[gvfs] dav: Implement truncate for output streams

[Ross Lagerwall <rossl src gnome org>]

commit 686776f1a6f932e7751069715d9693e00f672b5c
Author: Ross Lagerwall <rosslagerwall gmail com>
Date:   Sun Dec 8 22:46:17 2013 +0200

    dav: Implement truncate for output streams
    
    https://bugzilla.gnome.org/show_bug.cgi?id=720062

 daemon/gvfsbackenddav.c |   25 +++++++++++++++++++++++++
 1 files changed, 25 insertions(+), 0 deletions(-)
---
diff --git a/daemon/gvfsbackenddav.c b/daemon/gvfsbackenddav.c
index aed8603..b75ddff 100644
--- a/daemon/gvfsbackenddav.c
+++ b/daemon/gvfsbackenddav.c
@@ -2321,6 +2321,8 @@ try_create_tested_existence (SoupSession *session, SoupMessage *msg,
   g_vfs_job_open_for_write_set_handle (G_VFS_JOB_OPEN_FOR_WRITE (job), stream);
   g_vfs_job_open_for_write_set_can_seek (G_VFS_JOB_OPEN_FOR_WRITE (job),
                                          g_seekable_can_seek (G_SEEKABLE (stream)));
+  g_vfs_job_open_for_write_set_can_truncate (G_VFS_JOB_OPEN_FOR_WRITE (job),
+                                             g_seekable_can_truncate (G_SEEKABLE (stream)));
   g_vfs_job_succeeded (job);
 }  
 
@@ -2365,6 +2367,8 @@ open_for_replace_succeeded (GVfsBackendHttp *op_backend, GVfsJob *job,
   g_vfs_job_open_for_write_set_handle (G_VFS_JOB_OPEN_FOR_WRITE (job), stream);
   g_vfs_job_open_for_write_set_can_seek (G_VFS_JOB_OPEN_FOR_WRITE (job),
                                          g_seekable_can_seek (G_SEEKABLE (stream)));
+  g_vfs_job_open_for_write_set_can_truncate (G_VFS_JOB_OPEN_FOR_WRITE (job),
+                                             g_seekable_can_truncate (G_SEEKABLE (stream)));
   g_vfs_job_succeeded (job);
 }
 
@@ -2513,6 +2517,26 @@ do_seek_on_write (GVfsBackend *backend,
     }
 }
 
+static void
+do_truncate (GVfsBackend *backend,
+             GVfsJobTruncate *job,
+             GVfsBackendHandle handle,
+             goffset size)
+{
+  GSeekable *stream = G_SEEKABLE (handle);
+  GError *error = NULL;
+
+  if (g_seekable_truncate (stream, size, G_VFS_JOB (job)->cancellable, &error))
+    {
+      g_vfs_job_succeeded (G_VFS_JOB (job));
+    }
+  else
+    {
+      g_vfs_job_failed_from_error (G_VFS_JOB (job), error);
+      g_error_free (error);
+    }
+}
+
 /* *** close_write () *** */
 static void
 try_close_write_sent (SoupSession *session,
@@ -2717,6 +2741,7 @@ g_vfs_backend_dav_class_init (GVfsBackendDavClass *klass)
   backend_class->try_replace       = try_replace;
   backend_class->try_write         = try_write;
   backend_class->seek_on_write     = do_seek_on_write;
+  backend_class->truncate          = do_truncate;
   backend_class->try_close_write   = try_close_write;
   backend_class->make_directory    = do_make_directory;
   backend_class->delete            = do_delete;