Skip to content

AioKafkaBatchParser

faststream.kafka.parser.AioKafkaBatchParser #

AioKafkaBatchParser(
    msg_class: type[KafkaMessage],
    regex: Optional[Pattern[str]],
)

Bases: AioKafkaParser

Source code in faststream/kafka/parser.py 
23
24
25
26
27
28
29
30
31
def __init__(
    self,
    msg_class: type[KafkaMessage],
    regex: Optional["Pattern[str]"],
) -> None:
    self.msg_class = msg_class
    self.regex = regex

    self._consumer: ConsumerProtocol = FAKE_CONSUMER

msg_class instance-attribute #

msg_class = msg_class

regex instance-attribute #

regex = regex

parse_message async #

parse_message(
    message: tuple[ConsumerRecord, ...],
) -> StreamMessage[tuple[ConsumerRecord, ...]]

Parses a batch of messages from a Kafka consumer.

Source code in faststream/kafka/parser.py 
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
async def parse_message(
    self,
    message: tuple["ConsumerRecord", ...],
) -> "StreamMessage[tuple[ConsumerRecord, ...]]":
    """Parses a batch of messages from a Kafka consumer."""
    body: list[Any] = []
    batch_headers: list[dict[str, str]] = []

    first = message[0]
    last = message[-1]

    for m in message:
        body.append(m.value or b"")
        batch_headers.append({i: j.decode() for i, j in m.headers})

    headers = next(iter(batch_headers), {})

    return self.msg_class(
        body=body,
        headers=headers,
        batch_headers=batch_headers,
        reply_to=headers.get("reply_to", ""),
        content_type=headers.get("content-type"),
        message_id=f"{first.offset}-{last.offset}-{first.timestamp}",
        correlation_id=headers.get("correlation_id"),
        raw_message=message,
        path=self.get_path(first.topic),
        consumer=self._consumer,
    )

decode_message async #

decode_message(
    msg: StreamMessage[tuple[ConsumerRecord, ...]],
) -> DecodedMessage

Decode a batch of messages.

Source code in faststream/kafka/parser.py 
 99
100
101
102
103
104
105
106
107
async def decode_message(
    self,
    msg: "StreamMessage[tuple[ConsumerRecord, ...]]",
) -> "DecodedMessage":
    """Decode a batch of messages."""
    # super() should be here due python can't find it in comprehension
    super_obj = cast("AioKafkaParser", super())

    return [decode_message(await super_obj.parse_message(m)) for m in msg.raw_message]

get_path #

get_path(topic: str) -> dict[str, str]
Source code in faststream/kafka/parser.py 
62
63
64
65
def get_path(self, topic: str) -> dict[str, str]:
    if self.regex and (match := self.regex.match(topic)):
        return match.groupdict()
    return {}