The change clarifies the conditions for forcing routing steps and
simplifies the codebase to support it.
- Makes explicity the search runtime condition for forcing a routing
step. Namely, the node is a source of the forward and reverse searches,
and it's one of the pre-identified nodes that requires a step to
be forced.
- Consolidate the two lists of force nodes into one. Not only is there
no algorithmic value in separating the nodes by geometric direction,
the improvements to via-routes with u-turns mean atleast one of these
lists will be empty for any search.
- Rename 'force loop' to 'force step'. This moves the code away
from the original CH-specific language for checking for self-loops
in the case where this condition is met. MLD does not have loops.
Additional cucumber tests are added to cover the logic related to
negative search weights and forcing routing steps on via-route
paths.
This change takes the existing typedefs for weight, duration and
distance, and makes them proper types, using the existing Alias
functionality.
Primarily this is to prevent bugs where the metrics are switched,
but it also adds additional documentation. For example, it now
makes it clear (despite the naming of variables) that most of the
trip algorithm is running on the duration metric.
I've not made any changes to the casts performed between metrics
and numeric types, they now just more explicit.
This PR improves routing results by adding support for snapping to
multiple ways at input locations.
This means all edges at the snapped location can act as source/target
candidates for routing search, ensuring we always find the best route,
and not the one dependent on the edge selected.
In situations where there is not a valid source or target phantom
node (e.g. when snapping to an edge with a zero weight), a
heap assertion will fail in the MLD alternative search code.
We fix this by checking for empty heaps before proceeding with
the search.
For the MLD algorithm we can partition the NodeID range into boundary
and non-boundary nodes. Since there are only we boundary nodes we can
use the ArrayStorage for those yielding much faster query times.
Rename module partition to partitioner.
This cultivates naming used in existing modules like extractor,
customizer, etc. - noun vs verb (word partition is both though).
The viaroute plugin always expects a route to be there potentially
with invalid edge weight to represent no-route-found. By switching
to the many-route-result for the mld alternatives algorithm we might
return an empty many-route-result invalidating the post-condition.
