def download_data(filename, merge, java_application):
"""Download appstats data from memcache."""
oldrecords = []
oldfile = None
if merge:
try:
oldfile = open(filename, 'rb')
except IOError:
logging.info('No file to merge. Creating new file %s', filename)
if oldfile:
logging.info('Merging with existing file %s', filename)
oldrecords = loader.UnpickleFromFile(oldfile)
oldfile.close()
if oldrecords:
last_timestamp = oldrecords[0].start_timestamp_milliseconds()
records = loader.FromMemcache(filter_timestamp=last_timestamp,
java_application=java_application)
else:
records = loader.FromMemcache(java_application=java_application)
merged_records = records + oldrecords
try:
outfile = open(filename, 'wb')
except IOError:
logging.error('Cannot open %s', filename)
return
loader.PickleToFile(merged_records, outfile)
outfile.close()
def ReadData(self, source):
"""Parses source option and reads appropriate data source.
Args:
source: Source of Appstats data. Either filename if being read from
a file or MEMCACHE if being read from memcache.
Returns:
errormessage: An error message to display to the user if an error occured
while reading data, None if no error occured.
recordlist: A list of Appstats records in RequestStatProto protobuf format
in reverse chronological order (i.e. most recent first).
"""
errormessage = None
recordlist = None
if source == 'MEMCACHE':
recordlist = loader.FromMemcache()
else:
rootdir = self.GetRoot()
if rootdir is None:
errormessage = 'No parent directory has app.yaml!'
return errormessage, recordlist
source_root = os.path.join(rootdir, source)
try:
outfile = mockable_open(source_root, 'rb')
except IOError:
logging.error('Cannot open %s', source)
errormessage = 'Unable to open file!'
return errormessage, recordlist
mtime = os.path.getmtime(source_root)
if cache.IsCached(source, mtime):
logging.info('Using cached records from %s', source)
recordlist = cache.recordlist
else:
logging.info('Reading fresh records from %s', source)
recordlist = loader.UnpickleFromFile(outfile)
cache.Insert(source, mtime, recordlist)
return errormessage, recordlist