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Version: Main/Unreleased

rasa.engine.caching

TrainingCache Objects

class TrainingCache(abc.ABC)

Stores training results in a persistent cache.

Used to minimize re-retraining when the data / config didn't change in between training runs.

cache_output

@abc.abstractmethod
def cache_output(fingerprint_key: Text, output: Any, output_fingerprint: Text,
model_storage: ModelStorage) -> None

Adds the output to the cache.

If the output is of type Cacheable the output is persisted to disk in addition to its fingerprint.

Arguments:

  • fingerprint_key - The fingerprint key serves as key for the cache. Graph components can use their fingerprint key to lookup fingerprints of previous training runs.
  • output - The output. The output is only cached to disk if it's of type Cacheable.
  • output_fingerprint - The fingerprint of their output. This can be used to lookup potentially persisted outputs on disk.
  • model_storage - Required for caching Resource instances. E.g. Resources use that to copy data from the model storage to the cache.

get_cached_output_fingerprint

@abc.abstractmethod
def get_cached_output_fingerprint(fingerprint_key: Text) -> Optional[Text]

Retrieves fingerprint of output based on fingerprint key.

Arguments:

  • fingerprint_key - The fingerprint serves as key for the lookup of output fingerprints.

Returns:

The fingerprint of a matching output or None in case no cache entry was found for the given fingerprint key.

get_cached_result

@abc.abstractmethod
def get_cached_result(output_fingerprint_key: Text, node_name: Text,
model_storage: ModelStorage) -> Optional[Cacheable]

Returns a potentially cached output result.

Arguments:

  • output_fingerprint_key - The fingerprint key of the output serves as lookup key for a potentially cached version of this output.
  • node_name - The name of the graph node which wants to use this cached result.
  • model_storage - The current model storage (e.g. used when restoring Resource objects so that they can fill the model storage with data).

Returns:

None if no matching result was found or restored Cacheable.

Cacheable Objects

@runtime_checkable
class Cacheable(Protocol)

Protocol for cacheable graph component outputs.

We only cache graph component outputs which are Cacheable. We only store the output fingerprint for everything else.

to_cache

def to_cache(directory: Path, model_storage: ModelStorage) -> None

Persists Cacheable to disk.

Arguments:

  • directory - The directory where the Cacheable can persist itself to.
  • model_storage - The current model storage (e.g. used when caching Resource objects.

from_cache

@classmethod
def from_cache(cls, node_name: Text, directory: Path,
model_storage: ModelStorage,
output_fingerprint: Text) -> Cacheable

Loads Cacheable from cache.

Arguments:

  • node_name - The name of the graph node which wants to use this cached result.
  • directory - Directory containing the persisted Cacheable.
  • model_storage - The current model storage (e.g. used when restoring Resource objects so that they can fill the model storage with data).
  • output_fingerprint - The fingerprint of the cached result (e.g. used when restoring Resource objects as the fingerprint can not be easily calculated from the object itself).

Returns:

Instantiated Cacheable.

LocalTrainingCache Objects

class LocalTrainingCache(TrainingCache)

Caches training results on local disk (see parent class for full docstring).

CacheEntry Objects

class CacheEntry(Base)

Stores metadata about a single cache entry.

__init__

def __init__() -> None

Creates cache.

The Cache setting can be configured via environment variables.

cache_output

def cache_output(fingerprint_key: Text, output: Any, output_fingerprint: Text,
model_storage: ModelStorage) -> None

Adds the output to the cache (see parent class for full docstring).

get_cached_output_fingerprint

def get_cached_output_fingerprint(fingerprint_key: Text) -> Optional[Text]

Returns cached output fingerprint (see parent class for full docstring).

get_cached_result

def get_cached_result(output_fingerprint_key: Text, node_name: Text,
model_storage: ModelStorage) -> Optional[Cacheable]

Returns a potentially cached output (see parent class for full docstring).