From 31edce0ba1e64a8d2b9a30617f1eabe5c2630891 Mon Sep 17 00:00:00 2001
From: Griatch <griatch@gmail.com>
Date: Thu, 21 Oct 2010 20:15:11 +0000
Subject: [PATCH] Added utils.utils.run_async as a simple wrapper to the
 Twisted deferred system. This allows for easily making a long-time-running
 process or command asynchronous.

---
 game/gamesrc/commands/default/tests.py | 36 ++++++++++++++++++++------
 src/utils/utils.py                     | 33 +++++++++++++++++++++++
 2 files changed, 61 insertions(+), 8 deletions(-)

diff --git a/game/gamesrc/commands/default/tests.py b/game/gamesrc/commands/default/tests.py
index 4c895827f2..f249ef18b2 100644
--- a/game/gamesrc/commands/default/tests.py
+++ b/game/gamesrc/commands/default/tests.py
@@ -7,8 +7,7 @@ from django.conf import settings
 from django.db import IntegrityError
 from src.comms.models import Msg
 from src.permissions import permissions
-from src.utils import create 
-from src.utils import debug
+from src.utils import create, debug, utils
 from game.gamesrc.commands.default.muxcommand import MuxCommand
 
 from src.commands import cmdsethandler
@@ -29,17 +28,38 @@ class CmdTest(MuxCommand):
 
     key = "@test"
     aliases = ["@te", "@test all"]
-    permissions = "cmd:Immortals Wizards"
+    #permissions = "cmd:Immortals" #Wizards
 
     # the muxcommand class itself handles the display
     # so we just defer to it by not adding any function.
 
     def func(self):
-        cmdsetname = "game.gamesrc.commands.default.cmdset_default.DefaultCmdSet"
-        self.caller.msg(cmdsethandler.CACHED_CMDSETS)
-        cmdsethandler.import_cmdset(cmdsetname, self, self)
-        self.caller.msg("Imported %s" % cmdsetname)
-        self.caller.msg(cmdsethandler.CACHED_CMDSETS)
+        
+        def test():
+            li = []
+            for l in range(10000):
+                li.append(l)            
+            self.caller.msg(li[-1]) 
+            return "This is the return text"
+            #print 1/0
+        def succ(f):
+            self.caller.msg("This is called after successful completion. Return value: %s" % f)            
+        def err(e):
+            self.caller.msg("An error was encountered... %s" % e)
+
+        #self.caller.msg("printed before call to sync run ...")
+        #test()
+        #self.caller.msg("after after call to sync run...")
+
+        self.caller.msg("printed before call to async run ...")
+        utils.run_async(test, at_return=succ, at_err=err)
+        self.caller.msg("printed after call to async run ...")
+    
+        #cmdsetname = "game.gamesrc.commands.default.cmdset_default.DefaultCmdSet"
+        #self.caller.msg(cmdsethandler.CACHED_CMDSETS)
+        #cmdsethandler.import_cmdset(cmdsetname, self, self)
+        #self.caller.msg("Imported %s" % cmdsetname)
+        #self.caller.msg(cmdsethandler.CACHED_CMDSETS)
 
 
 
diff --git a/src/utils/utils.py b/src/utils/utils.py
index 365e26f1d3..b9dad415d6 100644
--- a/src/utils/utils.py
+++ b/src/utils/utils.py
@@ -7,6 +7,7 @@ be of use when designing your own game.
 import os
 import textwrap
 import datetime
+from twisted.internet import threads
 from django.conf import settings
 from src.utils import ansi
 
@@ -335,3 +336,35 @@ def format_table(table, extra_space=1):
         ftable.append([str(col[irow]).ljust(max_widths[icol]) + " " * extra_space 
                        for icol, col in enumerate(table)])
     return ftable
+
+def run_async(async_func, at_return=None, at_err=None):
+    """
+    This wrapper will use Twisted's asynchronous features to run a slow
+    function using a separate reactor thread. In effect this means that 
+    the server will not be blocked while the slow process finish. 
+
+    Use this function with restrain and only for features/commands
+    that you know has no influence on the cause-and-effect order of your
+    game (commands given after the async function might be executed before
+    it has finished).
+    
+    async_func() - function that should be run asynchroneously
+    at_return(r) - if given, this function will be called when async_func returns
+                   value r at the end of a successful execution
+    at_err(e) - if given, this function is called if async_func fails with an exception e. 
+                use e.trap(ExceptionType1, ExceptionType2)
+
+    """
+    # create deferred object 
+    
+    deferred = threads.deferToThread(async_func)
+    if at_return:
+        deferred.addCallback(at_return)
+    if at_err:
+        deferred.addErrback(at_err)
+    # always add a logging errback as a last catch
+    def default_errback(e):
+        from src.utils import logger
+        logger.log_trace(e)   
+    deferred.addErrback(default_errback)
+