[gvfs] dav: Use the native MOVE operation for moving

[Ross Lagerwall <rossl src gnome org>]

commit b4387906ba3d5e73025e19245b5058e0db17c84f
Author: Ross Lagerwall <rosslagerwall gmail com>
Date:   Wed Mar 26 23:04:03 2014 +0000

    dav: Use the native MOVE operation for moving
    
    This saves unnecessary round trips when moving files and directories.
    Based on a patch by Mads Chr. Olesen and the GLocalFile implementation.
    
    Backups are not yet implemented.  It tries to cover the various cases of
    overwriting files with directories and vice versa by doing what
    GLocalFile does.  Notably, webdav servers are capable of overwriting a
    directory with a file which is not a supported operation for
    g_file_move, while at least Apache's mod_dav gives a generic 400 Bad
    Request when trying to overwrite a file with a directory.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=572786

 daemon/gvfsbackenddav.c |  133 +++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 133 insertions(+), 0 deletions(-)
---
diff --git a/daemon/gvfsbackenddav.c b/daemon/gvfsbackenddav.c
index 694c7a6..e74fb25 100644
--- a/daemon/gvfsbackenddav.c
+++ b/daemon/gvfsbackenddav.c
@@ -2696,6 +2696,138 @@ do_set_display_name (GVfsBackend           *backend,
   soup_uri_free (source);
 }
 
+static void
+do_move (GVfsBackend *backend,
+         GVfsJobMove *job,
+         const char *source,
+         const char *destination,
+         GFileCopyFlags flags,
+         GFileProgressCallback progress_callback,
+         gpointer progress_callback_data)
+{
+  SoupMessage *msg;
+  SoupURI *source_uri;
+  SoupURI *target_uri;
+  guint status;
+  GFileType source_ft, target_ft;
+  GError *error = NULL;
+  gboolean res;
+
+  if (flags & G_FILE_COPY_BACKUP)
+    {
+      g_vfs_job_failed_literal (G_VFS_JOB(job),
+                                G_IO_ERROR,
+                                G_IO_ERROR_CANT_CREATE_BACKUP,
+                                _("Backup file creation failed"));
+      return;
+    }
+
+  source_uri = g_vfs_backend_dav_uri_for_path (backend, source, FALSE);
+  msg = soup_message_new_from_uri (SOUP_METHOD_MOVE, source_uri);
+  target_uri = g_vfs_backend_dav_uri_for_path (backend, destination, FALSE);
+
+  res = stat_location (backend, target_uri, &target_ft, NULL, &error);
+  if (!res && !g_error_matches (error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND))
+    {
+      g_vfs_job_failed_from_error (G_VFS_JOB (job), error);
+      g_error_free (error);
+      return;
+    }
+
+  if (res)
+    {
+      if (flags & G_FILE_COPY_OVERWRITE)
+        {
+          res = stat_location (backend, source_uri, &source_ft, NULL, &error);
+          if (res)
+            {
+              if (target_ft == G_FILE_TYPE_DIRECTORY)
+                {
+                  if (source_ft == G_FILE_TYPE_DIRECTORY)
+                    g_vfs_job_failed_literal (G_VFS_JOB(job),
+                                              G_IO_ERROR,
+                                              G_IO_ERROR_WOULD_MERGE,
+                                              _("Can't move directory over directory"));
+                  else
+                    g_vfs_job_failed_literal (G_VFS_JOB(job),
+                                              G_IO_ERROR,
+                                              G_IO_ERROR_IS_DIRECTORY,
+                                              _("Can't move over directory"));
+                  return;
+                }
+              else if (source_ft == G_FILE_TYPE_DIRECTORY)
+                {
+                  /* Overwriting a file with a directory, first remove the
+                   * file */
+                  SoupMessage *msg;
+
+                  msg = soup_message_new_from_uri (SOUP_METHOD_DELETE,
+                                                   target_uri);
+                  status = g_vfs_backend_dav_send_message (backend, msg);
+
+                  if (!SOUP_STATUS_IS_SUCCESSFUL (status))
+                    {
+                      http_job_failed (G_VFS_JOB (job), msg);
+                      g_object_unref (msg);
+                      return;
+                    }
+                  g_object_unref (msg);
+                }
+            }
+          else
+            {
+              g_vfs_job_failed_from_error (G_VFS_JOB (job), error);
+              g_error_free (error);
+              return;
+            }
+        }
+      else
+        {
+          g_vfs_job_failed_literal (G_VFS_JOB(job),
+                                    G_IO_ERROR,
+                                    G_IO_ERROR_EXISTS,
+                                    _("Target file exists"));
+        }
+    }
+
+  message_add_destination_header (msg, target_uri);
+  message_add_overwrite_header (msg, flags & G_FILE_COPY_OVERWRITE);
+
+  status = g_vfs_backend_dav_send_message (backend, msg);
+
+  /*
+   * The precondition of SOUP_STATUS_PRECONDITION_FAILED (412) in
+   * this case was triggered by the "Overwrite: F" header which
+   * means that the target already exists.
+   * Also if we get a REDIRECTION it means that there was no
+   * "Location" header, since otherwise that would have triggered
+   * our redirection handler. This probably means we are dealing
+   * with an web dav implementation (like mod_dav) that also sends
+   * redirects for the destionaion (i.e. "Destination: /foo" header)
+   * which very likely means that the target also exists (and is a
+   * directory). That or the webdav server is broken.
+   * We could find out by doing another stat and but I think this is
+   * such a corner case that we are totally fine with returning
+   * G_IO_ERROR_EXISTS.
+   * */
+
+  if (SOUP_STATUS_IS_SUCCESSFUL (status))
+    {
+      g_vfs_job_succeeded (G_VFS_JOB (job));
+    }
+  else if (status == SOUP_STATUS_PRECONDITION_FAILED ||
+           SOUP_STATUS_IS_REDIRECTION (status))
+    g_vfs_job_failed (G_VFS_JOB (job), G_IO_ERROR,
+                      G_IO_ERROR_EXISTS,
+                      _("Target file already exists"));
+  else
+    http_job_failed (G_VFS_JOB (job), msg);
+
+  g_object_unref (msg);
+  soup_uri_free (source_uri);
+  soup_uri_free (target_uri);
+}
+
 /* ************************************************************************* */
 /*  */
 static void
@@ -2725,4 +2857,5 @@ g_vfs_backend_dav_class_init (GVfsBackendDavClass *klass)
   backend_class->make_directory    = do_make_directory;
   backend_class->delete            = do_delete;
   backend_class->set_display_name  = do_set_display_name;
+  backend_class->move              = do_move;
 }