/* 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 "gcancellable.h" #include "gasyncresult.h" #include "gioerror.h" #include "glibintl.h" #include "gioalias.h" /** * SECTION:gfileinputstream * @short_description: File input streaming operations * @include: gio/gio.h * @see_also: #GInputStream, #GDataInputStream, #GSeekable * * GFileInputStream provides input streams that take their * content from a file. * * GFileInputStream implements #GSeekable, which allows the input * stream to jump to arbitrary positions in the file, provided the * filesystem of the file allows it. In addition to the generic * g_seekable_ API, GFileInputStream has its own API for seeking * and positioning. To find the position of a file input stream, * use g_file_input_stream_tell(). To find out if a file input * stream supports seeking, use g_file_input_stream_can_seek(). * To position a file input stream, use g_file_input_stream_seek(). **/ static void g_file_input_stream_seekable_iface_init (GSeekableIface *iface); static goffset g_file_input_stream_seekable_tell (GSeekable *seekable); static gboolean g_file_input_stream_seekable_can_seek (GSeekable *seekable); static gboolean g_file_input_stream_seekable_seek (GSeekable *seekable, goffset offset, GSeekType type, GCancellable *cancellable, GError **error); static gboolean g_file_input_stream_seekable_can_truncate (GSeekable *seekable); static gboolean g_file_input_stream_seekable_truncate (GSeekable *seekable, goffset offset, GCancellable *cancellable, GError **error); static void g_file_input_stream_real_query_info_async (GFileInputStream *stream, const char *attributes, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data); static GFileInfo *g_file_input_stream_real_query_info_finish (GFileInputStream *stream, GAsyncResult *result, GError **error); G_DEFINE_TYPE_WITH_CODE (GFileInputStream, g_file_input_stream, G_TYPE_INPUT_STREAM, G_IMPLEMENT_INTERFACE (G_TYPE_SEEKABLE, g_file_input_stream_seekable_iface_init)) struct _GFileInputStreamPrivate { GAsyncReadyCallback outstanding_callback; }; static void g_file_input_stream_class_init (GFileInputStreamClass *klass) { g_type_class_add_private (klass, sizeof (GFileInputStreamPrivate)); klass->query_info_async = g_file_input_stream_real_query_info_async; klass->query_info_finish = g_file_input_stream_real_query_info_finish; } static void g_file_input_stream_seekable_iface_init (GSeekableIface *iface) { iface->tell = g_file_input_stream_seekable_tell; iface->can_seek = g_file_input_stream_seekable_can_seek; iface->seek = g_file_input_stream_seekable_seek; iface->can_truncate = g_file_input_stream_seekable_can_truncate; iface->truncate_fn = g_file_input_stream_seekable_truncate; } static void g_file_input_stream_init (GFileInputStream *stream) { stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (stream, G_TYPE_FILE_INPUT_STREAM, GFileInputStreamPrivate); } /** * g_file_input_stream_query_info: * @stream: a #GFileInputStream. * @attributes: a file attribute query string. * @cancellable: optional #GCancellable object, %NULL to ignore. * @error: a #GError location to store the error occuring, or %NULL to * ignore. * * Queries a file input stream the given @attributes. This function blocks * while querying the stream. For the asynchronous (non-blocking) version * of this function, see g_file_input_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. * * Returns: a #GFileInfo, or %NULL on error. **/ GFileInfo * g_file_input_stream_query_info (GFileInputStream *stream, const char *attributes, GCancellable *cancellable, GError **error) { GFileInputStreamClass *class; GInputStream *input_stream; GFileInfo *info; g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream), NULL); input_stream = G_INPUT_STREAM (stream); if (!g_input_stream_set_pending (input_stream, error)) return NULL; info = NULL; if (cancellable) g_cancellable_push_current (cancellable); class = G_FILE_INPUT_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_input_stream_clear_pending (input_stream); return info; } static void async_ready_callback_wrapper (GObject *source_object, GAsyncResult *res, gpointer user_data) { GFileInputStream *stream = G_FILE_INPUT_STREAM (source_object); g_input_stream_clear_pending (G_INPUT_STREAM (stream)); if (stream->priv->outstanding_callback) (*stream->priv->outstanding_callback) (source_object, res, user_data); g_object_unref (stream); } /** * g_file_input_stream_query_info_async: * @stream: a #GFileInputStream. * @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 * * Queries the stream information asynchronously. * When the operation is finished @callback will be called. * You can then call g_file_input_stream_query_info_finish() * to get the result of the operation. * * For the synchronous version of this function, * see g_file_input_stream_query_info(). * * 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 * **/ void g_file_input_stream_query_info_async (GFileInputStream *stream, const char *attributes, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { GFileInputStreamClass *klass; GInputStream *input_stream; GError *error = NULL; g_return_if_fail (G_IS_FILE_INPUT_STREAM (stream)); input_stream = G_INPUT_STREAM (stream); if (!g_input_stream_set_pending (input_stream, &error)) { g_simple_async_report_gerror_in_idle (G_OBJECT (stream), callback, user_data, error); g_error_free (error); return; } klass = G_FILE_INPUT_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_input_stream_query_info_finish: * @stream: a #GFileInputStream. * @result: a #GAsyncResult. * @error: a #GError location to store the error occuring, * or %NULL to ignore. * * Finishes an asynchronous info query operation. * * Returns: #GFileInfo. **/ GFileInfo * g_file_input_stream_query_info_finish (GFileInputStream *stream, GAsyncResult *result, GError **error) { GSimpleAsyncResult *simple; GFileInputStreamClass *class; g_return_val_if_fail (G_IS_FILE_INPUT_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_INPUT_STREAM_GET_CLASS (stream); return class->query_info_finish (stream, result, error); } static goffset g_file_input_stream_tell (GFileInputStream *stream) { GFileInputStreamClass *class; goffset offset; g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream), 0); class = G_FILE_INPUT_STREAM_GET_CLASS (stream); offset = 0; if (class->tell) offset = class->tell (stream); return offset; } static goffset g_file_input_stream_seekable_tell (GSeekable *seekable) { return g_file_input_stream_tell (G_FILE_INPUT_STREAM (seekable)); } static gboolean g_file_input_stream_can_seek (GFileInputStream *stream) { GFileInputStreamClass *class; gboolean can_seek; g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream), FALSE); class = G_FILE_INPUT_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_input_stream_seekable_can_seek (GSeekable *seekable) { return g_file_input_stream_can_seek (G_FILE_INPUT_STREAM (seekable)); } static gboolean g_file_input_stream_seek (GFileInputStream *stream, goffset offset, GSeekType type, GCancellable *cancellable, GError **error) { GFileInputStreamClass *class; GInputStream *input_stream; gboolean res; g_return_val_if_fail (G_IS_FILE_INPUT_STREAM (stream), FALSE); input_stream = G_INPUT_STREAM (stream); class = G_FILE_INPUT_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_input_stream_set_pending (input_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_input_stream_clear_pending (input_stream); return res; } static gboolean g_file_input_stream_seekable_seek (GSeekable *seekable, goffset offset, GSeekType type, GCancellable *cancellable, GError **error) { return g_file_input_stream_seek (G_FILE_INPUT_STREAM (seekable), offset, type, cancellable, error); } static gboolean g_file_input_stream_seekable_can_truncate (GSeekable *seekable) { return FALSE; } static gboolean g_file_input_stream_seekable_truncate (GSeekable *seekable, goffset offset, GCancellable *cancellable, GError **error) { g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED, _("Truncate not allowed on input stream")); return FALSE; } /******************************************** * 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) { GFileInputStreamClass *class; GError *error = NULL; QueryInfoAsyncData *data; GFileInfo *info; data = g_simple_async_result_get_op_res_gpointer (res); info = NULL; class = G_FILE_INPUT_STREAM_GET_CLASS (object); if (class->query_info) info = class->query_info (G_FILE_INPUT_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_set_from_error (res, error); g_error_free (error); } else data->info = info; } static void g_file_input_stream_real_query_info_async (GFileInputStream *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_input_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_input_stream_real_query_info_finish (GFileInputStream *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_input_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; } #define __G_FILE_INPUT_STREAM_C__ #include "gioaliasdef.c"