Fix memcache.Interface.Get to return a memcache.Item

Fix memcache.Interface.Get to return a memcache.Item

This intentionally doesn't change GetMulti. Since GetMulti is used for batch
operations, it's actually more convenient to have a pipeline of actions (e.g.
AddMulti -> GetMulti). Otherwise you have to carry around a []Item and a
[]string and keep them both in sync (overhead, error prone).

R=dnj@chromium.org, estaab@chromium.org, maruel@chromium.org, tandrii@chromium.org, vadimsh@chromium.org
BUG=https://github.com/luci/gae/issues/3

Committed: https://github.com/luci/gae/commit/7ea0f5dc2195392a7cf840d5bfe59fee239ad7eb

[nodir, 2015-09-19 08:14:29]

nodir@chromium.org changed reviewers:
+ nodir@chromium.org

[nodir, 2015-09-19 08:14:30]

https://codereview.chromium.org/1354333002/diff/1/service/memcache/memcache.go
File service/memcache/memcache.go (right):

https://codereview.chromium.org/1354333002/diff/1/service/memcache/memcache.g...
service/memcache/memcache.go:26: err :=
errors.SingleError(m.GetMulti([]Item{ret}))
what about accepting ...Item in GetMulti?

[iannucci, 2015-09-19 08:39:37]

On 2015/09/19 at 08:14:30, nodir wrote:
> https://codereview.chromium.org/1354333002/diff/1/service/memcache/memcache.go
> File service/memcache/memcache.go (right):
> 
>
https://codereview.chromium.org/1354333002/diff/1/service/memcache/memcache.g...
> service/memcache/memcache.go:26: err :=
errors.SingleError(m.GetMulti([]Item{ret}))
> what about accepting ...Item in GetMulti?

Maybe... but all (2) uses of GetMulti that we have so far work better with an
actual slice. Part of the reason for this is that the returned MultiError
matches the number of entries in the slice, and if you free-hand them with the
... then it would be hard to associate them. Then you end up putting them in a
slice, and now the ... is actually hurting instead of helping :)

[Vadim Sh., 2015-09-19 19:59:37]

lgtm

[iannucci, 2015-09-19 20:03:35]

The CQ bit was checked by iannucci@chromium.org

[commit-bot: I haz the power, 2015-09-19 20:03:39]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1354333002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1354333002/1

[commit-bot: I haz the power, 2015-09-19 20:05:15]

Committed patchset #1 (id:1) as
https://github.com/luci/gae/commit/7ea0f5dc2195392a7cf840d5bfe59fee239ad7eb