1 files changed, 308 insertions, 0 deletions
diff --git a/qpid/python/qpid/session.py b/qpid/python/qpid/session.py
new file mode 100644
index 0000000000..95714a128a
--- /dev/null
+++ b/qpid/python/qpid/session.py
@@ -0,0 +1,308 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+#
+
+from threading import Condition, RLock, Lock, currentThread
+from generator import command_invoker
+from datatypes import RangedSet, Struct, Future
+from codec010 import StringCodec
+from queue import Queue
+from datatypes import Message, serial
+from ops import Command, MessageTransfer
+from util import wait, notify
+from exceptions import *
+from logging import getLogger
+
+log = getLogger("qpid.io.cmd")
+msg = getLogger("qpid.io.msg")
+
+class SessionException(Exception): pass
+class SessionClosed(SessionException): pass
+class SessionDetached(SessionException): pass
+
+def client(*args):
+  return Client(*args)
+
+def server(*args):
+  return Server(*args)
+
+INCOMPLETE = object()
+
+class Session(command_invoker()):
+
+  def __init__(self, name, auto_sync=True, timeout=10, delegate=client):
+    self.name = name
+    self.auto_sync = auto_sync
+    self.need_sync = True
+    self.timeout = timeout
+    self.channel = None
+    self.invoke_lock = Lock()
+    self._closing = False
+    self._closed = False
+
+    self.condition = Condition()
+
+    self.send_id = True
+    self.receiver = Receiver(self)
+    self.sender = Sender(self)
+
+    self.lock = RLock()
+    self._incoming = {}
+    self.results = {}
+    self.exceptions = []
+
+    self.delegate = delegate(self)
+
+  def incoming(self, destination):
+    self.lock.acquire()
+    try:
+      queue = self._incoming.get(destination)
+      if queue == None:
+        queue = Incoming(self, destination)
+        self._incoming[destination] = queue
+      return queue
+    finally:
+      self.lock.release()
+
+  def error(self):
+    exc = self.exceptions[:]
+    if len(exc) == 0:
+      return None
+    elif len(exc) == 1:
+      return exc[0]
+    else:
+      return tuple(exc)
+
+  def sync(self, timeout=None):
+    ch = self.channel
+    if ch is not None and currentThread() == ch.connection.thread:
+      raise SessionException("deadlock detected")
+    if self.need_sync:
+      self.execution_sync(sync=True)
+    last = self.sender.next_id - 1
+    if not wait(self.condition, lambda:
+                  last in self.sender._completed or self.exceptions,
+                timeout):
+      raise Timeout()
+    if self.exceptions:
+      raise SessionException(self.error())
+
+  def close(self, timeout=None):
+    self.invoke_lock.acquire()
+    try:
+      self._closing = True
+      self.channel.session_detach(self.name)
+    finally:
+      self.invoke_lock.release()
+    if not wait(self.condition, lambda: self._closed, timeout):
+      raise Timeout()
+
+  def closed(self):
+    self.lock.acquire()
+    try:
+      if self._closed: return
+
+      error = self.error()
+      for id in self.results:
+        f = self.results[id]
+        f.error(error)
+      self.results.clear()
+
+      for q in self._incoming.values():
+        q.close(error)
+
+      self._closed = True
+      notify(self.condition)
+    finally:
+      self.lock.release()
+
+  def invoke(self, op, args, kwargs):
+    if issubclass(op, Command):
+      self.invoke_lock.acquire()
+      try:
+        return self.do_invoke(op, args, kwargs)
+      finally:
+        self.invoke_lock.release()
+    else:
+      return op(*args, **kwargs)
+
+  def do_invoke(self, op, args, kwargs):
+    if self._closing:
+      raise SessionClosed()
+
+    ch = self.channel
+    if ch == None:
+      raise SessionDetached()
+
+    if op == MessageTransfer:
+      if len(args) == len(op.FIELDS) + 1:
+        message = args[-1]
+        args = args[:-1]
+      else:
+        message = kwargs.pop("message", None)
+      if message is not None:
+        kwargs["headers"] = message.headers
+        kwargs["payload"] = message.body
+
+    cmd = op(*args, **kwargs)
+    cmd.sync = self.auto_sync or cmd.sync
+    self.need_sync = not cmd.sync
+    cmd.channel = ch.id
+
+    if op.RESULT:
+      result = Future(exception=SessionException)
+      self.results[self.sender.next_id] = result
+
+    self.send(cmd)
+
+    log.debug("SENT %s", cmd)
+    if op == MessageTransfer:
+      msg.debug("SENT %s", cmd)
+
+    if op.RESULT:
+      if self.auto_sync:
+        return result.get(self.timeout)
+      else:
+        return result
+    elif self.auto_sync:
+      self.sync(self.timeout)
+
+  def received(self, cmd):
+    self.receiver.received(cmd)
+    self.dispatch(cmd)
+
+  def dispatch(self, cmd):
+    log.debug("RECV %s", cmd)
+
+    result = getattr(self.delegate, cmd.NAME)(cmd)
+    if result is INCOMPLETE:
+      return
+    elif result is not None:
+      self.execution_result(cmd.id, result)
+
+    self.receiver.completed(cmd)
+    # XXX: don't forget to obey sync for manual completion as well
+    if cmd.sync:
+      self.channel.session_completed(self.receiver._completed)
+
+  def send(self, cmd):
+    self.sender.send(cmd)
+
+  def __repr__(self):
+    return '<Session: %s, %s>' % (self.name, self.channel)
+
+class Receiver:
+
+  def __init__(self, session):
+    self.session = session
+    self.next_id = None
+    self._completed = RangedSet()
+
+  def received(self, cmd):
+    if self.next_id == None:
+      raise Exception("todo")
+    cmd.id = self.next_id
+    self.next_id += 1
+
+  def completed(self, cmd):
+    if cmd.id == None:
+      raise ValueError("cannot complete unidentified command")
+    self._completed.add(cmd.id)
+
+  def known_completed(self, commands):
+    completed = RangedSet()
+    for c in self._completed.ranges:
+      for kc in commands.ranges:
+        if c.lower in kc and c.upper in kc:
+          break
+      else:
+        completed.add_range(c)
+    self._completed = completed
+
+class Sender:
+
+  def __init__(self, session):
+    self.session = session
+    self.next_id = serial(0)
+    self.commands = []
+    self._completed = RangedSet()
+
+  def send(self, cmd):
+    ch = self.session.channel
+    if ch is None:
+      raise SessionDetached()
+    cmd.id = self.next_id
+    self.next_id += 1
+    if self.session.send_id:
+      self.session.send_id = False
+      ch.session_command_point(cmd.id, 0)
+    self.commands.append(cmd)
+    ch.connection.write_op(cmd)
+
+  def completed(self, commands):
+    idx = 0
+    while idx < len(self.commands):
+      cmd = self.commands[idx]
+      if cmd.id in commands:
+        del self.commands[idx]
+      else:
+        idx += 1
+    for range in commands.ranges:
+      self._completed.add(range.lower, range.upper)
+
+class Incoming(Queue):
+
+  def __init__(self, session, destination):
+    Queue.__init__(self)
+    self.session = session
+    self.destination = destination
+
+  def start(self):
+    self.session.message_set_flow_mode(self.destination, self.session.flow_mode.credit)
+    for unit in self.session.credit_unit.VALUES:
+      self.session.message_flow(self.destination, unit, 0xFFFFFFFFL)
+
+  def stop(self):
+    self.session.message_cancel(self.destination)
+    self.listen(None)
+
+class Delegate:
+
+  def __init__(self, session):
+    self.session = session
+
+  #XXX: do something with incoming accepts
+  def message_accept(self, ma): None
+
+  def execution_result(self, er):
+    future = self.session.results.pop(er.command_id)
+    future.set(er.value)
+
+  def execution_exception(self, ex):
+    self.session.exceptions.append(ex)
+
+class Client(Delegate):
+
+  def message_transfer(self, cmd):
+    m = Message(cmd.payload)
+    m.headers = cmd.headers
+    m.id = cmd.id
+    messages = self.session.incoming(cmd.destination)
+    messages.put(m)
+    msg.debug("RECV %s", m)
+    return INCOMPLETE