Clean up pick_random_server() and filter_protocol() and their

call sites.

Remove unused imports and redundant random pick of server

electrum

@@ -309,11 +309,7 @@ if __name__ == '__main__':
         else:
             password = prompt_password("Password (hit return if you do not wish to encrypt your wallet):")
 
-        # if config.server is set, the user either passed the server on command line
-        # or chose it previously already. if he didn't pass a server on the command line,
-        # we just pick up a random one.
-        if not config.get('server'):
-            config.set_key('server', pick_random_server())
+        # If config doesn't have a server, network.py will pick a random one
 
         #fee = options.tx_fee if options.tx_fee else raw_input("fee (default:%s):" % (str(Decimal(wallet.fee)/100000000)))
         #gap = options.gap_limit if options.gap_limit else raw_input("gap limit (default 5):")

gui/gtk.py

@@ -34,7 +34,6 @@ import platform
 MONOSPACE_FONT = 'Lucida Console' if platform.system() == 'Windows' else 'monospace'
 
 from electrum.util import format_satoshis, parse_URI
-from electrum.network import DEFAULT_SERVERS
 from electrum.bitcoin import MIN_RELAY_TX_FEE
 
 def numbify(entry, is_int = False):

gui/qt/network_dialog.py

@@ -23,7 +23,7 @@ import os.path, json, ast, traceback
 
 from PyQt4.QtGui import *
 from PyQt4.QtCore import *
-from electrum import DEFAULT_SERVERS, DEFAULT_PORTS
+from electrum import DEFAULT_PORTS
 
 from util import *
 

lib/network.py

@@ -68,19 +68,19 @@ def parse_servers(result):
 
     return servers
 
-
-
-def filter_protocol(servers, p):
-    l = []
-    for k, protocols in servers.items():
-        if p in protocols:
-            s = serialize_server(k, protocols[p], p)
-            l.append(s)
-    return l
-
-
-def pick_random_server(p='s'):
-    return random.choice( filter_protocol(DEFAULT_SERVERS,p) )
+def filter_protocol(hostmap = DEFAULT_SERVERS, protocol = 's'):
+    '''Filters the hostmap for those implementing protocol.
+    The result is a list in serialized form.'''
+    eligible = []
+    for host, portmap in hostmap.items():
+        port = portmap.get(protocol)
+        if port:
+            eligible.append(serialize_server(host, port, protocol))
+    return eligible
+
+def pick_random_server(hostmap = DEFAULT_SERVERS, protocol = 's', exclude_set = set()):
+    eligible = list(set(filter_protocol(hostmap, protocol)) - exclude_set)
+    return random.choice(eligible) if eligible else None
 
 from simple_config import SimpleConfig
 
@@ -149,7 +149,7 @@ class Network(util.DaemonThread):
         except:
             self.default_server = None
         if not self.default_server:
-            self.default_server = pick_random_server('s')
+            self.default_server = pick_random_server()
 
         self.irc_servers = {} # returned by interface (list from irc)
         self.recent_servers = self.read_recent_servers()
@@ -247,21 +247,6 @@ class Network(util.DaemonThread):
         value = self.get_status_value(key)
         self.response_queue.put({'method':'network.status', 'params':[key, value]})
 
-    def random_server(self):
-        choice_list = []
-        l = filter_protocol(self.get_servers(), self.protocol)
-        for s in l:
-            if s in self.pending_servers or s in self.disconnected_servers or s in self.interfaces.keys():
-                continue
-            else:
-                choice_list.append(s)
-
-        if not choice_list:
-            return
-
-        server = random.choice( choice_list )
-        return server
-
     def get_parameters(self):
         host, port, protocol = deserialize_server(self.default_server)
         auto_connect = self.config.get('auto_cycle', True)
@@ -293,7 +278,8 @@ class Network(util.DaemonThread):
             i.start()
 
     def start_random_interface(self):
-        server = self.random_server()
+        exclude_set = self.disconnected_servers.union(self.pending_servers).union(set(self.interfaces))
+        server = pick_random_server(self.get_servers(), self.protocol, exclude_set)
         if server:
             self.start_interface(server)
 

scripts/servers

@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 
 from electrum import SimpleConfig, set_verbosity
-from electrum.network import DEFAULT_SERVERS, filter_protocol
+from electrum.network import filter_protocol
 import time, Queue
 from collections import defaultdict
 
@@ -9,7 +9,7 @@ import util, json
 set_verbosity(False)
 
 config = SimpleConfig()
-servers = filter_protocol(DEFAULT_SERVERS,'t')
+servers = filter_protocol(protocol = 't')
 results = util.send_request(servers, {'method':'blockchain.headers.subscribe', 'params':[]})
 
 d = defaultdict(int)