Improve the g_file_make_symbolic_link docs
[platform/upstream/glib.git] / gio / gfileinputstream.c
index 0d52cf9..502584b 100644 (file)
  * Author: Alexander Larsson <alexl@redhat.com>
  */
 
-#include <config.h>
+#include "config.h"
 
 #include <glib.h>
 #include <gfileinputstream.h>
 #include <gseekable.h>
 #include "gsimpleasyncresult.h"
+#include "gcancellable.h"
+#include "gasyncresult.h"
+#include "gioerror.h"
 #include "glibintl.h"
 
 #include "gioalias.h"
 
 /**
  * SECTION:gfileinputstream
- * @short_description: file input streaming operations
+ * @short_description: File input streaming operations
+ * @include: gio/gio.h
  * @see_also: #GInputStream, #GDataInputStream, #GSeekable
- * 
- * 
  *
+ * GFileInputStream provides input streams that take their
+ * content from a file.
+ *
+ * GFileInputStream implements #GSeekable, which allows the input 
+ * stream to jump to arbitrary positions in the file, provided the 
+ * filesystem of the file allows it. To find the position of a file
+ * input stream, use g_seekable_tell(). To find out if a file input
+ * stream supports seeking, use g_seekable_stream_can_seek().
+ * To position a file input stream, use g_seekable_seek().
  **/
 
 static void       g_file_input_stream_seekable_iface_init    (GSeekableIface       *iface);
@@ -53,7 +64,7 @@ static gboolean   g_file_input_stream_seekable_truncate      (GSeekable
                                                              GCancellable         *cancellable,
                                                              GError              **error);
 static void       g_file_input_stream_real_query_info_async  (GFileInputStream     *stream,
-                                                             char                 *attributes,
+                                                             const char           *attributes,
                                                              int                   io_priority,
                                                              GCancellable         *cancellable,
                                                              GAsyncReadyCallback   callback,
@@ -87,7 +98,7 @@ g_file_input_stream_seekable_iface_init (GSeekableIface *iface)
   iface->can_seek = g_file_input_stream_seekable_can_seek;
   iface->seek = g_file_input_stream_seekable_seek;
   iface->can_truncate = g_file_input_stream_seekable_can_truncate;
-  iface->truncate = g_file_input_stream_seekable_truncate;
+  iface->truncate_fn = g_file_input_stream_seekable_truncate;
 }
 
 static void
@@ -106,19 +117,19 @@ g_file_input_stream_init (GFileInputStream *stream)
  * @error: a #GError location to store the error occuring, or %NULL to 
  * ignore.
  *
- * Queries a file input stream the given @attributes.his function blocks while querying
- * the stream. For the asynchronous (non-blocking) version of this function, see 
- * g_file_input_stream_query_info_async(). While the stream is blocked, 
- * the stream will set the pending flag internally, and any other operations on the 
- * stream will fail with %G_IO_ERROR_PENDING.
+ * Queries a file input stream the given @attributes. This function blocks 
+ * while querying the stream. For the asynchronous (non-blocking) version 
+ * of this function, see g_file_input_stream_query_info_async(). While the 
+ * stream is blocked, the stream will set the pending flag internally, and 
+ * any other operations on the stream will fail with %G_IO_ERROR_PENDING.
  *
  * Returns: a #GFileInfo, or %NULL on error.
  **/
 GFileInfo *
-g_file_input_stream_query_info (GFileInputStream     *stream,
-                                  char                 *attributes,
-                                  GCancellable         *cancellable,
-                                  GError              **error)
+g_file_input_stream_query_info (GFileInputStream  *stream,
+                                const char        *attributes,
+                                GCancellable      *cancellable,
+                                GError           **error)
 {
   GFileInputStreamClass *class;
   GInputStream *input_stream;
@@ -128,50 +139,37 @@ g_file_input_stream_query_info (GFileInputStream     *stream,
   
   input_stream = G_INPUT_STREAM (stream);
   
-  if (g_input_stream_is_closed (input_stream))
-    {
-      g_set_error (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
-                  _("Stream is already closed"));
-      return NULL;
-    }
-  
-  if (g_input_stream_has_pending (input_stream))
-    {
-      g_set_error (error, G_IO_ERROR, G_IO_ERROR_PENDING,
-                  _("Stream has outstanding operation"));
-      return NULL;
-    }
+  if (!g_input_stream_set_pending (input_stream, error))
+    return NULL;
       
   info = NULL;
   
-  g_input_stream_set_pending (input_stream, TRUE);
-
   if (cancellable)
-    g_push_current_cancellable (cancellable);
+    g_cancellable_push_current (cancellable);
   
   class = G_FILE_INPUT_STREAM_GET_CLASS (stream);
   if (class->query_info)
     info = class->query_info (stream, attributes, cancellable, error);
   else
-    g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
-                _("Stream doesn't support query_info"));
+    g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
+                         _("Stream doesn't support query_info"));
 
   if (cancellable)
-    g_pop_current_cancellable (cancellable);
+    g_cancellable_pop_current (cancellable);
   
-  g_input_stream_set_pending (input_stream, FALSE);
+  g_input_stream_clear_pending (input_stream);
   
   return info;
 }
 
 static void
-async_ready_callback_wrapper (GObject *source_object,
-                             GAsyncResult *res,
-                             gpointer      user_data)
+async_ready_callback_wrapper (GObject      *source_object,
+                              GAsyncResult *res,
+                              gpointer      user_data)
 {
   GFileInputStream *stream = G_FILE_INPUT_STREAM (source_object);
 
-  g_input_stream_set_pending (G_INPUT_STREAM (stream), FALSE);
+  g_input_stream_clear_pending (G_INPUT_STREAM (stream));
   if (stream->priv->outstanding_callback)
     (*stream->priv->outstanding_callback) (source_object, res, user_data);
   g_object_unref (stream);
@@ -181,13 +179,19 @@ async_ready_callback_wrapper (GObject *source_object,
  * g_file_input_stream_query_info_async:
  * @stream: a #GFileInputStream.
  * @attributes: a file attribute query string.
- * @io_priority: the i/o priority of the request.
+ * @io_priority: the <link linkend="io-priority">I/O priority</link> 
+ *     of the request.
  * @cancellable: optional #GCancellable object, %NULL to ignore. 
  * @callback: callback to call when the request is satisfied
  * @user_data: the data to pass to callback function
  * 
- * Queries the stream information asynchronously. For the synchronous version
- * of this function, see g_file_input_stream_query_info(). 
+ * Queries the stream information asynchronously.
+ * When the operation is finished @callback will be called. 
+ * You can then call g_file_input_stream_query_info_finish() 
+ * to get the result of the operation.
+ *
+ * For the synchronous version of this function, 
+ * see g_file_input_stream_query_info(). 
  * 
  * If @cancellable is not %NULL, then the operation can be cancelled by
  * triggering the cancellable object from another thread. If the operation
@@ -195,43 +199,33 @@ async_ready_callback_wrapper (GObject *source_object,
  *  
  **/
 void
-g_file_input_stream_query_info_async (GFileInputStream     *stream,
-                                        char                 *attributes,
-                                        int                   io_priority,
-                                        GCancellable         *cancellable,
-                                        GAsyncReadyCallback   callback,
-                                        gpointer              user_data)
+g_file_input_stream_query_info_async (GFileInputStream    *stream,
+                                      const char          *attributes,
+                                      int                  io_priority,
+                                      GCancellable        *cancellable,
+                                      GAsyncReadyCallback  callback,
+                                      gpointer             user_data)
 {
   GFileInputStreamClass *klass;
   GInputStream *input_stream;
+  GError *error = NULL;
 
   g_return_if_fail (G_IS_FILE_INPUT_STREAM (stream));
 
   input_stream = G_INPUT_STREAM (stream);
-  if (g_input_stream_is_closed (input_stream))
-    {
-      g_simple_async_report_error_in_idle (G_OBJECT (stream),
-                                          callback,
-                                          user_data,
-                                          G_IO_ERROR, G_IO_ERROR_CLOSED,
-                                          _("Stream is already closed"));
-      return;
-    }
   
-  if (g_input_stream_has_pending (input_stream))
+  if (!g_input_stream_set_pending (input_stream, &error))
     {
-      g_simple_async_report_error_in_idle (G_OBJECT (stream),
-                                          callback,
-                                          user_data,
-                                          G_IO_ERROR, G_IO_ERROR_PENDING,
-                                          _("Stream has outstanding operation"));
+      g_simple_async_report_gerror_in_idle (G_OBJECT (stream),
+                                           callback,
+                                           user_data,
+                                           error);
+      g_error_free (error);
       return;
     }
 
   klass = G_FILE_INPUT_STREAM_GET_CLASS (stream);
 
-  g_input_stream_set_pending (input_stream, TRUE);
   stream->priv->outstanding_callback = callback;
   g_object_ref (stream);
   klass->query_info_async (stream, attributes, io_priority, cancellable,
@@ -242,17 +236,17 @@ g_file_input_stream_query_info_async (GFileInputStream     *stream,
  * g_file_input_stream_query_info_finish:
  * @stream: a #GFileInputStream.
  * @result: a #GAsyncResult.
- * @error: a #GError location to store the error occuring, or %NULL to 
- * ignore.
+ * @error: a #GError location to store the error occuring, 
+ *     or %NULL to ignore.
  * 
  * Finishes an asynchronous info query operation.
  * 
  * Returns: #GFileInfo. 
  **/
 GFileInfo *
-g_file_input_stream_query_info_finish (GFileInputStream     *stream,
-                                         GAsyncResult         *result,
-                                         GError              **error)
+g_file_input_stream_query_info_finish (GFileInputStream  *stream,
+                                       GAsyncResult      *result,
+                                       GError           **error)
 {
   GSimpleAsyncResult *simple;
   GFileInputStreamClass *class;
@@ -271,16 +265,8 @@ g_file_input_stream_query_info_finish (GFileInputStream     *stream,
   return class->query_info_finish (stream, result, error);
 }
 
-/**
- * g_file_input_stream_tell:
- * @stream: a #GFileInputStream.
- * 
- * Gets the current position in the stream.
- * 
- * Returns: a #goffset with the position in the stream.
- **/
-goffset
-g_file_input_stream_tell (GFileInputStream  *stream)
+static goffset
+g_file_input_stream_tell (GFileInputStream *stream)
 {
   GFileInputStreamClass *class;
   goffset offset;
@@ -302,16 +288,8 @@ g_file_input_stream_seekable_tell (GSeekable *seekable)
   return g_file_input_stream_tell (G_FILE_INPUT_STREAM (seekable));
 }
 
-/**
- * g_file_input_stream_can_seek:
- * @stream: a #GFileInputStream.
- * 
- * Checks if a file input stream can be seeked.
- * 
- * Returns: %TRUE if stream can be seeked. %FALSE otherwise.
- **/
-gboolean
-g_file_input_stream_can_seek (GFileInputStream  *stream)
+static gboolean
+g_file_input_stream_can_seek (GFileInputStream *stream)
 {
   GFileInputStreamClass *class;
   gboolean can_seek;
@@ -337,25 +315,7 @@ g_file_input_stream_seekable_can_seek (GSeekable *seekable)
   return g_file_input_stream_can_seek (G_FILE_INPUT_STREAM (seekable));
 }
 
-/**
- * g_file_input_stream_seek:
- * @stream: a #GFileInputStream.
- * @offset: a #goffset to seek.
- * @type: a #GSeekType.
- * @cancellable: optional #GCancellable object, %NULL to ignore. 
- * @error: a #GError location to store the error occuring, or %NULL to 
- * ignore.
- * 
- * Seeks in the file input stream.
- * 
- * 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 set.
- * 
- * Returns: %TRUE if the stream was successfully seeked to the position.
- * %FALSE on error.
- **/
-gboolean
+static gboolean
 g_file_input_stream_seek (GFileInputStream  *stream,
                          goffset            offset,
                          GSeekType          type,
@@ -371,67 +331,54 @@ g_file_input_stream_seek (GFileInputStream  *stream,
   input_stream = G_INPUT_STREAM (stream);
   class = G_FILE_INPUT_STREAM_GET_CLASS (stream);
 
-  if (g_input_stream_is_closed (input_stream))
-    {
-      g_set_error (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
-                  _("Stream is already closed"));
-      return FALSE;
-    }
-  
-  if (g_input_stream_has_pending (input_stream))
-    {
-      g_set_error (error, G_IO_ERROR, G_IO_ERROR_PENDING,
-                  _("Stream has outstanding operation"));
-      return FALSE;
-    }
-  
   if (!class->seek)
     {
-      g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
-                  _("Seek not supported on stream"));
+      g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
+                           _("Seek not supported on stream"));
       return FALSE;
     }
 
-  g_input_stream_set_pending (input_stream, TRUE);
+  if (!g_input_stream_set_pending (input_stream, error))
+    return FALSE;
   
   if (cancellable)
-    g_push_current_cancellable (cancellable);
+    g_cancellable_push_current (cancellable);
   
   res = class->seek (stream, offset, type, cancellable, error);
   
   if (cancellable)
-    g_pop_current_cancellable (cancellable);
+    g_cancellable_pop_current (cancellable);
 
-  g_input_stream_set_pending (input_stream, FALSE);
+  g_input_stream_clear_pending (input_stream);
   
   return res;
 }
 
 static gboolean
-g_file_input_stream_seekable_seek (GSeekable  *seekable,
-                                  goffset     offset,
-                                  GSeekType   type,
+g_file_input_stream_seekable_seek (GSeekable     *seekable,
+                                  goffset        offset,
+                                  GSeekType      type,
                                   GCancellable  *cancellable,
-                                  GError    **error)
+                                  GError       **error)
 {
   return g_file_input_stream_seek (G_FILE_INPUT_STREAM (seekable),
                                   offset, type, cancellable, error);
 }
 
 static gboolean
-g_file_input_stream_seekable_can_truncate (GSeekable  *seekable)
+g_file_input_stream_seekable_can_truncate (GSeekable *seekable)
 {
   return FALSE;
 }
 
 static gboolean
-g_file_input_stream_seekable_truncate (GSeekable  *seekable,
-                                      goffset     offset,
+g_file_input_stream_seekable_truncate (GSeekable     *seekable,
+                                      goffset        offset,
                                       GCancellable  *cancellable,
-                                      GError    **error)
+                                      GError       **error)
 {
-  g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
-              _("Truncate not allowed on input stream"));
+  g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
+                       _("Truncate not allowed on input stream"));
   return FALSE;
 }
 
@@ -455,8 +402,8 @@ query_info_data_free (QueryInfoAsyncData *data)
 
 static void
 query_info_async_thread (GSimpleAsyncResult *res,
-                      GObject *object,
-                      GCancellable *cancellable)
+                        GObject            *object,
+                        GCancellable       *cancellable)
 {
   GFileInputStreamClass *class;
   GError *error = NULL;
@@ -471,8 +418,8 @@ query_info_async_thread (GSimpleAsyncResult *res,
   if (class->query_info)
     info = class->query_info (G_FILE_INPUT_STREAM (object), data->attributes, cancellable, &error);
   else
-    g_set_error (&error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
-                _("Stream doesn't support query_info"));
+    g_set_error_literal (&error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
+                         _("Stream doesn't support query_info"));
 
   if (info == NULL)
     {
@@ -484,12 +431,12 @@ query_info_async_thread (GSimpleAsyncResult *res,
 }
 
 static void
-g_file_input_stream_real_query_info_async (GFileInputStream     *stream,
-                                             char                 *attributes,
-                                             int                   io_priority,
-                                             GCancellable         *cancellable,
-                                             GAsyncReadyCallback   callback,
-                                             gpointer              user_data)
+g_file_input_stream_real_query_info_async (GFileInputStream    *stream,
+                                           const char          *attributes,
+                                           int                  io_priority,
+                                           GCancellable        *cancellable,
+                                           GAsyncReadyCallback  callback,
+                                           gpointer             user_data)
 {
   GSimpleAsyncResult *res;
   QueryInfoAsyncData *data;
@@ -505,14 +452,14 @@ g_file_input_stream_real_query_info_async (GFileInputStream     *stream,
 }
 
 static GFileInfo *
-g_file_input_stream_real_query_info_finish (GFileInputStream     *stream,
-                                              GAsyncResult         *res,
-                                              GError              **error)
+g_file_input_stream_real_query_info_finish (GFileInputStream  *stream,
+                                            GAsyncResult      *res,
+                                            GError           **error)
 {
   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (res);
   QueryInfoAsyncData *data;
 
-  g_assert (g_simple_async_result_get_source_tag (simple) == g_file_input_stream_real_query_info_async);
+  g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == g_file_input_stream_real_query_info_async);
 
   data = g_simple_async_result_get_op_res_gpointer (simple);
   if (data->info)