def _check_size(self, key, delete=True):
"""Check the size that a specific TimeMap value is using on disk.
It deletes if it is more than the maximum size.
:param key: The TimeMap original resource.
:param delete: (Optional) When true, the value is deleted.
Else only a warning is raised.
:return: The size of the value on disk (0 if it was deleted).
"""
try:
fname = md5(key).hexdigest() # werkzeug key
fpath = self.path + '/' + fname
size = os.path.getsize(fpath)
if size > self.max_file_size and delete:
message = ("Cache value too big (%dB, max %dB) "
"for the TimeMap of %s")
if delete:
message += ". Deleting cached value."
os.remove(fpath)
size = 0
logging.warning(message % (size, self.max_file_size, key))
return size
except Exception as e:
logging.error(
"Exception checking cache value size for TimeMap of %s "
"Exception: %s" % (key, e))
return 0
def _check_size(self, key, delete=True):
"""Check the size that a specific TimeMap value is using on disk.
It deletes if it is more than the maximum size.
:param key: The TimeMap original resource.
:param delete: (Optional) When true, the value is deleted.
Else only a warning is raised.
:return: The size of the value on disk (0 if it was deleted).
"""
try:
fname = md5(key).hexdigest() # werkzeug key
fpath = self.path + '/' + fname
size = os.path.getsize(fpath)
if size > self.max_file_size and delete:
message = ('Cache value too big (%dB, max %dB) '
'for the TimeMap of %s')
if delete:
message += '. Deleting cached value.'
os.remove(fpath)
size = 0
logging.warning(message % (size, self.max_file_size, key))
return size
except Exception as e:
logging.error(
'Exception checking cache value size for TimeMap of %s '
'Exception: %s' % (key, e))
return 0
def __init__(self,
path,
tolerance,
expiration,
max_values,
run_tests=True,
max_file_size=0):
"""Constructor method.
:param path: The path of the cache database file.
:param tolerance: The tolerance, in seconds to which a TimeMap is
considered young enough to be used as is.
:param expiration: How long, in seconds, the cache entries are stored
every get will be a CACHE MISS.
:param max_values: The maximum number of TimeMaps stored in cache
before some are deleted
:param run_tests: (Optional) Tests the cache at initialization.
:param max_file_size: (Optional) The maximum size (in Bytes) for a
TimeMap cache value. When max_file_size=0, there is no limit to
a cache value. When max_file_size=X > 0, the cache will not
store TimeMap that require more than X Bytes on disk.
"""
# Parameters Check
if tolerance <= 0 or expiration <= 0 or max_values <= 0:
raise CacheError('Cannot create cache: all parameters must be > 0')
self.tolerance = relativedelta(seconds=tolerance)
self.path = path.rstrip('/')
self.max_file_size = max(max_file_size, 0)
self.CHECK_SIZE = self.max_file_size > 0
self.max_values = max_values
self.backend = FileSystemCache(path,
threshold=self.max_values,
default_timeout=expiration)
# Testing cache
if run_tests:
try:
key = b'1'
val = 1
self.backend.set(key, val)
assert (not self.CHECK_SIZE) or self._check_size(key) > 0
assert self.backend.get(key) == val
os.remove(os.path.join(self.path, md5(key).hexdigest()))
except Exception as e:
raise CacheError('Error testing cache: %s' % e)
logging.debug('Cache created. max_files = %d. Expiration = %d. '
'max_file_size = %d' %
(self.max_values, expiration, self.max_file_size))
def __init__(self, path, tolerance, expiration, max_values, run_tests=True,
max_file_size=0):
"""Constructor method.
:param path: The path of the cache database file.
:param tolerance: The tolerance, in seconds to which a TimeMap is
considered young enough to be used as is.
:param expiration: How long, in seconds, the cache entries are stored
every get will be a CACHE MISS.
:param max_values: The maximum number of TimeMaps stored in cache
before some are deleted
:param run_tests: (Optional) Tests the cache at initialization.
:param max_file_size: (Optional) The maximum size (in Bytes) for a
TimeMap cache value. When max_file_size=0, there is no limit to
a cache value. When max_file_size=X > 0, the cache will not
store TimeMap that require more than X Bytes on disk.
"""
# Parameters Check
if tolerance <= 0 or expiration <= 0 or max_values <= 0:
raise CacheError("Cannot create cache: all parameters must be > 0")
self.tolerance = relativedelta(seconds=tolerance)
self.path = path.rstrip('/')
self.max_file_size = max(max_file_size, 0)
self.CHECK_SIZE = self.max_file_size > 0
self.max_values = max_values
self.backend = FileSystemCache(path,
threshold=self.max_values,
default_timeout=expiration)
# Testing cache
if run_tests:
try:
key = '1'
val = 1
self.backend.set(key, val)
assert (not self.CHECK_SIZE) or self._check_size(key) > 0
assert self.backend.get(key) == val
os.remove(self.path + '/' + md5(key).hexdigest())
except Exception as e:
raise CacheError("Error testing cache: %s" % e)
logging.debug(
"Cache created. max_files = %d. Expiration = %d. "
"max_file_size = %d" % (
self.max_values, expiration, self.max_file_size))
