added graph simulation script

scripts/graph-simulation.py

@@ -0,0 +1,92 @@
+from typing import NamedTuple, List
+
+from hashlib import sha3_256
+from secrets import randbelow
+from random import SystemRandom
+
+WeightedEdge = NamedTuple("WeightedEdge", "node", "weight")
+
+message_pool: Set["Message"] = set()  # This is just to save memory for the simulation
+
+def get_message(hash_id):
+    for m in message_pool:
+        if hash_id == m.hash_id:
+            return m
+    raise ValueError
+
+class Node:
+    def __init__(self, hidden_node: bool,
+                 edges: List[WeightedEdge], graph_ids=["main"]):
+        self.hidden_node = hidden_node
+        self.edges = edges
+        self._messages: List[str] = list()  # hashes point to message_pool
+        self._hidden_messages = List[str] = list()
+
+    def sharing_messages(self):
+        share = list(self._messages)
+        for m in self._hidden_messages:
+            share.remove(m)
+        return share
+
+
+    def add_message(self, hash_id):
+        if hash_id not in self._messages:
+            self._messages.append(message.hash_id)
+
+    def pick_edge(self):
+        selected = self.edges[0]
+        alt = []
+
+        for weighted_edge in self.edges[1:]:
+            if weighted_edge.weight > selected.weight:
+                selected = weighted_edge
+            elif weighted_edge.weight == selected.weight:
+                alt.append(selected)
+        alt.append(selected)
+        SystemRandom().shuffle(alt)
+        return alt[0]
+
+
+    def share_to_edges(self, message_id):
+        edge = self.pick_edge()
+        edge.node.add_message(message_id)
+        edge.weight += 1
+
+    def lookup_messages(self):
+        edge = self.pick_edge()
+        for message in edge.node.sharing_messages:
+            if message.hash_id not in self._messages:
+                self._messages.append(message.hash_id)
+        edge.weight += 1
+
+    def make_new_connections(self):
+        edge = self.pick_edge()
+        for new_edge in edge.edges:
+            if new_edge not in self.edges:
+                self.edges.append(WeightedEdge(new_edge.node, 0))
+        edge.weight += 1
+
+
+class Message:
+    def __init__(self, data):
+        def _do_hash(data):
+            h = sha3_256()
+            h.update(data)
+            return h.digest()
+        self.hash_id = _do_hash(data)
+        self.data = data
+
+bootstrap_node = Node(False, [])
+graph = [bootstrap_node]
+
+for i in range(10):
+    graph.append(Node(False, [bootstrap_node]))
+
+m = Message("hello world")
+message_pool.add(m)
+bootstrap_node.add_message(m)
+while True:
+    for node in graph:
+        node.make_new_connections()
+        node.lookup_messages()
+        bootstrap_node.add_message(m)