/* 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: Alexander Larsson */ #include "config.h" #include #include #include #include "gsimpleasyncresult.h" #include "gasyncresult.h" #include "gcancellable.h" #include "gioerror.h" #include "glibintl.h" /** * SECTION:gfileoutputstream * @short_description: File output streaming operations * @include: gio/gio.h * @see_also: #GOutputStream, #GDataOutputStream, #GSeekable * * GFileOutputStream provides output streams that write their * content to a file. * * GFileOutputStream implements #GSeekable, which allows the output * stream to jump to arbitrary positions in the file and to truncate * the file, provided the filesystem of the file supports these * operations. * * To find the position of a file output stream, use g_seekable_tell(). * To find out if a file output stream supports seeking, use * g_seekable_can_seek().To position a file output stream, use * g_seekable_seek(). To find out if a file output stream supports * truncating, use g_seekable_can_truncate(). To truncate a file output * stream, use g_seekable_truncate(). **/ static void g_file_output_stream_seekable_iface_init (GSeekableIface *iface); static goffset g_file_output_stream_seekable_tell (GSeekable *seekable); static gboolean g_file_output_stream_seekable_can_seek (GSeekable *seekable); static gboolean g_file_output_stream_seekable_seek (GSeekable *seekable, goffset offset, GSeekType type, GCancellable *cancellable, GError **error); static gboolean g_file_output_stream_seekable_can_truncate (GSeekable *seekable); static gboolean g_file_output_stream_seekable_truncate (GSeekable *seekable, goffset offset, GCancellable *cancellable, GError **error); static void g_file_output_stream_real_query_info_async (GFileOutputStream *stream, const char *attributes, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data); static GFileInfo *g_file_output_stream_real_query_info_finish (GFileOutputStream *stream, GAsyncResult *result, GError **error); G_DEFINE_TYPE_WITH_CODE (GFileOutputStream, g_file_output_stream, G_TYPE_OUTPUT_STREAM, G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE, g_file_output_stream_seekable_iface_init)); struct _GFileOutputStreamPrivate { GAsyncReadyCallback outstanding_callback; }; static void g_file_output_stream_class_init (GFileOutputStreamClass *klass) { g_type_class_add_private (klass, sizeof (GFileOutputStreamPrivate)); klass->query_info_async = g_file_output_stream_real_query_info_async; klass->query_info_finish = g_file_output_stream_real_query_info_finish; } static void g_file_output_stream_seekable_iface_init (GSeekableIface *iface) { iface->tell = g_file_output_stream_seekable_tell; iface->can_seek = g_file_output_stream_seekable_can_seek; iface->seek = g_file_output_stream_seekable_seek; iface->can_truncate = g_file_output_stream_seekable_can_truncate; iface->truncate_fn = g_file_output_stream_seekable_truncate; } static void g_file_output_stream_init (GFileOutputStream *stream) { stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (stream, G_TYPE_FILE_OUTPUT_STREAM, GFileOutputStreamPrivate); } /** * g_file_output_stream_query_info: * @stream: a #GFileOutputStream. * @attributes: a file attribute query string. * @cancellable: optional #GCancellable object, %NULL to ignore. * @error: a #GError, %NULL to ignore. * * Queries a file output stream for the given @attributes. * This function blocks while querying the stream. For the asynchronous * version of this function, see g_file_output_stream_query_info_async(). * While the stream is blocked, the stream will set the pending flag * internally, and any other operations on the stream will fail with * %G_IO_ERROR_PENDING. * * Can fail if the stream was already closed (with @error being set to * %G_IO_ERROR_CLOSED), the stream has pending operations (with @error being * set to %G_IO_ERROR_PENDING), or if querying info is not supported for * the stream's interface (with @error being set to %G_IO_ERROR_NOT_SUPPORTED). In * all cases of failure, %NULL will be returned. * * If @cancellable is not %NULL, then the operation can be cancelled by * triggering the cancellable object from another thread. If the operation * was cancelled, the error %G_IO_ERROR_CANCELLED will be set, and %NULL will * be returned. * * Returns: (transfer full): a #GFileInfo for the @stream, or %NULL on error. **/ GFileInfo * g_file_output_stream_query_info (GFileOutputStream *stream, const char *attributes, GCancellable *cancellable, GError **error) { GFileOutputStreamClass *class; GOutputStream *output_stream; GFileInfo *info; g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream), NULL); output_stream = G_OUTPUT_STREAM (stream); if (!g_output_stream_set_pending (output_stream, error)) return NULL; info = NULL; if (cancellable) g_cancellable_push_current (cancellable); class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream); if (class->query_info) info = class->query_info (stream, attributes, cancellable, error); else g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED, _("Stream doesn't support query_info")); if (cancellable) g_cancellable_pop_current (cancellable); g_output_stream_clear_pending (output_stream); return info; } static void async_ready_callback_wrapper (GObject *source_object, GAsyncResult *res, gpointer user_data) { GFileOutputStream *stream = G_FILE_OUTPUT_STREAM (source_object); g_output_stream_clear_pending (G_OUTPUT_STREAM (stream)); if (stream->priv->outstanding_callback) (*stream->priv->outstanding_callback) (source_object, res, user_data); g_object_unref (stream); } /** * g_file_output_stream_query_info_async: * @stream: a #GFileOutputStream. * @attributes: a file attribute query string. * @io_priority: the I/O priority * of the request. * @cancellable: optional #GCancellable object, %NULL to ignore. * @callback: callback to call when the request is satisfied * @user_data: the data to pass to callback function * * Asynchronously queries the @stream for a #GFileInfo. When completed, * @callback will be called with a #GAsyncResult which can be used to * finish the operation with g_file_output_stream_query_info_finish(). * * For the synchronous version of this function, see * g_file_output_stream_query_info(). * **/ void g_file_output_stream_query_info_async (GFileOutputStream *stream, const char *attributes, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { GFileOutputStreamClass *klass; GOutputStream *output_stream; GError *error = NULL; g_return_if_fail (G_IS_FILE_OUTPUT_STREAM (stream)); output_stream = G_OUTPUT_STREAM (stream); if (!g_output_stream_set_pending (output_stream, &error)) { g_simple_async_report_gerror_in_idle (G_OBJECT (stream), callback, user_data, error); g_error_free (error); return; } klass = G_FILE_OUTPUT_STREAM_GET_CLASS (stream); stream->priv->outstanding_callback = callback; g_object_ref (stream); klass->query_info_async (stream, attributes, io_priority, cancellable, async_ready_callback_wrapper, user_data); } /** * g_file_output_stream_query_info_finish: * @stream: a #GFileOutputStream. * @result: a #GAsyncResult. * @error: a #GError, %NULL to ignore. * * Finalizes the asynchronous query started * by g_file_output_stream_query_info_async(). * * Returns: (transfer full): A #GFileInfo for the finished query. **/ GFileInfo * g_file_output_stream_query_info_finish (GFileOutputStream *stream, GAsyncResult *result, GError **error) { GSimpleAsyncResult *simple; GFileOutputStreamClass *class; g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream), NULL); g_return_val_if_fail (G_IS_ASYNC_RESULT (result), NULL); if (G_IS_SIMPLE_ASYNC_RESULT (result)) { simple = G_SIMPLE_ASYNC_RESULT (result); if (g_simple_async_result_propagate_error (simple, error)) return NULL; } class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream); return class->query_info_finish (stream, result, error); } /** * g_file_output_stream_get_etag: * @stream: a #GFileOutputStream. * * Gets the entity tag for the file when it has been written. * This must be called after the stream has been written * and closed, as the etag can change while writing. * * Returns: the entity tag for the stream. **/ char * g_file_output_stream_get_etag (GFileOutputStream *stream) { GFileOutputStreamClass *class; GOutputStream *output_stream; char *etag; g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream), NULL); output_stream = G_OUTPUT_STREAM (stream); if (!g_output_stream_is_closed (output_stream)) { g_warning ("stream is not closed yet, can't get etag"); return NULL; } etag = NULL; class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream); if (class->get_etag) etag = class->get_etag (stream); return etag; } static goffset g_file_output_stream_tell (GFileOutputStream *stream) { GFileOutputStreamClass *class; goffset offset; g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream), 0); class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream); offset = 0; if (class->tell) offset = class->tell (stream); return offset; } static goffset g_file_output_stream_seekable_tell (GSeekable *seekable) { return g_file_output_stream_tell (G_FILE_OUTPUT_STREAM (seekable)); } static gboolean g_file_output_stream_can_seek (GFileOutputStream *stream) { GFileOutputStreamClass *class; gboolean can_seek; g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream), FALSE); class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream); can_seek = FALSE; if (class->seek) { can_seek = TRUE; if (class->can_seek) can_seek = class->can_seek (stream); } return can_seek; } static gboolean g_file_output_stream_seekable_can_seek (GSeekable *seekable) { return g_file_output_stream_can_seek (G_FILE_OUTPUT_STREAM (seekable)); } static gboolean g_file_output_stream_seek (GFileOutputStream *stream, goffset offset, GSeekType type, GCancellable *cancellable, GError **error) { GFileOutputStreamClass *class; GOutputStream *output_stream; gboolean res; g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream), FALSE); output_stream = G_OUTPUT_STREAM (stream); class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream); if (!class->seek) { g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED, _("Seek not supported on stream")); return FALSE; } if (!g_output_stream_set_pending (output_stream, error)) return FALSE; if (cancellable) g_cancellable_push_current (cancellable); res = class->seek (stream, offset, type, cancellable, error); if (cancellable) g_cancellable_pop_current (cancellable); g_output_stream_clear_pending (output_stream); return res; } static gboolean g_file_output_stream_seekable_seek (GSeekable *seekable, goffset offset, GSeekType type, GCancellable *cancellable, GError **error) { return g_file_output_stream_seek (G_FILE_OUTPUT_STREAM (seekable), offset, type, cancellable, error); } static gboolean g_file_output_stream_can_truncate (GFileOutputStream *stream) { GFileOutputStreamClass *class; gboolean can_truncate; g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream), FALSE); class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream); can_truncate = FALSE; if (class->truncate_fn) { can_truncate = TRUE; if (class->can_truncate) can_truncate = class->can_truncate (stream); } return can_truncate; } static gboolean g_file_output_stream_seekable_can_truncate (GSeekable *seekable) { return g_file_output_stream_can_truncate (G_FILE_OUTPUT_STREAM (seekable)); } static gboolean g_file_output_stream_truncate (GFileOutputStream *stream, goffset size, GCancellable *cancellable, GError **error) { GFileOutputStreamClass *class; GOutputStream *output_stream; gboolean res; g_return_val_if_fail (G_IS_FILE_OUTPUT_STREAM (stream), FALSE); output_stream = G_OUTPUT_STREAM (stream); class = G_FILE_OUTPUT_STREAM_GET_CLASS (stream); if (!class->truncate_fn) { g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED, _("Truncate not supported on stream")); return FALSE; } if (!g_output_stream_set_pending (output_stream, error)) return FALSE; if (cancellable) g_cancellable_push_current (cancellable); res = class->truncate_fn (stream, size, cancellable, error); if (cancellable) g_cancellable_pop_current (cancellable); g_output_stream_clear_pending (output_stream); return res; } static gboolean g_file_output_stream_seekable_truncate (GSeekable *seekable, goffset size, GCancellable *cancellable, GError **error) { return g_file_output_stream_truncate (G_FILE_OUTPUT_STREAM (seekable), size, cancellable, error); } /******************************************** * Default implementation of async ops * ********************************************/ typedef struct { char *attributes; GFileInfo *info; } QueryInfoAsyncData; static void query_info_data_free (QueryInfoAsyncData *data) { if (data->info) g_object_unref (data->info); g_free (data->attributes); g_free (data); } static void query_info_async_thread (GSimpleAsyncResult *res, GObject *object, GCancellable *cancellable) { GFileOutputStreamClass *class; GError *error = NULL; QueryInfoAsyncData *data; GFileInfo *info; data = g_simple_async_result_get_op_res_gpointer (res); info = NULL; class = G_FILE_OUTPUT_STREAM_GET_CLASS (object); if (class->query_info) info = class->query_info (G_FILE_OUTPUT_STREAM (object), data->attributes, cancellable, &error); else g_set_error_literal (&error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED, _("Stream doesn't support query_info")); if (info == NULL) g_simple_async_result_take_error (res, error); else data->info = info; } static void g_file_output_stream_real_query_info_async (GFileOutputStream *stream, const char *attributes, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { GSimpleAsyncResult *res; QueryInfoAsyncData *data; data = g_new0 (QueryInfoAsyncData, 1); data->attributes = g_strdup (attributes); res = g_simple_async_result_new (G_OBJECT (stream), callback, user_data, g_file_output_stream_real_query_info_async); g_simple_async_result_set_op_res_gpointer (res, data, (GDestroyNotify)query_info_data_free); g_simple_async_result_run_in_thread (res, query_info_async_thread, io_priority, cancellable); g_object_unref (res); } static GFileInfo * g_file_output_stream_real_query_info_finish (GFileOutputStream *stream, GAsyncResult *res, GError **error) { GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (res); QueryInfoAsyncData *data; g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_file_output_stream_real_query_info_async); data = g_simple_async_result_get_op_res_gpointer (simple); if (data->info) return g_object_ref (data->info); return NULL; }