gio/gpollableoutputstream.h

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright (C) 2010 Red Hat, Inc.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2.1 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General
  16  * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #ifndef __G_POLLABLE_OUTPUT_STREAM_H__
  20 #define __G_POLLABLE_OUTPUT_STREAM_H__
  21
  22 #if !defined (__GIO_GIO_H_INSIDE__) && !defined (GIO_COMPILATION)
  23 #error "Only <gio/gio.h> can be included directly."
  24 #endif
  25
  26 #include <gio/gio.h>
  27
  28 G_BEGIN_DECLS
  29
  30 #define G_TYPE_POLLABLE_OUTPUT_STREAM               (g_pollable_output_stream_get_type ())
  31 #define G_POLLABLE_OUTPUT_STREAM(obj)               (G_TYPE_CHECK_INSTANCE_CAST ((obj), G_TYPE_POLLABLE_OUTPUT_STREAM, GPollableOutputStream))
  32 #define G_IS_POLLABLE_OUTPUT_STREAM(obj)            (G_TYPE_CHECK_INSTANCE_TYPE ((obj), G_TYPE_POLLABLE_OUTPUT_STREAM))
  33 #define G_POLLABLE_OUTPUT_STREAM_GET_INTERFACE(obj) (G_TYPE_INSTANCE_GET_INTERFACE ((obj), G_TYPE_POLLABLE_OUTPUT_STREAM, GPollableOutputStreamInterface))
  34
  35 /**
  36  * GPollableOutputStream:
  37  *
  38  * An interface for a #GOutputStream that can be polled for writeability.
  39  *
  40  * Since: 2.28
  41  */
  42 typedef struct _GPollableOutputStreamInterface GPollableOutputStreamInterface;
  43
  44 /**
  45  * GPollableOutputStreamInterface:
  46  * @g_iface: The parent interface.
  47  * @can_poll: Checks if the #GPollableOutputStream instance is actually pollable
  48  * @is_writable: Checks if the stream is writable
  49  * @create_source: Creates a #GSource to poll the stream
  50  * @write_nonblocking: Does a non-blocking write or returns
  51  *   %G_IO_ERROR_WOULD_BLOCK
  52  * @writev_nonblocking: Does a vectored non-blocking write, or returns
  53  *   %G_POLLABLE_RETURN_WOULD_BLOCK
  54  *
  55  * The interface for pollable output streams.
  56  *
  57  * The default implementation of @can_poll always returns %TRUE.
  58  *
  59  * The default implementation of @write_nonblocking calls
  60  * g_pollable_output_stream_is_writable(), and then calls
  61  * g_output_stream_write() if it returns %TRUE. This means you only
  62  * need to override it if it is possible that your @is_writable
  63  * implementation may return %TRUE when the stream is not actually
  64  * writable.
  65  *
  66  * The default implementation of @writev_nonblocking calls
  67  * g_pollable_output_stream_write_nonblocking() for each vector, and converts
  68  * its return value and error (if set) to a #GPollableReturn. You should
  69  * override this where possible to avoid having to allocate a #GError to return
  70  * %G_IO_ERROR_WOULD_BLOCK.
  71  *
  72  * Since: 2.28
  73  */
  74 struct _GPollableOutputStreamInterface
  75 {
  76   GTypeInterface g_iface;
  77
  78   /* Virtual Table */
  79   gboolean     (*can_poll)          (GPollableOutputStream  *stream);
  80
  81   gboolean     (*is_writable)       (GPollableOutputStream  *stream);
  82   GSource *    (*create_source)     (GPollableOutputStream  *stream,
  83                                      GCancellable           *cancellable);
  84   gssize       (*write_nonblocking) (GPollableOutputStream  *stream,
  85                                      const void             *buffer,
  86                                      gsize                   count,
  87                                      GError                **error);
  88   GPollableReturn (*writev_nonblocking) (GPollableOutputStream  *stream,
  89                                          const GOutputVector    *vectors,
  90                                          gsize                   n_vectors,
  91                                          gsize                  *bytes_written,
  92                                          GError                **error);
  93 };
  94
  95 GLIB_AVAILABLE_IN_ALL
  96 GType    g_pollable_output_stream_get_type          (void) G_GNUC_CONST;
  97
  98 GLIB_AVAILABLE_IN_ALL
  99 gboolean g_pollable_output_stream_can_poll          (GPollableOutputStream  *stream);
 100
 101 GLIB_AVAILABLE_IN_ALL
 102 gboolean g_pollable_output_stream_is_writable       (GPollableOutputStream  *stream);
 103 GLIB_AVAILABLE_IN_ALL
 104 GSource *g_pollable_output_stream_create_source     (GPollableOutputStream  *stream,
 105                                                      GCancellable           *cancellable);
 106
 107 GLIB_AVAILABLE_IN_ALL
 108 gssize   g_pollable_output_stream_write_nonblocking (GPollableOutputStream  *stream,
 109                                                      const void             *buffer,
 110                                                      gsize                   count,
 111                                                      GCancellable           *cancellable,
 112                                                      GError                **error);
 113
 114 GLIB_AVAILABLE_IN_2_60
 115 GPollableReturn g_pollable_output_stream_writev_nonblocking (GPollableOutputStream  *stream,
 116                                                              const GOutputVector    *vectors,
 117                                                              gsize                   n_vectors,
 118                                                              gsize                  *bytes_written,
 119                                                              GCancellable           *cancellable,
 120                                                              GError                **error);
 121
 122 G_END_DECLS
 123
 124
 125 #endif /* __G_POLLABLE_OUTPUT_STREAM_H__ */