Stanislav Hejny
120 lines
3.9 KiB
Python
120 lines
3.9 KiB
Python
"""
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method to create, serialize and deserialize DataResponse message
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"""
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import base64
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import re
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from io import BytesIO
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from amqp.model.model import DataResponse
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from amqp.model.snowflake_id import SnowflakeId
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from amqp.adapter.serializer import parse_map_string, map_as_string
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class DataResponseFactory:
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MAGIC_BYTE_HTTP_REQUEST = "A"
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@staticmethod
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def create_async_response_message(_id: SnowflakeId) -> DataResponse:
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"""
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Helper method to create standard OK response.
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:param _id: ID
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:return: Response message
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"""
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return DataResponse(
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str(_id), 200, "application/text", "OK".encode("utf-8"), "", "", {}
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)
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@staticmethod
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def of(id: SnowflakeId, response_code: int, content_type: str, body: bytes, trace_info: dict[str,str]) -> DataResponse:
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"""
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Create the DataResponse message supplying all key values
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:param id: SnowflakeID
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:param response_code: HTTP response code
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:param content_type: MIME content type
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:param body: payload
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:param trace_info: Jaeger trace info (id)
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:return: DataResponseMessage object
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"""
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return DataResponse(
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id=id.as_string(),
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response_code=response_code,
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content_type=content_type,
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response=body,
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error=None,
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error_cause=None,
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trace_info=trace_info
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)
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@staticmethod
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def serialize(response: DataResponse) -> bytes:
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"""
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Serialize the message to byte array (to be sent over RabbitMQ)
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:param response: Object to serialize
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:return: byte array as serialized message
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"""
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id_bytes = response.id.encode('utf-8')
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prolog = (
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f"|r={response.response_code}|c={response.content_type}|e={response.error}|f={response.error_cause}|t={{{map_as_string(response.trace_info)}}}|b="
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).encode('utf-8')
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header_length = 1 + len(id_bytes) + len(prolog)
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prolog_len = header_length.to_bytes(2, byteorder='big')
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msg_length = 2 + header_length + len(response.response)
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with BytesIO(bytearray(msg_length)) as baos:
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baos.write(prolog_len)
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baos.write(DataResponseFactory.MAGIC_BYTE_HTTP_REQUEST.encode('utf-8'))
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baos.write(id_bytes)
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baos.write(prolog)
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baos.write(base64.b64encode(response.response))
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return baos.getvalue()
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@staticmethod
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def from_bytes(input_bytes: bytes) -> DataResponse:
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"""
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Buil;ds the DataResponse object from its serialized form
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:param input_bytes: byte array - serialized response
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:return: DataResponse object
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"""
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prolog_len = (input_bytes[0] << 8) + input_bytes[1]
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metadata = input_bytes[2:prolog_len + 2].decode()
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pattern = re.compile(
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f"{DataResponseFactory.MAGIC_BYTE_HTTP_REQUEST}"
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r"([0-9A-Fa-f]+)\|"
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r"r=([^|]*)\|"
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r"c=([^|]*)\|"
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r"e=([^|]*)\|"
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r"f=([^|]*)\|"
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r"t=(\{[^}]*\})\|"
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r"b="
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)
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match = pattern.match(metadata)
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if not match:
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raise ValueError(
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f"DataResponse format does not match expected format. "
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f"Input string [{metadata}] does not match pattern: {pattern.pattern}"
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)
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id_str = match.group(1)
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response_code = int(match.group(2))
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content_type = match.group(3)
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error = match.group(4)
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error_cause = match.group(5)
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trace_info_str = match.group(6)
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body_b64 = input_bytes[prolog_len + 2:]
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trace_info = parse_map_string(trace_info_str)
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return DataResponse(
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id_str,
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response_code,
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content_type,
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base64.b64decode(body_b64),
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error,
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error_cause,
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trace_info,
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)
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# Ensure backward compatibility
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AMQResponseFactory = DataResponseFactory
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