Add datastore iterating query filter.

Add datastore iterating query filter.

BUG=

Committed: https://github.com/luci/gae/commit/0a4fa8065e6843ebbbca94561b3df42447150ec4

[dnj, 2016-03-31 00:24:44]

dnj@chromium.org changed reviewers:
+ iannucci@chromium.org

[dnj, 2016-03-31 00:24:45]

PTAL

[iannucci, 2016-03-31 22:40:31]

generally lgtm

https://chromiumcodereview.appspot.com/1843313004/diff/20001/filter/dsQueryBa...
File filter/dsQueryBatch/context.go (right):

https://chromiumcodereview.appspot.com/1843313004/diff/20001/filter/dsQueryBa...
filter/dsQueryBatch/context.go:20: // some guarantees afforded to single queries
by the backing implementation.
concise please!

https://chromiumcodereview.appspot.com/1843313004/diff/20001/filter/dsQueryBa...
File filter/dsQueryBatch/filter.go (right):

https://chromiumcodereview.appspot.com/1843313004/diff/20001/filter/dsQueryBa...
filter/dsQueryBatch/filter.go:37: return fmt.Errorf("failed to finalize internal
query: %v", err)
panic: this can't fail if we started with a FinalizedQuery

https://chromiumcodereview.appspot.com/1843313004/diff/20001/filter/dsQueryBa...
filter/dsQueryBatch/filter.go:45: return fmt.Errorf("iterating past batch size")
yeah let's panic here too. maybe more comment explaining that this can only
happen if the underlying implementation improperly ignores Limit.

https://chromiumcodereview.appspot.com/1843313004/diff/20001/filter/dsQueryBa...
filter/dsQueryBatch/filter.go:48: // Call backing iterator.
doesn't need a comment

https://chromiumcodereview.appspot.com/1843313004/diff/20001/filter/dsQueryBa...
filter/dsQueryBatch/filter.go:58: if err != nil {
if cursor, err = .......; .... {

https://chromiumcodereview.appspot.com/1843313004/diff/20001/filter/dsQueryBa...
File filter/dsQueryBatch/filter_test.go (right):

https://chromiumcodereview.appspot.com/1843313004/diff/20001/filter/dsQueryBa...
filter/dsQueryBatch/filter_test.go:59: Convey(`With a limit of 128, will
retrieve 128 items.`, func() {
other tests?
batch 128 limit 127/129
non-even batch size?

[dnj, 2016-03-31 23:54:06]

https://chromiumcodereview.appspot.com/1843313004/diff/20001/filter/dsQueryBa...
File filter/dsQueryBatch/context.go (right):

https://chromiumcodereview.appspot.com/1843313004/diff/20001/filter/dsQueryBa...
filter/dsQueryBatch/context.go:20: // some guarantees afforded to single queries
by the backing implementation.
On 2016/03/31 22:40:30, iannucci wrote:
> concise please!

Done.

https://chromiumcodereview.appspot.com/1843313004/diff/20001/filter/dsQueryBa...
File filter/dsQueryBatch/filter.go (right):

https://chromiumcodereview.appspot.com/1843313004/diff/20001/filter/dsQueryBa...
filter/dsQueryBatch/filter.go:37: return fmt.Errorf("failed to finalize internal
query: %v", err)
On 2016/03/31 22:40:31, iannucci wrote:
> panic: this can't fail if we started with a FinalizedQuery

Done.

https://chromiumcodereview.appspot.com/1843313004/diff/20001/filter/dsQueryBa...
filter/dsQueryBatch/filter.go:45: return fmt.Errorf("iterating past batch size")
On 2016/03/31 22:40:30, iannucci wrote:
> yeah let's panic here too. maybe more comment explaining that this can only
> happen if the underlying implementation improperly ignores Limit.

Done.

https://chromiumcodereview.appspot.com/1843313004/diff/20001/filter/dsQueryBa...
filter/dsQueryBatch/filter.go:48: // Call backing iterator.
On 2016/03/31 22:40:30, iannucci wrote:
> doesn't need a comment

Done.

https://chromiumcodereview.appspot.com/1843313004/diff/20001/filter/dsQueryBa...
File filter/dsQueryBatch/filter_test.go (right):

https://chromiumcodereview.appspot.com/1843313004/diff/20001/filter/dsQueryBa...
filter/dsQueryBatch/filter_test.go:59: Convey(`With a limit of 128, will
retrieve 128 items.`, func() {
On 2016/03/31 22:40:31, iannucci wrote:
> other tests?
> batch 128 limit 127/129
> non-even batch size?

Done.

[dnj, 2016-03-31 23:54:33]

The CQ bit was checked by dnj@chromium.org

[dnj, 2016-03-31 23:54:33]

The patchset sent to the CQ was uploaded after l-g-t-m from
iannucci@chromium.org
Link to the patchset: https://chromiumcodereview.appspot.com/1843313004/#ps40001
(title: "Comments, test edges.")

[commit-bot: I haz the power, 2016-03-31 23:54:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1843313004/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1843313004/40001

[commit-bot: I haz the power, 2016-03-31 23:57:39]

Description was changed from

==========
Add datastore iterating query filter.

BUG=
==========

to

==========
Add datastore iterating query filter.

BUG=

Committed:
https://github.com/luci/gae/commit/0a4fa8065e6843ebbbca94561b3df42447150ec4
==========

[commit-bot: I haz the power, 2016-03-31 23:57:40]

Committed patchset #3 (id:40001) as
https://github.com/luci/gae/commit/0a4fa8065e6843ebbbca94561b3df42447150ec4