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- """
- kombu.transport.message
- =======================
-
- Message class.
-
- """
- from __future__ import absolute_import
-
- import sys
-
- from .compression import decompress
- from .exceptions import MessageStateError
- from .five import reraise, text_t
- from .serialization import loads
-
- ACK_STATES = frozenset(['ACK', 'REJECTED', 'REQUEUED'])
-
-
- class Message(object):
- """Base class for received messages."""
- __slots__ = ('_state', 'channel', 'delivery_tag',
- 'content_type', 'content_encoding',
- 'delivery_info', 'headers', 'properties',
- 'body', '_decoded_cache', 'accept', '__dict__')
- MessageStateError = MessageStateError
-
- errors = None
-
- def __init__(self, channel, body=None, delivery_tag=None,
- content_type=None, content_encoding=None, delivery_info={},
- properties=None, headers=None, postencode=None,
- accept=None, **kwargs):
- self.errors = [] if self.errors is None else self.errors
- self.channel = channel
- self.delivery_tag = delivery_tag
- self.content_type = content_type
- self.content_encoding = content_encoding
- self.delivery_info = delivery_info
- self.headers = headers or {}
- self.properties = properties or {}
- self._decoded_cache = None
- self._state = 'RECEIVED'
- self.accept = accept
-
- compression = self.headers.get('compression')
- if not self.errors and compression:
- try:
- body = decompress(body, compression)
- except Exception:
- self.errors.append(sys.exc_info())
-
- if not self.errors and postencode and isinstance(body, text_t):
- try:
- body = body.encode(postencode)
- except Exception:
- self.errors.append(sys.exc_info())
- self.body = body
-
- def _reraise_error(self, callback=None):
- try:
- reraise(*self.errors[0])
- except Exception as exc:
- if not callback:
- raise
- callback(self, exc)
-
- def ack(self):
- """Acknowledge this message as being processed.,
- This will remove the message from the queue.
-
- :raises MessageStateError: If the message has already been
- acknowledged/requeued/rejected.
-
- """
- if self.channel.no_ack_consumers is not None:
- try:
- consumer_tag = self.delivery_info['consumer_tag']
- except KeyError:
- pass
- else:
- if consumer_tag in self.channel.no_ack_consumers:
- return
- if self.acknowledged:
- raise self.MessageStateError(
- 'Message already acknowledged with state: {0._state}'.format(
- self))
- self.channel.basic_ack(self.delivery_tag)
- self._state = 'ACK'
-
- def ack_log_error(self, logger, errors):
- try:
- self.ack()
- except errors as exc:
- logger.critical("Couldn't ack %r, reason:%r",
- self.delivery_tag, exc, exc_info=True)
-
- def reject_log_error(self, logger, errors, requeue=False):
- try:
- self.reject(requeue=requeue)
- except errors as exc:
- logger.critical("Couldn't reject %r, reason: %r",
- self.delivery_tag, exc, exc_info=True)
-
- def reject(self, requeue=False):
- """Reject this message.
-
- The message will be discarded by the server.
-
- :raises MessageStateError: If the message has already been
- acknowledged/requeued/rejected.
-
- """
- if self.acknowledged:
- raise self.MessageStateError(
- 'Message already acknowledged with state: {0._state}'.format(
- self))
- self.channel.basic_reject(self.delivery_tag, requeue=requeue)
- self._state = 'REJECTED'
-
- def requeue(self):
- """Reject this message and put it back on the queue.
-
- You must not use this method as a means of selecting messages
- to process.
-
- :raises MessageStateError: If the message has already been
- acknowledged/requeued/rejected.
-
- """
- if self.acknowledged:
- raise self.MessageStateError(
- 'Message already acknowledged with state: {0._state}'.format(
- self))
- self.channel.basic_reject(self.delivery_tag, requeue=True)
- self._state = 'REQUEUED'
-
- def decode(self):
- """Deserialize the message body, returning the original
- python structure sent by the publisher."""
- return loads(self.body, self.content_type,
- self.content_encoding, accept=self.accept)
-
- @property
- def acknowledged(self):
- """Set to true if the message has been acknowledged."""
- return self._state in ACK_STATES
-
- @property
- def payload(self):
- """The decoded message body."""
- if not self._decoded_cache:
- self._decoded_cache = self.decode()
- return self._decoded_cache
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