/* 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 #include "gfileenumerator.h" #include "gioscheduler.h" #include "gasynchelper.h" #include "gsimpleasyncresult.h" #include "glibintl.h" #include "gioalias.h" /** * 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_file_async(). Note that the asynchronous * version will return a list of #GFileInfos, whereas the * synchronous will only return the next file in the enumerator. * * 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 (GFileEnumerator, g_file_enumerator, G_TYPE_OBJECT); struct _GFileEnumeratorPrivate { /* TODO: Should be public for subclasses? */ guint closed : 1; guint pending : 1; GAsyncReadyCallback outstanding_callback; GError *outstanding_error; }; 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_finalize (GObject *object) { GFileEnumerator *enumerator; enumerator = G_FILE_ENUMERATOR (object); if (!enumerator->priv->closed) g_file_enumerator_close (enumerator, NULL, NULL); if (G_OBJECT_CLASS (g_file_enumerator_parent_class)->finalize) (*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); g_type_class_add_private (klass, sizeof (GFileEnumeratorPrivate)); 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; } static void g_file_enumerator_init (GFileEnumerator *enumerator) { enumerator->priv = G_TYPE_INSTANCE_GET_PRIVATE (enumerator, G_TYPE_FILE_ENUMERATOR, GFileEnumeratorPrivate); } /** * g_file_enumerator_next_file: * @enumerator: a #GFileEnumerator. * @cancellable: optional #GCancellable object, %NULL to ignore. * @error: location to store the error occuring, 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. * * 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. * * Return value: A #GFileInfo or %NULL on error or end of enumerator **/ 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 (error, G_IO_ERROR, G_IO_ERROR_CLOSED, _("Enumerator is closed")); return NULL; } if (enumerator->priv->pending) { g_set_error (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: optional #GCancellable object, %NULL to ignore. * @error: location to store the error occuring, 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. * * Return value: #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 (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 io priority * of the request. * @cancellable: optional #GCancellable object, %NULL to ignore. * @callback: a #GAsyncReadyCallback to call when the request is satisfied * @user_data: 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. * * 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; GSimpleAsyncResult *simple; 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) { simple = g_simple_async_result_new (G_OBJECT (enumerator), callback, user_data, g_file_enumerator_next_files_async); g_simple_async_result_complete_in_idle (simple); g_object_unref (simple); return; } if (enumerator->priv->closed) { g_simple_async_report_error_in_idle (G_OBJECT (enumerator), callback, user_data, G_IO_ERROR, G_IO_ERROR_CLOSED, _("File enumerator is already closed")); return; } if (enumerator->priv->pending) { g_simple_async_report_error_in_idle (G_OBJECT (enumerator), callback, user_data, 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 occuring, or %NULL to * ignore. * * Finishes the asynchronous operation started with g_file_enumerator_next_files_async(). * * Returns: 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; GSimpleAsyncResult *simple; g_return_val_if_fail (G_IS_FILE_ENUMERATOR (enumerator), 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; /* Special case read of 0 files */ if (g_simple_async_result_get_source_tag (simple) == g_file_enumerator_next_files_async) return NULL; } 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 * of the request. * @cancellable: optional #GCancellable object, %NULL to ignore. * @callback: a #GAsyncReadyCallback to call when the request is satisfied * @user_data: 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_simple_async_report_error_in_idle (G_OBJECT (enumerator), callback, user_data, G_IO_ERROR, G_IO_ERROR_CLOSED, _("File enumerator is already closed")); return; } if (enumerator->priv->pending) { g_simple_async_report_error_in_idle (G_OBJECT (enumerator), callback, user_data, 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 occuring, 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) { GSimpleAsyncResult *simple; 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_IS_SIMPLE_ASYNC_RESULT (result)) { simple = G_SIMPLE_ASYNC_RESULT (result); if (g_simple_async_result_propagate_error (simple, error)) return FALSE; } 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; } typedef struct { int num_files; GList *files; } NextAsyncOp; static void next_async_op_free (NextAsyncOp *op) { /* Free the list, if finish wasn't called */ g_list_foreach (op->files, (GFunc)g_object_unref, NULL); g_list_free (op->files); g_free (op); } static void next_files_thread (GSimpleAsyncResult *res, GObject *object, GCancellable *cancellable) { NextAsyncOp *op; GFileEnumeratorClass *class; GError *error = NULL; GFileInfo *info; GFileEnumerator *enumerator; int i; enumerator = G_FILE_ENUMERATOR (object); op = g_simple_async_result_get_op_res_gpointer (res); class = G_FILE_ENUMERATOR_GET_CLASS (object); for (i = 0; i < op->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 (error->domain == G_IO_ERROR && error->code == 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 op->files = g_list_prepend (op->files, info); } } static void g_file_enumerator_real_next_files_async (GFileEnumerator *enumerator, int num_files, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { GSimpleAsyncResult *res; NextAsyncOp *op; op = g_new0 (NextAsyncOp, 1); op->num_files = num_files; op->files = NULL; res = g_simple_async_result_new (G_OBJECT (enumerator), callback, user_data, g_file_enumerator_real_next_files_async); g_simple_async_result_set_op_res_gpointer (res, op, (GDestroyNotify) next_async_op_free); g_simple_async_result_run_in_thread (res, next_files_thread, io_priority, cancellable); g_object_unref (res); } static GList * g_file_enumerator_real_next_files_finish (GFileEnumerator *enumerator, GAsyncResult *result, GError **error) { GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result); NextAsyncOp *op; GList *res; g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_file_enumerator_real_next_files_async); op = g_simple_async_result_get_op_res_gpointer (simple); res = op->files; op->files = NULL; return res; } static void close_async_thread (GSimpleAsyncResult *res, GObject *object, GCancellable *cancellable) { GFileEnumeratorClass *class; GError *error = NULL; gboolean result; /* Auto handling of cancelation disabled, and ignore cancellation, since we want to close things anyway, although possibly in a quick-n-dirty way. At least we never want to leak open handles */ class = G_FILE_ENUMERATOR_GET_CLASS (object); result = class->close_fn (G_FILE_ENUMERATOR (object), cancellable, &error); if (!result) { g_simple_async_result_set_from_error (res, error); g_error_free (error); } } static void g_file_enumerator_real_close_async (GFileEnumerator *enumerator, int io_priority, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { GSimpleAsyncResult *res; res = g_simple_async_result_new (G_OBJECT (enumerator), callback, user_data, g_file_enumerator_real_close_async); g_simple_async_result_set_handle_cancellation (res, FALSE); g_simple_async_result_run_in_thread (res, close_async_thread, io_priority, cancellable); g_object_unref (res); } static gboolean g_file_enumerator_real_close_finish (GFileEnumerator *enumerator, GAsyncResult *result, GError **error) { GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result); g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_file_enumerator_real_close_async); return TRUE; } #define __G_FILE_ENUMERATOR_C__ #include "gioaliasdef.c"