On Tue, 1 Feb 2005 00:32:25 -0500, James Y Knight <foom@fuhm.net> wrote:
Yes, it is. One thing that I think would make it more useful, if it can be pulled off, is to allow caching at any level. That is, something like the following stan: html[body[cached(timeout=10, keys=(IFoo, IBar))[semi_constant_header_stuff], very_dynamic_content]]
That is, a function which will render its contents to a string the first time it's called, and store/return it for the next 10 seconds, using the same mechanism as the posted patch. The cache would be keyed off certain interfaces, and only those will get passed on to the functions being rendered inside, thus ensuring the safety of the cache.
I think there are a lot of pages that are mostly "semi-static", but have some very dynamic content in them, so something like could be *very* useful.
Anyhow, this is just an outline of how I think it might work, but I haven't tried to implement it yet, so I don't know if it will work out the way I'd like it to. :)
Here I am. Below there's a more fine grained implementation. You can use it like this: cached(name="foo", lifetime=10)[t.p['hi boy']] the name should be enough to give a cache for everyone since you can do: cached(name=IAvatar(ctx).uid, lifetime=60)[t.p['Hi ', IAvatar(ctx).username]] If you don't pass the lifetime parameter it won't be cached. I must admit I haven't tested it yet since I don't know how to write unittests for this stuff... ;P. Let me know what do you think about. I also think that having another nevow tag for this cached would be ok. Index: nevow/tags.py =================================================================== --- nevow/tags.py (revision 1136) +++ nevow/tags.py (working copy) @@ -62,7 +62,9 @@ def inlineJS(s): return script(type="text/javascript", language="JavaScript")[xml('\n//<![CDATA[\n%s\n//]]>\n' % s)] -__all__ = tags + ['invisible', 'comment', '_dir', '_del', '_object', '_map', 'drange', 'Tag', 'directive', 'xml', 'raw', 'slot', 'cdata', 'inlineJS'] + ['_%s' % x for x in range(100)] +__all__ = tags + ['invisible', 'comment', '_dir', '_del', '_object', + '_map', 'drange', 'Tag', 'directive', 'xml', 'raw', + 'slot', 'cached', 'cdata', 'inlineJS'] + ['_%s' % x for x in range(100)] ######################## Index: nevow/flat/flatstan.py =================================================================== --- nevow/flat/flatstan.py (revision 1136) +++ nevow/flat/flatstan.py (working copy) @@ -226,6 +226,31 @@ return serialize(original.default, context) return serialize(data, context) +_CACHE = {} +from time import time as now +def CachedSerializer(original, context): + if context.precompile: + original.children = precompile(original.children, context) + return original + + cached = _CACHE.get(original.name, None) + if cached and cached[0] > now()-original.lifetime: + return cached[1] + toSerialize = serialize(original.children, context) + tmp = [] + while 1: + try: + d = toSerialize.next() + tmp.append(d) + except StopIteration: + c = ''.join(tmp) + break + except AttributeError: + c = toSerialize + break + _CACHE[original.name] = (now(), c) + return c + def ContextSerializer(original, context): originalContext = original.clone(deep=False) originalContext.precompile = context and context.precompile or False Index: nevow/__init__.py =================================================================== --- nevow/__init__.py (revision 1136) +++ nevow/__init__.py (working copy) @@ -182,6 +182,7 @@ nevow.flat.flatstan.RendererSerializer nevow.inevow.IRenderer nevow.flat.flatstan.DirectiveSerializer nevow.stan.directive nevow.flat.flatstan.SlotSerializer nevow.stan.slot +nevow.flat.flatstan.CachedSerializer nevow.stan.cached nevow.flat.flatstan.ContextSerializer nevow.context.WovenContext nevow.flat.flatstan.DeferredSerializer twisted.internet.defer.Deferred nevow.flat.flatstan.DeferredSerializer twisted.internet.defer.DeferredList Index: nevow/stan.py =================================================================== --- nevow/stan.py (revision 1136) +++ nevow/stan.py (working copy) @@ -119,8 +119,33 @@ """ raise NotImplementedError, "Stan slot instances are not iterable." +class cached(object): + """Marker for cached content + """ + __slots__ = ['name', 'children', 'lifetime'] + def __init__(self, name, lifetime=0): + self.name = name + self.children = [] + self.lifetime = lifetime + def __repr__(self): + return "cached('%s','%s')" % self.name, self.lifetime + + def __getitem__(self, children): + """cached content is what is being cached + """ + if not isinstance(children, (list, tuple)): + children = [children] + self.children.extend(children) + return self + + def __iter__(self): + """Prevent an infinite loop if someone tries to do + for x in cached('foo'): + """ + raise NotImplementedError, "Stan slot instances are not iterable." + class Tag(object): """Tag instances represent XML tags with a tag name, attributes, and children. Tag instances can be constructed using the Prototype