Skip to content

CONFORMANCE.md

Latest commit

 

History

History
48 lines (36 loc) · 2.51 KB

CONFORMANCE.md

File metadata and controls

48 lines (36 loc) · 2.51 KB

OGC API – Moving Features – Part 4 (Stream Extension) — conformance

This tier implements the Continuous Query requirements class of OGC API – Moving Features – Part 4. The class is declared at GET /conformance:

http://www.opengis.net/spec/ogcapi-movingfeatures-4/1.0/conf/cquery

Requirements

Requirement Status Where
Req 1 cquery_link — the cquery link object carries rel, queryId, href, channel, status, type met cqueryLink (stream.go); asserted by TestCqueryLinkShape
Req 2 window — a query carries a window; the result carries [windowStart, windowEnd] met postQuery window parsing; the meos engine emits the bounds; TestWindowResultShape
Req 3 window_tumbling — fixed-duration, non-overlapping windows met runAggregate TUMBLING (stream_engine_meos.go)
Req 4 window_hopping — fixed-duration, overlapping windows met runHopping (stream_engine_meos.go); TestMeosHoppingWindow
Req 5 window_count — windows over a record count met runAggregate COUNT; TestMeosWindowAggregate

Aggregations

TemporalProperty — met for all scalar types, computed through MEOS:

  • TReal / TInt: COUNT, SUM, AVG, MIN, MAX (temporal_num_instants, tfloat_min_value/tfloat_max_value, tnumber_avg_value, value sum).
  • TText: COUNT, COUNT_DISTINCT (ttext_values).
  • TBoolean: COUNT, ANY, ALL, COUNT_TRUE, COUNT_FALSE (tbool_values).

The TemporalPrimitiveGeometry operations of Table 7 (LENGTH, AREA, TO_TRAJ, …) are not yet exposed.

Lifecycle and delivery

  • Lifecycle states running, stopped, failed are reported by the cquery status (registered is transient — a query enters running on submission).
  • Results are delivered over Server-Sent Events, one of the channel bindings Part 4 allows; the Kafka and WebSocket result bindings are not yet exposed.
  • Live ingestion: a query with "live": true sources pushed records. Producers push over HTTP (…/ingest) or MQTT (MFAPI_MQTT_BROKER, topic mfapi/<cid>/<fid>/<pname>) — the EDR Pub/Sub source over a real broker. A Kafka source feeds the same hub the same way.

Extensions beyond Part 4

Lifted scalar transforms over a streaming tfloat (ln, exp, ×, +, …), a geometry position stream (…/tgsequence/queries) for an animated map, and the Flink streaming engine behind the same StreamEngine seam are additions, not Part 4 requirements.