DataChannel

class maize.core.channels.DataChannel(size: int)

Bases: Channel[T]

A communication channel for data in the form of python objects.

Any item sent needs to be serializable using dill.

Parameters:

size – Size of the item queue

See also

FileChannel

Channel for files

__init__(size: int) → None

Methods

__init__(size)
close()	Closes the channel.
flush([timeout])	Flush the contents of the channel.
kill()	Kills the channel, called at network shutdown and ensures no orphaned processes.
preload(items)	Pre-load the channel with a serialized item.
receive([timeout])	Receive an item.
send(item[, timeout])	Send an item.

Attributes

active	Returns whether the channel is active.
ready	Returns whether the channel is ready to receive from.
size	Returns the current approximate size of the buffer

property active: bool

Returns whether the channel is active.

close() → None

Closes the channel.

flush(timeout: float = 0.5) → list[T]

Flush the contents of the channel.

Parameters:

timeout – The timeout for item retrieval

Returns:

List of unserialized channel contents

Return type:

list[T]

kill() → None

Kills the channel, called at network shutdown and ensures no orphaned processes.

preload(items: list[bytes] | bytes) → None

Pre-load the channel with a serialized item. Used by restarts.

Parameters:

items – Serialized items to pre-load the channel with

property ready: bool

Returns whether the channel is ready to receive from.

receive(timeout: float | None = None) → T | None

Receive an item.

Parameters:

timeout – Timeout in seconds to wait for an item

Returns:

The received item, or None if the channel is empty

Return type:

T | None

send(item: T, timeout: float | None = None) → None

Send an item.

Will attempt to send an item of any type into a channel, potentially blocking if the channel is full.

Parameters:

• item – Item to send

• timeout – Timeout in seconds to wait for space in the channel

Raises:

ChannelFull – If the channel is already full

property size: int

Returns the current approximate size of the buffer