def init_app(self, app):
self.app = app
config = app.config.copy()
appenv = config.get('APPENV')
(_k, _v) = ('key31415926', '3.1415926')
if config['DEBUG']:
_cache = NullCache()
else:
if appenv == 'bae':
from bae_memcache.cache import BaeMemcache
CACHE_USER = config.get('CACHE_USER')
CACHE_PWD = config.get('CACHE_PWD')
CACHE_ID = config.get('CACHE_ID')
CACHE_ADDR = config.get('CACHE_ADDR')
_cache = BaeMemcache(CACHE_ID, CACHE_ADDR, CACHE_USER, CACHE_PWD)
try:
_cache.set(_k, _v)
except:
_cache = NullCache()
elif appenv == 'sae':
import pylibmc as memcache
_cache = memcache.Client()
try:
_cache.set(_k, _v)
except:
_cache = NullCache()
elif appenv == 'production':
_cache = SimpleCache()
else:
_cache = NullCache()
app.extensions['cache'] = _cache
class Cache(object):
"""
This class is used to control the cache objects.
If TESTING is True it will use NullCache.
"""
def __init__(self, app=None):
self.cache = None
if app is not None:
self.init_app(app)
else:
self.app = None
self._memoized = []
def init_app(self, app):
"This is used to initialize cache with your app object"
app.config.setdefault('CACHE_DEFAULT_TIMEOUT', 300)
app.config.setdefault('CACHE_THRESHOLD', 500)
app.config.setdefault('CACHE_KEY_PREFIX', None)
app.config.setdefault('CACHE_MEMCACHED_SERVERS', None)
app.config.setdefault('CACHE_DIR', None)
app.config.setdefault('CACHE_OPTIONS', None)
app.config.setdefault('CACHE_ARGS', [])
app.config.setdefault('CACHE_TYPE', 'null')
self.app = app
self._set_cache()
def _set_cache(self):
if self.app.config['TESTING']:
self.cache = NullCache()
else:
import_me = self.app.config['CACHE_TYPE']
if '.' not in import_me:
import_me = 'flaskext.cache.backends.' + \
import_me
cache_obj = import_string(import_me)
cache_args = self.app.config['CACHE_ARGS'][:]
cache_options = dict(default_timeout= \
self.app.config['CACHE_DEFAULT_TIMEOUT'])
if self.app.config['CACHE_OPTIONS']:
cache_options.update(self.app.config['CACHE_OPTIONS'])
self.cache = cache_obj(self.app, cache_args, cache_options)
if not isinstance(self.cache, BaseCache):
raise TypeError("Cache object must subclass "
"werkzeug.contrib.cache.BaseCache")
def get(self, *args, **kwargs):
"Proxy function for internal cache object."
return self.cache.get(*args, **kwargs)
def set(self, *args, **kwargs):
"Proxy function for internal cache object."
self.cache.set(*args, **kwargs)
def add(self, *args, **kwargs):
"Proxy function for internal cache object."
self.cache.add(*args, **kwargs)
def delete(self, *args, **kwargs):
"Proxy function for internal cache object."
self.cache.delete(*args, **kwargs)
def cached(self, timeout=None, key_prefix='view/%s', unless=None):
"""
Decorator. Use this to cache a function. By default the cache key
is `view/request.path`. You are able to use this decorator with any
function by changing the `key_prefix`. If the token `%s` is located
within the `key_prefix` then it will replace that with `request.path`
Example::
# An example view function
@cache.cached(timeout=50)
def big_foo():
return big_bar_calc()
# An example misc function to cache.
@cache.cached(key_prefix='MyCachedList')
def get_list():
return [random.randrange(0, 1) for i in range(50000)]
.. code-block:: pycon
>>> my_list = get_list()
.. note::
You MUST have a request context to actually called any functions
that are cached.
:param timeout: Default None. If set to an integer, will cache for that
amount of time. Unit of time is in seconds.
:param key_prefix: Default 'view/%(request.path)s'. Beginning key to .
use for the cache key.
:param unless: Default None. Cache will *always* execute the caching
facilities unless this callable is true.
This will bypass the caching entirely.
"""
def decorator(f):
@wraps(f)
def decorated_function(*args, **kwargs):
#: Bypass the cache entirely.
if callable(unless) and unless() is True:
return f(*args, **kwargs)
if '%s' in key_prefix:
cache_key = key_prefix % request.path
else:
cache_key = key_prefix
cache_key = cache_key.encode('utf-8')
rv = self.cache.get(cache_key)
if rv is None:
rv = f(*args, **kwargs)
self.cache.set(cache_key, rv, timeout=timeout)
return rv
return decorated_function
return decorator
def get_memoize_names(self):
"""
Returns all function names used for memoized functions.
This *will* include multiple function names when the memoized function
has been called with differing arguments.
:return: set of function names
"""
return set([item[0] for item in self._memoized])
def get_memoize_keys(self):
"""
Returns all cache_keys used for memoized functions.
:return: list generator of cache_keys
"""
return [item[1] for item in self._memoized]
def memoize(self, timeout=None):
"""
Use this to cache the result of a function, taking its arguments into
account in the cache key.
Information on
`Memoization <http://en.wikipedia.org/wiki/Memoization>`_.
Example::
@cache.memoize(timeout=50)
def big_foo(a, b):
return a + b + random.randrange(0, 1000)
.. code-block:: pycon
>>> big_foo(5, 2)
753
>>> big_foo(5, 3)
234
>>> big_foo(5, 2)
753
:param timeout: Default None. If set to an integer, will cache for that
amount of time. Unit of time is in seconds.
"""
def memoize(f):
@wraps(f)
def decorated_function(*args, **kwargs):
cache_key = hashlib.md5()
try:
updated = "{0}{1}{2}".format(f.__name__, args, kwargs)
except AttributeError:
updated = "%s%s%s" % (f.__name__, args, kwargs)
cache_key.update(updated)
cache_key = cache_key.digest().encode('base64')[:22]
rv = self.cache.get(cache_key)
if rv is None:
rv = f(*args, **kwargs)
self.cache.set(cache_key, rv, timeout=timeout)
self._memoized.append((f.__name__, cache_key))
return rv
return decorated_function
return memoize
def delete_memoized(self, fname, *args, **kwargs):
"""
Deletes the specified functions caches, based by given parameters.
If parameters are given, only the functions that were memoized with them
will be erased. Otherwise all the versions of the caches will be deleted.
Example::
@cache.memoize(50)
def random_func():
return random.randrange(1, 50)
@cache.memoize()
def param_func(a, b):
return a+b+random.randrange(1, 50)
.. code-block:: pycon
>>> random_func()
43
>>> random_func()
43
>>> cache.delete_memoized('random_func')
>>> random_func()
16
>>> param_func(1, 2)
32
>>> param_func(1, 2)
32
>>> param_func(2, 2)
47
>>> cache.delete_memoized('param_func', 1, 2)
>>> param_func(1, 2)
13
>>> param_func(2, 2)
47
:param fname: Name of the memoized function.
:param \*args: A list of positional parameters used with memoized function.
:param \**kwargs: A dict of named parameters used with memoized function.
"""
def deletes(item):
# If no parameters given, delete all memoized versions of the function
if not args and not kwargs:
if item[0] == fname:
self.cache.delete(item[1])
return True
return False
# Construct the cache key as in memoized function
cache_key = hashlib.md5()
try:
updated = "{0}{1}{2}".format(fname, args, kwargs)
except AttributeError:
updated = "%s%s%s" % (fname, args, kwargs)
cache_key.update(updated)
cache_key = cache_key.digest().encode('base64')[:22]
if item[1] == cache_key:
self.cache.delete(item[1])
return True
return False
self._memoized[:] = [x for x in self._memoized if not deletes(x)]
class ConfigSyncSchedules(object):
__name__ = "ConfigSyncSchedules"
sub_ips = EC.sub_ips
range_nb_ips = EC.range_nb_ips
skip_ips = EC.skip_ips
def __init__(self,
api_uri: str,
matchbox_path: str,
ignition_dict: dict,
extra_selector_dict=None):
"""
:param api_uri: http://1.1.1.1:5000
:param matchbox_path: /var/lib/matchbox
:param ignition_dict: ignition.yaml
"""
self.api_uri = api_uri
os.environ["API_URI"] = self.api_uri
self.matchbox_path = matchbox_path
self.ignition_dict = ignition_dict
self._reporting_ignitions()
self.extra_selector = extra_selector_dict if extra_selector_dict else {}
# inMemory cache for http queries
if EC.sync_cache_ttl > 0:
self._cache_query = SimpleCache(default_timeout=EC.sync_cache_ttl)
else:
self._cache_query = NullCache()
def _reporting_ignitions(self):
for k, v in self.ignition_dict.items():
f = "%s/ignition/%s.yaml" % (self.matchbox_path, v)
if os.path.isfile(f) is False:
logger.error("%s:%s -> %s is not here" % (k, v, f))
raise IOError(f)
with open(f, 'rb') as ignition_file:
blob = ignition_file.read()
data = {v: blob.decode()}
url = "%s/ignition/version/%s" % (self.api_uri, v)
try:
req = requests.post(url, data=json.dumps(data))
req.close()
response = json.loads(req.content.decode())
logger.info("%s:%s -> %s is here content reported: %s" %
(k, v, f, response))
except requests.exceptions.ConnectionError as e:
logger.error("%s:%s -> %s is here content NOT reported: %s" %
(k, v, f, e))
@staticmethod
def get_dns_attr(fqdn: str):
"""
TODO: Use LLDP to avoid vendor specific usage
:param fqdn: e.g: r13-srv3.dc-1.foo.bar.cr
:return:
"""
d = {
"shortname": "",
"dc": "",
"domain": "",
"rack": "",
"pos": "",
}
s = fqdn.split(".")
d["shortname"] = s[0]
try:
d["dc"] = s[1]
except IndexError:
logger.error("IndexError %s[1] after split(.)" % fqdn)
return d
d["domain"] = ".".join(s[1:])
try:
rack, pos = s[0].split("-")
d["rack"] = re.sub("[^0-9]+", "", rack)
d["pos"] = re.sub("[^0-9]+", "", pos)
except ValueError:
logger.error("error during the split rack/pos %s" % s[0])
return d
@staticmethod
def _cni_ipam(host_cidrv4: str, host_gateway: str):
"""
see: https://github.com/containernetworking/cni/blob/master/SPEC.md#ip-allocation
see: https://github.com/containernetworking/plugins/tree/master/plugins/ipam/host-local
With the class variables provide a way to generate a static host-local ipam
:param host_cidrv4: an host IP with its CIDR prefixlen, eg: '10.0.0.42/8'
:param host_gateway: an host IP for the gateway, eg: '10.0.0.1'
:return: dict
"""
interface = IPv4Interface(host_cidrv4)
subnet = interface.network
try:
assert 0 <= ConfigSyncSchedules.sub_ips <= 256
assert (lambda x: x & (x - 1) == 0)(ConfigSyncSchedules.sub_ips)
except AssertionError:
raise ValueError(
'sub_ips must be a power of two, in [0, 256] interval')
if ConfigSyncSchedules.sub_ips > 0:
ip_last_decimal_field = int(str(interface.ip).split('.')[-1])
interface = IPv4Interface(interface.network.network_address +
ip_last_decimal_field *
ConfigSyncSchedules.sub_ips)
range_start = interface.ip + ConfigSyncSchedules.skip_ips
range_end = range_start + ConfigSyncSchedules.range_nb_ips
ipam = {
"type":
"host-local",
"subnet":
"%s" % (str(subnet)),
"rangeStart":
str(range_start),
"rangeEnd":
str(range_end),
"gateway":
host_gateway,
"routes": [
{
"dst": "%s/32" % EC.perennial_local_host_ip,
"gw": str(IPv4Interface(host_cidrv4).ip)
},
{
"dst": "0.0.0.0/0"
},
],
"dataDir":
"/var/lib/cni/networks"
}
return ipam
@staticmethod
def get_extra_selectors(extra_selectors: dict):
"""
Extra selectors are passed to Matchbox
:param extra_selectors: dict
:return:
"""
if extra_selectors:
if type(extra_selectors) is dict:
logger.debug("extra selectors: %s" % extra_selectors)
return extra_selectors
logger.error("invalid extra selectors: %s" % extra_selectors)
raise TypeError("%s %s is not type dict" %
(extra_selectors, type(extra_selectors)))
logger.debug("no extra selectors")
return {}
@property
def etcd_member_ip_list(self):
return self._query_ip_list(schedulerv2.ScheduleRoles.etcd_member)
@property
def kubernetes_control_plane_ip_list(self):
return self._query_ip_list(
schedulerv2.ScheduleRoles.kubernetes_control_plane)
@property
def kubernetes_nodes_ip_list(self):
return self._query_ip_list(schedulerv2.ScheduleRoles.kubernetes_node)
@staticmethod
def order_http_uri(ips: list, ec_value: int, secure=False):
ips.sort()
e = [
"http{}://%s:%d".format("s" if secure else "") % (k, ec_value)
for k in ips
]
return e
@staticmethod
def order_etcd_named(ips: list, ec_value: int, secure=False):
ips.sort()
e = [
"%s=http{}://%s:%d".format("s" if secure else "") %
(k, k, ec_value) for k in ips
]
return ",".join(e)
@property
def kubernetes_etcd_initial_cluster(self):
return self.order_etcd_named(self.etcd_member_ip_list,
EC.kubernetes_etcd_peer_port,
secure=True)
@property
def vault_etcd_initial_cluster(self):
return self.order_etcd_named(self.etcd_member_ip_list,
EC.vault_etcd_peer_port,
secure=True)
@property
def fleet_etcd_initial_cluster(self):
return self.order_etcd_named(self.etcd_member_ip_list,
EC.fleet_etcd_peer_port,
secure=True)
@property
def kubernetes_etcd_member_client_uri_list(self):
return self.order_http_uri(self.etcd_member_ip_list,
EC.kubernetes_etcd_client_port,
secure=True)
@property
def vault_etcd_member_client_uri_list(self):
return self.order_http_uri(self.etcd_member_ip_list,
EC.vault_etcd_client_port,
secure=True)
@property
def fleet_etcd_member_client_uri_list(self):
return self.order_http_uri(self.etcd_member_ip_list,
EC.fleet_etcd_client_port,
secure=True)
@property
def kubernetes_etcd_member_peer_uri_list(self):
return self.order_http_uri(self.etcd_member_ip_list,
EC.kubernetes_etcd_peer_port,
secure=True)
@property
def vault_etcd_member_peer_uri_list(self):
return self.order_http_uri(self.etcd_member_ip_list,
EC.vault_etcd_peer_port,
secure=True)
@property
def fleet_etcd_member_peer_uri_list(self):
return self.order_http_uri(self.etcd_member_ip_list,
EC.fleet_etcd_peer_port,
secure=True)
@property
def kubernetes_control_plane(self):
return self.order_http_uri(self.kubernetes_control_plane_ip_list,
EC.kubernetes_apiserver_insecure_port)
@staticmethod
def compute_disks_size(disks: list):
total_size_gb = 0
if not disks:
return "inMemory"
for d in disks:
total_size_gb += d["size-bytes"] >> 30
ladder = list(EC.disks_ladder_gb.items())
ladder.sort(key=lambda x: x[1])
for k, v in ladder:
if total_size_gb < v:
return k
return ladder[-1][0]
def produce_matchbox_data(self,
marker: str,
i: int,
m: dict,
automatic_name: str,
update_extra_metadata=None):
fqdn = automatic_name
try:
if m["fqdn"]:
fqdn = m["fqdn"]
except KeyError as e:
logger.warning("%s for %s" % (e, m["mac"]))
etc_hosts = [k for k in EC.etc_hosts]
dns_attr = self.get_dns_attr(fqdn)
etc_hosts.append("127.0.1.1 %s %s" % (fqdn, dns_attr["shortname"]))
cni_attr = self._cni_ipam(m["cidrv4"], m["gateway"])
extra_metadata = {
"etc_hosts":
etc_hosts,
# Etcd
"etcd_name":
m["ipv4"],
"kubernetes_etcd_initial_cluster":
self.kubernetes_etcd_initial_cluster,
"vault_etcd_initial_cluster":
self.vault_etcd_initial_cluster,
"fleet_etcd_initial_cluster":
self.fleet_etcd_initial_cluster,
"kubernetes_etcd_initial_advertise_peer_urls":
"https://%s:%d" % (m["ipv4"], EC.kubernetes_etcd_peer_port),
"vault_etcd_initial_advertise_peer_urls":
"https://%s:%d" % (m["ipv4"], EC.vault_etcd_peer_port),
"fleet_etcd_initial_advertise_peer_urls":
"https://%s:%d" % (m["ipv4"], EC.fleet_etcd_peer_port),
"kubernetes_etcd_member_client_uri_list":
",".join(self.kubernetes_etcd_member_client_uri_list),
"vault_etcd_member_client_uri_list":
",".join(self.vault_etcd_member_client_uri_list),
"fleet_etcd_member_client_uri_list":
",".join(self.fleet_etcd_member_client_uri_list),
"kubernetes_etcd_data_dir":
EC.kubernetes_etcd_data_dir,
"vault_etcd_data_dir":
EC.vault_etcd_data_dir,
"fleet_etcd_data_dir":
EC.fleet_etcd_data_dir,
"kubernetes_etcd_client_port":
EC.kubernetes_etcd_client_port,
"vault_etcd_client_port":
EC.vault_etcd_client_port,
"fleet_etcd_client_port":
EC.fleet_etcd_client_port,
"kubernetes_etcd_advertise_client_urls":
"https://%s:%d" % (m["ipv4"], EC.kubernetes_etcd_client_port),
"vault_etcd_advertise_client_urls":
"https://%s:%d" % (m["ipv4"], EC.vault_etcd_client_port),
"fleet_etcd_advertise_client_urls":
"https://%s:%d" % (m["ipv4"], EC.fleet_etcd_client_port),
# Kubernetes
"kubernetes_apiserver_insecure_port":
EC.kubernetes_apiserver_insecure_port,
"kubernetes_node_ip":
"%s" % m["ipv4"],
"kubernetes_node_name":
"%s" % m["ipv4"] if fqdn == automatic_name else fqdn,
"kubernetes_service_cluster_ip_range":
EC.kubernetes_service_cluster_ip_range,
# Vault are located with the etcd members
"vault_ip_list":
",".join(self.etcd_member_ip_list),
"vault_port":
EC.vault_port,
"kubelet_healthz_port":
EC.kubelet_healthz_port,
"etcd_member_kubernetes_control_plane_ip_list":
",".join(self.etcd_member_ip_list),
"etcd_member_kubernetes_control_plane_ip":
self.etcd_member_ip_list,
"hyperkube_image_url":
EC.hyperkube_image_url,
"cephtools_image_url":
EC.cephtools_image_url,
# IPAM
"cni":
json.dumps(cni_attr, sort_keys=True),
"network": {
"cidrv4": m["cidrv4"],
"gateway": m["gateway"],
"ip": m["ipv4"],
"subnet": cni_attr["subnet"],
"perennial_host_ip": EC.perennial_local_host_ip,
"ip_or_fqdn":
fqdn if EC.sync_replace_ip_by_fqdn else m["ipv4"],
},
# host
"hostname":
dns_attr["shortname"],
"dns_attr":
dns_attr,
"nameservers":
" ".join(EC.nameservers),
"ntp":
" ".join(EC.ntp),
"fallbackntp":
" ".join(EC.fallbackntp),
"vault_polling_sec":
EC.vault_polling_sec,
"lifecycle_update_polling_sec":
EC.lifecycle_update_polling_sec,
"disk_profile":
self.compute_disks_size(m["disks"]),
}
selector = {"mac": m["mac"]}
selector.update(self.get_extra_selectors(self.extra_selector))
if update_extra_metadata:
extra_metadata.update(update_extra_metadata)
gen = generator.Generator(
api_uri=self.api_uri,
group_id="%s-%d" % (marker, i), # one per machine
profile_id=marker, # link to ignition
name=marker,
ignition_id="%s.yaml" % self.ignition_dict[marker],
matchbox_path=self.matchbox_path,
selector=selector,
extra_metadata=extra_metadata,
)
gen.dumps()
def etcd_member_kubernetes_control_plane(self):
marker = self.etcd_member_kubernetes_control_plane.__name__
roles = schedulerv2.EtcdMemberKubernetesControlPlane.roles
machine_roles = self._query_roles(*roles)
for i, m in enumerate(machine_roles):
update_md = {
# Roles
"roles":
",".join(roles),
# Etcd Members
"kubernetes_etcd_member_peer_uri_list":
",".join(self.kubernetes_etcd_member_peer_uri_list),
"vault_etcd_member_peer_uri_list":
",".join(self.vault_etcd_member_peer_uri_list),
"fleet_etcd_member_peer_uri_list":
",".join(self.fleet_etcd_member_peer_uri_list),
"kubernetes_etcd_peer_port":
EC.kubernetes_etcd_peer_port,
"vault_etcd_peer_port":
EC.vault_etcd_peer_port,
"fleet_etcd_peer_port":
EC.fleet_etcd_peer_port,
# K8s Control Plane
"kubernetes_apiserver_count":
len(machine_roles),
"kubernetes_apiserver_insecure_bind_address":
EC.kubernetes_apiserver_insecure_bind_address,
}
self.produce_matchbox_data(
marker=marker,
i=i,
m=m,
automatic_name="cp-%d-%s" % (i, m["ipv4"].replace(".", "-")),
update_extra_metadata=update_md,
)
logger.info("synced %d" % len(machine_roles))
return len(machine_roles)
def kubernetes_nodes(self):
marker = self.kubernetes_nodes.__name__
roles = schedulerv2.KubernetesNode.roles
machine_roles = self._query_roles(*roles)
for i, m in enumerate(machine_roles):
update_md = {
# Roles
"roles": ",".join(roles),
}
self.produce_matchbox_data(
marker=marker,
i=i,
m=m,
automatic_name="no-%d-%s" % (i, m["ipv4"].replace(".", "-")),
update_extra_metadata=update_md,
)
logger.info("synced %d" % len(machine_roles))
return len(machine_roles)
def notify(self):
"""
TODO if we need to notify the API for any reason
:return:
"""
req = requests.post("%s/sync-notify" % self.api_uri)
req.close()
logger.debug("notified API")
def apply(self, nb_try=2, seconds_sleep=0):
logger.info("start syncing...")
for i in range(nb_try):
try:
nb = self.etcd_member_kubernetes_control_plane()
nb += self.kubernetes_nodes()
self.notify()
return nb
except Exception as e:
logger.error("fail to apply the sync %s %s" % (type(e), e))
if i + 1 == nb_try:
raise
logger.warning("retry %d/%d in %d s" %
(i + 1, nb_try, seconds_sleep))
time.sleep(seconds_sleep)
raise RuntimeError("fail to apply after %d try" % nb_try)
def _query_roles(self, *roles):
roles = "&".join(roles)
url = "/scheduler/%s" % roles
logger.debug("roles='%s'" % roles)
data = self._cache_query.get(url)
if data is None:
# not in cache or evicted
logger.debug("cache is empty for %s" % url)
req = requests.get("%s%s" % (self.api_uri, url))
data = json.loads(req.content.decode())
req.close()
data.sort(key=lambda k: k["mac"])
self._cache_query.set(url, data)
return data
def _query_ip_list(self, role):
logger.debug("role='%s'" % role)
url = "/scheduler/ip-list/%s" % role
data = self._cache_query.get(url)
if data is None:
# not in cache or evicted
logger.debug("cache is empty for %s" % url)
req = requests.get("%s%s" % (self.api_uri, url))
data = json.loads(req.content.decode())
req.close()
data.sort()
self._cache_query.set(url, data)
return data
class Cache(object):
"""
This class is used to control the cache objects.
If TESTING is True it will use NullCache.
"""
def __init__(self, app=None):
self.cache = None
if app is not None:
self.init_app(app)
else:
self.app = None
self._memoized = []
def init_app(self, app):
"This is used to initialize cache with your app object"
app.config.setdefault('CACHE_DEFAULT_TIMEOUT', 300)
app.config.setdefault('CACHE_THRESHOLD', 500)
app.config.setdefault('CACHE_KEY_PREFIX', None)
app.config.setdefault('CACHE_MEMCACHED_SERVERS', None)
app.config.setdefault('CACHE_DIR', None)
app.config.setdefault('CACHE_OPTIONS', None)
app.config.setdefault('CACHE_ARGS', [])
app.config.setdefault('CACHE_TYPE', 'null')
self.app = app
self._set_cache()
def _set_cache(self):
if self.app.config['TESTING']:
self.cache = NullCache()
else:
import_me = self.app.config['CACHE_TYPE']
if '.' not in import_me:
import_me = 'flaskext.cache.backends.' + \
import_me
cache_obj = import_string(import_me)
cache_args = self.app.config['CACHE_ARGS'][:]
cache_options = dict(default_timeout= \
self.app.config['CACHE_DEFAULT_TIMEOUT'])
if self.app.config['CACHE_OPTIONS']:
cache_options.update(self.app.config['CACHE_OPTIONS'])
self.cache = cache_obj(self.app, cache_args, cache_options)
if not isinstance(self.cache, BaseCache):
raise TypeError("Cache object must subclass "
"werkzeug.contrib.cache.BaseCache")
def get(self, *args, **kwargs):
"Proxy function for internal cache object."
return self.cache.get(*args, **kwargs)
def set(self, *args, **kwargs):
"Proxy function for internal cache object."
self.cache.set(*args, **kwargs)
def add(self, *args, **kwargs):
"Proxy function for internal cache object."
self.cache.add(*args, **kwargs)
def delete(self, *args, **kwargs):
"Proxy function for internal cache object."
self.cache.delete(*args, **kwargs)
def cached(self, timeout=None, key_prefix='view/%s', unless=None):
"""
Decorator. Use this to cache a function. By default the cache key
is `view/request.path`. You are able to use this decorator with any
function by changing the `key_prefix`. If the token `%s` is located
within the `key_prefix` then it will replace that with `request.path`
Example::
# An example view function
@cache.cached(timeout=50)
def big_foo():
return big_bar_calc()
# An example misc function to cache.
@cache.cached(key_prefix='MyCachedList')
def get_list():
return [random.randrange(0, 1) for i in range(50000)]
my_list = get_list()
.. note::
You MUST have a request context to actually called any functions
that are cached.
.. versionadded:: 0.4
The returned decorated function now has three function attributes
assigned to it. These attributes are readable/writable.
**uncached**
The original undecorated function
**cache_timeout**
The cache timeout value for this function. For a custom value
to take affect, this must be set before the function is called.
**make_cache_key**
A function used in generating the cache_key used.
:param timeout: Default None. If set to an integer, will cache for that
amount of time. Unit of time is in seconds.
:param key_prefix: Default 'view/%(request.path)s'. Beginning key to .
use for the cache key.
.. versionadded:: 0.3.4
Can optionally be a callable which takes no arguments
but returns a string that will be used as the cache_key.
:param unless: Default None. Cache will *always* execute the caching
facilities unless this callable is true.
This will bypass the caching entirely.
"""
def decorator(f):
@wraps(f)
def decorated_function(*args, **kwargs):
#: Bypass the cache entirely.
if callable(unless) and unless() is True:
return f(*args, **kwargs)
cache_key = decorated_function.make_cache_key(*args, **kwargs)
rv = self.cache.get(cache_key)
if rv is None:
rv = f(*args, **kwargs)
self.cache.set(cache_key,
rv,
timeout=decorated_function.cache_timeout)
return rv
def make_cache_key(*args, **kwargs):
if '%s' in key_prefix:
cache_key = key_prefix % request.path
elif callable(key_prefix):
cache_key = key_prefix()
else:
cache_key = key_prefix
cache_key = cache_key.encode('utf-8')
return cache_key
decorated_function.uncached = f
decorated_function.cache_timeout = timeout
decorated_function.make_cache_key = make_cache_key
return decorated_function
return decorator
def get_memoize_names(self):
"""
Returns all function names used for memoized functions.
This *will* include multiple function names when the memoized function
has been called with differing arguments.
:return: set of function names
"""
return set([item[0] for item in self._memoized])
def get_memoize_keys(self):
"""
Returns all cache_keys used for memoized functions.
:return: list generator of cache_keys
"""
return [item[1] for item in self._memoized]
def memoize(self, timeout=None):
"""
Use this to cache the result of a function, taking its arguments into
account in the cache key.
Information on
`Memoization <http://en.wikipedia.org/wiki/Memoization>`_.
Example::
@cache.memoize(timeout=50)
def big_foo(a, b):
return a + b + random.randrange(0, 1000)
.. code-block:: pycon
>>> big_foo(5, 2)
753
>>> big_foo(5, 3)
234
>>> big_foo(5, 2)
753
.. versionadded:: 0.4
The returned decorated function now has three function attributes
assigned to it. These attributes are readable/writable.
**uncached**
The original undecorated function
**cache_timeout**
The cache timeout value for this function. For a custom value
to take affect, this must be set before the function is called.
**make_cache_key**
A function used in generating the cache_key used.
:param timeout: Default None. If set to an integer, will cache for that
amount of time. Unit of time is in seconds.
"""
def memoize(f):
@wraps(f)
def decorated_function(*args, **kwargs):
cache_key = decorated_function.make_cache_key(*args, **kwargs)
rv = self.cache.get(cache_key)
if rv is None:
rv = f(*args, **kwargs)
self.cache.set(cache_key,
rv,
timeout=decorated_function.cache_timeout)
self._memoized.append((f.__name__, cache_key))
return rv
def make_cache_key(*args, **kwargs):
cache_key = hashlib.md5()
try:
updated = "{0}{1}{2}".format(f.__name__, args, kwargs)
except AttributeError:
updated = "%s%s%s" % (f.__name__, args, kwargs)
cache_key.update(updated)
cache_key = cache_key.digest().encode('base64')[:22]
return cache_key
decorated_function.uncached = f
decorated_function.cache_timeout = timeout
decorated_function.make_cache_key = make_cache_key
return decorated_function
return memoize
def delete_memoized(self, fname, *args, **kwargs):
"""
Deletes the specified functions caches, based by given parameters.
If parameters are given, only the functions that were memoized with them
will be erased. Otherwise all the versions of the caches will be deleted.
Example::
@cache.memoize(50)
def random_func():
return random.randrange(1, 50)
@cache.memoize()
def param_func(a, b):
return a+b+random.randrange(1, 50)
.. code-block:: pycon
>>> random_func()
43
>>> random_func()
43
>>> cache.delete_memoized('random_func')
>>> random_func()
16
>>> param_func(1, 2)
32
>>> param_func(1, 2)
32
>>> param_func(2, 2)
47
>>> cache.delete_memoized('param_func', 1, 2)
>>> param_func(1, 2)
13
>>> param_func(2, 2)
47
:param fname: Name of the memoized function.
:param \*args: A list of positional parameters used with memoized function.
:param \**kwargs: A dict of named parameters used with memoized function.
"""
def deletes(item):
# If no parameters given, delete all memoized versions of the function
if not args and not kwargs:
if item[0] == fname:
self.cache.delete(item[1])
return True
return False
# Construct the cache key as in memoized function
cache_key = hashlib.md5()
try:
updated = "{0}{1}{2}".format(fname, args, kwargs)
except AttributeError:
updated = "%s%s%s" % (fname, args, kwargs)
cache_key.update(updated)
cache_key = cache_key.digest().encode('base64')[:22]
if item[1] == cache_key:
self.cache.delete(item[1])
return True
return False
self._memoized[:] = [x for x in self._memoized if not deletes(x)]
class Cache(object):
"""
This class is used to control the cache objects.
If TESTING is True it will use NullCache.
"""
def __init__(self, app=None, with_jinja2_ext=True):
self.with_jinja2_ext = with_jinja2_ext
self.cache = None
if app is not None:
self.init_app(app)
else:
self.app = None
self._memoized = []
def init_app(self, app):
"This is used to initialize cache with your app object"
app.config.setdefault('CACHE_DEFAULT_TIMEOUT', 300)
app.config.setdefault('CACHE_THRESHOLD', 500)
app.config.setdefault('CACHE_KEY_PREFIX', None)
app.config.setdefault('CACHE_MEMCACHED_SERVERS', None)
app.config.setdefault('CACHE_DIR', None)
app.config.setdefault('CACHE_OPTIONS', None)
app.config.setdefault('CACHE_ARGS', [])
app.config.setdefault('CACHE_TYPE', 'null')
if self.with_jinja2_ext:
setattr(app.jinja_env, JINJA_CACHE_ATTR_NAME, self)
app.jinja_env.add_extension(CacheExtension)
self.app = app
self._set_cache()
def _set_cache(self):
if self.app.config['TESTING']:
self.cache = NullCache()
else:
import_me = self.app.config['CACHE_TYPE']
if '.' not in import_me:
import_me = 'flaskext.cache.backends.' + \
import_me
cache_obj = import_string(import_me)
cache_args = self.app.config['CACHE_ARGS'][:]
cache_options = dict(default_timeout= \
self.app.config['CACHE_DEFAULT_TIMEOUT'])
if self.app.config['CACHE_OPTIONS']:
cache_options.update(self.app.config['CACHE_OPTIONS'])
self.cache = cache_obj(self.app, cache_args, cache_options)
if not isinstance(self.cache, BaseCache):
raise TypeError("Cache object must subclass "
"werkzeug.contrib.cache.BaseCache")
def get(self, *args, **kwargs):
"Proxy function for internal cache object."
return self.cache.get(*args, **kwargs)
def set(self, *args, **kwargs):
"Proxy function for internal cache object."
self.cache.set(*args, **kwargs)
def add(self, *args, **kwargs):
"Proxy function for internal cache object."
self.cache.add(*args, **kwargs)
def delete(self, *args, **kwargs):
"Proxy function for internal cache object."
self.cache.delete(*args, **kwargs)
def delete_many(self, *args, **kwargs):
"Proxy function for internal cache object."
self.cache.delete_many(*args, **kwargs)
def cached(self, timeout=None, key_prefix='view/%s', unless=None):
"""
Decorator. Use this to cache a function. By default the cache key
is `view/request.path`. You are able to use this decorator with any
function by changing the `key_prefix`. If the token `%s` is located
within the `key_prefix` then it will replace that with `request.path`
Example::
# An example view function
@cache.cached(timeout=50)
def big_foo():
return big_bar_calc()
# An example misc function to cache.
@cache.cached(key_prefix='MyCachedList')
def get_list():
return [random.randrange(0, 1) for i in range(50000)]
my_list = get_list()
.. note::
You MUST have a request context to actually called any functions
that are cached.
.. versionadded:: 0.4
The returned decorated function now has three function attributes
assigned to it. These attributes are readable/writable.
**uncached**
The original undecorated function
**cache_timeout**
The cache timeout value for this function. For a custom value
to take affect, this must be set before the function is called.
**make_cache_key**
A function used in generating the cache_key used.
:param timeout: Default None. If set to an integer, will cache for that
amount of time. Unit of time is in seconds.
:param key_prefix: Default 'view/%(request.path)s'. Beginning key to .
use for the cache key.
.. versionadded:: 0.3.4
Can optionally be a callable which takes no arguments
but returns a string that will be used as the cache_key.
:param unless: Default None. Cache will *always* execute the caching
facilities unless this callable is true.
This will bypass the caching entirely.
"""
def decorator(f):
@wraps(f)
def decorated_function(*args, **kwargs):
#: Bypass the cache entirely.
if callable(unless) and unless() is True:
return f(*args, **kwargs)
cache_key = decorated_function.make_cache_key(*args, **kwargs)
rv = self.cache.get(cache_key)
if rv is None:
rv = f(*args, **kwargs)
self.cache.set(cache_key,
rv,
timeout=decorated_function.cache_timeout)
return rv
def make_cache_key(*args, **kwargs):
if '%s' in key_prefix:
cache_key = key_prefix % request.path
elif callable(key_prefix):
cache_key = key_prefix()
else:
cache_key = key_prefix
cache_key = cache_key.encode('utf-8')
return cache_key
decorated_function.uncached = f
decorated_function.cache_timeout = timeout
decorated_function.make_cache_key = make_cache_key
return decorated_function
return decorator
def _memvname(self, funcname):
return funcname + '_memver'
def memoize_make_version_hash(self):
return uuid.uuid4().bytes.encode('base64')[:6]
def memoize_make_cache_key(self, fname, make_name=None):
"""
Function used to create the cache_key for memoized functions.
"""
def make_cache_key(f, *args, **kwargs):
version_key = self._memvname(fname)
version_data = self.cache.get(version_key)
if version_data is None:
version_data = self.memoize_make_version_hash()
self.cache.set(version_key, version_data)
cache_key = hashlib.md5()
#: this should have to be after version_data, so that it
#: does not break the delete_memoized functionality.
if callable(make_name):
altfname = make_name(fname)
else:
altfname = fname
if callable(f):
args, kwargs = self.memoize_kwargs_to_args(f, *args, **kwargs)
try:
updated = "{0}{1}{2}".format(altfname, args, kwargs)
except AttributeError:
updated = "%s%s%s" % (altfname, args, kwargs)
cache_key.update(updated)
cache_key = cache_key.digest().encode('base64')[:16]
cache_key += version_data
return cache_key
return make_cache_key
def memoize_kwargs_to_args(self, f, *args, **kwargs):
#: Inspect the arguments to the function
#: This allows the memoization to be the same
#: whether the function was called with
#: 1, b=2 is equivilant to a=1, b=2, etc.
new_args = []
arg_num = 0
m_args = inspect.getargspec(f)[0]
for i in range(len(m_args)):
if m_args[i] in kwargs:
new_args.append(kwargs[m_args[i]])
elif arg_num < len(args):
new_args.append(args[arg_num])
arg_num += 1
return tuple(new_args), {}
def memoize(self, timeout=None, make_name=None, unless=None):
"""
Use this to cache the result of a function, taking its arguments into
account in the cache key.
Information on
`Memoization <http://en.wikipedia.org/wiki/Memoization>`_.
Example::
@cache.memoize(timeout=50)
def big_foo(a, b):
return a + b + random.randrange(0, 1000)
.. code-block:: pycon
>>> big_foo(5, 2)
753
>>> big_foo(5, 3)
234
>>> big_foo(5, 2)
753
.. versionadded:: 0.4
The returned decorated function now has three function attributes
assigned to it.
**uncached**
The original undecorated function. readable only
**cache_timeout**
The cache timeout value for this function. For a custom value
to take affect, this must be set before the function is called.
readable and writable
**make_cache_key**
A function used in generating the cache_key used.
readable and writable
:param timeout: Default None. If set to an integer, will cache for that
amount of time. Unit of time is in seconds.
:param make_name: Default None. If set this is a function that accepts
a single argument, the function name, and returns a
new string to be used as the function name. If not set
then the function name is used.
:param unless: Default None. Cache will *always* execute the caching
facilities unelss this callable is true.
This will bypass the caching entirely.
.. versionadded:: 0.5
params ``make_name``, ``unless``
"""
def memoize(f):
@wraps(f)
def decorated_function(*args, **kwargs):
#: bypass cache
if callable(unless) and unless() is True:
return f(*args, **kwargs)
cache_key = decorated_function.make_cache_key(
f, *args, **kwargs)
rv = self.cache.get(cache_key)
if rv is None:
rv = f(*args, **kwargs)
self.cache.set(cache_key,
rv,
timeout=decorated_function.cache_timeout)
return rv
decorated_function.uncached = f
decorated_function.cache_timeout = timeout
decorated_function.make_cache_key = self.memoize_make_cache_key(
f.__name__, make_name)
return decorated_function
return memoize
def delete_memoized(self, fname, *args, **kwargs):
"""
Deletes the specified functions caches, based by given parameters.
If parameters are given, only the functions that were memoized with them
will be erased. Otherwise all the versions of the caches will be deleted.
Example::
@cache.memoize(50)
def random_func():
return random.randrange(1, 50)
@cache.memoize()
def param_func(a, b):
return a+b+random.randrange(1, 50)
.. code-block:: pycon
>>> random_func()
43
>>> random_func()
43
>>> cache.delete_memoized('random_func')
>>> random_func()
16
>>> param_func(1, 2)
32
>>> param_func(1, 2)
32
>>> param_func(2, 2)
47
>>> cache.delete_memoized('param_func', 1, 2)
>>> param_func(1, 2)
13
>>> param_func(2, 2)
47
:param fname: Name of the memoized function, or a reference to the function.
:param \*args: A list of positional parameters used with memoized function.
:param \**kwargs: A dict of named parameters used with memoized function.
.. note::
Flask-Cache uses inspect to order kwargs into positional args when
the function is memoized. If you pass a function reference into ``fname``
instead of the function name, Flask-Cache will be able to place
the args/kwargs in the proper order, and delete the positional cache.
However, if ``delete_memozied`` is just called with the name of the
function, be sure to pass in potential arguments in the same order
as defined in your function as args only, otherwise Flask-Cache
will not be able to compute the same cache key.
.. note::
Flask-Cache maintains an internal random version hash for the function.
Using delete_memoized will only swap out the version hash, causing
the memoize function to recompute results and put them into another key.
This leaves any computed caches for this memoized function within the
caching backend.
It is recommended to use a very high timeout with memoize if using
this function, so that when the version has is swapped, the old cached
results would eventually be reclaimed by the caching backend.
"""
if callable(fname):
assert hasattr(fname, 'uncached')
f = fname.uncached
_fname = f.__name__
else:
f = None
_fname = fname
if not args and not kwargs:
version_key = self._memvname(fname)
version_data = self.memoize_make_version_hash()
self.cache.set(version_key, version_data)
else:
cache_key = self.memoize_make_cache_key(_fname)(f, *args, **kwargs)
self.cache.delete(cache_key)
class Cache(object):
"""
This class is used to control the cache objects.
If TESTING is True it will use NullCache.
"""
def __init__(self, app=None):
self.cache = None
if app is not None:
self.init_app(app)
else:
self.app = None
self._memoized = []
def init_app(self, app):
"This is used to initialize cache with your app object"
app.config.setdefault('CACHE_DEFAULT_TIMEOUT', 300)
app.config.setdefault('CACHE_THRESHOLD', 500)
app.config.setdefault('CACHE_KEY_PREFIX', None)
app.config.setdefault('CACHE_MEMCACHED_SERVERS', None)
app.config.setdefault('CACHE_DIR', None)
app.config.setdefault('CACHE_OPTIONS', None)
app.config.setdefault('CACHE_ARGS', [])
app.config.setdefault('CACHE_TYPE', 'null')
self.app = app
self._set_cache()
def _set_cache(self):
if self.app.config['TESTING']:
self.cache = NullCache()
else:
import_me = self.app.config['CACHE_TYPE']
if '.' not in import_me:
import_me = 'flaskext.cache.backends.' + \
import_me
cache_obj = import_string(import_me)
cache_args = self.app.config['CACHE_ARGS'][:]
cache_options = dict(default_timeout= \
self.app.config['CACHE_DEFAULT_TIMEOUT'])
if self.app.config['CACHE_OPTIONS']:
cache_options.update(self.app.config['CACHE_OPTIONS'])
self.cache = cache_obj(self.app, cache_args, cache_options)
if not isinstance(self.cache, BaseCache):
raise TypeError("Cache object must subclass "
"werkzeug.contrib.cache.BaseCache")
def get(self, *args, **kwargs):
"Proxy function for internal cache object."
return self.cache.get(*args, **kwargs)
def set(self, *args, **kwargs):
"Proxy function for internal cache object."
self.cache.set(*args, **kwargs)
def add(self, *args, **kwargs):
"Proxy function for internal cache object."
self.cache.add(*args, **kwargs)
def delete(self, *args, **kwargs):
"Proxy function for internal cache object."
self.cache.delete(*args, **kwargs)
def cached(self, timeout=None, key_prefix='view/%s', unless=None):
"""
Decorator. Use this to cache a function. By default the cache key
is `view/request.path`. You are able to use this decorator with any
function by changing the `key_prefix`. If the token `%s` is located
within the `key_prefix` then it will replace that with `request.path`
Example::
# An example view function
@cache.cached(timeout=50)
def big_foo():
return big_bar_calc()
# An example misc function to cache.
@cache.cached(key_prefix='MyCachedList')
def get_list():
return [random.randrange(0, 1) for i in range(50000)]
.. code-block:: pycon
>>> my_list = get_list()
.. note::
You MUST have a request context to actually called any functions
that are cached.
:param timeout: Default None. If set to an integer, will cache for that
amount of time. Unit of time is in seconds.
:param key_prefix: Default 'view/%(request.path)s'. Beginning key to .
use for the cache key.
:param unless: Default None. Cache will *always* execute the caching
facilities unless this callable is true.
This will bypass the caching entirely.
"""
def decorator(f):
@wraps(f)
def decorated_function(*args, **kwargs):
#: Bypass the cache entirely.
if callable(unless) and unless() is True:
return f(*args, **kwargs)
if '%s' in key_prefix:
cache_key = key_prefix % request.path
else:
cache_key = key_prefix
rv = self.cache.get(cache_key)
if rv is None:
rv = f(*args, **kwargs)
self.cache.set(cache_key, rv, timeout=timeout)
return rv
return decorated_function
return decorator
def memoize(self, timeout=None):
"""
Use this to cache the result of a function, taking its arguments into
account in the cache key.
Information on
`Memoization <http://en.wikipedia.org/wiki/Memoization>`_.
Example::
@cache.memoize(timeout=50)
def big_foo(a, b):
return a + b + random.randrange(0, 1000)
.. code-block:: pycon
>>> big_foo(5, 2)
753
>>> big_foo(5, 3)
234
>>> big_foo(5, 2)
753
:param timeout: Default None. If set to an integer, will cache for that
amount of time. Unit of time is in seconds.
"""
def memoize(f):
@wraps(f)
def decorated_function(*args, **kwargs):
cache_key = ('memoize', f.__name__, id(f), args, str(kwargs))
rv = self.cache.get(cache_key)
if rv is None:
rv = f(*args, **kwargs)
self.cache.set(cache_key, rv, timeout=timeout)
if cache_key not in self._memoized:
self._memoized.append(cache_key)
return rv
return decorated_function
return memoize
def delete_memoized(self, *keys):
"""
Deletes all of the cached functions that used Memoize for caching.
Example::
@cache.memoize(50)
def random_func():
return random.randrange(1, 50)
.. code-block:: pycon
>>> random_func()
43
>>> random_func()
43
>>> cache.delete_memoized('random_func')
>>> random_func()
16
:param \*keys: A list of function names to clear from cache.
"""
def deletes(item):
if item[0] == 'memoize' and item[1] in keys:
self.cache.delete(item)
return True
return False
self._memoized[:] = [x for x in self._memoized if not deletes(x)]
class Cache(object):
"""
This class is used to control the cache objects.
If TESTING is True it will use NullCache.
"""
def __init__(self, app=None, with_jinja2_ext=True):
self.with_jinja2_ext = with_jinja2_ext
self.cache = None
if app is not None:
self.init_app(app)
else:
self.app = None
self._memoized = []
def init_app(self, app):
"This is used to initialize cache with your app object"
app.config.setdefault('CACHE_DEFAULT_TIMEOUT', 300)
app.config.setdefault('CACHE_THRESHOLD', 500)
app.config.setdefault('CACHE_KEY_PREFIX', None)
app.config.setdefault('CACHE_MEMCACHED_SERVERS', None)
app.config.setdefault('CACHE_DIR', None)
app.config.setdefault('CACHE_OPTIONS', None)
app.config.setdefault('CACHE_ARGS', [])
app.config.setdefault('CACHE_TYPE', 'null')
if self.with_jinja2_ext:
setattr(app.jinja_env, JINJA_CACHE_ATTR_NAME, self)
app.jinja_env.add_extension(CacheExtension)
self.app = app
self._set_cache()
def _set_cache(self):
if self.app.config['TESTING']:
self.cache = NullCache()
else:
import_me = self.app.config['CACHE_TYPE']
if '.' not in import_me:
import_me = 'flaskext.cache.backends.' + \
import_me
cache_obj = import_string(import_me)
cache_args = self.app.config['CACHE_ARGS'][:]
cache_options = dict(default_timeout= \
self.app.config['CACHE_DEFAULT_TIMEOUT'])
if self.app.config['CACHE_OPTIONS']:
cache_options.update(self.app.config['CACHE_OPTIONS'])
self.cache = cache_obj(self.app, cache_args, cache_options)
if not isinstance(self.cache, BaseCache):
raise TypeError("Cache object must subclass "
"werkzeug.contrib.cache.BaseCache")
def get(self, *args, **kwargs):
"Proxy function for internal cache object."
return self.cache.get(*args, **kwargs)
def set(self, *args, **kwargs):
"Proxy function for internal cache object."
self.cache.set(*args, **kwargs)
def add(self, *args, **kwargs):
"Proxy function for internal cache object."
self.cache.add(*args, **kwargs)
def delete(self, *args, **kwargs):
"Proxy function for internal cache object."
self.cache.delete(*args, **kwargs)
def delete_many(self, *args, **kwargs):
"Proxy function for internal cache object."
self.cache.delete_many(*args, **kwargs)
def cached(self, timeout=None, key_prefix='view/%s', unless=None):
"""
Decorator. Use this to cache a function. By default the cache key
is `view/request.path`. You are able to use this decorator with any
function by changing the `key_prefix`. If the token `%s` is located
within the `key_prefix` then it will replace that with `request.path`
Example::
# An example view function
@cache.cached(timeout=50)
def big_foo():
return big_bar_calc()
# An example misc function to cache.
@cache.cached(key_prefix='MyCachedList')
def get_list():
return [random.randrange(0, 1) for i in range(50000)]
my_list = get_list()
.. note::
You MUST have a request context to actually called any functions
that are cached.
.. versionadded:: 0.4
The returned decorated function now has three function attributes
assigned to it. These attributes are readable/writable.
**uncached**
The original undecorated function
**cache_timeout**
The cache timeout value for this function. For a custom value
to take affect, this must be set before the function is called.
**make_cache_key**
A function used in generating the cache_key used.
:param timeout: Default None. If set to an integer, will cache for that
amount of time. Unit of time is in seconds.
:param key_prefix: Default 'view/%(request.path)s'. Beginning key to .
use for the cache key.
.. versionadded:: 0.3.4
Can optionally be a callable which takes no arguments
but returns a string that will be used as the cache_key.
:param unless: Default None. Cache will *always* execute the caching
facilities unless this callable is true.
This will bypass the caching entirely.
"""
def decorator(f):
@wraps(f)
def decorated_function(*args, **kwargs):
#: Bypass the cache entirely.
if callable(unless) and unless() is True:
return f(*args, **kwargs)
cache_key = decorated_function.make_cache_key(*args, **kwargs)
rv = self.cache.get(cache_key)
if rv is None:
rv = f(*args, **kwargs)
self.cache.set(cache_key, rv,
timeout=decorated_function.cache_timeout)
return rv
def make_cache_key(*args, **kwargs):
if callable(key_prefix):
cache_key = key_prefix()
elif '%s' in key_prefix:
cache_key = key_prefix % request.path
else:
cache_key = key_prefix
cache_key = cache_key.encode('utf-8')
return cache_key
decorated_function.uncached = f
decorated_function.cache_timeout = timeout
decorated_function.make_cache_key = make_cache_key
return decorated_function
return decorator
def _memvname(self, funcname):
return funcname + '_memver'
def memoize_make_version_hash(self):
return uuid.uuid4().bytes.encode('base64')[:6]
def memoize_make_cache_key(self, fname, make_name=None):
"""
Function used to create the cache_key for memoized functions.
"""
def make_cache_key(f, *args, **kwargs):
version_key = self._memvname(fname)
version_data = self.cache.get(version_key)
if version_data is None:
version_data = self.memoize_make_version_hash()
self.cache.set(version_key, version_data)
cache_key = hashlib.md5()
#: this should have to be after version_data, so that it
#: does not break the delete_memoized functionality.
if callable(make_name):
altfname = make_name(fname)
else:
altfname = fname
if callable(f):
args, kwargs = self.memoize_kwargs_to_args(f, *args, **kwargs)
try:
updated = "{0}{1}{2}".format(altfname, args, kwargs)
except AttributeError:
updated = "%s%s%s" % (altfname, args, kwargs)
cache_key.update(updated)
cache_key = cache_key.digest().encode('base64')[:16]
cache_key += version_data
return cache_key
return make_cache_key
def memoize_kwargs_to_args(self, f, *args, **kwargs):
#: Inspect the arguments to the function
#: This allows the memoization to be the same
#: whether the function was called with
#: 1, b=2 is equivilant to a=1, b=2, etc.
new_args = []
arg_num = 0
m_args = inspect.getargspec(f)[0]
for i in range(len(m_args)):
if m_args[i] in kwargs:
new_args.append(kwargs[m_args[i]])
elif arg_num < len(args):
new_args.append(args[arg_num])
arg_num += 1
return tuple(new_args), {}
def memoize(self, timeout=None, make_name=None, unless=None):
"""
Use this to cache the result of a function, taking its arguments into
account in the cache key.
Information on
`Memoization <http://en.wikipedia.org/wiki/Memoization>`_.
Example::
@cache.memoize(timeout=50)
def big_foo(a, b):
return a + b + random.randrange(0, 1000)
.. code-block:: pycon
>>> big_foo(5, 2)
753
>>> big_foo(5, 3)
234
>>> big_foo(5, 2)
753
.. versionadded:: 0.4
The returned decorated function now has three function attributes
assigned to it.
**uncached**
The original undecorated function. readable only
**cache_timeout**
The cache timeout value for this function. For a custom value
to take affect, this must be set before the function is called.
readable and writable
**make_cache_key**
A function used in generating the cache_key used.
readable and writable
:param timeout: Default None. If set to an integer, will cache for that
amount of time. Unit of time is in seconds.
:param make_name: Default None. If set this is a function that accepts
a single argument, the function name, and returns a
new string to be used as the function name. If not set
then the function name is used.
:param unless: Default None. Cache will *always* execute the caching
facilities unelss this callable is true.
This will bypass the caching entirely.
.. versionadded:: 0.5
params ``make_name``, ``unless``
"""
def memoize(f):
@wraps(f)
def decorated_function(*args, **kwargs):
#: bypass cache
if callable(unless) and unless() is True:
return f(*args, **kwargs)
cache_key = decorated_function.make_cache_key(f, *args, **kwargs)
rv = self.cache.get(cache_key)
if rv is None:
rv = f(*args, **kwargs)
self.cache.set(cache_key, rv,
timeout=decorated_function.cache_timeout)
return rv
decorated_function.uncached = f
decorated_function.cache_timeout = timeout
decorated_function.make_cache_key = self.memoize_make_cache_key(f.__name__,
make_name)
return decorated_function
return memoize
def delete_memoized(self, fname, *args, **kwargs):
"""
Deletes the specified functions caches, based by given parameters.
If parameters are given, only the functions that were memoized with them
will be erased. Otherwise all the versions of the caches will be deleted.
Example::
@cache.memoize(50)
def random_func():
return random.randrange(1, 50)
@cache.memoize()
def param_func(a, b):
return a+b+random.randrange(1, 50)
.. code-block:: pycon
>>> random_func()
43
>>> random_func()
43
>>> cache.delete_memoized('random_func')
>>> random_func()
16
>>> param_func(1, 2)
32
>>> param_func(1, 2)
32
>>> param_func(2, 2)
47
>>> cache.delete_memoized('param_func', 1, 2)
>>> param_func(1, 2)
13
>>> param_func(2, 2)
47
:param fname: Name of the memoized function, or a reference to the function.
:param \*args: A list of positional parameters used with memoized function.
:param \**kwargs: A dict of named parameters used with memoized function.
.. note::
Flask-Cache uses inspect to order kwargs into positional args when
the function is memoized. If you pass a function reference into ``fname``
instead of the function name, Flask-Cache will be able to place
the args/kwargs in the proper order, and delete the positional cache.
However, if ``delete_memozied`` is just called with the name of the
function, be sure to pass in potential arguments in the same order
as defined in your function as args only, otherwise Flask-Cache
will not be able to compute the same cache key.
.. note::
Flask-Cache maintains an internal random version hash for the function.
Using delete_memoized will only swap out the version hash, causing
the memoize function to recompute results and put them into another key.
This leaves any computed caches for this memoized function within the
caching backend.
It is recommended to use a very high timeout with memoize if using
this function, so that when the version has is swapped, the old cached
results would eventually be reclaimed by the caching backend.
"""
if callable(fname):
assert hasattr(fname, 'uncached')
f = fname.uncached
_fname = f.__name__
else:
f = None
_fname = fname
if not args and not kwargs:
version_key = self._memvname(fname)
version_data = self.memoize_make_version_hash()
self.cache.set(version_key, version_data)
else:
cache_key = self.memoize_make_cache_key(_fname)(f, *args, **kwargs)
self.cache.delete(cache_key)
class Provider(object):
def __init__(self, config):
self._config = config
self.cache = NullCache()
self.statsd = NullStats()
attribution = Attribution(
licence_name="Open Government Licence",
licence_url="http://www.nationalarchives.gov.uk/doc/open-government-licence/",
attribution_text="Contains public sector information provided by the Met Office",
)
def latest_observations(self):
response = self.cache.get(self._CACHE_KEY.format(self._config["location_id"]))
if not response:
self.statsd.incr(__name__ + ".cache_miss")
with self.statsd.timer(__name__ + ".request_time"):
response = self._make_request()
max_age = parse_cache_control_header(response.info().getparam("Cache-Control")).max_age
response = json.load(response)
self.cache.set(self._CACHE_KEY.format(self._config["location_id"]), response, max_age)
else:
self.statsd.incr(__name__ + ".cache_hit")
source_period = response["SiteRep"]["DV"]["Location"]["Period"]
if isinstance(source_period, list):
source_period = source_period[-1]
source_observation = source_period["Rep"][-1]
minutes_since_midnight = timedelta(minutes=int(source_observation["$"]))
obs_time = datetime(*time.strptime(source_period["value"], "%Y-%m-%dZ")[:6], tzinfo=utc)
obs_time += minutes_since_midnight
weather_type, weather_type_id = self.WEATHER_TYPES.get(source_observation["W"])
return {
"type": weather_type,
"type_id": weather_type_id,
"temperature": u"{} °C".format(source_observation["T"]),
"wind_speed": "{} mph".format(source_observation["S"]),
"gust_speed": "{} mph".format(source_observation["G"]) if "G" in source_observation else "N/A",
"wind_direction": source_observation["D"],
"pressure": "{} mb".format(source_observation["P"]),
"obs_location": capwords(response["SiteRep"]["DV"]["Location"]["name"]),
"obs_time": obs_time.isoformat(),
}
def _make_request(self):
return urlopen(
"http://datapoint.metoffice.gov.uk/public/data/val/wxobs/all"
+ "/json/{location_id}?res=hourly&key={api_key}".format(**self._config)
)
_CACHE_KEY = "weather/metoffice/{}"
WEATHER_TYPES = {
"NA": (_("Not available"), ""),
"0": (_("Clear night"), "clear_night"),
"1": (_("Sunny day"), "sun"),
"2": (_("Partly cloudy"), "cloud"),
"3": (_("Partly cloudy"), "cloud"),
"5": (_("Mist"), "fog"),
"6": (_("Fog"), "fog"),
"7": (_("Cloudy"), "cloud"),
"8": (_("Overcast"), "cloud"),
"9": (_("Light rain shower"), "rain"),
"10": (_("Light rain shower"), "rain"),
"11": (_("Drizzle"), "rain"),
"12": (_("Light rain"), "rain"),
"13": (_("Heavy rain shower"), "rain"),
"14": (_("Heavy rain shower"), "rain"),
"15": (_("Heavy rain"), "rain"),
"16": (_("Sleet shower"), "rain"),
"17": (_("Sleet shower"), "rain"),
"18": (_("Sleet"), "rain"),
"19": (_("Hail shower"), "rain"),
"20": (_("Hail shower"), "rain"),
"21": (_("Hail"), "rain"),
"22": (_("Light snow shower"), "snow"),
"23": (_("Light snow shower"), "snow"),
"24": (_("Light snow"), "snow"),
"25": (_("Heavy snow shower"), "snow"),
"26": (_("Heavy snow shower"), "snow"),
"27": (_("Heavy snow"), "snow"),
"28": (_("Thunder shower"), "thunder"),
"29": (_("Thunder shower"), "thunder"),
"30": (_("Thunder"), "thunder"),
}