Am 14.07.2011 12:00, schrieb Stefan Hajnoczi: > On Thu, Jul 14, 2011 at 10:55 AM, Kevin Wolf <kw...@redhat.com> wrote: >> Am 14.07.2011 11:39, schrieb Stefan Hajnoczi: >>> Events: >>> >>> On completion the BLOCK_STREAM_COMPLETED event is raised with the following >>> fields: >>> >>> - device: device name (json-string) >>> - len: size of the device, in bytes (json-int) >>> - offset: last offset of completed I/O, in bytes (json-int) >>> - error: error message (json-string, only on error) >>> >>> The completion event is raised both on success and on failure. >> >> Why do len/offset matter in a completion event? > > For completeness. You could see it as telling you how much progress > was made before an error occurred. In the success case offset will > always be equal to len. But in the error case you get the last > completed progress before error, which could be useful (for example if > you weren't polling but want to display "Streaming virtio-blk0 failed > at 33%").
Makes sense. We also need to define the possible error messages, and probably use an enum instead of a string. Kevin
