/* GIO - GLib Input, IO 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 "gasyncresult.h" #include "gtask.h" #include "gcancellable.h" #include "gioerror.h" #include "gfileoutputstream.h" #include "glibintl.h" /** * SECTION:gfileiostream * @short_description: File read and write streaming operations * @include: gio/gio.h * @see_also: #GIOStream, #GFileInputStream, #GFileOutputStream, #GSeekable * * GFileIOStream provides io streams that both read and write to the same * file handle. * * GFileIOStream implements #GSeekable, which allows the io * 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 io stream, use * g_seekable_tell(). * * To find out if a file io stream supports seeking, use g_seekable_can_seek(). * To position a file io stream, use g_seekable_seek(). * To find out if a file io stream supports truncating, use * g_seekable_can_truncate(). To truncate a file io * stream, use g_seekable_truncate(). * * The default implementation of all the #GFileIOStream operations * and the implementation of #GSeekable just call into the same operations * on the output stream. * Since: 2.22 **/ static void g_file_io_stream_seekable_iface_init (GSeekableIface *iface); static goffset g_file_io_stream_seekable_tell (GSeekable *seekable); static gboolean g_file_io_stream_seekable_can_seek (GSeekable *seekable); static gboolean g_file_io_stream_seekable_seek (GSeekable *seekable, goffset offset, GSeekType type, GCancellable *cancellable, GError **error); static gboolean g_file_io_stream_seekable_can_truncate (GSeekable *seekable); static gboolean g_file_io_stream_seekable_truncate (GSeekable *seekable, goffset offset, GCancellable *cancellable, GError **error); static void g_file_io_stream_real_query_info_async (GFileIOStream *stream, const char *attributes, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data); static GFileInfo *g_file_io_stream_real_query_info_finish (GFileIOStream *stream, GAsyncResult *result, GError **error); struct _GFileIOStreamPrivate { GAsyncReadyCallback outstanding_callback; }; G_DEFINE_TYPE_WITH_CODE (GFileIOStream, g_file_io_stream, G_TYPE_IO_STREAM, G_ADD_PRIVATE (GFileIOStream) G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE, g_file_io_stream_seekable_iface_init)) static void g_file_io_stream_seekable_iface_init (GSeekableIface *iface) { iface->tell = g_file_io_stream_seekable_tell; iface->can_seek = g_file_io_stream_seekable_can_seek; iface->seek = g_file_io_stream_seekable_seek; iface->can_truncate = g_file_io_stream_seekable_can_truncate; iface->truncate_fn = g_file_io_stream_seekable_truncate; } static void g_file_io_stream_init (GFileIOStream *stream) { stream->priv = g_file_io_stream_get_instance_private (stream); } /** * g_file_io_stream_query_info: * @stream: a #GFileIOStream. * @attributes: a file attribute query string. * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore. * @error: a #GError, %NULL to ignore. * * Queries a file io stream for the given @attributes. * This function blocks while querying the stream. For the asynchronous * version of this function, see g_file_io_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). I * 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. * * Since: 2.22 **/ GFileInfo * g_file_io_stream_query_info (GFileIOStream *stream, const char *attributes, GCancellable *cancellable, GError **error) { GFileIOStreamClass *class; GIOStream *io_stream; GFileInfo *info; g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream), NULL); io_stream = G_IO_STREAM (stream); if (!g_io_stream_set_pending (io_stream, error)) return NULL; info = NULL; if (cancellable) g_cancellable_push_current (cancellable); class = G_FILE_IO_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_io_stream_clear_pending (io_stream); return info; } static void async_ready_callback_wrapper (GObject *source_object, GAsyncResult *res, gpointer user_data) { GFileIOStream *stream = G_FILE_IO_STREAM (source_object); g_io_stream_clear_pending (G_IO_STREAM (stream)); if (stream->priv->outstanding_callback) (*stream->priv->outstanding_callback) (source_object, res, user_data); g_object_unref (stream); } /** * g_file_io_stream_query_info_async: * @stream: a #GFileIOStream. * @attributes: a file attribute query string. * @io_priority: the I/O priority * of the request. * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore. * @callback: (scope async): callback to call when the request is satisfied * @user_data: (closure): 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_io_stream_query_info_finish(). * * For the synchronous version of this function, see * g_file_io_stream_query_info(). * * Since: 2.22 **/ void g_file_io_stream_query_info_async (GFileIOStream *stream, const char *attributes, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { GFileIOStreamClass *klass; GIOStream *io_stream; GError *error = NULL; g_return_if_fail (G_IS_FILE_IO_STREAM (stream)); io_stream = G_IO_STREAM (stream); if (!g_io_stream_set_pending (io_stream, &error)) { g_task_report_error (stream, callback, user_data, g_file_io_stream_query_info_async, error); return; } klass = G_FILE_IO_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_io_stream_query_info_finish: * @stream: a #GFileIOStream. * @result: a #GAsyncResult. * @error: a #GError, %NULL to ignore. * * Finalizes the asynchronous query started * by g_file_io_stream_query_info_async(). * * Returns: (transfer full): A #GFileInfo for the finished query. * * Since: 2.22 **/ GFileInfo * g_file_io_stream_query_info_finish (GFileIOStream *stream, GAsyncResult *result, GError **error) { GFileIOStreamClass *class; g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream), NULL); g_return_val_if_fail (G_IS_ASYNC_RESULT (result), NULL); if (g_async_result_legacy_propagate_error (result, error)) return NULL; else if (g_async_result_is_tagged (result, g_file_io_stream_query_info_async)) return g_task_propagate_pointer (G_TASK (result), error); class = G_FILE_IO_STREAM_GET_CLASS (stream); return class->query_info_finish (stream, result, error); } /** * g_file_io_stream_get_etag: * @stream: a #GFileIOStream. * * 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. * * Since: 2.22 **/ char * g_file_io_stream_get_etag (GFileIOStream *stream) { GFileIOStreamClass *class; GIOStream *io_stream; char *etag; g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream), NULL); io_stream = G_IO_STREAM (stream); if (!g_io_stream_is_closed (io_stream)) { g_warning ("stream is not closed yet, can't get etag"); return NULL; } etag = NULL; class = G_FILE_IO_STREAM_GET_CLASS (stream); if (class->get_etag) etag = class->get_etag (stream); return etag; } static goffset g_file_io_stream_tell (GFileIOStream *stream) { GFileIOStreamClass *class; goffset offset; g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream), 0); class = G_FILE_IO_STREAM_GET_CLASS (stream); offset = 0; if (class->tell) offset = class->tell (stream); return offset; } static goffset g_file_io_stream_seekable_tell (GSeekable *seekable) { return g_file_io_stream_tell (G_FILE_IO_STREAM (seekable)); } static gboolean g_file_io_stream_can_seek (GFileIOStream *stream) { GFileIOStreamClass *class; gboolean can_seek; g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream), FALSE); class = G_FILE_IO_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_io_stream_seekable_can_seek (GSeekable *seekable) { return g_file_io_stream_can_seek (G_FILE_IO_STREAM (seekable)); } static gboolean g_file_io_stream_seek (GFileIOStream *stream, goffset offset, GSeekType type, GCancellable *cancellable, GError **error) { GFileIOStreamClass *class; GIOStream *io_stream; gboolean res; g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream), FALSE); io_stream = G_IO_STREAM (stream); class = G_FILE_IO_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_io_stream_set_pending (io_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_io_stream_clear_pending (io_stream); return res; } static gboolean g_file_io_stream_seekable_seek (GSeekable *seekable, goffset offset, GSeekType type, GCancellable *cancellable, GError **error) { return g_file_io_stream_seek (G_FILE_IO_STREAM (seekable), offset, type, cancellable, error); } static gboolean g_file_io_stream_can_truncate (GFileIOStream *stream) { GFileIOStreamClass *class; gboolean can_truncate; g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream), FALSE); class = G_FILE_IO_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_io_stream_seekable_can_truncate (GSeekable *seekable) { return g_file_io_stream_can_truncate (G_FILE_IO_STREAM (seekable)); } static gboolean g_file_io_stream_truncate (GFileIOStream *stream, goffset size, GCancellable *cancellable, GError **error) { GFileIOStreamClass *class; GIOStream *io_stream; gboolean res; g_return_val_if_fail (G_IS_FILE_IO_STREAM (stream), FALSE); io_stream = G_IO_STREAM (stream); class = G_FILE_IO_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_io_stream_set_pending (io_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_io_stream_clear_pending (io_stream); return res; } static gboolean g_file_io_stream_seekable_truncate (GSeekable *seekable, goffset size, GCancellable *cancellable, GError **error) { return g_file_io_stream_truncate (G_FILE_IO_STREAM (seekable), size, cancellable, error); } /***************************************************** * Default implementations based on output stream * *****************************************************/ static goffset g_file_io_stream_real_tell (GFileIOStream *stream) { GOutputStream *out; GSeekable *seekable; out = g_io_stream_get_output_stream (G_IO_STREAM (stream)); seekable = G_SEEKABLE (out); return g_seekable_tell (seekable); } static gboolean g_file_io_stream_real_can_seek (GFileIOStream *stream) { GOutputStream *out; GSeekable *seekable; out = g_io_stream_get_output_stream (G_IO_STREAM (stream)); seekable = G_SEEKABLE (out); return g_seekable_can_seek (seekable); } static gboolean g_file_io_stream_real_seek (GFileIOStream *stream, goffset offset, GSeekType type, GCancellable *cancellable, GError **error) { GOutputStream *out; GSeekable *seekable; out = g_io_stream_get_output_stream (G_IO_STREAM (stream)); seekable = G_SEEKABLE (out); return g_seekable_seek (seekable, offset, type, cancellable, error); } static gboolean g_file_io_stream_real_can_truncate (GFileIOStream *stream) { GOutputStream *out; GSeekable *seekable; out = g_io_stream_get_output_stream (G_IO_STREAM (stream)); seekable = G_SEEKABLE (out); return g_seekable_can_truncate (seekable); } static gboolean g_file_io_stream_real_truncate_fn (GFileIOStream *stream, goffset size, GCancellable *cancellable, GError **error) { GOutputStream *out; GSeekable *seekable; out = g_io_stream_get_output_stream (G_IO_STREAM (stream)); seekable = G_SEEKABLE (out); return g_seekable_truncate (seekable, size, cancellable, error); } static char * g_file_io_stream_real_get_etag (GFileIOStream *stream) { GOutputStream *out; GFileOutputStream *file_out; out = g_io_stream_get_output_stream (G_IO_STREAM (stream)); file_out = G_FILE_OUTPUT_STREAM (out); return g_file_output_stream_get_etag (file_out); } static GFileInfo * g_file_io_stream_real_query_info (GFileIOStream *stream, const char *attributes, GCancellable *cancellable, GError **error) { GOutputStream *out; GFileOutputStream *file_out; out = g_io_stream_get_output_stream (G_IO_STREAM (stream)); file_out = G_FILE_OUTPUT_STREAM (out); return g_file_output_stream_query_info (file_out, attributes, cancellable, error); } typedef struct { GObject *object; GAsyncReadyCallback callback; gpointer user_data; } AsyncOpWrapper; static AsyncOpWrapper * async_op_wrapper_new (gpointer object, GAsyncReadyCallback callback, gpointer user_data) { AsyncOpWrapper *data; data = g_new0 (AsyncOpWrapper, 1); data->object = g_object_ref (object); data->callback = callback; data->user_data = user_data; return data; } static void async_op_wrapper_callback (GObject *source_object, GAsyncResult *res, gpointer user_data) { AsyncOpWrapper *data = user_data; data->callback (data->object, res, data->user_data); g_object_unref (data->object); g_free (data); } static void g_file_io_stream_real_query_info_async (GFileIOStream *stream, const char *attributes, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { GOutputStream *out; GFileOutputStream *file_out; AsyncOpWrapper *data; out = g_io_stream_get_output_stream (G_IO_STREAM (stream)); file_out = G_FILE_OUTPUT_STREAM (out); data = async_op_wrapper_new (stream, callback, user_data); g_file_output_stream_query_info_async (file_out, attributes, io_priority, cancellable, async_op_wrapper_callback, data); } static GFileInfo * g_file_io_stream_real_query_info_finish (GFileIOStream *stream, GAsyncResult *res, GError **error) { GOutputStream *out; GFileOutputStream *file_out; out = g_io_stream_get_output_stream (G_IO_STREAM (stream)); file_out = G_FILE_OUTPUT_STREAM (out); return g_file_output_stream_query_info_finish (file_out, res, error); } static void g_file_io_stream_class_init (GFileIOStreamClass *klass) { klass->tell = g_file_io_stream_real_tell; klass->can_seek = g_file_io_stream_real_can_seek; klass->seek = g_file_io_stream_real_seek; klass->can_truncate = g_file_io_stream_real_can_truncate; klass->truncate_fn = g_file_io_stream_real_truncate_fn; klass->query_info = g_file_io_stream_real_query_info; klass->query_info_async = g_file_io_stream_real_query_info_async; klass->query_info_finish = g_file_io_stream_real_query_info_finish; klass->get_etag = g_file_io_stream_real_get_etag; }