ostream, offset, FALSE, error))
     return FALSE;

   return TRUE;
 }

 #define __G_MEMORY_OUTPUT_STREAM_C__
 #include "gioaliasdef.c"
	/* 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 "gmemoryoutputstream.h"
	#include "goutputstream.h"
	#include "gseekable.h"
	#include "gsimpleasyncresult.h"
	#include "string.h"
	#include "glibintl.h"

	#include "gioalias.h"

	/**
	* SECTION:gmemoryoutputstream
	* @short_description: Streaming output operations on memory chunks
	* @include: gio.h
	* @see_also: #GMemoryInputStream
	*
	* #GMemoryOutputStream is a class for using arbitrary
	* memory chunks as output for GIO streaming output operations.
	*
	*/

	#define MIN_ARRAY_SIZE 16

	struct _GMemoryOutputStreamPrivate {

	gpointer data;
	gsize len;

	goffset pos;

	GReallocFunc realloc_fn;
	GDestroyNotify destroy;
	};

	static void g_memory_output_stream_finalize (GObject *object);

	static gssize g_memory_output_stream_write (GOutputStream *stream,
	const void *buffer,
	gsize count,
	GCancellable *cancellable,
	GError **error);

	static gboolean g_memory_output_stream_close (GOutputStream *stream,
	GCancellable *cancellable,
	GError **error);

	static void g_memory_output_stream_write_async (GOutputStream *stream,
	const void *buffer,
	gsize count,
	int io_priority,
	GCancellable *cancellable,
	GAsyncReadyCallback callback,
	gpointer data);
	static gssize g_memory_output_stream_write_finish (GOutputStream *stream,
	GAsyncResult *result,
	GError **error);
	static void g_memory_output_stream_close_async (GOutputStream *stream,
	int io_priority,
	GCancellable *cancellable,
	GAsyncReadyCallback callback,
	gpointer data);
	static gboolean g_memory_output_stream_close_finish (GOutputStream *stream,
	GAsyncResult *result,
	GError **error);

	static void g_memory_output_stream_seekable_iface_init (GSeekableIface *iface);
	static goffset g_memory_output_stream_tell (GSeekable *seekable);
	static gboolean g_memory_output_stream_can_seek (GSeekable *seekable);
	static gboolean g_memory_output_stream_seek (GSeekable *seekable,
	goffset offset,
	GSeekType type,
	GCancellable *cancellable,
	GError **error);
	static gboolean g_memory_output_stream_can_truncate (GSeekable *seekable);
	static gboolean g_memory_output_stream_truncate (GSeekable *seekable,
	goffset offset,
	GCancellable *cancellable,
	GError **error);

	G_DEFINE_TYPE_WITH_CODE (GMemoryOutputStream, g_memory_output_stream, G_TYPE_OUTPUT_STREAM,
	G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE,
	g_memory_output_stream_seekable_iface_init))


	static void
	g_memory_output_stream_class_init (GMemoryOutputStreamClass *klass)
	{
	GOutputStreamClass *ostream_class;
	GObjectClass *gobject_class;

	g_type_class_add_private (klass, sizeof (GMemoryOutputStreamPrivate));

	gobject_class = G_OBJECT_CLASS (klass);
	gobject_class->finalize = g_memory_output_stream_finalize;

	ostream_class = G_OUTPUT_STREAM_CLASS (klass);

	ostream_class->write_fn = g_memory_output_stream_write;
	ostream_class->close_fn = g_memory_output_stream_close;
	ostream_class->write_async = g_memory_output_stream_write_async;
	ostream_class->write_finish = g_memory_output_stream_write_finish;
	ostream_class->close_async = g_memory_output_stream_close_async;
	ostream_class->close_finish = g_memory_output_stream_close_finish;
	}

	static void
	g_memory_output_stream_finalize (GObject *object)
	{
	GMemoryOutputStream *stream;
	GMemoryOutputStreamPrivate *priv;

	stream = G_MEMORY_OUTPUT_STREAM (object);
	priv = stream->priv;

	if (priv->destroy)
	priv->destroy (priv->data);

	if (G_OBJECT_CLASS (g_memory_output_stream_parent_class)->finalize)
	(*G_OBJECT_CLASS (g_memory_output_stream_parent_class)->finalize) (object);
	}

	static void
	g_memory_output_stream_seekable_iface_init (GSeekableIface *iface)
	{
	iface->tell = g_memory_output_stream_tell;
	iface->can_seek = g_memory_output_stream_can_seek;
	iface->seek = g_memory_output_stream_seek;
	iface->can_truncate = g_memory_output_stream_can_truncate;
	iface->truncate_fn = g_memory_output_stream_truncate;
	}


	static void
	g_memory_output_stream_init (GMemoryOutputStream *stream)
	{
	stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (stream,
	G_TYPE_MEMORY_OUTPUT_STREAM,
	GMemoryOutputStreamPrivate);
	}

	/**
	* g_memory_output_stream_new:
	* @data: pointer to a chunk of memory to use, or %NULL
	* @len: the size of @data
	* @realloc_fn: a function with realloc() semantics to be called when
	* @data needs to be grown, or %NULL
	* @destroy: a function to be called on @data when the stream is finalized,
	* or %NULL
	*
	* Creates a new #GMemoryOutputStream.
	*
	* If @data is non-%NULL, the stream will use that for its internal storage.
	* If @realloc_fn is non-%NULL, it will be used for resizing the internal
	* storage when necessary. To construct a fixed-size output stream,
	* pass %NULL as @realloc_fn.
	* \|[
	* /&ast; a stream that can grow &ast;/
	* stream = g_memory_output_stream_new (NULL, 0, realloc, free);
	*
	* /&ast; a fixed-size stream &ast;/
	* data = malloc (200);
	* stream2 = g_memory_output_stream_new (data, 200, NULL, free);
	* ]\|
	*
	* Return value: A newly created #GMemoryOutputStream object.
	**/
	GOutputStream *
	g_memory_output_stream_new (gpointer data,
	gsize len,
	GReallocFunc realloc_fn,
	GDestroyNotify destroy)
	{
	GOutputStream *stream;
	GMemoryOutputStreamPrivate *priv;

	stream = g_object_new (G_TYPE_MEMORY_OUTPUT_STREAM, NULL);

	priv = G_MEMORY_OUTPUT_STREAM (stream)->priv;

	priv->data = data;
	priv->len = len;
	priv->realloc_fn = realloc_fn;
	priv->destroy = destroy;

	priv->pos = 0;

	return stream;
	}

	/**
	* g_memory_output_stream_get_data:
	* @ostream: a #GMemoryOutputStream
	*
	* Gets any loaded data from the @ostream.
	*
	* Note that the returned pointer may become invalid on the next
	* write or truncate operation on the stream.
	*
	* Returns: pointer to the stream's data
	**/
	gpointer
	g_memory_output_stream_get_data (GMemoryOutputStream *ostream)
	{
	g_return_val_if_fail (G_IS_MEMORY_OUTPUT_STREAM (ostream), NULL);

	return ostream->priv->data;
	}

	/**
	* g_memory_output_stream_get_size:
	* @ostream: a #GMemoryOutputStream
	*
	* Gets the size of the loaded data from the @ostream.
	*
	* Note that the returned size may become invalid on the next
	* write or truncate operation on the stream.
	*
	* Returns: the size of the stream's data
	*/
	gsize
	g_memory_output_stream_get_size (GMemoryOutputStream *ostream)
	{
	g_return_val_if_fail (G_IS_MEMORY_OUTPUT_STREAM (ostream), 0);

	return ostream->priv->len;
	}

	static gboolean
	array_check_boundary (GMemoryOutputStream *stream,
	goffset size,
	GError **error)
	{
	if (size > G_MAXUINT)
	{
	g_set_error (error,
	G_IO_ERROR,
	G_IO_ERROR_FAILED,
	_("Reached maximum data array limit"));

	return FALSE;
	}

	return TRUE;
	}

	static gboolean
	array_resize (GMemoryOutputStream *ostream,
	gsize size,
	gboolean allow_partial,
	GError **error)
	{
	GMemoryOutputStreamPrivate *priv;
	gpointer data;
	gsize len;

	priv = ostream->priv;

	if (!array_check_boundary (ostream, size, error))
	return FALSE;

	if (priv->len == size)
	return TRUE;

	if (!priv->realloc_fn)
	{
	if (allow_partial &&
	priv->pos < priv->len)
	return TRUE; /* Short write */

	g_set_error (error,
	G_IO_ERROR,
	G_IO_ERROR_NO_SPACE,
	_("Memory output stream not resizable"));
	return FALSE;
	}

	len = priv->len;
	data = priv->realloc_fn (priv->data, size);

	if (!data)
	{
	if (allow_partial &&
	priv->pos < priv->len)
	return TRUE; /* Short write */

	g_set_error (error,
	G_IO_ERROR,
	G_IO_ERROR_NO_SPACE,
	_("Failed to resize memory output stream"));
	return FALSE;
	}

	if (size > len)
	memset ((guint8 *)data + len, 0, size - len);

	priv->data = data;
	priv->len = size;

	return TRUE;
	}

	static gint
	g_nearest_pow (gint num)
	{
	gint n = 1;

	while (n < num)
	n <<= 1;

	return n;
	}

	static gssize
	g_memory_output_stream_write (GOutputStream *stream,
	const void *buffer,
	gsize count,
	GCancellable *cancellable,
	GError **error)
	{
	GMemoryOutputStream *ostream;
	GMemoryOutputStreamPrivate *priv;
	guint8 *dest;
	gsize new_size;

	ostream = G_MEMORY_OUTPUT_STREAM (stream);
	priv = ostream->priv;

	if (count == 0)
	return 0;

	if (priv->pos + count > priv->len)
	{
	/* At least enought to fit the write, rounded up
	for greater than linear growth */
	new_size = g_nearest_pow (priv->pos + count);
	new_size = MAX (new_size, MIN_ARRAY_SIZE);

	if (!array_resize (ostream, new_size, TRUE, error))
	return -1;
	}

	/* Make sure we handle short writes if the array_resize
	only added part of the required memory */
	count = MIN (count, priv->len - priv->pos);

	dest = (guint8 *)priv->data + priv->pos;
	memcpy (dest, buffer, count);
	priv->pos += count;

	return count;
	}

	static gboolean
	g_memory_output_stream_close (GOutputStream *stream,
	GCancellable *cancellable,
	GError **error)
	{
	return TRUE;
	}

	static void
	g_memory_output_stream_write_async (GOutputStream *stream,
	const void *buffer,
	gsize count,
	int io_priority,
	GCancellable *cancellable,
	GAsyncReadyCallback callback,
	gpointer data)
	{
	GSimpleAsyncResult *simple;
	gssize nwritten;

	nwritten = g_memory_output_stream_write (stream,
	buffer,
	count,
	cancellable,
	NULL);


	simple = g_simple_async_result_new (G_OBJECT (stream),
	callback,
	data,
	g_memory_output_stream_write_async);

	g_simple_async_result_set_op_res_gssize (simple, nwritten);
	g_simple_async_result_complete_in_idle (simple);
	g_object_unref (simple);
	}

	static gssize
	g_memory_output_stream_write_finish (GOutputStream *stream,
	GAsyncResult *result,
	GError **error)
	{
	GSimpleAsyncResult *simple;
	gssize nwritten;

	simple = G_SIMPLE_ASYNC_RESULT (result);

	g_warn_if_fail (g_simple_async_result_get_source_tag (simple) ==
	g_memory_output_stream_write_async);

	nwritten = g_simple_async_result_get_op_res_gssize (simple);

	return nwritten;
	}

	static void
	g_memory_output_stream_close_async (GOutputStream *stream,
	int io_priority,
	GCancellable *cancellable,
	GAsyncReadyCallback callback,
	gpointer data)
	{
	GSimpleAsyncResult *simple;

	simple = g_simple_async_result_new (G_OBJECT (stream),
	callback,
	data,
	g_memory_output_stream_close_async);


	/* will always return TRUE */
	g_memory_output_stream_close (stream, cancellable, NULL);

	g_simple_async_result_complete_in_idle (simple);
	g_object_unref (simple);
	}

	static gboolean
	g_memory_output_stream_close_finish (GOutputStream *stream,
	GAsyncResult *result,
	GError **error)
	{
	GSimpleAsyncResult *simple;

	simple = G_SIMPLE_ASYNC_RESULT (result);

	g_warn_if_fail (g_simple_async_result_get_source_tag (simple) ==
	g_memory_output_stream_close_async);

	return TRUE;
	}

	static goffset
	g_memory_output_stream_tell (GSeekable *seekable)
	{
	GMemoryOutputStream *stream;
	GMemoryOutputStreamPrivate *priv;

	stream = G_MEMORY_OUTPUT_STREAM (seekable);
	priv = stream->priv;

	return priv->pos;
	}

	static gboolean
	g_memory_output_stream_can_seek (GSeekable *seekable)
	{
	return TRUE;
	}

	static gboolean
	g_memory_output_stream_seek (GSeekable *seekable,
	goffset offset,
	GSeekType type,
	GCancellable *cancellable,
	GError **error)
	{
	GMemoryOutputStream *stream;
	GMemoryOutputStreamPrivate *priv;
	goffset absolute;

	stream = G_MEMORY_OUTPUT_STREAM (seekable);
	priv = 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 (error,
	G_IO_ERROR,
	G_IO_ERROR_INVALID_ARGUMENT,
	_("Invalid GSeekType supplied"));

	return FALSE;
	}

	if (absolute < 0)
	{
	g_set_error (error,
	G_IO_ERROR,
	G_IO_ERROR_INVALID_ARGUMENT,
	_("Invalid seek request"));
	return FALSE;
	}

	if (!array_check_boundary (stream, absolute, error))
	return FALSE;

	priv->pos = absolute;

	return TRUE;
	}

	static gboolean
	g_memory_output_stream_can_truncate (GSeekable *seekable)
	{
	GMemoryOutputStream *ostream;
	GMemoryOutputStreamPrivate *priv;

	ostream = G_MEMORY_OUTPUT_STREAM (seekable);
	priv = ostream->priv;

	return priv->realloc_fn != NULL;
	}

	static gboolean
	g_memory_output_stream_truncate (GSeekable *seekable,
	goffset offset,
	GCancellable *cancellable,
	GError **error)
	{
	GMemoryOutputStream *ostream;
	GMemoryOutputStreamPrivate *priv;

	ostream = G_MEMORY_OUTPUT_STREAM (seekable);
	priv = ostream->priv;

	if (!array_resize (ostream, offset, FALSE, error))
	return FALSE;

	return TRUE;
	}

	#define __G_MEMORY_OUTPUT_STREAM_C__
	#include "gioaliasdef.c"