implement a connector wrapper for sockets, thus it makes the Connection

objects independant from the low level library used


git-svn-id: https://svn.erp5.org/repos/neo/branches/prototype3@250 71dcc9de-d417-0410-9af5-da40c76e7ee4

neo/client/Storage.py

@@ -24,6 +24,7 @@ import logging
 from neo.client.dispatcher import Dispatcher
 from neo.event import EventManager
 from neo.util import dump
+from neo import connector as Connector
 
 class NEOStorageError(POSException.StorageError):
     pass
@@ -40,7 +41,7 @@ class Storage(BaseStorage.BaseStorage,
 
     __name__ = 'NEOStorage'
 
-    def __init__(self, master_nodes, name, read_only=False, **kw):
+    def __init__(self, master_nodes, name, connector, read_only=False, **kw):
         self._is_read_only = read_only
         # Transaction must be under protection of lock
         l = Lock()
@@ -56,11 +57,12 @@ class Storage(BaseStorage.BaseStorage,
         dispatcher = Dispatcher(em, request_queue)
         dispatcher.setDaemon(True)
         # Import here to prevent recursive import
+        connector_handler = getattr(Connector, connector)
         from neo.client.app import Application
         self.app = Application(master_nodes, name, em, dispatcher,
-                               request_queue)
+                               request_queue, connector_handler)
         # Connect to primary master node
-        dispatcher.connectToPrimaryMasterNode(self.app)
+        dispatcher.connectToPrimaryMasterNode(self.app, self.app.connector_handler)
         # Start dispatcher
         dispatcher.start()
 

neo/client/app.py

@@ -69,10 +69,11 @@ class ConnectionPool(object):
         while 1:
             logging.info('trying to connect to %s:%d', *addr)
             app.local_var.node_not_ready = 0
-            conn = MTClientConnection(app.em, handler, addr)
+            conn = MTClientConnection(app.em, handler, addr,
+                                      connector_handler=self.app.connector_handler)
             conn.lock()
             try:
-                if conn.getSocket() is None:
+                if conn.getConnector() is None:
                     # This happens, if a connection could not be established.
                     logging.error('Connection to storage node %s failed', addr)
                     return None
@@ -176,12 +177,13 @@ class ConnectionPool(object):
 class Application(object):
     """The client node application."""
 
-    def __init__(self, master_nodes, name, em, dispatcher, request_queue, **kw):
+    def __init__(self, master_nodes, name, em, dispatcher, request_queue, connector, **kw):
         logging.basicConfig(level = logging.DEBUG)
         logging.debug('master node address are %s' %(master_nodes,))
         # Internal Attributes common to all thread
         self.name = name
         self.em = em
+        self.connector_handler = connector
         self.dispatcher = dispatcher
         self.nm = NodeManager()
         self.cp = ConnectionPool(self)

neo/client/config.py

@@ -21,6 +21,7 @@ class NeoStorage(BaseConfig):
 
   def open(self):
     from Storage import Storage
-    return Storage(master_nodes = self.config.master_nodes, name = self.config.name)
+    return Storage(master_nodes = self.config.master_nodes, name = self.config.name,
+                   connector = self.config.connector)
 
 

neo/client/dispatcher.py

@@ -63,7 +63,7 @@ class Dispatcher(Thread):
                 return True
         return False
 
-    def connectToPrimaryMasterNode(self, app):
+    def connectToPrimaryMasterNode(self, app, connector):
         """Connect to a primary master node.
         This can be called either at bootstrap or when
         client got disconnected during process"""
@@ -95,7 +95,7 @@ class Dispatcher(Thread):
                 else:
                     addr, port = app.primary_master_node.getServer()
                 # Request Node Identification
-                conn = MTClientConnection(app.em, handler, (addr, port))
+                conn = MTClientConnection(app.em, handler, (addr, port), connector_handler=connector)
                 if app.nm.getNodeByServer((addr, port)) is None:
                     n = MasterNode(server = (addr, port))
                     app.nm.add(n)

neo/component.xml

@@ -14,5 +14,10 @@
        Give the name of the cluster
       </description>
      </key>
+     <key name="connector" required="yes">
+      <description>
+       Give the name of the connector used at low-level
+      </description>
+     </key>
   </sectiontype>
 </component>

neo/config.py

@@ -69,6 +69,9 @@ class ConfigurationManager:
     def getPartitions(self):
         return int(self['partitions'])
 
+    def getConnector(self):
+        return str(self['connector'])
+
     def getName(self):
         return self['name']
 

neo/connection.py

@@ -15,24 +15,27 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
-
-import socket
-import errno
 import logging
 from threading import RLock
 
 from neo.protocol import Packet, ProtocolError
 from neo.event import IdleEvent
+from neo.connector import *
 
 class BaseConnection(object):
     """A base connection."""
-    def __init__(self, event_manager, handler, s = None, addr = None):
+
+    def __init__(self, event_manager, handler, connector = None,
+                 addr = None, connector_handler = None):
         self.em = event_manager
-        self.s = s
+        self.connector = connector
         self.addr = addr
         self.handler = handler
-        if s is not None:
+        if connector is not None:
+            self.connector_handler = connector.__class__
             event_manager.register(self)
+        else:            
+            self.connector_handler = connector_handler
             
     def lock(self):
         return 1
@@ -40,17 +43,17 @@ class BaseConnection(object):
     def unlock(self):
         return None
 
-    def getSocket(self):
-        return self.s
+    def getConnector(self):
+        return self.connector
 
     def getDescriptor(self):
-        return self.s.fileno()
+        return self.connector.getDescriptor()
 
-    def setSocket(self, s):
-        if self.s is not None:
-            raise RuntimeError, 'cannot overwrite a socket in a connection'
-        if s is not None:
-            self.s = s
+    def setConnector(self, connector):
+        if self.connector is not None:
+            raise RuntimeError, 'cannot overwrite a connector in a connection'
+        if connector is not None:
+            self.connector = connector
             self.em.register(self)
 
     def getAddress(self):
@@ -76,41 +79,40 @@ class BaseConnection(object):
 
 class ListeningConnection(BaseConnection):
     """A listen connection."""
-    def __init__(self, event_manager, handler, addr = None, **kw):
+    def __init__(self, event_manager, handler, addr = None,
+                 connector_handler = None, **kw):
         logging.info('listening to %s:%d', *addr)
-        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-        try:
-            s.setblocking(0)
-            s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
-            s.bind(addr)
-            s.listen(5)
-        except:
-            s.close()
-            raise
-        BaseConnection.__init__(self, event_manager, handler, s = s, addr = addr)
+        BaseConnection.__init__(self, event_manager, handler,
+                                addr = addr,
+                                connector_handler = connector_handler)
+        connector = self.connector_handler()
+        connector.makeListeningConnection(addr)
+        self.setConnector(connector)
         self.em.addReader(self)
 
     def readable(self):
         try:
-            new_s, addr = self.s.accept()
+            new_s, addr = self.connector.getNewConnection()
             logging.info('accepted a connection from %s:%d', *addr)
             self.handler.connectionAccepted(self, new_s, addr)
-        except socket.error, m:
-            if m[0] == errno.EAGAIN:
-                return
-            raise
+        except ConnectorTryAgainException:
+            pass
             
 class Connection(BaseConnection):
     """A connection."""
-    def __init__(self, event_manager, handler, s = None, addr = None):
+    def __init__(self, event_manager, handler,
+                 connector = None, addr = None,
+                 connector_handler = None):
         self.read_buf = []
         self.write_buf = []
         self.cur_id = 0
         self.event_dict = {}
         self.aborted = False
         self.uuid = None
-        BaseConnection.__init__(self, event_manager, handler, s = s, addr = addr)
-        if s is not None:
+        BaseConnection.__init__(self, event_manager, handler,
+                                connector = connector, addr = addr,
+                                connector_handler = connector_handler)
+        if connector is not None:
             event_manager.addReader(self)
 
     def getUUID(self):
@@ -130,20 +132,15 @@ class Connection(BaseConnection):
 
     def close(self):
         """Close the connection."""
-        s = self.s
         em = self.em
-        if s is not None:
-            logging.debug('closing a socket for %s:%d', *(self.addr))
+        if self.connector is not None:
+            logging.debug('closing a connector for %s:%d', *(self.addr))
             em.removeReader(self)
             em.removeWriter(self)
             em.unregister(self)            
-            try:
-                # This may fail if the socket is not connected.
-                s.shutdown(socket.SHUT_RDWR)
-            except socket.error:
-                pass
-            s.close()
-            self.s = None
+            self.connector.shutdown()
+            self.connector.close()
+            self.connector = None
             for event in self.event_dict.itervalues():
                 em.removeIdleEvent(event)
             self.event_dict.clear()
@@ -153,7 +150,7 @@ class Connection(BaseConnection):
 
     def abort(self):
         """Abort dealing with this connection."""
-        logging.debug('aborting a socket for %s:%d', *(self.addr))
+        logging.debug('aborting a connetor for %s:%d', *(self.addr))
         self.aborted = True
 
     def writable(self):
@@ -209,37 +206,33 @@ class Connection(BaseConnection):
                 del self.read_buf[:]
 
     def pending(self):
-        return self.s is not None and len(self.write_buf) != 0
+        return self.connector is not None and len(self.write_buf) != 0
 
     def recv(self):
-        """Receive data from a socket."""
-        s = self.s
+        """Receive data from a connector."""
         try:
-            r = s.recv(4096)
+            r = self.connector.receive()
             if not r:
                 logging.error('cannot read')
                 self.handler.connectionClosed(self)
                 self.close()
             else:
                 self.read_buf.append(r)
-        except socket.error, m:
-            if m[0] == errno.EAGAIN:
+        except ConnectorTryAgainException:
             pass
-            else:
-                logging.error('%s', m[1])
+        except:
             self.handler.connectionClosed(self)
             self.close()
 
     def send(self):
-        """Send data to a socket."""
-        s = self.s
+        """Send data to a connector."""
         if self.write_buf:
             if len(self.write_buf) == 1:
                 msg = self.write_buf[0]
             else:
                 msg = ''.join(self.write_buf)
             try:
-                r = s.send(msg)
+                r = self.connector.send(msg)
                 if not r:
                     logging.error('cannot write')
                     self.handler.connectionClosed(self)
@@ -248,17 +241,15 @@ class Connection(BaseConnection):
                     del self.write_buf[:]
                 else:
                     self.write_buf = [msg[r:]]
-            except socket.error, m:
-                if m[0] == errno.EAGAIN:
+            except ConnectorTryAgainException:
                 return
-                else:
-                    logging.error('%s', m[1])
+            except:
                 self.handler.connectionClosed(self)
                 self.close()
 
     def addPacket(self, packet):
         """Add a packet into the write buffer."""
-        if self.s is None:
+        if self.connector is None:
             return
 
         try:
@@ -291,7 +282,7 @@ class Connection(BaseConnection):
         The additional timeout defines the amount of time after the timeout
         to invoke a timeoutExpired callback. If it is zero, no ping is sent, and
         the callback is executed immediately."""
-        if self.s is None:
+        if self.connector is None:
             return
 
         event = IdleEvent(self, msg_id, timeout, additional_timeout)
@@ -300,22 +291,19 @@ class Connection(BaseConnection):
 
 class ClientConnection(Connection):
     """A connection from this node to a remote node."""
-    def __init__(self, event_manager, handler, addr = None, **kw):
+    def __init__(self, event_manager, handler, addr = None,
+                 connector_handler = None, **kw):
         self.connecting = True
-        Connection.__init__(self, event_manager, handler, addr = addr)
+        Connection.__init__(self, event_manager, handler, addr = addr,
+                            connector_handler = connector_handler)
         handler.connectionStarted(self)
         try:
-            s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-            self.setSocket(s)
-
+            connector = self.connector_handler()
+            self.setConnector(connector)
             try:
-                s.setblocking(0)
-                s.connect(addr)
-            except socket.error, m:
-                if m[0] == errno.EINPROGRESS:
+                connector.makeClientConnection(addr)
+            except ConnectorInProgressException:
                 event_manager.addWriter(self)
-                else:
-                    raise
             else:
                 self.connecting = False
                 self.handler.connectionCompleted(self)
@@ -327,7 +315,7 @@ class ClientConnection(Connection):
     def writable(self):
         """Called when self is writable."""
         if self.connecting:
-            err = self.s.getsockopt(socket.SOL_SOCKET, socket.SO_ERROR)
+            err = self.connector.getError()
             if err:
                 self.handler.connectionFailed(self)
                 self.close()
@@ -378,3 +366,4 @@ class MTServerConnection(ServerConnection):
 
     def unlock(self):
         self.release()
+

neo/connector.py

+#
+# Copyright (C) 2009  Nexedi SA
+# 
+# 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; either version 2
+# of the License, or (at your option) any later version.
+# 
+# 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 socket
+import errno
+import logging
+
+class SocketConnector:
+  """ This class is a wrapper for a socket """
+
+  def __init__(self, s=None):
+    if s is None:      
+      self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    else:
+      self.socket = s
+
+  def __getattr__(self, name):
+    """ fallback to default socket methods """
+    return getattr(self.socket, name)
+  
+  def makeClientConnection(self, addr):
+    try:
+      self.socket.setblocking(0)
+      self.socket.connect(addr)
+    except socket.error, m:
+      if m[0] == errno.EINPROGRESS:
+        raise ConnectorInProgressException
+      else:
+        logging.error('%s', m[1])        
+        raise
+
+  def makeListeningConnection(self, addr):
+    try:
+      self.socket.setblocking(0)
+      self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+      self.socket.bind(addr)
+      self.socket.listen(5)
+    except:
+      self.socket.close()
+      raise
+
+  def getError(self):
+    return self.socket.getsockopt(socket.SOL_SOCKET, socket.SO_ERROR)
+
+  def getDescriptor(self):
+    return self.socket.fileno()
+
+  def getNewConnection(self):
+    try:
+      new_s, addr =  self.socket.accept()
+      new_s = SocketConnector(new_s)
+      return new_s, addr
+    except socket.error, m:
+      if m[0] == errno.EAGAIN:
+        raise ConnectorTryAgainException
+      else:
+        logging.error('%s', m[1])        
+        raise
+
+  def shutdown(self):
+    # This may fail if the socket is not connected.
+    try:
+      self.socket.shutdown(socket.SHUT_RDWR)
+    except socket.error:
+      pass
+
+  def receive(self):
+    try:
+      return self.socket.recv(4096)
+    except socket.error, m:
+      if m[0] == errno.EAGAIN:
+        raise ConnectorTryAgainException
+      else:
+        logging.error('%s', m[1])                    
+        raise
+
+  def send(self, msg):
+    try:
+      return self.socket.send(msg)
+    except socket.error, m:
+      if m[0] == errno.EAGAIN:
+        raise ConnectorTryAgainException
+      else:
+        logging.error('%s', m[1])        
+        raise
+
+
+class ConnectorTryAgainException(Exception): pass
+class ConnectorInProgressException(Exception): pass  
+
+
+
+
+
+
+
+
+
+
+
+
+
+

neo/event.py

@@ -89,10 +89,10 @@ class SelectEventManager(object):
         return self.connection_dict.values()
 
     def register(self, conn):
-        self.connection_dict[conn.getSocket()] = conn
+        self.connection_dict[conn.getConnector()] = conn
 
     def unregister(self, conn):
-        del self.connection_dict[conn.getSocket()]
+        del self.connection_dict[conn.getConnector()]
 
     def poll(self, timeout = 1):
         rlist, wlist, xlist = select(self.reader_set, self.writer_set, self.exc_list,
@@ -146,16 +146,16 @@ class SelectEventManager(object):
             pass
 
     def addReader(self, conn):
-        self.reader_set.add(conn.getSocket())
+        self.reader_set.add(conn.getConnector())
 
     def removeReader(self, conn):
-        self.reader_set.discard(conn.getSocket())
+        self.reader_set.discard(conn.getConnector())
 
     def addWriter(self, conn):
-        self.writer_set.add(conn.getSocket())
+        self.writer_set.add(conn.getConnector())
 
     def removeWriter(self, conn):
-        self.writer_set.discard(conn.getSocket())
+        self.writer_set.discard(conn.getConnector())
 
 class EpollEventManager(object):
     """This class manages connections and events based on epoll(5)."""
@@ -186,6 +186,7 @@ class EpollEventManager(object):
         for fd in rlist:
             try:
                 conn = self.connection_dict[fd]
+                #logging.info("conn is %s" %(conn,))
                 conn.lock()
                 try:
                     conn.readable()

neo/handler.py

@@ -57,11 +57,11 @@ class EventHandler(object):
         """Called when a connection failed."""
         logging.debug('connection failed for %s:%d', *(conn.getAddress()))
 
-    def connectionAccepted(self, conn, s, addr):
+    def connectionAccepted(self, conn, connector, addr):
         """Called when a connection is accepted."""
         logging.debug('connection accepted from %s:%d', *addr)
         new_conn = ServerConnection(conn.getEventManager(), conn.getHandler(),
-                                    s = s, addr = addr)
+                                    connector = connector, addr = addr)
         # A request for a node identification should arrive.
         new_conn.expectMessage(timeout = 10, additional_timeout = 0)
 

neo/master/app.py

@@ -36,6 +36,7 @@ from neo.master.service import ServiceEventHandler
 from neo.master.secondary import SecondaryEventHandler
 from neo.pt import PartitionTable
 from neo.util import dump
+from neo import connector
 
 class Application(object):
     """The master node application."""
@@ -46,6 +47,8 @@ class Application(object):
         self.num_replicas = config.getReplicas()
         self.num_partitions = config.getPartitions()
         self.name = config.getName()
+        connector_handler = config.getConnector()
+        self.connector_handler = getattr(connector, connector_handler)
         logging.debug('the number of replicas is %d, the number of partitions is %d, the name is %s',
                       self.num_replicas, self.num_partitions, self.name)
 
@@ -94,7 +97,8 @@ class Application(object):
             self.nm.add(MasterNode(server = server))
 
         # Make a listening port.
-        ListeningConnection(self.em, None, addr = self.server)
+        ListeningConnection(self.em, None, addr = self.server,
+                            connector_handler = self.connector_handler)
 
         # Start the election of a primary master node.
         self.electPrimary()
@@ -172,8 +176,8 @@ class Application(object):
                         # Try to connect to master nodes.
                         if self.unconnected_master_node_set:
                             for addr in list(self.unconnected_master_node_set):
-                                ClientConnection(em, handler, addr = addr)
-
+                                ClientConnection(em, handler, addr = addr,
+                                                 connector_handler = self.connector_handler)
                     if len(self.unconnected_master_node_set) == 0 \
                             and len(self.negotiating_master_node_set) == 0:
                         break

neo/storage/app.py

@@ -33,6 +33,7 @@ from neo.storage.bootstrap import BootstrapEventHandler
 from neo.storage.verification import VerificationEventHandler
 from neo.storage.operation import OperationEventHandler
 from neo.storage.replicator import Replicator
+from neo import connector
 
 class Application(object):
     """The storage node application."""
@@ -44,6 +45,8 @@ class Application(object):
         self.num_replicas = None
         self.name = config.getName()
         logging.debug('the name is %s', self.name)
+        connector_handler = config.getConnector()
+        self.connector_handler = getattr(connector, connector_handler)
 
         self.server = config.getServer()
         logging.debug('IP address is %s, port is %d', *(self.server))
@@ -126,7 +129,8 @@ class Application(object):
             self.nm.add(MasterNode(server = server))
 
         # Make a listening port.
-        ListeningConnection(self.em, None, addr = self.server)
+        ListeningConnection(self.em, None, addr = self.server,
+                            connector_handler = self.connector_handler)
 
         # Connect to a primary master node, verify data, and
         # start the operation. This cycle will be executed permentnly,
@@ -208,7 +212,8 @@ class Application(object):
                     index += 1
 
                 ClientConnection(em, handler, \
-                        addr = self.trying_master_node.getServer())
+                                 addr = self.trying_master_node.getServer(),
+                                 connector_handler = self.connector_handler)
                 t = time()
 
     def verifyData(self):

neo/storage/replicator.py

@@ -339,7 +339,8 @@ class Replicator(object):
         if self.current_connection is None:
             handler = ReplicationEventHandler(app)
             self.current_connection = ClientConnection(app.em, handler, 
-                                                       addr = addr)
+                                                       addr = addr,
+                                                       connector_handler = app.connector_handler)
             msg_id = self.current_connection.getNextId()
             p = Packet()
             p.requestNodeIdentification(msg_id, STORAGE_NODE_TYPE, app.uuid,