Hi all,
Wendy, Richard, and I are considering the incremental updates subscription
model for ALTO using Server-Sent Event (SSE) streams. In this model, the
client subscribes to an event stream, and the server push updates as events
via the stream.
We use an "event" field to encode the unique identifier of the resource
that the event should update, which should be a subset of {resource-id,
resource-parameters, input-parameters}. (The client also has the IRD in its
possession so that it can do certain look-ups).
We would like a __minimal__ unique identifier of each resource and each
resource object. One resource could have multiple objects, e.g. when the
"accepts" field is non-empty (i.e. they have input params), or they could
have filters etc. Below are the proposal solutions:
For full network/cost map objects, resource-id is sufficient.
object {
ResourceID resource-id;
} NetworkMapEventName;
object {
ResourceID resource-id;
} CostMapEventName;
For resource objects that have non-empty "accepts" field or filters (i.e.
input params) in the IRD, there are multiple solutions:
*Solution 1. put the the input params in the events field*
For filtered network map objects, resource-id coupled with the pids for
the filter:
object {
ResourceID resource-id;
PIDName pids<0..*>;
[AddressType address-types<0..*>;]
} FilteredNetworkMapEventName;
For filtered cost map objects, we need to identify the costmap objects and
the filter:
object {
ResourceID resource-id;
CostType cost-type;
[JSONString constraints<0..*>;]
[PIDFilter pids;]
} CostMapEventName;
e.g. the event for a filtered network map would start with:
event: {"resource-id":"my-default-network-map", "pids":["PID2", "PID4"]}\n
*Solution 2. add the input params information as meta information for an
update.*
We put the merge-patch object with the meta information together to form
the update object:
object {
ResponseMeta update-meta;
JSONObject merge-patch;
} ALTOUpdate;
What do people think?
Best,
Xiao
_______________________________________________
alto mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/alto
