Flow API - update gateway (#357)

* Altered API to incorporate Flow IDs, refactored for dynamic start/stop of flows
* Gateway: Split endpoint / dispatcher for maintainability

trustgraph-flow/trustgraph/gateway/dispatch/graph_embeddings_import.py

@@ -0,0 +1,64 @@
+
+import asyncio
+import uuid
+from aiohttp import WSMsgType
+
+from ... schema import Metadata
+from ... schema import GraphEmbeddings, EntityEmbeddings
+from ... base import Publisher
+
+from . serialize import to_subgraph, to_value
+
+class GraphEmbeddingsImport:
+
+    def __init__(
+            self, ws, running, pulsar_client, queue
+    ):
+
+        self.ws = ws
+        self.running = running
+        
+        self.publisher = Publisher(
+            pulsar_client, topic = queue, schema = GraphEmbeddings
+        )
+
+    async def destroy(self):
+        self.running.stop()
+
+        if self.ws:
+            await self.ws.close()
+
+        await self.publisher.stop()
+
+    async def receive(self, msg):
+
+        data = msg.json()
+
+        elt = GraphEmbeddings(
+            metadata=Metadata(
+                id=data["metadata"]["id"],
+                metadata=to_subgraph(data["metadata"]["metadata"]),
+                user=data["metadata"]["user"],
+                collection=data["metadata"]["collection"],
+            ),
+            entities=[
+                EntityEmbeddings(
+                    entity=to_value(ent["entity"]),
+                    vectors=ent["vectors"],
+                )
+                for ent in data["entities"]
+            ]
+        )
+
+        await self.publisher.send(None, elt)
+
+    async def run(self):
+
+        while self.running.get():
+            await asyncio.sleep(0.5)
+
+        if self.ws:
+            await self.ws.close()
+
+        self.ws = None
+