persist CM server list in credential location

fix #31

When credential location is set, SteamClient will save CM server list
and use it to bootstrap when necessary.

steam/client/__init__.py

@@ -25,6 +25,9 @@ Events
 
 """
 import os
+import json
+from time import time
+from io import open
 import logging
 import gevent
 import gevent.monkey
@@ -39,14 +42,16 @@ from steam.core.msg import MsgProto
 from steam.core.cm import CMClient
 from steam import SteamID
 from steam.client.builtins import BuiltinBase
+from steam.util import ip_from_int
 
 
 class SteamClient(CMClient, BuiltinBase):
+    _cm_servers_timestamp = None       # used to decide when to update CM list on disk
     _reconnect_backoff_c = 0
     current_jobid = 0
-    credential_location = None  #: location for sentry
+    credential_location = None         #: location for sentry
-    username = None  #: username when logged on
+    username = None                    #: username when logged on
-    login_key = None  #: can be used for subsequent logins (no 2FA code will be required)
+    login_key = None                   #: can be used for subsequent logins (no 2FA code will be required)
 
     def __init__(self):
         CMClient.__init__(self)
@@ -78,13 +83,56 @@ class SteamClient(CMClient, BuiltinBase):
         """
         self.credential_location = path
 
+    def connect(self, *args, **kwargs):
+        """Attempt to establish connection, see :method:`.CMClient.connect`"""
+        self._bootstrap_cm_list_from_file()
+        CMClient.connect(self, *args, **kwargs)
+
     def disconnect(self, *args, **kwargs):
-        """
+        """Close connection, see :method:`.CMClient.disconnect`"""
-        Close connection
-        """
         self.logged_on = False
         CMClient.disconnect(self, *args, **kwargs)
 
+    def _bootstrap_cm_list_from_file(self):
+        if not self.credential_location or self._cm_servers_timestamp is not None: return
+
+        filepath = os.path.join(self.credential_location, 'cm_servers.json')
+        if not os.path.isfile(filepath): return
+
+        self._LOG.debug("Reading CM servers from %s" % repr(filepath))
+        try:
+            with open(filepath, 'r') as f:
+                data = json.load(f)
+        except IOError as e:
+            self._LOG.error("load %s: %s" % (repr(filepath), str(e)))
+            return
+
+        self.cm_servers.clear()
+        self.cm_servers.merge_list(data['servers'])
+        self._cm_servers_timestamp = int(data['timestamp'])
+
+    def _handle_cm_list(self, msg):
+        if self._cm_servers_timestamp is None:
+            self.cm_servers.clear()
+            self._cm_servers_timestamp = int(time())
+
+        CMClient._handle_cm_list(self, msg)  # just merges the list
+
+        if self.credential_location:
+            filepath = os.path.join(self.credential_location, 'cm_servers.json')
+
+            if not os.path.exists(filepath) or time() - (3600*24) > self._cm_servers_timestamp:
+                data = {
+                    'timestamp': self._cm_servers_timestamp,
+                    'servers': list(zip(map(ip_from_int, msg.body.cm_addresses), msg.body.cm_ports)),
+                }
+                try:
+                    with open(filepath, 'wb') as f:
+                        f.write(json.dumps(data, indent=True).encode('ascii'))
+                    self._LOG.debug("Saved CM servers to %s" % repr(filepath))
+                except IOError as e:
+                    self._LOG.error("saving %s: %s" % (filepath, str(e)))
+
     def _handle_jobs(self, event, *args):
         if isinstance(event, EMsg):
             message = args[0]

steam/core/cm.py

@@ -34,7 +34,7 @@ class CMClient(EventEmitter):
     UDP = 1                                 #: UDP protocol enum
     verbose_debug = False                   #: print message connects in debug
 
-    servers = None                          #: a instance of :class:`steam.core.cm.CMServerList`
+    cm_servers = None                       #: a instance of :class:`steam.core.cm.CMServerList`
     current_server_addr = None              #: (ip, port) tuple
     _seen_logon = False
     _connecting = False
@@ -54,7 +54,7 @@ class CMClient(EventEmitter):
 
     def __init__(self, protocol=0):
         self._LOG = logging.getLogger("CMClient")
-        self.servers = CMServerList()
+        self.cm_servers = CMServerList()
 
         if protocol == CMClient.TCP:
             self.connection = TCPConnection()
@@ -64,7 +64,7 @@ class CMClient(EventEmitter):
         self.on(EMsg.ChannelEncryptRequest, self.__handle_encrypt_request),
         self.on(EMsg.Multi, self.__handle_multi),
         self.on(EMsg.ClientLogOnResponse, self._handle_logon),
-        self.on(EMsg.ClientCMList, self.__handle_cm_list),
+        self.on(EMsg.ClientCMList, self._handle_cm_list),
 
     def emit(self, event, *args):
         if event is not None:
@@ -96,7 +96,7 @@ class CMClient(EventEmitter):
 
         self._LOG.debug("Connect initiated.")
 
-        for i, server_addr in enumerate(self.servers):
+        for i, server_addr in enumerate(self.cm_servers):
             if retry and i > retry:
                 return False
 
@@ -278,7 +278,7 @@ class CMClient(EventEmitter):
         result = self.wait_event(EMsg.ChannelEncryptResult, timeout=5)
 
         if result is None:
-            self.servers.mark_bad(self.current_server_addr)
+            self.cm_servers.mark_bad(self.current_server_addr)
             gevent.spawn(self.disconnect)
             return
 
@@ -337,7 +337,7 @@ class CMClient(EventEmitter):
         if result in (EResult.TryAnotherCM,
                       EResult.ServiceUnavailable
                       ):
-            self.servers.mark_bad(self.current_server_addr)
+            self.cm_servers.mark_bad(self.current_server_addr)
             self.disconnect()
         elif result == EResult.OK:
             self._seen_logon = True
@@ -360,11 +360,11 @@ class CMClient(EventEmitter):
             self.emit("error", EResult(result))
             self.disconnect()
 
-    def __handle_cm_list(self, msg):
+    def _handle_cm_list(self, msg):
         self._LOG.debug("Updating CM list")
 
         new_servers = zip(map(ip_from_int, msg.body.cm_addresses), msg.body.cm_ports)
-        self.servers.merge_list(new_servers)
+        self.cm_servers.merge_list(new_servers)
 
 
 class CMServerList(object):
@@ -397,12 +397,19 @@ class CMServerList(object):
 
         self.bootstrap_from_builtin_list()
 
+    def clear(self):
+        """Clears the server list"""
+        if len(self.list):
+            self._log.debug("List cleared.")
+        self.list.clear()
+
     def bootstrap_from_builtin_list(self):
         """
         Resets the server list to the built in one.
         This method is called during initialization.
         """
-        self.list.clear()
+        self._log.debug("Bootstraping from builtin list")
+        self.clear()
 
         # build-in list
         self.merge_list([('162.254.195.44', 27019), ('146.66.152.11', 27017),
@@ -431,8 +438,9 @@ class CMServerList(object):
         :return: booststrap success
         :rtype: :class:`bool`
         """
-        from steam import _webapi
+        self._log.debug("Attempting bootstrap via WebAPI")
 
+        from steam import _webapi
         try:
             resp = _webapi.get('ISteamDirectory', 'GetCMList', 1, params={'cellid': cellid})
         except Exception as exp:
@@ -452,12 +460,11 @@ class CMServerList(object):
             ip, port = serveraddr.split(':')
             return str(ip), int(port)
 
-        self.list.clear()
+        self.clear()
         self.merge_list(map(str_to_tuple, serverlist))
 
         return True
 
-
     def __iter__(self):
         def genfunc():
             while True:
@@ -502,13 +509,14 @@ class CMServerList(object):
     def merge_list(self, new_list):
         """Add new CM servers to the list
 
-        :param new_list: a list of (ip, port) tuples
+        :param new_list: a list of ``(ip, port)`` tuples
         :type new_list: :class:`list`
         """
         total = len(self.list)
 
         for ip, port in new_list:
-            self.mark_good((ip, port))
+            if (ip, port) not in self.list:
+                self.mark_good((ip, port))
 
-        if total:
+        if len(self.list) > total:
             self._log.debug("Added %d new CM addresses." % (len(self.list) - total))