src/class_objectHashHolder.py

@@ -0,0 +1,39 @@
+# objectHashHolder is a timer-driven thread. One objectHashHolder thread is used
+# by each sendDataThread. It uses it whenever a sendDataThread needs to
+# advertise an object to peers. Instead of sending it out immediately, it must
+# wait a random number of seconds for each connection so that different peers
+# get different objects at different times. Thus an attacker who is
+# connecting to many network nodes who receives a message first from Alice
+# cannot be sure if Alice is the node who originated the message.
+
+import random
+import time
+import threading
+
+class objectHashHolder(threading.Thread):
+    def __init__(self, sendDataThreadMailbox):
+        threading.Thread.__init__(self)
+        self.shutdown = False
+        self.sendDataThreadMailbox = sendDataThreadMailbox # This queue is used to submit data back to our associated sendDataThread.
+        self.collectionOfLists = {}
+        for i in range(10):
+            self.collectionOfLists[i] = []
+
+    def run(self):
+        print 'objectHashHolder running.'
+        iterator = 0
+        while not self.shutdown:
+            if len(self.collectionOfLists[iterator]) > 0:
+                print 'objectHashHolder is submitting', len(self.collectionOfLists[iterator]), 'items to the queue.'
+                self.sendDataThreadMailbox.put((0, 'sendinv', self.collectionOfLists[iterator]))
+                self.collectionOfLists[iterator] = []
+            iterator += 1
+            iterator %= 10
+            time.sleep(1)
+        print 'objectHashHolder shutting down.'
+
+    def holdHash(self,hash):
+        self.collectionOfLists[random.randrange(0, 10)].append(hash)
+
+    def close(self):
+        self.shutdown = True