def init(self, cfg=None):
""" This method will be called twice, once with a cfg parameter
and once without """
if cfg is None:
HttpServlet.init(self)
else:
HttpServlet.init(self, cfg)
# These are the things we only do once
if WMS.timer is None:
WMS.timer = Timer(1) # timer is a daemon
# Load the Log4j configuration file
file = self.getInitParameter("log4j-init-file")
if file is not None:
prefix = self.getServletContext().getRealPath("/")
PropertyConfigurator.configure(prefix + file)
WMS.logger.debug("Initialized logging system")
# Initialize the cache of datasets
DatasetCache.init()
WMS.logger.debug("Initialized DatasetCache")
# Start a timer that will clear the cache at regular intervals
# so that NcML aggregations are reloaded
# TODO: get the interval value from a config file
intervalInMs = int(60 * 1000) # Runs once a minute
WMS.cacheWiper = CacheWiper()
WMS.timer.scheduleAtFixedRate(WMS.cacheWiper, intervalInMs, intervalInMs)
WMS.logger.debug("Initialized NetcdfDatasetCache refresher")
WMS.logger.debug("ncWMS Servlet initialized")
def getVariableMetadata(location):
""" returns a dictionary of VariableMetadata objects. The keys
in the dictionary are the unique ids of the variables and
the values are VariableMetadata objects
location = location of dataset (full file path, OPeNDAP URL etc) """
# Get the dataset from the cache
return DatasetCache.getVariableMetadata(location)
def destroy(self):
DatasetCache.exit()
if WMS.timer is not None:
WMS.timer.cancel()
WMS.logger.debug("ncWMS Servlet destroyed")
def run(self):
DatasetCache.clear()
self.timeLastRan = time.time()
self.logger.debug("Cleared cache")