nvflare.fuel.f3.streaming.stream_types module

class Stream(size: int = 0, headers: dict | None = None)

Bases: ABC

A raw, read-only, seekable binary byte stream

Constructor for stream

Parameters:

• size – The total size of stream. 0 if unknown

• headers – Optional headers to be passed to the receiver

close()

Close the stream

get_headers() → dict | None

get_pos()

get_size() → int

abstract read(size: int) → bytes | bytearray | memoryview | list

Read and return up to size bytes. It can return less but not more than the size. An empty bytes object is returned if the stream reaches the end.

Parameters:

size – Up to (but maybe less) this many bytes will be returned

Returns:

Binary data. If empty, it means the stream is depleted (EOS)

seek(offset: int)

Change the stream position to the given byte offset. :param offset: Offset relative to the start of the stream

Exception:

StreamError: If the stream is not seekable

exception StreamCancelled

Bases: StreamError

Streaming is cancelled by sender

exception StreamError

Bases: Exception

All stream API throws this error

class StreamFuture(stream_id: int, headers: dict | None = None, task_handle: StreamTaskSpec | None = None)

Bases: object

Future class for all stream calls.

Fashioned after concurrent.futures.Future

add_done_callback(done_cb: Callable, *args, **kwargs)

Attaches a callable that will be called when the future finishes.

Parameters:

done_cb – A callable that will be called with this future completes

cancel()

Cancel the future if possible.

Returns True if the future was cancelled, False otherwise. A future cannot be cancelled if it is running or has already completed.

cancelled()

done()

Return True of the future was cancelled or finished executing.

exception(timeout=None)

Return the exception raised by the call that the future represents.

Parameters:

timeout – The number of seconds to wait for the exception if the future isn’t done. If None, then there is no limit on the wait time.

Returns:

The exception raised by the call that the future represents or None if the call completed without raising.

Raises:

• CancelledError – If the future was cancelled.

• TimeoutError – If the future didn’t finish executing before the given timeout.

get_headers() → dict | None

get_progress() → int

get_size() → int

get_stream_id() → int

result(timeout=None) → Any

Return the result of the call that the future represents.

Parameters:

timeout – The number of seconds to wait for the result if the future isn’t done. If None, then there is no limit on the wait time.

Returns:

The final result

Raises:

• CancelledError – If the future was cancelled.

• TimeoutError – If the future didn’t finish executing before the given timeout.

running()

Return True if the future is currently executing.

set_exception(exception)

Sets the result of the future as being the given exception.

set_progress(progress: int)

set_result(value: Any)

Sets the return value of work associated with the future.

set_size(size: int)

class StreamTaskSpec

Bases: ABC

cancel()

Cancel the task

Returns: