keystone.common.cache.core module

Keystone Caching Layer Implementation.

class keystone.common.cache.core.DistributedInvalidationStrategy(region_manager)

Bases: RegionInvalidationStrategy

invalidate(hard=None)

Region invalidation.

CacheRegion propagated call. The default invalidation system works by setting a current timestamp (using time.time()) to consider all older timestamps effectively invalidated.

is_hard_invalidated(timestamp)

Check timestamp to determine if it was hard invalidated.

Returns:

Boolean. True if timestamp is older than the last region invalidation time and region is invalidated in hard mode.

is_invalidated(timestamp)

Check timestamp to determine if it was invalidated.

Returns:

Boolean. True if timestamp is older than the last region invalidation time.

is_soft_invalidated(timestamp)

Check timestamp to determine if it was soft invalidated.

Returns:

Boolean. True if timestamp is older than the last region invalidation time and region is invalidated in soft mode.

was_hard_invalidated()

Indicate the region was invalidated in hard mode.

Returns:

Boolean. True if region was invalidated in hard mode.

was_soft_invalidated()

Indicate the region was invalidated in soft mode.

Returns:

Boolean. True if region was invalidated in soft mode.

class keystone.common.cache.core.RegionInvalidationManager(invalidation_region, region_name)

Bases: object

REGION_KEY_PREFIX = '<<<region>>>:'

invalidate_region()

is_region_key(key)

property region_id

keystone.common.cache.core.configure_cache(region=None)

keystone.common.cache.core.configure_invalidation_region()

keystone.common.cache.core.create_region(name)

Create a dopile region.

Wraps oslo_cache.core.create_region. This is used to ensure that the Region is properly patched and allows us to more easily specify a region name.

Parameters:

name (str) – The region name

Returns:

The new region.

Return type:

dogpile.cache.region.CacheRegion

keystone.common.cache.core.get_memoization_decorator(group, expiration_group=None, region=None)

keystone.common.cache.core.is_replay(region, key, expiration_time=None)

Return whether key has already been recorded in region.

Check this before honoring a one-time-use value (nonce, passcode, receipt, …), then call mark_used() once it is consumed.

Parameters:

• region – a configured dogpile CacheRegion.

• key – the identifying string for the one-time-use value.

• expiration_time – seconds to honor a recorded value for, overriding the region’s own expiration_time. Pass the value’s real validity window plus a margin, so protection isn’t at the mercy of an operator’s general-purpose [cache] expiration_time.

Returns:

True if key was already recorded (a replay).

keystone.common.cache.core.key_mangler_factory(invalidation_manager, orig_key_mangler)

keystone.common.cache.core.mark_used(region, key)

Record key in region for a later is_replay() check.

Expiration is enforced on the read side by is_replay().