Disable hierarchy pruning as costing option

[nilsnolde]

As agreed on in #3851 , we should add a costing option to disable hierarchy pruning. It's fairly easy:

• add a max_distance_disable_hierarchy_culling (long, but exact) to the JSON config generator under service_limits and default to 0
• add a max_distance_disable_hierarchy_culling to thor/worker.h and assign in thor/worker.cc when parsing the config JSON
• add a disable_hierarchy_pruning (?) to the costing options
• somewhere we'll need to check that the arc distance(s) between locations are not above the max_distance_disable_hierarchy_culling config option. IMO we can add a function to thor_worker_t which the actions, which should support this, can call it. I think it doesn't make sense for isochrones, since the algo doesn't use hierarchy limits, and for matrix we can call that new thor_worker_t method on all source/target pairs. That new function should set the disable_hierarchy_pruning costing option to false. That makes me think.. Maybe we shouldn't do this check at all in thor, but rather in loki, that's where most config & distance checks are done. Then you can safely simply replace thor with loki in the above description everywhere. What do you think @kevinkreiser @dnesbitt61 ?
• parse the disable_hierarchy_pruning costing option in DynamicCost::ParseBaseCostOptions and set all max_up_transitions to kUnlimitedTransitions if the value is true

Then the routing algorithms don't cull down transitions anymore, which will be kinda disastrous for longer routes (hence the JSON config option, actually pretty much overlapping with the max_distance service limit for bike/ped). And when used with shortest: true it'd return a true shortest route for drive types. In fact, I just realized that isochrones always returned true shortest, since there isn't any hierarchy limits at play, interesting..

[vesperlou]

Hi Nils, this is Junzhen. I think I am capable of solving this issue. Could you please assign this issue to me? Thanks.

[kevinkreiser]

@vesperlou thanks for volunteering, let us know if you need any help apart from the excellent description