Add an async actor cluster spawner prototype

tractor/_clustering.py

@@ -0,0 +1,49 @@
+'''
+Actor cluster helpers.
+
+'''
+from contextlib import asynccontextmanager as acm
+from multiprocessing import cpu_count
+from typing import AsyncGenerator, Optional
+
+import trio
+import tractor
+
+
+@acm
+async def open_actor_cluster(
+
+    modules: list[str],
+    count: int = cpu_count(),
+    names: Optional[list[str]] = None,
+
+) -> AsyncGenerator[..., dict[str, tractor.Portal]]:
+
+    portals: dict[str, tractor.Portal] = {}
+    uid = tractor.current_actor().uid
+
+    if not names:
+        suffix = '_'.join(uid)
+        names = [f'worker_{i}.' + suffix for i in range(count)]
+
+    if not len(names) == count:
+        raise ValueError(
+            'Number of names is {len(names)} but count it {count}')
+
+    async with (
+        tractor.open_nursery() as an,
+        trio.open_nursery() as n,
+    ):
+        for index, key in zip(range(count), names):
+
+            async def start(i) -> None:
+                key = f'worker_{i}.' + '_'.join(uid)
+                portals[key] = await an.start_actor(
+                    enable_modules=modules,
+                    name=key,
+                )
+
+            n.start_soon(start, index)
+
+        assert len(portals) == count
+        yield portals