func (*fileSuite) TestMoveFile(c *gc.C) {
d := c.MkDir()
dest := filepath.Join(d, "foo")
f1Name := filepath.Join(d, ".foo1")
f2Name := filepath.Join(d, ".foo2")
err := ioutil.WriteFile(f1Name, []byte("macaroni"), 0644)
c.Assert(err, gc.IsNil)
err = ioutil.WriteFile(f2Name, []byte("cheese"), 0644)
c.Assert(err, gc.IsNil)
ok, err := utils.MoveFile(f1Name, dest)
c.Assert(ok, gc.Equals, true)
c.Assert(err, gc.IsNil)
ok, err = utils.MoveFile(f2Name, dest)
c.Assert(ok, gc.Equals, false)
c.Assert(err, gc.NotNil)
contents, err := ioutil.ReadFile(dest)
c.Assert(err, gc.IsNil)
c.Assert(contents, gc.DeepEquals, []byte("macaroni"))
}
// Close implements io.Closer.
func (f *metricFile) Close() error {
err := f.File.Close()
if err != nil {
return errors.Trace(err)
}
ok, err := utils.MoveFile(f.Name(), f.finalName)
if err != nil {
// ok can be true even when there is an error completing the move, on
// platforms that implement it in multiple steps that can fail
// separately. POSIX for example, uses link(2) to claim the new
// location atomically, followed by an unlink(2) to release the old
// location.
if !ok {
return errors.Trace(err)
}
logger.Errorf("failed to remove temporary file %q: %v", f.Name(), err)
}
return nil
}