[glib/glib-2-20] only query file info in g_file_copy() when we need it

[Matthias Clasen <matthiasc src gnome org>]

commit 1feacdd38b347711e9f9459790ded6f987f375cb
Author: Benjamin Otte <otte gnome org>
Date:   Mon Jun 8 15:27:12 2009 +0200

    only query file info in g_file_copy() when we need it
    
    The default implementation of g_file_copy() checked the size of the file
    to copy to give useful progress updates unconditionally. This can cause
    long delays on 1-connection FTP servers while it tries to open a second
    connection before it returns EBUSY. This patch makes this query only
    happen when we actually send progress updates.

 gio/gfile.c |   34 +++++++++++++++++++---------------
 1 files changed, 19 insertions(+), 15 deletions(-)
---
diff --git a/gio/gfile.c b/gio/gfile.c
index 36c66ec..df86364 100644
--- a/gio/gfile.c
+++ b/gio/gfile.c
@@ -2210,28 +2210,32 @@ copy_stream_with_progress (GInputStream           *in,
   GFileInfo *info;
 
   total_size = -1;
-  info = g_file_input_stream_query_info (G_FILE_INPUT_STREAM (in),
-					 G_FILE_ATTRIBUTE_STANDARD_SIZE,
-					 cancellable, NULL);
-  if (info)
-    {
-      if (g_file_info_has_attribute (info, G_FILE_ATTRIBUTE_STANDARD_SIZE))
-        total_size = g_file_info_get_size (info);
-      g_object_unref (info);
-    }
-
-  if (total_size == -1)
+  /* avoid performance impact of querying total size when it's not needed */
+  if (progress_callback)
     {
-      info = g_file_query_info (source, 
-                                G_FILE_ATTRIBUTE_STANDARD_SIZE,
-                                G_FILE_QUERY_INFO_NONE,
-                                cancellable, NULL);
+      info = g_file_input_stream_query_info (G_FILE_INPUT_STREAM (in),
+                                             G_FILE_ATTRIBUTE_STANDARD_SIZE,
+                                             cancellable, NULL);
       if (info)
         {
           if (g_file_info_has_attribute (info, G_FILE_ATTRIBUTE_STANDARD_SIZE))
             total_size = g_file_info_get_size (info);
           g_object_unref (info);
         }
+
+      if (total_size == -1)
+        {
+          info = g_file_query_info (source, 
+                                    G_FILE_ATTRIBUTE_STANDARD_SIZE,
+                                    G_FILE_QUERY_INFO_NONE,
+                                    cancellable, NULL);
+          if (info)
+            {
+              if (g_file_info_has_attribute (info, G_FILE_ATTRIBUTE_STANDARD_SIZE))
+                total_size = g_file_info_get_size (info);
+              g_object_unref (info);
+            }
+        }
     }
 
   if (total_size == -1)