The template:
Timed cache: $*.5m*voom
The command line and the output:
% voom='Voom!' python x.py --env Timed cache: Voom!
The generated method's docstring:
""" This is the main method generated by Cheetah This cache will be refreshed every 30.0 seconds. """
The generated code:
1 write('Timed cache: ') 2 ## START CACHE REGION: at line, col (1, 15) in the source. 3 RECACHE = True 4 if not self._cacheData.has_key('55048032'): 5 self.__cache55048032__refreshTime = currentTime() + 30.0 6 elif currentTime() > self.__cache55048032__refreshTime: 7 self.__cache55048032__refreshTime = currentTime() + 30.0 8 else: 9 RECACHE = False 10 if RECACHE: 11 orig_trans = trans 12 trans = cacheCollector = DummyTransaction() 13 write = cacheCollector.response().write 14 write(filter(VFS(SL,"voom",1))) # generated from '$*.5m*voom' at # line 1, col 15. 15 trans = orig_trans 16 write = trans.response().write 17 self._cacheData['55048032'] = cacheCollector.response().getvalue() 18 del cacheCollector 19 write(self._cacheData['55048032']) 20 ## END CACHE REGION 21 write('\n')
This code is identical to the static cache example except for the docstring and the first if-block. (OK, so the cache ID is different and the comment on line 14 is different too. Big deal.)
Each timed-refresh cache item has a corrsponding private attribute
.__cache########__refreshTime
giving the refresh time
in ticks (=seconds since January 1, 1970). The first if-block (lines 3-9)
checks whether the cache value is missing or its update time has passed, and if
so, sets RECHARGE
to true and also schedules another refresh at the next
interval.
The method docstring reminds the user how often the cache will be refreshed. This information is unfortunately not as robust as it could be. Each timed-cache placeholder blindly generates a line in the docstring. If all refreshes are at the same interval, there will be multiple identical lines in the docstring. If the refreshes are at different intervals, you get a situation like this:
""" This is the main method generated by Cheetah This cache will be refreshed every 30.0 seconds. This cache will be refreshed every 60.0 seconds. This cache will be refreshed every 120.0 seconds. """