feat(roles): requester role

konsensus/models/roles/requester.py

@@ -0,0 +1,35 @@
+from typing import Callable
+from itertools import count
+from . import Role
+from ..node import Node
+from konsensus.entities.messages_types import Invoke
+from konsensus.constants import INVOKE_RETRANSMIT
+
+
+class Requester(Role):
+    """
+    The requester role manages a request to the distributed state machine. 
+    The role class simply sends Invoke messages to the local replica until it receives a corresponding Invoked.
+    """
+
+    client_ids = count(start=100000)
+
+    def __init__(self, node: Node, n, callback: Callable) -> None:
+        super().__init__(node)
+        self.client_id = self.client_ids.next()
+        self.n = n
+        self.output = None
+        self.callback = callback
+
+    def start(self):
+        self.node.send([self.node.address], Invoke(
+            caller=self.node.address, client_id=self.client_id, input_value=self.n))
+        self.invoke_timer = self.set_timer(INVOKE_RETRANSMIT, self.start)
+
+    def do_invoked(self, sender, client_id, output):
+        if client_id != self.client_id:
+            return
+        self.logger.debug(f"received output {output}")
+        self.invoke_timer.cancel()
+        self.callback(output)
+        self.stop()

konsensus/models/roles/seed.py

@@ -2,7 +2,7 @@
 from . import Role
 from ..node import Node
 from .bootstrap import Bootstrap
-from konsensus.entities.messages_types import Join, Welcome
+from konsensus.entities.messages_types import Welcome
 from konsensus.constants import JOIN_RETRANSMIT