1 files changed, 145 insertions, 0 deletions
diff --git a/distbuild/connection_machine.py b/distbuild/connection_machine.py
new file mode 100644
index 00000000..3d4e8d04
--- /dev/null
+++ b/distbuild/connection_machine.py
@@ -0,0 +1,145 @@
+# distbuild/connection_machine.py -- state machine for connecting to server
+#
+# Copyright (C) 2014  Codethink Limited
+# 
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA..
+
+
+import errno
+import logging
+import socket
+
+import distbuild
+
+
+class Reconnect(object):
+
+    pass
+    
+    
+class StopConnecting(object):
+
+    pass
+
+
+class ConnectError(object):
+
+    pass
+
+
+class ProxyEventSource(object):
+
+    '''Proxy event sources that may come and go.'''
+
+    def __init__(self):
+        self.event_source = None
+
+    def get_select_params(self):
+        if self.event_source:
+            return self.event_source.get_select_params()
+        else:
+            return [], [], [], None
+            
+    def get_events(self, r, w, x):
+        if self.event_source:
+            return self.event_source.get_events(r, w, x)
+        else:
+            return []
+            
+    def is_finished(self):
+        return False
+
+
+class ConnectionMachine(distbuild.StateMachine):
+
+    def __init__(self, addr, port, machine, extra_args):
+        distbuild.StateMachine.__init__(self, 'connecting')
+        self._addr = addr
+        self._port = port
+        self._machine = machine
+        self._extra_args = extra_args
+        self._socket = None
+        self.reconnect_interval = 1
+
+    def setup(self):
+        self._sock_proxy = ProxyEventSource()
+        self.mainloop.add_event_source(self._sock_proxy)
+        self._start_connect()
+        
+        self._timer = distbuild.TimerEventSource(self.reconnect_interval)
+        self.mainloop.add_event_source(self._timer)
+
+        spec = [
+            ('connecting', self._sock_proxy, distbuild.SocketWriteable, 
+                'connected', self._connect),
+            ('connecting', self, StopConnecting, None, self._stop),
+            ('connected', self, Reconnect, 'connecting', self._reconnect),
+            ('connected', self, ConnectError, 'timeout', self._start_timer),
+            ('connected', self, StopConnecting, None, self._stop),
+            ('timeout', self._timer, distbuild.Timer, 'connecting',
+                self._reconnect),
+            ('timeout', self, StopConnecting, None, self._stop),
+        ]
+        self.add_transitions(spec)
+        
+    def _start_connect(self):
+        logging.debug(
+            'ConnectionMachine: connecting to %s:%s' % 
+                (self._addr, self._port))
+        self._socket = socket.socket()
+        distbuild.set_nonblocking(self._socket)
+        try:
+            self._socket.connect((self._addr, self._port))
+        except socket.error, e:
+            if e.errno != errno.EINPROGRESS:
+                raise socket.error(
+                    "%s (attempting connection to distbuild controller "
+                    "at %s:%s)" % (e, self._addr, self._port))
+
+        src = distbuild.SocketEventSource(self._socket)
+        self._sock_proxy.event_source = src
+        
+    def _connect(self, event_source, event):
+        try:
+            self._socket.connect((self._addr, self._port))
+        except socket.error, e:
+            logging.error(
+                'Failed to connect to %s:%s: %s' % 
+                    (self._addr, self._port, str(e)))
+            self.mainloop.queue_event(self, ConnectError())
+            return
+        self._sock_proxy.event_source = None
+        logging.info('Connected to %s:%s' % (self._addr, self._port))
+        m = self._machine(self, self._socket, *self._extra_args)
+        self.mainloop.add_state_machine(m)
+        self._socket = None
+
+    def _reconnect(self, event_source, event):
+        logging.info('Reconnecting to %s:%s' % (self._addr, self._port))
+        if self._socket is not None:
+            self._socket.close()
+        self._timer.stop()
+        self._start_connect()
+
+    def _stop(self, event_source, event):
+        logging.info(
+            'Stopping connection attempts to %s:%s' % (self._addr, self._port))
+        self.mainloop.remove_event_source(self._timer)
+        if self._socket is not None:
+            self._socket.close()
+            self._socket = None
+
+    def _start_timer(self, event_source, event):
+        self._timer.start()
+