예제 #1
0
 def fallback():
     """
     fallback method to use, if reading from cache data is not possible
     """
     tsa = self.load_tsa(datestring=datestring, filterkeys=None, timedelta=timedelta) # load full tsa, and generate statistics
     tsastats = TimeseriesArrayStats(tsa) # generate full Stats
     tsastats.dump(cachedir) # save
     tsastats = TimeseriesArrayStats.load(cachedir, self.__index_keynames, filterkeys=filterkeys) # read specific
     return tsastats
예제 #2
0
    def load_tsastats(self, datestring, filterkeys=None, timedelta=0, cleancache=False):
        """
        caching version to load_tsa_raw
        if never called, get ts from load_tsa_raw, and afterwards dump_tsa
        on every consecutive call read from cached version
        use cleancache to remove caches

        parameters:
        datestring <str>
        timedelta <int>
        cleancache <bool>

        returns
        <TimeseriesArrayLazy> object read from cachefile or from raw data
        """
        try:
            assert not_today(datestring)
        except AssertionError:
            raise DataLoggerLiveDataError("Reading from live data is not allowed")
        cachedir = self.__get_cachedir(datestring)
        cachefilename = os.path.join(cachedir, TimeseriesArrayStats.get_dumpfilename(self.__index_keynames))
        def fallback():
            """
            fallback method to use, if reading from cache data is not possible
            """
            tsa = self.load_tsa(datestring=datestring, filterkeys=None, timedelta=timedelta) # load full tsa, and generate statistics
            tsastats = TimeseriesArrayStats(tsa) # generate full Stats
            tsastats.dump(cachedir) # save
            tsastats = TimeseriesArrayStats.load(cachedir, self.__index_keynames, filterkeys=filterkeys) # read specific
            return tsastats
        if not os.path.isfile(cachefilename):
            logging.info("cachefile %s does not exist, fallback read from tsa archive", cachefilename)
            return fallback()
        if (os.path.isfile(cachefilename)) and (cleancache == True):
            logging.info("deleting cachefile %s and read from raw", cachefilename)
            os.unlink(cachefilename)
            return fallback()
        logging.debug("loading stored TimeseriesArrayLazy object file %s", cachefilename)
        try:
            tsastats = TimeseriesArrayStats.load(cachedir, self.__index_keynames, filterkeys=filterkeys)
            return tsastats
        except IOError:
            logging.error("IOError while reading from %s, using fallback", cachefilename)
            os.unlink(cachefilename)
            return fallback()
        except EOFError:
            logging.error("EOFError while reading from %s, using fallback", cachefilename)
            os.unlink(cachefilename)
            return fallback()