Fixed new_addr()

When changing addresses (think ZooKeeper :) ), we needed to be more
careful about current connection status. If we're still trying to
connect, we should stop and start over with the new addresses.

src/ZEO/ClientStorage.py

@@ -282,7 +282,18 @@ class ClientStorage(object):
 
     def new_addr(self, addr):
         self._addr = addr
-        self._server.new_addrs(addr)
+        self._server.new_addrs(self._normalize_addr(addr))
+
+    def _normalize_addr(self, addr):
+        if isinstance(addr, int):
+            addr = ('127.0.0.1', addr)
+
+        if isinstance(addr, str):
+            addr = [addr]
+        elif (isinstance(addr, tuple) and len(addr) == 2 and
+              isinstance(addr[0], str) and isinstance(addr[1], int)):
+            addr = [addr]
+        return addr
 
     def close(self):
         "Storage API: finalize the storage, releasing external resources."

src/ZEO/asyncio/client.py

@@ -105,7 +105,7 @@ class Protocol(asyncio.Protocol):
         @cr.add_done_callback
         def done_connecting(future):
             if future.exception() is not None:
-                logger.info("Connection to %rfailed, retrying, %s",
+                logger.info("Connection to %r failed, retrying, %s",
                             self.addr, future.exception())
                 # keep trying
                 if not self.closed:
@@ -384,6 +384,20 @@ class Client:
         self.protocols = ()
         self.disconnected(None)
 
+    def new_addrs(self, addrs):
+        self.addrs = addrs
+        if self.trying_to_connect():
+            self.disconnected(None)
+
+    def trying_to_connect(self):
+        """Return whether we're trying to connect
+
+        Either because we're disconnected, or because we're connected
+        read-only, but want a writable connection if we can get one.
+        """
+        return (not self.ready or
+                self.is_read_only() and self.read_only is Fallback)
+
     closed = False
     def close(self):
         if not self.closed:
@@ -443,7 +457,7 @@ class Client:
             protocol.close() # too late, we went home with another
 
     def register_failed(self, protocol, exc):
-        # A protcol failed registration. That's weird.  If they've all
+        # A protocol failed registration. That's weird.  If they've all
         # failed, we should try again in a bit.
         protocol.close()
         logger.exception("Registration or cache validation failed, %s", exc)
@@ -755,10 +769,16 @@ class ClientRunner:
 
         self.__call = call_closed
 
-    def new_addr(self, addrs):
+    def apply_threadsafe(self, future, func, *args):
+        try:
+            future.set_result(func(*args))
+        except Exception as exc:
+            future.set_exception(exc)
+
+    def new_addrs(self, addrs):
         # This usually doesn't have an immediate effect, since the
         # addrs aren't used until the client disconnects.xs
-        self.client.addrs = addrs
+        self.__call(self.apply_threadsafe, self.client.new_addrs, addrs)
 
     def wait(self, timeout=None):
         if timeout is None:

src/ZEO/tests/new_addr.test

@@ -29,6 +29,8 @@ Now, we'll restart the server and update the connection:
     >>> server = ZEO.StorageServer.StorageServer(
     ...     ('127.0.0.1', 0), {'1': ZODB.FileStorage.FileStorage('t.fs')})
     >>> server.start_thread()
+
+
     >>> client.new_addr(server.addr)