templates.random_sources.file_source module

Object that provides randomness from a file.

class templates.random_sources.file_source.FileSource(path: Path, delimiter: str = ..., queue_size: int = ..., queue: Queue[RR] | None = ..., retry_attempts: int = ..., retry_wait_s: float | None = ..., debug: bool = ..., *, deserializer: Callable[[str], RR])

class templates.random_sources.file_source.FileSource(path: Path, delimiter: str = ..., queue_size: int = ..., queue: Queue[RR] | None = ..., retry_attempts: int = ..., retry_wait_s: float | None = ..., debug: bool = ...)

Bases: RandomnessSource[RR]

Object for providing randomness from a file.

Implements tno.mpc.encryption_schemes.templates._randomness_manager.RandomnessSource.

__init__(path, delimiter=',', queue_size=1000, queue=None, retry_attempts=3, retry_wait_s=1, debug=False, *, deserializer=None)

Object that reads randomness from files.

Parameters:

• path (Path) – Path to file containing randomness.

• delimiter (str) – Separator between random numbers in the file.

• queue_size (int) – Maximum number of elements that can be put in the queue. Ignored if argument queue is also provided.

• queue (Queue[TypeVar(RR)] | None) – Queue to use for storing randomness from files.

• retry_attempts (int) – Number of attempts to get random value from the queue.

• retry_wait_s (float | None) – Number of seconds to wait between attempts to get random value from the queue. If None, wait until a value is yielded (e.g. wait=infinity).

• debug (bool) – Flag to determine whether debug information should be displayed.

• deserializer (Optional[Callable[[str], TypeVar(RR)]]) – Function for converting string from provided file into randomness object. Defaults to built-in “int” function.

Raises:

TypeError – Argument to path is of incorrect type.

close()

Shuts down all file reading threads.

Return type:

None

get_one()

Get one random value.

Raises:

• StopIteration – Randomness queue is empty and no active file thread remain.

• TimeoutError – Randomness queue is empty and active file thread does not put new values into it.

• ValueError – No threads instantiated for reading file.

Return type:

TypeVar(RR)

Returns:

One random value.

property nr_yielded: int

Number of random elements yielded.

Returns:

Number of random elements yielded.

open()

Boot thread to read file.

Return type:

None

property path: Path

Path to file that is read for randomness.

Returns:

Path to file.