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Version: 2.0.0

Class: PackedMessage

A packed message represents an ordinary Message, but in a compressed format. This is useful in case you need to retain a large number of messages in memory, and reduce memory overhead.

The only way to create a packed message is by invoking the 'Message.pack' method.

Properties​

type​

type: DataDictionary

The type of the packed message. This is a reference to the data dictionary that was used to pack the message.

Example​

# Pack message
packed_msg = message.pack()
type_ = packed_msg.type  # Returns the data dictionary used to pack the message

# Unpack message
unpacked_msg = packed_msg.unpack()

Methods​

unpack()​

unpack() -> Message

Unpacks a previously packed message.

Returns​

Message - Unpacked Message

Example​

# Pack message
packed_msg = message.pack()

# Unpack message
unpacked_msg = packed_msg.unpack()

Usage Notes​

  1. Memory Efficiency: Use PackedMessage when you need to store multiple messages in memory efficiently. The packed format reduces memory usage compared to full Message objects.

  2. Read-Only Access: Once a message is packed, you cannot modify its contents directly. You need to unpack it first, make changes, and then pack it again if needed.

  3. Type Information: The type property allows you to inspect the structure of the packed message without unpacking it, which can be useful for routing or filtering packed messages.

  4. Serialization: PackedMessage objects are typically more suitable for serialization and transmission compared to full Message objects, due to their compressed nature.

  5. Performance Considerations: While packing and unpacking introduce some overhead, the memory savings can be significant when dealing with large numbers of messages. Consider the trade-off between processing time and memory usage in your specific use case.

  6. Error Handling: When unpacking a message, be prepared to handle potential errors, especially if the packed message might have been corrupted or if the data dictionary has changed since the message was packed.

Example of error handling:

try:
    unpacked_msg = packed_msg.unpack()
except Exception as e:
    print(f"Error unpacking message: {e}")
    # Handle the error appropriately

Remember to refer to the latest layline.io documentation for the most up-to-date information on using PackedMessage in your Python scripts.