Improved resource transfers over unreliable links

RNS/Resource.py

@@ -26,6 +26,7 @@ import bz2
 import math
 import time
 import threading
+from threading import Lock
 from .vendor import umsgpack as umsgpack
 from time import sleep
 
@@ -47,7 +48,7 @@ class Resource:
     WINDOW               = 4
 
     # Absolute minimum window size during transfer
-    WINDOW_MIN           = 1
+    WINDOW_MIN           = 2
 
     # The maximum window size for transfers on slow links
     WINDOW_MAX_SLOW      = 10
@@ -103,7 +104,7 @@ class Resource:
 
     PART_TIMEOUT_FACTOR           = 4
     PART_TIMEOUT_FACTOR_AFTER_RTT = 2
-    MAX_RETRIES                   = 8
+    MAX_RETRIES                   = 16
     MAX_ADV_RETRIES               = 4
     SENDER_GRACE_TIME             = 10
     RETRY_GRACE_TIME              = 0.25
@@ -170,7 +171,8 @@ class Resource:
 
             resource.receiving_part = False
 
-            resource.consecutive_completed_height = 0
+            # TODO: Recheck
+            resource.consecutive_completed_height = -1
             
             if not resource.link.has_incoming_resource(resource):
                 resource.link.register_incoming_resource(resource)
@@ -366,7 +368,8 @@ class Resource:
             if advertise:
                 self.advertise()
         else:
-            pass
+            self.receive_lock = Lock()
+            
 
     def hashmap_update_packet(self, plaintext):
         if not self.status == Resource.FAILED:
@@ -623,8 +626,7 @@ class Resource:
 
 
     def receive_part(self, packet):
-        while self.receiving_part:
-            sleep(0.001)
+        with self.receive_lock:
 
             self.receiving_part = True
             self.last_activity = time.time()
@@ -658,8 +660,9 @@ class Resource:
                 part_data = packet.data
                 part_hash = self.get_map_hash(part_data)
 
-            i = self.consecutive_completed_height
-            for map_hash in self.hashmap[self.consecutive_completed_height:self.consecutive_completed_height+self.window]:
+                consecutive_index = self.consecutive_completed_height if self.consecutive_completed_height >= 0 else 0
+                i = consecutive_index
+                for map_hash in self.hashmap[consecutive_index:consecutive_index+self.window]:
                     if map_hash == part_hash:
                         if self.parts[i] == None:
 
@@ -728,11 +731,25 @@ class Resource:
                 hashmap_exhausted = Resource.HASHMAP_IS_NOT_EXHAUSTED
                 requested_hashes = b""
 
-                offset = (1 if self.consecutive_completed_height > 0 else 0)
-                i = 0; pn = self.consecutive_completed_height+offset
+                i = 0; pn = self.consecutive_completed_height+1
                 search_start = pn
+                search_size = self.window
 
-                for part in self.parts[search_start:search_start+self.window]:
+                # TODO: Remove
+                # tpm = []
+                # tpi = 0
+                # try:
+                #     for p in self.parts:
+                #         if p == None:
+                #             tpm.append(None)
+                #         else:
+                #             tpm.append(tpi)
+                #         tpi+=1
+                # except Exception as e:
+                #     print(str(e))
+                # RNS.log(f"Partmap: "+str(tpm))
+                
+                for part in self.parts[search_start:search_start+search_size]:
                     if part == None:
                         part_hash = self.hashmap[pn]
                         if part_hash != None:
@@ -752,7 +769,6 @@ class Resource:
                     hmu_part += last_map_hash
                     self.waiting_for_hmu = True
 
-                requested_data = b""
                 request_data = hmu_part + self.hash + requested_hashes
                 request_packet = RNS.Packet(self.link, request_data, context = RNS.Packet.RESOURCE_REQ)
 
@@ -908,8 +924,7 @@ class Resource:
             else:
                 self.progress_total_parts = float(self.total_parts)
 
-        
-        progress = self.processed_parts / self.progress_total_parts
+        progress = min(1.0, self.processed_parts / self.progress_total_parts)
         return progress
 
     def get_transfer_size(self):