silo.low_code.framework.caching module

silo.low_code.framework.caching.cleanup_expired_udc(cache_mgr, metadata_key, metadata, sigkill_time)

Remove expired metadata entries

Remove any cached values that have expired related to this metadata. Only one process can perform the deletion at once to address potential race-condition issues.

Parameters

  • cache_mgr (silo.apps.cache.CacheManager) – CacheManager responsible for removing the expired entries

  • metadata_key (str) – Key to the metadata field

  • metadata (list) – Metadata contained in the primary key

  • sigkill_time (int) – Time until a sigterm deletion should occur

silo.low_code.framework.caching.read_cached_results(cache_key, reuse_for=None)

Return the most recent cached element for the given cache_key

This function enables the lookup of Snippet Framework cached elements outside of the Snippet Framework. While this function could work with automatic cache keys the Snippet Framework generates, its best used by overriding the cache_key name within the steps configuration.

The functionality of reuse_for operates the same way within the Snippet Framework. This value is specified in minutes before a cached entry is considered stale. If this value is specified, an entry is considered stale if the following criteria is met:

\[collection\_time + reuse\_for <= current\_time\]

If the newest entry is considered stale, the exception silo.apps.cache.CacheDataIsExpired will be raised.

If an invalid object is found (bad formatting within the cache), the exception MetadataError will be raised.

Parameters

  • cache_key (str) – Specified cache_key for the step

  • reuse_for (int) – Time (in seconds) before considering an entry as stale

Return type

object

silo.low_code.framework.caching.read_step_cache(step, reuse_for, metadata_key, gmtimestamp)

Check the cache for step data prior to step execution

Parameters

  • step (int) – Number of the current step

  • reuse_for (int) – Cache use limit in seconds

  • metadata_key (str) – Current step request id or key hashed

  • gmtimestamp (int) – gmtimestamp of the current collection window

Returns

Cached data if it exists, otherwise None

silo.low_code.framework.caching.write_udc(cache_mgr, cache_config, gmtimestamp, metadata_key, value)

Updates the current metadata using a lock

Parameters

  • cache_mgr (silo.apps.cache.CacheManager) – CacheManager responsible for removing the expired entries

  • cache_config (dict) – Cache configuration for the step

  • gmtimestamp (int) – epoch time when the collection will be stored

  • metadata_key (str) – Primary metadata key

  • value (object) – Value to cache