/* 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, see . * * Author: Alexander Larsson */ #include "config.h" #include "gfileenumerator.h" #include "gfile.h" #include "gioscheduler.h" #include "gasyncresult.h" #include "gasynchelper.h" #include "gioerror.h" #include "glibintl.h" struct _GFileEnumeratorPrivate { /* TODO: Should be public for subclasses? */ GFile *container; guint closed : 1; guint pending : 1; GAsyncReadyCallback outstanding_callback; GError *outstanding_error; }; /** * SECTION:gfileenumerator * @short_description: Enumerated Files Routines * @include: gio/gio.h * * #GFileEnumerator allows you to operate on a set of #GFiles, * returning a #GFileInfo structure for each file enumerated (e.g. * g_file_enumerate_children() will return a #GFileEnumerator for each * of the children within a directory). * * To get the next file's information from a #GFileEnumerator, use * g_file_enumerator_next_file() or its asynchronous version, * g_file_enumerator_next_files_async(). Note that the asynchronous * version will return a list of #GFileInfos, whereas the * synchronous will only return the next file in the enumerator. * * The ordering of returned files is unspecified for non-Unix * platforms; for more information, see g_dir_read_name(). On Unix, * when operating on local files, returned files will be sorted by * inode number. Effectively you can assume that the ordering of * returned files will be stable between successive calls (and * applications) assuming the directory is unchanged. * * If your application needs a specific ordering, such as by name or * modification time, you will have to implement that in your * application code. * * To close a #GFileEnumerator, use g_file_enumerator_close(), or * its asynchronous version, g_file_enumerator_close_async(). Once * a #GFileEnumerator is closed, no further actions may be performed * on it, and it should be freed with g_object_unref(). * **/ G_DEFINE_TYPE_WITH_PRIVATE (GFileEnumerator, g_file_enumerator, G_TYPE_OBJECT) enum { PROP_0, PROP_CONTAINER }; static void g_file_enumerator_real_next_files_async (GFileEnumerator *enumerator, int num_files, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data); static GList * g_file_enumerator_real_next_files_finish (GFileEnumerator *enumerator, GAsyncResult *res, GError **error); static void g_file_enumerator_real_close_async (GFileEnumerator *enumerator, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data); static gboolean g_file_enumerator_real_close_finish (GFileEnumerator *enumerator, GAsyncResult *res, GError **error); static void g_file_enumerator_set_property (GObject *object, guint property_id, const GValue *value, GParamSpec *pspec) { GFileEnumerator *enumerator; enumerator = G_FILE_ENUMERATOR (object); switch (property_id) { case PROP_CONTAINER: enumerator->priv->container = g_value_dup_object (value); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec); break; } } static void g_file_enumerator_dispose (GObject *object) { GFileEnumerator *enumerator; enumerator = G_FILE_ENUMERATOR (object); if (enumerator->priv->container) { g_object_unref (enumerator->priv->container); enumerator->priv->container = NULL; } G_OBJECT_CLASS (g_file_enumerator_parent_class)->dispose (object); } static void g_file_enumerator_finalize (GObject *object) { GFileEnumerator *enumerator; enumerator = G_FILE_ENUMERATOR (object); if (!enumerator->priv->closed) g_file_enumerator_close (enumerator, NULL, NULL); G_OBJECT_CLASS (g_file_enumerator_parent_class)->finalize (object); } static void g_file_enumerator_class_init (GFileEnumeratorClass *klass) { GObjectClass *gobject_class = G_OBJECT_CLASS (klass); gobject_class->set_property = g_file_enumerator_set_property; gobject_class->dispose = g_file_enumerator_dispose; gobject_class->finalize = g_file_enumerator_finalize; klass->next_files_async = g_file_enumerator_real_next_files_async; klass->next_files_finish = g_file_enumerator_real_next_files_finish; klass->close_async = g_file_enumerator_real_close_async; klass->close_finish = g_file_enumerator_real_close_finish; g_object_class_install_property (gobject_class, PROP_CONTAINER, g_param_spec_object ("container", P_("Container"), P_("The container that is being enumerated"), G_TYPE_FILE, G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS)); } static void g_file_enumerator_init (GFileEnumerator *enumerator) { enumerator->priv = g_file_enumerator_get_instance_private (enumerator); } /** * g_file_enumerator_next_file: * @enumerator: a #GFileEnumerator. * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore. * @error: location to store the error occurring, or %NULL to ignore * * Returns information for the next file in the enumerated object. * Will block until the information is available. The #GFileInfo * returned from this function will contain attributes that match the * attribute string that was passed when the #GFileEnumerator was created. * * See the documentation of #GFileEnumerator for information about the * order of returned files. * * On error, returns %NULL and sets @error to the error. If the * enumerator is at the end, %NULL will be returned and @error will * be unset. * * Returns: (nullable) (transfer full): A #GFileInfo or %NULL on error * or end of enumerator. Free the returned object with * g_object_unref() when no longer needed. **/ GFileInfo * g_file_enumerator_next_file (GFileEnumerator *enumerator, GCancellable *cancellable, GError **error) { GFileEnumeratorClass *class; GFileInfo *info; g_return_val_if_fail (G_IS_FILE_ENUMERATOR (enumerator), NULL); g_return_val_if_fail (enumerator != NULL, NULL); if (enumerator->priv->closed) { g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED, _("Enumerator is closed")); return NULL; } if (enumerator->priv->pending) { g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PENDING, _("File enumerator has outstanding operation")); return NULL; } if (enumerator->priv->outstanding_error) { g_propagate_error (error, enumerator->priv->outstanding_error); enumerator->priv->outstanding_error = NULL; return NULL; } class = G_FILE_ENUMERATOR_GET_CLASS (enumerator); if (cancellable) g_cancellable_push_current (cancellable); enumerator->priv->pending = TRUE; info = (* class->next_file) (enumerator, cancellable, error); enumerator->priv->pending = FALSE; if (cancellable) g_cancellable_pop_current (cancellable); return info; } /** * g_file_enumerator_close: * @enumerator: a #GFileEnumerator. * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore. * @error: location to store the error occurring, or %NULL to ignore * * Releases all resources used by this enumerator, making the * enumerator return %G_IO_ERROR_CLOSED on all calls. * * This will be automatically called when the last reference * is dropped, but you might want to call this function to make * sure resources are released as early as possible. * * Returns: #TRUE on success or #FALSE on error. **/ gboolean g_file_enumerator_close (GFileEnumerator *enumerator, GCancellable *cancellable, GError **error) { GFileEnumeratorClass *class; g_return_val_if_fail (G_IS_FILE_ENUMERATOR (enumerator), FALSE); g_return_val_if_fail (enumerator != NULL, FALSE); class = G_FILE_ENUMERATOR_GET_CLASS (enumerator); if (enumerator->priv->closed) return TRUE; if (enumerator->priv->pending) { g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PENDING, _("File enumerator has outstanding operation")); return FALSE; } if (cancellable) g_cancellable_push_current (cancellable); enumerator->priv->pending = TRUE; (* class->close_fn) (enumerator, cancellable, error); enumerator->priv->pending = FALSE; enumerator->priv->closed = TRUE; if (cancellable) g_cancellable_pop_current (cancellable); return TRUE; } static void next_async_callback_wrapper (GObject *source_object, GAsyncResult *res, gpointer user_data) { GFileEnumerator *enumerator = G_FILE_ENUMERATOR (source_object); enumerator->priv->pending = FALSE; if (enumerator->priv->outstanding_callback) (*enumerator->priv->outstanding_callback) (source_object, res, user_data); g_object_unref (enumerator); } /** * g_file_enumerator_next_files_async: * @enumerator: a #GFileEnumerator. * @num_files: the number of file info objects to request * @io_priority: the [I/O priority][io-priority] of the request * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore. * @callback: (scope async): a #GAsyncReadyCallback to call when the request is satisfied * @user_data: (closure): the data to pass to callback function * * Request information for a number of files from the enumerator asynchronously. * When all i/o for the operation is finished the @callback will be called with * the requested information. * See the documentation of #GFileEnumerator for information about the * order of returned files. * * The callback can be called with less than @num_files files in case of error * or at the end of the enumerator. In case of a partial error the callback will * be called with any succeeding items and no error, and on the next request the * error will be reported. If a request is cancelled the callback will be called * with %G_IO_ERROR_CANCELLED. * * During an async request no other sync and async calls are allowed, and will * result in %G_IO_ERROR_PENDING errors. * * Any outstanding i/o request with higher priority (lower numerical value) will * be executed before an outstanding request with lower priority. Default * priority is %G_PRIORITY_DEFAULT. **/ void g_file_enumerator_next_files_async (GFileEnumerator *enumerator, int num_files, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { GFileEnumeratorClass *class; g_return_if_fail (G_IS_FILE_ENUMERATOR (enumerator)); g_return_if_fail (enumerator != NULL); g_return_if_fail (num_files >= 0); if (num_files == 0) { GTask *task; task = g_task_new (enumerator, cancellable, callback, user_data); g_task_set_source_tag (task, g_file_enumerator_next_files_async); g_task_return_pointer (task, NULL, NULL); g_object_unref (task); return; } if (enumerator->priv->closed) { g_task_report_new_error (enumerator, callback, user_data, g_file_enumerator_next_files_async, G_IO_ERROR, G_IO_ERROR_CLOSED, _("File enumerator is already closed")); return; } if (enumerator->priv->pending) { g_task_report_new_error (enumerator, callback, user_data, g_file_enumerator_next_files_async, G_IO_ERROR, G_IO_ERROR_PENDING, _("File enumerator has outstanding operation")); return; } class = G_FILE_ENUMERATOR_GET_CLASS (enumerator); enumerator->priv->pending = TRUE; enumerator->priv->outstanding_callback = callback; g_object_ref (enumerator); (* class->next_files_async) (enumerator, num_files, io_priority, cancellable, next_async_callback_wrapper, user_data); } /** * g_file_enumerator_next_files_finish: * @enumerator: a #GFileEnumerator. * @result: a #GAsyncResult. * @error: a #GError location to store the error occurring, or %NULL to * ignore. * * Finishes the asynchronous operation started with g_file_enumerator_next_files_async(). * * Returns: (transfer full) (element-type Gio.FileInfo): a #GList of #GFileInfos. You must free the list with * g_list_free() and unref the infos with g_object_unref() when you're * done with them. **/ GList * g_file_enumerator_next_files_finish (GFileEnumerator *enumerator, GAsyncResult *result, GError **error) { GFileEnumeratorClass *class; g_return_val_if_fail (G_IS_FILE_ENUMERATOR (enumerator), 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_enumerator_next_files_async)) return g_task_propagate_pointer (G_TASK (result), error); class = G_FILE_ENUMERATOR_GET_CLASS (enumerator); return class->next_files_finish (enumerator, result, error); } static void close_async_callback_wrapper (GObject *source_object, GAsyncResult *res, gpointer user_data) { GFileEnumerator *enumerator = G_FILE_ENUMERATOR (source_object); enumerator->priv->pending = FALSE; enumerator->priv->closed = TRUE; if (enumerator->priv->outstanding_callback) (*enumerator->priv->outstanding_callback) (source_object, res, user_data); g_object_unref (enumerator); } /** * g_file_enumerator_close_async: * @enumerator: a #GFileEnumerator. * @io_priority: the [I/O priority][io-priority] of the request * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore. * @callback: (scope async): a #GAsyncReadyCallback to call when the request is satisfied * @user_data: (closure): the data to pass to callback function * * Asynchronously closes the file enumerator. * * 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 returned in * g_file_enumerator_close_finish(). **/ void g_file_enumerator_close_async (GFileEnumerator *enumerator, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { GFileEnumeratorClass *class; g_return_if_fail (G_IS_FILE_ENUMERATOR (enumerator)); if (enumerator->priv->closed) { g_task_report_new_error (enumerator, callback, user_data, g_file_enumerator_close_async, G_IO_ERROR, G_IO_ERROR_CLOSED, _("File enumerator is already closed")); return; } if (enumerator->priv->pending) { g_task_report_new_error (enumerator, callback, user_data, g_file_enumerator_close_async, G_IO_ERROR, G_IO_ERROR_PENDING, _("File enumerator has outstanding operation")); return; } class = G_FILE_ENUMERATOR_GET_CLASS (enumerator); enumerator->priv->pending = TRUE; enumerator->priv->outstanding_callback = callback; g_object_ref (enumerator); (* class->close_async) (enumerator, io_priority, cancellable, close_async_callback_wrapper, user_data); } /** * g_file_enumerator_close_finish: * @enumerator: a #GFileEnumerator. * @result: a #GAsyncResult. * @error: a #GError location to store the error occurring, or %NULL to * ignore. * * Finishes closing a file enumerator, started from g_file_enumerator_close_async(). * * If the file enumerator was already closed when g_file_enumerator_close_async() * was called, then this function will report %G_IO_ERROR_CLOSED in @error, and * return %FALSE. If the file enumerator had pending operation when the close * operation was started, then this function will report %G_IO_ERROR_PENDING, and * return %FALSE. If @cancellable was not %NULL, then the operation may have been * cancelled by triggering the cancellable object from another thread. If the operation * was cancelled, the error %G_IO_ERROR_CANCELLED will be set, and %FALSE will be * returned. * * Returns: %TRUE if the close operation has finished successfully. **/ gboolean g_file_enumerator_close_finish (GFileEnumerator *enumerator, GAsyncResult *result, GError **error) { GFileEnumeratorClass *class; g_return_val_if_fail (G_IS_FILE_ENUMERATOR (enumerator), FALSE); g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE); if (g_async_result_legacy_propagate_error (result, error)) return FALSE; else if (g_async_result_is_tagged (result, g_file_enumerator_close_async)) return g_task_propagate_boolean (G_TASK (result), error); class = G_FILE_ENUMERATOR_GET_CLASS (enumerator); return class->close_finish (enumerator, result, error); } /** * g_file_enumerator_is_closed: * @enumerator: a #GFileEnumerator. * * Checks if the file enumerator has been closed. * * Returns: %TRUE if the @enumerator is closed. **/ gboolean g_file_enumerator_is_closed (GFileEnumerator *enumerator) { g_return_val_if_fail (G_IS_FILE_ENUMERATOR (enumerator), TRUE); return enumerator->priv->closed; } /** * g_file_enumerator_has_pending: * @enumerator: a #GFileEnumerator. * * Checks if the file enumerator has pending operations. * * Returns: %TRUE if the @enumerator has pending operations. **/ gboolean g_file_enumerator_has_pending (GFileEnumerator *enumerator) { g_return_val_if_fail (G_IS_FILE_ENUMERATOR (enumerator), TRUE); return enumerator->priv->pending; } /** * g_file_enumerator_set_pending: * @enumerator: a #GFileEnumerator. * @pending: a boolean value. * * Sets the file enumerator as having pending operations. **/ void g_file_enumerator_set_pending (GFileEnumerator *enumerator, gboolean pending) { g_return_if_fail (G_IS_FILE_ENUMERATOR (enumerator)); enumerator->priv->pending = pending; } /** * g_file_enumerator_iterate: * @direnum: an open #GFileEnumerator * @out_info: (out) (transfer none) (allow-none): Output location for the next #GFileInfo, or %NULL * @out_child: (out) (transfer none) (allow-none): Output location for the next #GFile, or %NULL * @cancellable: a #GCancellable * @error: a #GError * * This is a version of g_file_enumerator_next_file() that's easier to * use correctly from C programs. With g_file_enumerator_next_file(), * the gboolean return value signifies "end of iteration or error", which * requires allocation of a temporary #GError. * * In contrast, with this function, a %FALSE return from * g_file_enumerator_iterate() *always* means * "error". End of iteration is signaled by @out_info or @out_child being %NULL. * * Another crucial difference is that the references for @out_info and * @out_child are owned by @direnum (they are cached as hidden * properties). You must not unref them in your own code. This makes * memory management significantly easier for C code in combination * with loops. * * Finally, this function optionally allows retrieving a #GFile as * well. * * You must specify at least one of @out_info or @out_child. * * The code pattern for correctly using g_file_enumerator_iterate() from C * is: * * |[ * direnum = g_file_enumerate_children (file, ...); * while (TRUE) * { * GFileInfo *info; * if (!g_file_enumerator_iterate (direnum, &info, NULL, cancellable, error)) * goto out; * if (!info) * break; * ... do stuff with "info"; do not unref it! ... * } * * out: * g_object_unref (direnum); // Note: frees the last @info * ]| * * * Since: 2.44 */ gboolean g_file_enumerator_iterate (GFileEnumerator *direnum, GFileInfo **out_info, GFile **out_child, GCancellable *cancellable, GError **error) { gboolean ret = FALSE; GError *temp_error = NULL; GFileInfo *ret_info = NULL; static GQuark cached_info_quark; static GQuark cached_child_quark; static gsize quarks_initialized; g_return_val_if_fail (direnum != NULL, FALSE); g_return_val_if_fail (out_info != NULL || out_child != NULL, FALSE); if (g_once_init_enter (&quarks_initialized)) { cached_info_quark = g_quark_from_static_string ("g-cached-info"); cached_child_quark = g_quark_from_static_string ("g-cached-child"); g_once_init_leave (&quarks_initialized, 1); } ret_info = g_file_enumerator_next_file (direnum, cancellable, &temp_error); if (temp_error != NULL) { g_propagate_error (error, temp_error); goto out; } if (ret_info) { if (out_child != NULL) { const char *name = g_file_info_get_name (ret_info); if (G_UNLIKELY (name == NULL)) g_warning ("g_file_enumerator_iterate() created without standard::name"); else { *out_child = g_file_get_child (g_file_enumerator_get_container (direnum), name); g_object_set_qdata_full ((GObject*)direnum, cached_child_quark, *out_child, (GDestroyNotify)g_object_unref); } } if (out_info != NULL) { g_object_set_qdata_full ((GObject*)direnum, cached_info_quark, ret_info, (GDestroyNotify)g_object_unref); *out_info = ret_info; } else g_object_unref (ret_info); } else { if (out_info) *out_info = NULL; if (out_child) *out_child = NULL; } ret = TRUE; out: return ret; } /** * g_file_enumerator_get_container: * @enumerator: a #GFileEnumerator * * Get the #GFile container which is being enumerated. * * Returns: (transfer none): the #GFile which is being enumerated. * * Since: 2.18 */ GFile * g_file_enumerator_get_container (GFileEnumerator *enumerator) { g_return_val_if_fail (G_IS_FILE_ENUMERATOR (enumerator), NULL); return enumerator->priv->container; } /** * g_file_enumerator_get_child: * @enumerator: a #GFileEnumerator * @info: a #GFileInfo gotten from g_file_enumerator_next_file() * or the async equivalents. * * Return a new #GFile which refers to the file named by @info in the source * directory of @enumerator. This function is primarily intended to be used * inside loops with g_file_enumerator_next_file(). * * This is a convenience method that's equivalent to: * |[ * gchar *name = g_file_info_get_name (info); * GFile *child = g_file_get_child (g_file_enumerator_get_container (enumr), * name); * ]| * * Returns: (transfer full): a #GFile for the #GFileInfo passed it. * * Since: 2.36 */ GFile * g_file_enumerator_get_child (GFileEnumerator *enumerator, GFileInfo *info) { g_return_val_if_fail (G_IS_FILE_ENUMERATOR (enumerator), NULL); return g_file_get_child (enumerator->priv->container, g_file_info_get_name (info)); } static void next_async_op_free (GList *files) { g_list_free_full (files, g_object_unref); } static void next_files_thread (GTask *task, gpointer source_object, gpointer task_data, GCancellable *cancellable) { GFileEnumerator *enumerator = source_object; int num_files = GPOINTER_TO_INT (task_data); GFileEnumeratorClass *class; GList *files = NULL; GError *error = NULL; GFileInfo *info; int i; class = G_FILE_ENUMERATOR_GET_CLASS (enumerator); for (i = 0; i < num_files; i++) { if (g_cancellable_set_error_if_cancelled (cancellable, &error)) info = NULL; else info = class->next_file (enumerator, cancellable, &error); if (info == NULL) { /* If we get an error after first file, return that on next operation */ if (error != NULL && i > 0) { if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED)) g_error_free (error); /* Never propagate cancel errors to other call */ else enumerator->priv->outstanding_error = error; error = NULL; } break; } else files = g_list_prepend (files, info); } if (error) g_task_return_error (task, error); else g_task_return_pointer (task, files, (GDestroyNotify)next_async_op_free); } static void g_file_enumerator_real_next_files_async (GFileEnumerator *enumerator, int num_files, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { GTask *task; task = g_task_new (enumerator, cancellable, callback, user_data); g_task_set_source_tag (task, g_file_enumerator_real_next_files_async); g_task_set_task_data (task, GINT_TO_POINTER (num_files), NULL); g_task_set_priority (task, io_priority); g_task_run_in_thread (task, next_files_thread); g_object_unref (task); } static GList * g_file_enumerator_real_next_files_finish (GFileEnumerator *enumerator, GAsyncResult *result, GError **error) { g_return_val_if_fail (g_task_is_valid (result, enumerator), NULL); return g_task_propagate_pointer (G_TASK (result), error); } static void close_async_thread (GTask *task, gpointer source_object, gpointer task_data, GCancellable *cancellable) { GFileEnumerator *enumerator = source_object; GFileEnumeratorClass *class; GError *error = NULL; gboolean result; class = G_FILE_ENUMERATOR_GET_CLASS (enumerator); result = class->close_fn (enumerator, cancellable, &error); if (result) g_task_return_boolean (task, TRUE); else g_task_return_error (task, error); } static void g_file_enumerator_real_close_async (GFileEnumerator *enumerator, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { GTask *task; task = g_task_new (enumerator, cancellable, callback, user_data); g_task_set_source_tag (task, g_file_enumerator_real_close_async); g_task_set_priority (task, io_priority); g_task_run_in_thread (task, close_async_thread); g_object_unref (task); } static gboolean g_file_enumerator_real_close_finish (GFileEnumerator *enumerator, GAsyncResult *result, GError **error) { g_return_val_if_fail (g_task_is_valid (result, enumerator), FALSE); return g_task_propagate_boolean (G_TASK (result), error); }