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KeyHeader

Overview​

KeyHeader is a typed dictionary (with optional fields) that contains metadata about a key message in the KeySquare platform. It provides detailed information about the message's origin, type, timing, and unique identifiers.

Definition​

from typing import TypedDict

class KeyHeader(TypedDict, total=False):
    """
    Contains metadata about a key message.

    Attributes:
        sequencerId: Identifier for the sequencer
        applicationId: Identifier for the application
        topicSource: Source of the topic
        topicGroup: Group the topic belongs to
        topicId: Unique identifier for the topic
        messageType: Type of the message
        inceptionNanoTime: Timestamp in nanoseconds when the message was created
        flags: Flags indicating properties of the key message
    """
    sequencerId: int
    applicationId: int
    topicSource: str
    topicGroup: str
    topicId: str
    messageType: str
    inceptionNanoTime: int
    sequencerNanoTime: int
    relayNanoTime: int
    sourceSequencerId: int
    flags: KeyHeaderFlags

Attributes​

  • sequencerId: Identifier for the sequencer (int)
  • applicationId: Identifier for the application (int)
  • topicSource: Source of the topic (str)
  • topicGroup: Group the topic belongs to (str)
  • topicId: Unique identifier for the topic (str)
  • messageType: Type of the message (str)
  • inceptionNanoTime: Timestamp in nanoseconds when the message was created (int)
  • sequencerNanoTime: Sequencer timestamp in nanoseconds (int, optional)
  • relayNanoTime: Relay timestamp in nanoseconds (int, optional)
  • sourceSequencerId: Source sequencer identifier (int, optional)
  • flags: Flags indicating properties of the key message (KeyHeaderFlags)

Usage Example​

from keysquarepy import KeyHeader

key_header: KeyHeader = {
    "sequencerId": 10,
    "applicationId": 42,
    "topicSource": "EXCHANGE",
    "topicGroup": "EQUITIES",
    "topicId": "AAPL",
    "messageType": "SNAPSHOT",
    "inceptionNanoTime": 1723123200000000000,
    "flags": 0
}
print(key_header)

See Also​