[tahoe-lafs-trac-stream] [Tahoe-LAFS] #1518: zero-byte MDMF reads should not fetch any segments

[Tahoe-LAFS]

#1518: zero-byte MDMF reads should not fetch any segments
------------------------------+-------------------------------------------
     Reporter:  warner        |      Owner:
         Type:  defect        |     Status:  new
     Priority:  minor         |  Milestone:  eventually
    Component:  code-mutable  |    Version:  1.9.0a1
   Resolution:                |   Keywords:  mutable mdmf performance easy
Launchpad Bug:                |
------------------------------+-------------------------------------------

Old description:

> A minor leftover from #1512 is a low-yield performance improvement: if
> somebody does a zero-byte read, the code should return without actually
> fetching any segments. The current code (as of
> [changeset:32e30c9023479e3c]) fetches the first segment, then throws away
> all of its data.
>
> This ought to be a two-liner: it's probably enough to return
> {{{defer.succeed(something)}}} without ever even talking to the
> {{{IConsumer}}}.

New description:

 A minor leftover from #1512 is a low-yield performance improvement: if
 somebody does a zero-byte read, the code should return without actually
 fetching any segments. The current code (as of
 [changeset:32e30c9023479e3c]) fetches the first segment, then throws away
 all of its data.

 This ought to be a two-liner: it's probably enough to return
 {{{defer.succeed(something)}}} without ever even talking to the
 {{{IConsumer}}}.

--

Comment (by warner):

 I *think* I might have fixed this in [89e9076c4], but it needs closer
 examination to be sure.

--
Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1518#comment:1>
Tahoe-LAFS <https://Tahoe-LAFS.org>
secure decentralized storage