[Twisted-web] NamedAnyError

[Andrea Arcangeli]

On Fri, May 06, 2005 at 09:00:47PM +0200, Valentino Volonghi wrote:
> Stackless is a patched version of CPython that has support for
> microthreads, done with tasklets and greenlets.
> you can simulate continuations for example.

Ok, since this is not the official python, I wonder why it warns then,
what I advantage would I get if I would patch python with stackless when
using it with twisted/nevow?

> usually stackless is used in games where there are tons of threads that
> it can handle without much hassles. :)

But still it won't scale at all in HT/multicore/smp ;). What about the
syscalls, will they block hanging the whole thing like it would happen
with twisted?

BTW, this is my whole patch against SVN, it also switch off the warning
in production with -W ingore, plus it adds caching and it removes the
annoying __start_* that breaks wget. Feel free to pick whatever you find
good enough for merging into SVN. thanks!

Index: Nevow/nevow/flat/ten.py
===================================================================
--- Nevow/nevow/flat/ten.py	(revision 1502)
+++ Nevow/nevow/flat/ten.py	(working copy)
@@ -37,7 +37,7 @@
             flattener = util._namedAnyWithBuiltinTranslation(flattener)
             forType = util._namedAnyWithBuiltinTranslation(forType)
         except util._NamedAnyError:
-            print "NamedAnyError:", flattener, forType
+            warnings.warn('NamedAnyError: %r %r' % (flattener, forType))
 
     if not isinstance(forType, interface.InterfaceClass):
         # fix up __implements__ if it's old style
Index: Nevow/nevow/compy.py
===================================================================
--- Nevow/nevow/compy.py	(revision 1502)
+++ Nevow/nevow/compy.py	(working copy)
@@ -32,7 +32,7 @@
             origInterface = _namedAnyWithBuiltinTranslation(origInterface)
             interfaceClasses = [_namedAnyWithBuiltinTranslation(x) for x in interfaceClasses]
         except _NamedAnyError, nae:
-            print 'NamedAnyError:', nae
+            warnings.warn('NamedAnyError: %r' % nae)
             return
         # print "_registerAdapter:",adapterFactory, origInterface, interfaceClasses
     if 'nevow.inevow.ISerializable' in interfaceClasses or filter(
Index: Nevow/nevow/rend.py
===================================================================
--- Nevow/nevow/rend.py	(revision 1502)
+++ Nevow/nevow/rend.py	(working copy)
@@ -31,6 +31,7 @@
 from nevow import flat
 from nevow.util import log
 from nevow import util
+from nevow import url
 
 import formless
 from formless import iformless
@@ -402,6 +403,8 @@
         self.children[name] = child
     
 
+_CACHE = {}
+
 class Page(Fragment, ConfigurableFactory, ChildLookupMixin):
     """A page is the main Nevow resource and renders a document loaded
     via the document factory (docFactory).
@@ -415,8 +418,37 @@
     afterRender = None
     addSlash = None
 
+    cache = False
+    lifetime = -1
+    __lastCacheRendering = 0
+
     flattenFactory = lambda self, *args: flat.flattenFactory(*args)
 
+    def hasCache(self, ctx):
+        if not self.cache:
+            return
+
+        _now = now() # run gettimeofday only once
+        timeout = _now > self.__lastCacheRendering + self.lifetime and \
+                  self.lifetime >= 0
+        c = self.lookupCache(ctx)
+        if timeout or c is None:
+            # stop other renders
+            self.__lastCacheRendering = _now
+            c = None
+        return c
+    def cacheRendered(self, ctx, c):
+        if not self.cache:
+            return
+        # overwrite the deferred with the data
+        self.storeCache(ctx, c)
+    def cacheIDX(self, ctx):
+        return str(url.URL.fromContext(ctx))
+    def storeCache(self, ctx, c):
+        _CACHE[self.cacheIDX(ctx)] = c
+    def lookupCache(self, ctx):
+        return _CACHE.get(self.cacheIDX(ctx))
+
     def renderHTTP(self, ctx):
         if self.beforeRender is not None:
             return util.maybeDeferred(self.beforeRender,ctx).addCallback(
@@ -441,11 +473,18 @@
             if self.afterRender is not None:
                 return util.maybeDeferred(self.afterRender,ctx)
 
-        if self.buffered:
+        c = self.hasCache(ctx)
+        if c is not None:
+            finishRequest()
+            return c
+
+        if self.buffered or self.cache:
             io = StringIO()
             writer = io.write
             def finisher(result):
-                request.write(io.getvalue())
+                c = io.getvalue()
+                self.cacheRendered(ctx, c)
+                request.write(c)
                 return util.maybeDeferred(finishRequest).addCallback(lambda r: result)
         else:
             writer = request.write
@@ -529,7 +568,6 @@
             else:
                 ## Use the redirectAfterPost url
                 ref = str(redirectAfterPost)
-            from nevow import url
             refpath = url.URL.fromString(ref)
             magicCookie = '%s%s%s' % (now(),request.getClientIP(),random.random())
             refpath = refpath.replace('_nevow_carryover_', magicCookie)
Index: Nevow/nevow/guard.py
===================================================================
--- Nevow/nevow/guard.py	(revision 1502)
+++ Nevow/nevow/guard.py	(working copy)
@@ -263,7 +263,8 @@
         if path.startswith(SESSION_KEY):
             key = path[len(SESSION_KEY):]
             if key not in self.sessions:
-                return urlToChild(request, *segments[1:], **{'__start_session__':1}), ()
+                #return urlToChild(request, *segments[1:], **{'__start_session__':1}), ()
+                return urlToChild(request, *segments[1:]), ()
             self.sessions[key].setLifetime(self.sessionLifetime)
             if cookie == key:
                 # /sessionized-url/${SESSION_KEY}aef9c34aecc3d9148/foo
@@ -271,7 +272,8 @@
                 #                  we are this getChild
                 # with a matching cookie
                 self.sessions[key].sessionJustStarted = True
-                return urlToChild(request, *segments[1:], **{'__session_just_started__':1}), ()
+                #return urlToChild(request, *segments[1:], **{'__session_just_started__':1}), ()
+                return urlToChild(request, *segments[1:]), ()
             else:
                 # We attempted to negotiate the session but failed (the user
                 # probably has cookies disabled): now we're going to return the