Decide how ElggBatch can handle callbacks that delete rows (Trac #4288)

[elgg-gitbot]

Original ticket http://trac.elgg.org/ticket/4288 on 42028116-10-15 by brettp, assigned to brettp.

Elgg version: 1.8

ElggBatch uses offsets and limits to grab subsets of rows and then passes those rows though a callback. If the callback deletes rows, ElggBatch will never touch some of the rows because of the changing offset.

We need to come up with a way to allow the callback to delete entities.

Part of this fix is to restore elgg_delete_annotations() and elgg_delete_metadata() to using ElggBatch.

See also #4269.

[elgg-gitbot]

brettp wrote on 42039262-10-18

The best idea I have for this right now is to pass a flag to ElggBatch to ignore offset when grabbing chunks of data from the db. Other thoughts?

[elgg-gitbot]

brettp wrote on 42067453-12-03

Current plan is to add an optional argument to the ElggBatch constructor to always force the offset to 0. Does anyone have other ideas?

[elgg-gitbot]

cash wrote on 42067483-01-17

callback doesn't know about ElggBatch. The code that uses ElggBatch doesn't have a chance to rewind between queries. It has to be done by setting a parameter in ElggBatch - either in the constructor or in a setter.

[elgg-gitbot]

trac user Brett Profitt wrote on 42069425-05-17

Fixes #4288. Added setIncrementOffset() to ElggBatch.
Changeset: e2af7b7

[elgg-gitbot]

trac user Brett Profitt wrote on 42088991-01-29

Fixes #4288. Added setIncrementOffset() to ElggBatch.
Changeset: e2af7b7