feat(gateway): slot v2 loader (contract C1)

ingestor/io/slots.py

@@ -0,0 +1,25 @@
+"""Parse the slot v2 structure written by the Orchestrator to Redis (contract C1)."""
+
+SERVER_FIELDS = ('server_id', 'url', 'server_uri', 'use_security', 'subscription_period_ms')
+
+
+def _parse_tag(address: str, tag: dict) -> dict:
+    names = tag.get('names')
+    if not names:
+        raise ValueError(f'tag {address!r} has no names')
+    return {
+        'frequency': tag['frequency'],
+        'names': names,
+        'active_read': tag.get('active_read', {'enabled': False}),
+    }
+
+
+def _parse_server(server: dict) -> dict:
+    parsed = {field: server[field] for field in SERVER_FIELDS if field in server}
+    parsed['tags'] = {addr: _parse_tag(addr, tag) for addr, tag in server['tags'].items()}
+    return parsed
+
+
+def parse_slot(raw: dict) -> dict:
+    """Normalize a raw slot v2 dict into `{server_name: {..., tags: {addr: tag}}}`."""
+    return {name: _parse_server(server) for name, server in raw.items()}