gio/gpollableoutputstream.h

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright (C) 2010 Red Hat, Inc.
   4  *
   5  * SPDX-License-Identifier: LGPL-2.1-or-later
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General
  18  * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #ifndef __G_POLLABLE_OUTPUT_STREAM_H__
  22 #define __G_POLLABLE_OUTPUT_STREAM_H__
  23
  24 #if !defined (__GIO_GIO_H_INSIDE__) && !defined (GIO_COMPILATION)
  25 #error "Only <gio/gio.h> can be included directly."
  26 #endif
  27
  28 #include <gio/gio.h>
  29
  30 G_BEGIN_DECLS
  31
  32 #define G_TYPE_POLLABLE_OUTPUT_STREAM               (g_pollable_output_stream_get_type ())
  33 #define G_POLLABLE_OUTPUT_STREAM(obj)               (G_TYPE_CHECK_INSTANCE_CAST ((obj), G_TYPE_POLLABLE_OUTPUT_STREAM, GPollableOutputStream))
  34 #define G_IS_POLLABLE_OUTPUT_STREAM(obj)            (G_TYPE_CHECK_INSTANCE_TYPE ((obj), G_TYPE_POLLABLE_OUTPUT_STREAM))
  35 #define G_POLLABLE_OUTPUT_STREAM_GET_INTERFACE(obj) (G_TYPE_INSTANCE_GET_INTERFACE ((obj), G_TYPE_POLLABLE_OUTPUT_STREAM, GPollableOutputStreamInterface))
  36
  37 /**
  38  * GPollableOutputStream:
  39  *
  40  * An interface for a #GOutputStream that can be polled for writeability.
  41  *
  42  * Since: 2.28
  43  */
  44 typedef struct _GPollableOutputStreamInterface GPollableOutputStreamInterface;
  45
  46 /**
  47  * GPollableOutputStreamInterface:
  48  * @g_iface: The parent interface.
  49  * @can_poll: Checks if the #GPollableOutputStream instance is actually pollable
  50  * @is_writable: Checks if the stream is writable
  51  * @create_source: Creates a #GSource to poll the stream
  52  * @write_nonblocking: Does a non-blocking write or returns
  53  *   %G_IO_ERROR_WOULD_BLOCK
  54  * @writev_nonblocking: Does a vectored non-blocking write, or returns
  55  *   %G_POLLABLE_RETURN_WOULD_BLOCK
  56  *
  57  * The interface for pollable output streams.
  58  *
  59  * The default implementation of @can_poll always returns %TRUE.
  60  *
  61  * The default implementation of @write_nonblocking calls
  62  * g_pollable_output_stream_is_writable(), and then calls
  63  * g_output_stream_write() if it returns %TRUE. This means you only
  64  * need to override it if it is possible that your @is_writable
  65  * implementation may return %TRUE when the stream is not actually
  66  * writable.
  67  *
  68  * The default implementation of @writev_nonblocking calls
  69  * g_pollable_output_stream_write_nonblocking() for each vector, and converts
  70  * its return value and error (if set) to a #GPollableReturn. You should
  71  * override this where possible to avoid having to allocate a #GError to return
  72  * %G_IO_ERROR_WOULD_BLOCK.
  73  *
  74  * Since: 2.28
  75  */
  76 struct _GPollableOutputStreamInterface
  77 {
  78   GTypeInterface g_iface;
  79
  80   /* Virtual Table */
  81   gboolean     (*can_poll)          (GPollableOutputStream  *stream);
  82
  83   gboolean     (*is_writable)       (GPollableOutputStream  *stream);
  84   GSource *    (*create_source)     (GPollableOutputStream  *stream,
  85                                      GCancellable           *cancellable);
  86   gssize       (*write_nonblocking) (GPollableOutputStream  *stream,
  87                                      const void             *buffer,
  88                                      gsize                   count,
  89                                      GError                **error);
  90   GPollableReturn (*writev_nonblocking) (GPollableOutputStream  *stream,
  91                                          const GOutputVector    *vectors,
  92                                          gsize                   n_vectors,
  93                                          gsize                  *bytes_written,
  94                                          GError                **error);
  95 };
  96
  97 GIO_AVAILABLE_IN_ALL
  98 GType    g_pollable_output_stream_get_type          (void) G_GNUC_CONST;
  99
 100 GIO_AVAILABLE_IN_ALL
 101 gboolean g_pollable_output_stream_can_poll          (GPollableOutputStream  *stream);
 102
 103 GIO_AVAILABLE_IN_ALL
 104 gboolean g_pollable_output_stream_is_writable       (GPollableOutputStream  *stream);
 105 GIO_AVAILABLE_IN_ALL
 106 GSource *g_pollable_output_stream_create_source     (GPollableOutputStream  *stream,
 107                                                      GCancellable           *cancellable);
 108
 109 GIO_AVAILABLE_IN_ALL
 110 gssize   g_pollable_output_stream_write_nonblocking (GPollableOutputStream  *stream,
 111                                                      const void             *buffer,
 112                                                      gsize                   count,
 113                                                      GCancellable           *cancellable,
 114                                                      GError                **error);
 115
 116 GIO_AVAILABLE_IN_2_60
 117 GPollableReturn g_pollable_output_stream_writev_nonblocking (GPollableOutputStream  *stream,
 118                                                              const GOutputVector    *vectors,
 119                                                              gsize                   n_vectors,
 120                                                              gsize                  *bytes_written,
 121                                                              GCancellable           *cancellable,
 122                                                              GError                **error);
 123
 124 G_END_DECLS
 125
 126
 127 #endif /* __G_POLLABLE_OUTPUT_STREAM_H__ */