The data facade interface contains numerous methods for looking up
datapoints by identifiers.
Many of the parameters use the NodeID or EdgeID types. However, these two
identifier types are used for representing three different contexts:
1. Node-based graph edges and nodes
2. Edge-based graph edges and nodes
3. Packed geometries
Consider the use of identifier parameters in these examples:
---
GetWeightPenaltyForEdgeID(const EdgeID id) <- edge-based edge
GetUncompressedForwardWeights(const EdgeID id) <- packed geometry
IsLeftHandDriving(const NodeID id) <- edge-based node
GetBearingClass(const NodeID node) <- node-based node
---
This mixing of contexts within the same interface makes it
difficult to understand the relationships and dependencies between
the OSRM datasets.
For 1. and 2. we continue to use the NodeID and EdgeID types, but
change the interface parameter names to identify them as
edge-based or node-based graph properties.
For 3. we define a new type definition, PackedGeometryID.
These changes are to aid with readability. A next step would be
to strongly type these definitions, leveraging the Alias template
already used for OSM identifiers.
When using non-default constructors for the API parameter classes,
vector arguments like coordinates and hints are copied at least once
(twice when passed as lvalue arguments).
Enable perfect forwarding of BaseParameter arguments and
pass-by-value in the constructor that uses the argument. This
ensures we copy at most once (zero for rvalue arguments).
In cases where we are unable to find a phantom node for an input
coordinate, we return an error indicating which coordinate failed.
This would always refer to the coordinate with index equal to the
number of valid phantom nodes found.
We fix this by instead returning the first index for which a
phantom node could not be found.
It actually makes no sence, as the only output on the 'Nearest' service
is a list of wypoints. On the other hand it can be used now as a simple
health check.
* Replaced Response union with nullable fields
* "Ok" code replaced with a boolean and a separate structure for a error code and message.
* Inlined geometry, thus removing one layer of indirection.
