/* 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 <alexl@redhat.com>
*/
#include "config.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "gsimpleasyncresult.h"
#include "gasyncresult.h"
#include "gcancellable.h"
#include "gioscheduler.h"
#include <gio/gioerror.h>
#include "glibintl.h"
#include "gioalias.h"
/**
* SECTION:gsimpleasyncresult
* @short_description: Simple asynchronous results implementation
* @include: gio/gio.h
* @see_also: #GAsyncResult
*
* Implements #GAsyncResult for simple cases. Most of the time, this
* will be all an application needs, and will be used transparently.
* Because of this, #GSimpleAsyncResult is used throughout GIO for
* handling asynchronous functions.
*
* GSimpleAsyncResult handles #GAsyncReadyCallback<!-- -->s, error
* reporting, operation cancellation and the final state of an operation,
* completely transparent to the application. Results can be returned
* as a pointer e.g. for functions that return data that is collected
* asynchronously, a boolean value for checking the success or failure
* of an operation, or a #gssize for operations which return the number
* of bytes modified by the operation; all of the simple return cases
* are covered.
*
* Most of the time, an application will not need to know of the details
* of this API; it is handled transparently, and any necessary operations
* are handled by #GAsyncResult's interface. However, if implementing a
* new GIO module, for writing language bindings, or for complex
* applications that need better control of how asynchronous operations
* are completed, it is important to understand this functionality.
*
* GSimpleAsyncResults are tagged with the calling function to ensure
* that asynchronous functions and their finishing functions are used
* together correctly.
*
* To create a new #GSimpleAsyncResult, call g_simple_async_result_new().
* If the result needs to be created for a #GError, use
* g_simple_async_result_new_from_error(). If a #GError is not available
* (e.g. the asynchronous operation's doesn't take a #GError argument),
* but the result still needs to be created for an error condition, use
* g_simple_async_result_new_error() (or g_simple_async_result_set_error_va()
* if your application or binding requires passing a variable argument list
* directly), and the error can then be propegated through the use of
* g_simple_async_result_propagate_error().
*
* An asynchronous operation can be made to ignore a cancellation event by
* calling g_simple_async_result_set_handle_cancellation() with a
* #GSimpleAsyncResult for the operation and %FALSE. This is useful for
* operations that are dangerous to cancel, such as close (which would
* cause a leak if cancelled before being run).
*
* GSimpleAsyncResult can integrate into GLib's event loop, #GMainLoop,
* or it can use #GThread<!-- -->s if available.
* g_simple_async_result_complete() will finish an I/O task directly within
* the main event loop. g_simple_async_result_complete_in_idle() will
* integrate the I/O task into the main event loop as an idle function and
* g_simple_async_result_run_in_thread() will run the job in a separate
* thread.
*
* To set the results of an asynchronous function,
* g_simple_async_result_set_op_res_gpointer(),
* g_simple_async_result_set_op_res_gboolean(), and
* g_simple_async_result_set_op_res_gssize()
* are provided, setting the operation's result to a gpointer, gboolean, or
* gssize, respectively.
*
* Likewise, to get the result of an asynchronous function,
* g_simple_async_result_get_op_res_gpointer(),
* g_simple_async_result_get_op_res_gboolean(), and
* g_simple_async_result_get_op_res_gssize() are
* provided, getting the operation's result as a gpointer, gboolean, and
* gssize, respectively.
**/
static void g_simple_async_result_async_result_iface_init (GAsyncResultIface *iface);
struct _GSimpleAsyncResult
{
GObject parent_instance;
GObject *source_object;
GAsyncReadyCallback callback;
gpointer user_data;
GError *error;
gboolean failed;
gboolean handle_cancellation;
gpointer source_tag;
union {
gpointer v_pointer;
gboolean v_boolean;
gssize v_ssize;
} op_res;
GDestroyNotify destroy_op_res;
};
struct _GSimpleAsyncResultClass
{
GObjectClass parent_class;
};
G_DEFINE_TYPE_WITH_CODE (GSimpleAsyncResult, g_simple_async_result, G_TYPE_OBJECT,
G_IMPLEMENT_INTERFACE (G_TYPE_ASYNC_RESULT,
g_simple_async_result_async_result_iface_init))
static void
g_simple_async_result_finalize (GObject *object)
{
GSimpleAsyncResult *simple;
simple = G_SIMPLE_ASYNC_RESULT (object);
if (simple->source_object)
g_object_unref (simple->source_object);
if (simple->destroy_op_res)
simple->destroy_op_res (simple->op_res.v_pointer);
if (simple->error)
g_error_free (simple->error);
G_OBJECT_CLASS (g_simple_async_result_parent_class)->finalize (object);
}
static void
g_simple_async_result_class_init (GSimpleAsyncResultClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
gobject_class->finalize = g_simple_async_result_finalize;
}
static void
g_simple_async_result_init (GSimpleAsyncResult *simple)
{
simple->handle_cancellation = TRUE;
}
/**
* g_simple_async_result_new:
* @source_object: a #GObject the asynchronous function was called with,
* or %NULL.
* @callback: a #GAsyncReadyCallback.
* @user_data: user data passed to @callback.
* @source_tag: the asynchronous function.
*
* Creates a #GSimpleAsyncResult.
*
* Returns: a #GSimpleAsyncResult.
**/
GSimpleAsyncResult *
g_simple_async_result_new (GObject *source_object,
GAsyncReadyCallback callback,
gpointer user_data,
gpointer source_tag)
{
GSimpleAsyncResult *simple;
g_return_val_if_fail (!source_object || G_IS_OBJECT (source_object), NULL);
simple = g_object_new (G_TYPE_SIMPLE_ASYNC_RESULT, NULL);
simple->callback = callback;
if (source_object)
simple->source_object = g_object_ref (source_object);
else
simple->source_object = NULL;
simple->user_data = user_data;
simple->source_tag = source_tag;
return simple;
}
/**
* g_simple_async_result_new_from_error:
* @source_object: a #GObject, or %NULL.
* @callback: a #GAsyncReadyCallback.
* @user_data: user data passed to @callback.
* @error: a #GError location.
*
* Creates a #GSimpleAsyncResult from an error condition.
*
* Returns: a #GSimpleAsyncResult.
**/
GSimpleAsyncResult *
g_simple_async_result_new_from_error (GObject *source_object,
GAsyncReadyCallback callback,
gpointer user_data,
GError *error)
{
GSimpleAsyncResult *simple;
g_return_val_if_fail (!source_object || G_IS_OBJECT (source_object), NULL);
simple = g_simple_async_result_new (source_object,
callback,
user_data, NULL);
g_simple_async_result_set_from_error (simple, error);
return simple;
}
/**
* g_simple_async_result_new_error:
* @source_object: a #GObject, or %NULL.
* @callback: a #GAsyncReadyCallback.
* @user_data: user data passed to @callback.
* @domain: a #GQuark.
* @code: an error code.
* @format: a string with format characters.
* @...: a list of values to insert into @format.
*
* Creates a new #GSimpleAsyncResult with a set error.
*
* Returns: a #GSimpleAsyncResult.
**/
GSimpleAsyncResult *
g_simple_async_result_new_error (GObject *source_object,
GAsyncReadyCallback callback,
gpointer user_data,
GQuark domain,
gint code,
const char *format,
...)
{
GSimpleAsyncResult *simple;
va_list args;
g_return_val_if_fail (!source_object || G_IS_OBJECT (source_object), NULL);
g_return_val_if_fail (domain != 0, NULL);
g_return_val_if_fail (format != NULL, NULL);
simple = g_simple_async_result_new (source_object,
callback,
user_data, NULL);
va_start (args, format);
g_simple_async_result_set_error_va (simple, domain, code, format, args);
va_end (args);
return simple;
}
static gpointer
g_simple_async_result_get_user_data (GAsyncResult *res)
{
return G_SIMPLE_ASYNC_RESULT (res)->user_data;
}
static GObject *
g_simple_async_result_get_source_object (GAsyncResult *res)
{
if (G_SIMPLE_ASYNC_RESULT (res)->source_object)
return g_object_ref (G_SIMPLE_ASYNC_RESULT (res)->source_object);
return NULL;
}
static void
g_simple_async_result_async_result_iface_init (GAsyncResultIface *iface)
{
iface->get_user_data = g_simple_async_result_get_user_data;
iface->get_source_object = g_simple_async_result_get_source_object;
}
/**
* g_simple_async_result_set_handle_cancellation:
* @simple: a #GSimpleAsyncResult.
* @handle_cancellation: a #gboolean.
*
* Sets whether to handle cancellation within the asynchronous operation.
*
**/
void
g_simple_async_result_set_handle_cancellation (GSimpleAsyncResult *simple,
gboolean handle_cancellation)
{
g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
simple->handle_cancellation = handle_cancellation;
}
/**
* g_simple_async_result_get_source_tag:
* @simple: a #GSimpleAsyncResult.
*
* Gets the source tag for the #GSimpleAsyncResult.
*
* Returns: a #gpointer to the source object for the #GSimpleAsyncResult.
**/
gpointer
g_simple_async_result_get_source_tag (GSimpleAsyncResult *simple)
{
g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple), NULL);
return simple->source_tag;
}
/**
* g_simple_async_result_propagate_error:
* @simple: a #GSimpleAsyncResult.
* @dest: a location to propegate the error to.
*
* Propagates an error from within the simple asynchronous result to
* a given destination.
*
* Returns: %TRUE if the error was propegated to @dest. %FALSE otherwise.
**/
gboolean
g_simple_async_result_propagate_error (GSimpleAsyncResult *simple,
GError **dest)
{
g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple), FALSE);
if (simple->failed)
{
g_propagate_error (dest, simple->error);
simple->error = NULL;
return TRUE;
}
return FALSE;
}
/**
* g_simple_async_result_set_op_res_gpointer:
* @simple: a #GSimpleAsyncResult.
* @op_res: a pointer result from an asynchronous function.
* @destroy_op_res: a #GDestroyNotify function.
*
* Sets the operation result within the asynchronous result to a pointer.
**/
void
g_simple_async_result_set_op_res_gpointer (GSimpleAsyncResult *simple,
gpointer op_res,
GDestroyNotify destroy_op_res)
{
g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
simple->op_res.v_pointer = op_res;
simple->destroy_op_res = destroy_op_res;
}
/**
* g_simple_async_result_get_op_res_gpointer:
* @simple: a #GSimpleAsyncResult.
*
* Gets a pointer result as returned by the asynchronous function.
*
* Returns: a pointer from the result.
**/
gpointer
g_simple_async_result_get_op_res_gpointer (GSimpleAsyncResult *simple)
{
g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple), NULL);
return simple->op_res.v_pointer;
}
/**
* g_simple_async_result_set_op_res_gssize:
* @simple: a #GSimpleAsyncResult.
* @op_res: a #gssize.
*
* Sets the operation result within the asynchronous result to
* the given @op_res.
**/
void
g_simple_async_result_set_op_res_gssize (GSimpleAsyncResult *simple,
gssize op_res)
{
g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
simple->op_res.v_ssize = op_res;
}
/**
* g_simple_async_result_get_op_res_gssize:
* @simple: a #GSimpleAsyncResult.
*
* Gets a gssize from the asynchronous result.
*
* Returns: a gssize returned from the asynchronous function.
**/
gssize
g_simple_async_result_get_op_res_gssize (GSimpleAsyncResult *simple)
{
g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple), 0);
return simple->op_res.v_ssize;
}
/**
* g_simple_async_result_set_op_res_gboolean:
* @simple: a #GSimpleAsyncResult.
* @op_res: a #gboolean.
*
* Sets the operation result to a boolean within the asynchronous result.
**/
void
g_simple_async_result_set_op_res_gboolean (GSimpleAsyncResult *simple,
gboolean op_res)
{
g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
simple->op_res.v_boolean = !!op_res;
}
/**
* g_simple_async_result_get_op_res_gboolean:
* @simple: a #GSimpleAsyncResult.
*
* Gets the operation result boolean from within the asynchronous result.
*
* Returns: %TRUE if the operation's result was %TRUE, %FALSE
* if the operation's result was %FALSE.
**/
gboolean
g_simple_async_result_get_op_res_gboolean (GSimpleAsyncResult *simple)
{
g_return_val_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple), FALSE);
return simple->op_res.v_boolean;
}
/**
* g_simple_async_result_set_from_error:
* @simple: a #GSimpleAsyncResult.
* @error: #GError.
*
* Sets the result from a #GError.
**/
void
g_simple_async_result_set_from_error (GSimpleAsyncResult *simple,
GError *error)
{
g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
g_return_if_fail (error != NULL);
if (simple->error)
g_error_free (simple->error);
simple->error = g_error_copy (error);
simple->failed = TRUE;
}
static GError*
_g_error_new_valist (GQuark domain,
gint code,
const char *format,
va_list args)
{
GError *error;
char *message;
message = g_strdup_vprintf (format, args);
error = g_error_new_literal (domain, code, message);
g_free (message);
return error;
}
/**
* g_simple_async_result_set_error_va:
* @simple: a #GSimpleAsyncResult.
* @domain: a #GQuark (usually #G_IO_ERROR).
* @code: an error code.
* @format: a formatted error reporting string.
* @args: va_list of arguments.
*
* Sets an error within the asynchronous result without a #GError.
* Unless writing a binding, see g_simple_async_result_set_error().
**/
void
g_simple_async_result_set_error_va (GSimpleAsyncResult *simple,
GQuark domain,
gint code,
const char *format,
va_list args)
{
g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
g_return_if_fail (domain != 0);
g_return_if_fail (format != NULL);
if (simple->error)
g_error_free (simple->error);
simple->error = _g_error_new_valist (domain, code, format, args);
simple->failed = TRUE;
}
/**
* g_simple_async_result_set_error:
* @simple: a #GSimpleAsyncResult.
* @domain: a #GQuark (usually #G_IO_ERROR).
* @code: an error code.
* @format: a formatted error reporting string.
* @...: a list of variables to fill in @format.
*
* Sets an error within the asynchronous result without a #GError.
**/
void
g_simple_async_result_set_error (GSimpleAsyncResult *simple,
GQuark domain,
gint code,
const char *format,
...)
{
va_list args;
g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
g_return_if_fail (domain != 0);
g_return_if_fail (format != NULL);
va_start (args, format);
g_simple_async_result_set_error_va (simple, domain, code, format, args);
va_end (args);
}
/**
* g_simple_async_result_complete:
* @simple: a #GSimpleAsyncResult.
*
* Completes an asynchronous I/O job.
* Must be called in the main thread, as it invokes the callback that
* should be called in the main thread. If you are in a different thread
* use g_simple_async_result_complete_in_idle().
**/
void
g_simple_async_result_complete (GSimpleAsyncResult *simple)
{
g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
if (simple->callback)
simple->callback (simple->source_object,
G_ASYNC_RESULT (simple),
simple->user_data);
}
static gboolean
complete_in_idle_cb (gpointer data)
{
GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (data);
g_simple_async_result_complete (simple);
return FALSE;
}
/**
* g_simple_async_result_complete_in_idle:
* @simple: a #GSimpleAsyncResult.
*
* Completes an asynchronous function in the main event loop using
* an idle function.
**/
void
g_simple_async_result_complete_in_idle (GSimpleAsyncResult *simple)
{
GSource *source;
guint id;
g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
g_object_ref (simple);
source = g_idle_source_new ();
g_source_set_priority (source, G_PRIORITY_DEFAULT);
g_source_set_callback (source, complete_in_idle_cb, simple, g_object_unref);
id = g_source_attach (source, NULL);
g_source_unref (source);
}
typedef struct {
GSimpleAsyncResult *simple;
GCancellable *cancellable;
GSimpleAsyncThreadFunc func;
} RunInThreadData;
static gboolean
complete_in_idle_cb_for_thread (gpointer _data)
{
RunInThreadData *data = _data;
GSimpleAsyncResult *simple;
simple = data->simple;
if (simple->handle_cancellation &&
g_cancellable_is_cancelled (data->cancellable))
g_simple_async_result_set_error (simple,
G_IO_ERROR,
G_IO_ERROR_CANCELLED,
"%s", _("Operation was cancelled"));
g_simple_async_result_complete (simple);
if (data->cancellable)
g_object_unref (data->cancellable);
g_object_unref (data->simple);
g_free (data);
return FALSE;
}
static gboolean
run_in_thread (GIOSchedulerJob *job,
GCancellable *c,
gpointer _data)
{
RunInThreadData *data = _data;
GSimpleAsyncResult *simple = data->simple;
GSource *source;
guint id;
if (simple->handle_cancellation &&
g_cancellable_is_cancelled (c))
g_simple_async_result_set_error (simple,
G_IO_ERROR,
G_IO_ERROR_CANCELLED,
"%s", _("Operation was cancelled"));
else
data->func (simple,
simple->source_object,
c);
source = g_idle_source_new ();
g_source_set_priority (source, G_PRIORITY_DEFAULT);
g_source_set_callback (source, complete_in_idle_cb_for_thread, data, NULL);
id = g_source_attach (source, NULL);
g_source_unref (source);
return FALSE;
}
/**
* g_simple_async_result_run_in_thread:
* @simple: a #GSimpleAsyncResult.
* @func: a #GSimpleAsyncThreadFunc.
* @io_priority: the io priority of the request.
* @cancellable: optional #GCancellable object, %NULL to ignore.
*
* Runs the asynchronous job in a separated thread.
**/
void
g_simple_async_result_run_in_thread (GSimpleAsyncResult *simple,
GSimpleAsyncThreadFunc func,
int io_priority,
GCancellable *cancellable)
{
RunInThreadData *data;
g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
g_return_if_fail (func != NULL);
data = g_new (RunInThreadData, 1);
data->func = func;
data->simple = g_object_ref (simple);
data->cancellable = cancellable;
if (cancellable)
g_object_ref (cancellable);
g_io_scheduler_push_job (run_in_thread, data, NULL, io_priority, cancellable);
}
/**
* g_simple_async_result_is_valid:
* @result: the #GAsyncResult passed to the _finish function.
* @source: the #GObject passed to the _finish function.
* @source_tag: the asynchronous function.
*
* Ensures that the data passed to the _finish function of an async
* operation is consistent. Three checks are performed.
*
* First, @result is checked to ensure that it is really a
* #GSimpleAsyncResult. Second, @source is checked to ensure that it
* matches the source object of @result. Third, @source_tag is
* checked to ensure that it is equal to the source_tag argument given
* to g_simple_async_result_new() (which, by convention, is a pointer
* to the _async function corresponding to the _finish function from
* which this function is called).
*
* Returns: #TRUE if all checks passed or #FALSE if any failed.
**/
gboolean
g_simple_async_result_is_valid (GAsyncResult *result,
GObject *source,
gpointer source_tag)
{
GSimpleAsyncResult *simple;
GObject *cmp_source;
if (!G_IS_SIMPLE_ASYNC_RESULT (result))
return FALSE;
simple = (GSimpleAsyncResult *)result;
cmp_source = g_async_result_get_source_object (result);
if (cmp_source != source)
{
g_object_unref (cmp_source);
return FALSE;
}
g_object_unref (cmp_source);
return source_tag == g_simple_async_result_get_source_tag (simple);
}
/**
* g_simple_async_report_error_in_idle:
* @object: a #GObject.
* @callback: a #GAsyncReadyCallback.
* @user_data: user data passed to @callback.
* @domain: a #GQuark containing the error domain (usually #G_IO_ERROR).
* @code: a specific error code.
* @format: a formatted error reporting string.
* @...: a list of variables to fill in @format.
*
* Reports an error in an asynchronous function in an idle function by
* directly setting the contents of the #GAsyncResult with the given error
* information.
**/
void
g_simple_async_report_error_in_idle (GObject *object,
GAsyncReadyCallback callback,
gpointer user_data,
GQuark domain,
gint code,
const char *format,
...)
{
GSimpleAsyncResult *simple;
va_list args;
g_return_if_fail (G_IS_OBJECT (object));
g_return_if_fail (domain != 0);
g_return_if_fail (format != NULL);
simple = g_simple_async_result_new (object,
callback,
user_data, NULL);
va_start (args, format);
g_simple_async_result_set_error_va (simple, domain, code, format, args);
va_end (args);
g_simple_async_result_complete_in_idle (simple);
g_object_unref (simple);
}
/**
* g_simple_async_report_gerror_in_idle:
* @object: a #GObject.
* @callback: a #GAsyncReadyCallback.
* @user_data: user data passed to @callback.
* @error: the #GError to report
*
* Reports an error in an idle function. Similar to
* g_simple_async_report_error_in_idle(), but takes a #GError rather
* than building a new one.
**/
void
g_simple_async_report_gerror_in_idle (GObject *object,
GAsyncReadyCallback callback,
gpointer user_data,
GError *error)
{
GSimpleAsyncResult *simple;
g_return_if_fail (G_IS_OBJECT (object));
g_return_if_fail (error != NULL);
simple = g_simple_async_result_new_from_error (object,
callback,
user_data,
error);
g_simple_async_result_complete_in_idle (simple);
g_object_unref (simple);
}
#define __G_SIMPLE_ASYNC_RESULT_C__
#include "gioaliasdef.c"