Added long time missing flow.py library file.

git-svn-id: http://yate.null.ro/svn/yate/trunk@5132 acf43c95-373e-0410-b603-e72c3f656dc1

share/scripts/yaypm/yaypm/flow.py

@@ -0,0 +1,105 @@
+#!/usr/bin/python
+# -*- coding: iso-8859-2; -*-
+"""
+ flow.py
+
+ Flow submodule for YAYPM.
+ 
+ Copyright (C) 2005 Maciek Kaminski 
+
+ 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+"""
+
+from twisted.internet import reactor, defer
+import types
+
+import sys, logging, random, time, types, traceback, yaypm
+
+logger_flow = logging.getLogger('yaypm.flow')
+
+current_result = None
+
+def logFailure(f):
+    if f.type!=yaypm.AbandonedException:
+        if logger_flow.isEnabledFor(logging.WARN):
+            logger_flow.warn("Exception in flow: %s" % str(f))
+    return f
+
+class Result:
+    def __init__(self, result = None, failure = None):
+        self.result = result
+        self.failure = failure
+    
+    def getResult(self):
+        current_result = None                    
+        if self.failure:
+            if self.failure.value:
+                raise self.failure.value
+            else:
+                raise Exception(self.failure)
+        else:
+            return self.result
+
+def getResult():
+    global current_result    
+    if current_result:
+        return current_result.getResult()
+    else:
+        None
+        
+class Flow:
+    def step(self):
+        d = None
+        try:
+            d = self.fun_todo.next()
+            if isinstance(d, defer.Deferred):
+                d.addCallbacks(self.callback, self.errback)
+                d.addErrback(logFailure)
+                d.addErrback(self.unhandled_exception)
+            else:
+                self.return_with.callback(d)
+        except StopIteration:
+            if d:
+                self.return_with.callback(d)
+            self.return_with.callback(None)       
+    
+    def __init__(self, fun_todo, return_with):
+        self.fun_todo = fun_todo
+        self.return_with = return_with
+        global current_result
+        current_result = None        
+        self.step()
+
+    def callback(self, result):
+        global current_result
+        current_result = Result(result)
+        self.step()
+
+    def errback(self, failure):
+        global current_result
+        current_result = Result(failure = failure)
+        self.step()
+
+    def unhandled_exception(self, failure):
+        self.return_with.errback(failure)
+
+def go(fun_todo):
+    return_with = defer.Deferred()
+    if isinstance(fun_todo, types.GeneratorType):
+        Flow(fun_todo, return_with)
+    else:
+        reactor.callLater(0, return_with.callback, fun_todo)
+    return return_with
+