# ----------------------------------------------------------------------------- # Copyright (c) 2021, 2023, Oracle and/or its affiliates. # # This software is dual-licensed to you under the Universal Permissive License # (UPL) 1.0 as shown at https://oss.oracle.com/licenses/upl and Apache License # 2.0 as shown at http://www.apache.org/licenses/LICENSE-2.0. You may choose # either license. # # If you elect to accept the software under the Apache License, Version 2.0, # the following applies: # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # https://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. # ----------------------------------------------------------------------------- # ----------------------------------------------------------------------------- # aq.py # # Contains the classes used for handling Advanced Queuing (AQ): Queue, # DeqOptions, EnqOptions and MessageProperties. # ----------------------------------------------------------------------------- import datetime from . import connection as connection_module from typing import Any, Union, List from . import errors from .dbobject import DbObject, DbObjectType class Queue: @classmethod def _from_impl(cls, connection, impl): queue = cls.__new__(cls) queue._connection = connection queue._deq_options = DeqOptions._from_impl(impl.deq_options_impl) queue._enq_options = EnqOptions._from_impl(impl.enq_options_impl) queue._payload_type = None queue._impl = impl return queue def _verify_message(self, message: "MessageProperties") -> None: """ Internal method used for verifying a message. """ if not isinstance(message, MessageProperties): raise TypeError("expecting MessageProperties object") if message.payload is None: errors._raise_err(errors.ERR_MESSAGE_HAS_NO_PAYLOAD) @property def connection(self) -> "connection_module.Connection": """ Returns the connection on which the queue was created. """ return self._connection def deqmany(self, max_num_messages: int) -> list: """ Dequeues up to the specified number of messages from the queue and returns a list of these messages. """ message_impls = self._impl.deq_many(max_num_messages) return [MessageProperties._from_impl(impl) for impl in message_impls] def deqMany(self, max_num_messages: int) -> List["MessageProperties"]: """ Deprecated: use deqmany() instead. """ return self.deqmany(max_num_messages) def deqone(self) -> Union["MessageProperties", None]: """ Dequeues at most one message from the queue and returns it. If no message is dequeued, None is returned. """ message_impl = self._impl.deq_one() if message_impl is not None: return MessageProperties._from_impl(message_impl) def deqOne(self) -> Union["MessageProperties", None]: """ Deprecated: use deqone() instead. """ return self.deqone() @property def deqoptions(self) -> "DeqOptions": """ Returns the options that will be used when dequeuing messages from the queue. """ return self._deq_options @property def deqOptions(self) -> "DeqOptions": """ Deprecated: use deqoptions instead. """ return self.deqoptions def enqmany(self, messages: list) -> None: """ Enqueues multiple messages into the queue. The messages parameter must be a sequence containing message property objects which have all had their payload attribute set to a value that the queue supports. Warning: calling this function in parallel on different connections acquired from the same pool may fail due to Oracle bug 29928074. Ensure that this function is not run in parallel, use standalone connections or connections from different pools, or make multiple calls to enqOne() instead. The function Queue.deqMany() call is not affected. """ for message in messages: self._verify_message(message) message_impls = [m._impl for m in messages] self._impl.enq_many(message_impls) def enqMany(self, messages: list) -> None: """ Deprecated: use enqmany() instead. """ return self.enqmany(messages) def enqone(self, message: "MessageProperties") -> None: """ Enqueues a single message into the queue. The message must be a message property object which has had its payload attribute set to a value that the queue supports. """ self._verify_message(message) self._impl.enq_one(message._impl) def enqOne(self, message: "MessageProperties") -> None: """ Deprecated: use enqone() instead. """ return self.enqone(message) @property def enqoptions(self) -> "EnqOptions": """ Returns the options that will be used when enqueuing messages into the queue. """ return self._enq_options @property def enqOptions(self) -> "EnqOptions": """ Deprecated: use enqoptions() instead. """ return self.enqoptions @property def name(self) -> str: """ Returns the name of the queue. """ return self._impl.name @property def payload_type(self) -> Union[DbObjectType, None]: """ Returns the object type for payloads that can be enqueued and dequeued. If using a raw queue, this returns the value None. """ if self._payload_type is None: if self._impl.is_json: self._payload_type = "JSON" elif self._impl.payload_type is not None: self._payload_type = DbObjectType._from_impl( self._impl.payload_type ) return self._payload_type @property def payloadType(self) -> Union[DbObjectType, None]: """ Deprecated: use payload_type instead. """ return self.payload_type class DeqOptions: @classmethod def _from_impl(cls, impl): options = cls.__new__(cls) options._impl = impl return options @property def condition(self) -> str: """ Specifies a boolean expression similar to the where clause of a SQL query. The boolean expression can include conditions on message properties, user data properties and PL/SQL or SQL functions. The default is to have no condition specified. """ return self._impl.get_condition() @condition.setter def condition(self, value: str) -> None: self._impl.set_condition(value) @property def consumername(self) -> str: """ Specifies the name of the consumer. Only messages matching the consumer name will be accessed. If the queue is not set up for multiple consumers this attribute should not be set. The default is to have no consumer name specified. """ return self._impl.get_consumer_name() @consumername.setter def consumername(self, value: str) -> None: self._impl.set_consumer_name(value) @property def correlation(self) -> str: """ Specifies the correlation identifier of the message to be dequeued. Special pattern-matching characters, such as the percent sign (%) and the underscore (_), can be used. If multiple messages satisfy the pattern, the order of dequeuing is indeterminate. The default is to have no correlation specified. """ return self._impl.get_correlation() @correlation.setter def correlation(self, value: str) -> None: self._impl.set_correlation(value) @property def deliverymode(self) -> None: """ Specifies what types of messages should be dequeued. It should be one of the values MSG_PERSISTENT (default), MSG_BUFFERED or MSG_PERSISTENT_OR_BUFFERED. """ raise AttributeError("deliverymode can only be written") @deliverymode.setter def deliverymode(self, value: int) -> None: self._impl.set_delivery_mode(value) @property def mode(self) -> int: """ Specifies the locking behaviour associated with the dequeue operation. It should be one of the values DEQ_BROWSE, DEQ_LOCKED, DEQ_REMOVE (default), or DEQ_REMOVE_NODATA. """ return self._impl.get_mode() @mode.setter def mode(self, value: int) -> None: self._impl.set_mode(value) @property def msgid(self) -> bytes: """ Specifies the identifier of the message to be dequeued. The default is to have no message identifier specified. """ return self._impl.get_message_id() @msgid.setter def msgid(self, value: bytes) -> None: self._impl.set_message_id(value) @property def navigation(self) -> int: """ Specifies the position of the message that is retrieved. It should be one of the values DEQ_FIRST_MSG, DEQ_NEXT_MSG (default), or DEQ_NEXT_TRANSACTION. """ return self._impl.get_navigation() @navigation.setter def navigation(self, value: int) -> None: self._impl.set_navigation(value) @property def transformation(self) -> str: """ Specifies the name of the transformation that must be applied after the message is dequeued from the database but before it is returned to the calling application. The transformation must be created using dbms_transform. The default is to have no transformation specified. """ return self._impl.get_transformation() @transformation.setter def transformation(self, value: str) -> None: self._impl.set_transformation(value) @property def visibility(self) -> int: """ Specifies the transactional behavior of the dequeue request. It should be one of the values DEQ_ON_COMMIT (default) or DEQ_IMMEDIATE. This attribute is ignored when using the DEQ_BROWSE mode. Note the value of autocommit is always ignored. """ return self._impl.get_visibility() @visibility.setter def visibility(self, value: int) -> None: self._impl.set_visibility(value) @property def wait(self) -> int: """ Specifies the time to wait, in seconds, for a message matching the search criteria to become available for dequeuing. One of the values DEQ_NO_WAIT or DEQ_WAIT_FOREVER can also be used. The default is DEQ_WAIT_FOREVER. """ return self._impl.get_wait() @wait.setter def wait(self, value: int) -> None: self._impl.set_wait(value) class EnqOptions: @classmethod def _from_impl(cls, impl): options = cls.__new__(cls) options._impl = impl return options @property def deliverymode(self) -> int: """ Specifies what type of messages should be enqueued. It should be one of the values MSG_PERSISTENT (default) or MSG_BUFFERED. """ raise AttributeError("deliverymode can only be written") @deliverymode.setter def deliverymode(self, value: int) -> None: self._impl.set_delivery_mode(value) @property def transformation(self) -> str: """ Specifies the name of the transformation that must be applied before the message is enqueued into the database. The transformation must be created using dbms_transform. The default is to have no transformation specified. """ return self._impl.get_transformation() @transformation.setter def transformation(self, value: str) -> None: self._impl.set_transformation(value) @property def visibility(self) -> int: """ Specifies the transactional behavior of the enqueue request. It should be one of the values ENQ_ON_COMMIT (default) or ENQ_IMMEDIATE. Note the value of autocommit is ignored. """ return self._impl.get_visibility() @visibility.setter def visibility(self, value: int) -> None: self._impl.set_visibility(value) class MessageProperties: _recipients = [] @classmethod def _from_impl(cls, impl): props = cls.__new__(cls) props._impl = impl return props @property def attempts(self) -> int: """ Specifies the number of attempts that have been made to dequeue the message. """ return self._impl.get_num_attempts() @property def correlation(self) -> str: """ Specifies the correlation used when the message was enqueued. """ return self._impl.get_correlation() @correlation.setter def correlation(self, value: str) -> None: self._impl.set_correlation(value) @property def delay(self) -> int: """ Specifies the number of seconds to delay an enqueued message. Any integer is acceptable but the constant MSG_NO_DELAY can also be used indicating that the message is available for immediate dequeuing. """ return self._impl.get_delay() @delay.setter def delay(self, value: int) -> None: self._impl.set_delay(value) @property def deliverymode(self) -> int: """ Specifies the type of message that was dequeued. It will be one of the values MSG_PERSISTENT or MSG_BUFFERED. """ return self._impl.get_delivery_mode() @property def enqtime(self) -> datetime.datetime: """ Specifies the time that the message was enqueued. """ return self._impl.get_enq_time() @property def exceptionq(self) -> str: """ Specifies the name of the queue to which the message is moved if it cannot be processed successfully. Messages are moved if the number of unsuccessful dequeue attempts has exceeded the maximum number of retries or if the message has expired. All messages in the exception queue are in the MSG_EXPIRED state. The default value is the name of the exception queue associated with the queue table. """ return self._impl.get_exception_queue() @exceptionq.setter def exceptionq(self, value: str) -> None: self._impl.set_exception_queue(value) @property def expiration(self) -> int: """ Specifies, in seconds, how long the message is available for dequeuing. This attribute is an offset from the delay attribute. Expiration processing requires the queue monitor to be running. Any integer is accepted but the constant MSG_NO_EXPIRATION can also be used indicating that the message never expires. """ return self._impl.get_expiration() @expiration.setter def expiration(self, value: int) -> None: self._impl.set_expiration(value) @property def msgid(self) -> bytes: """ Specifies the id of the message in the last queue that enqueued or dequeued this message. If the message has never been dequeued or enqueued, the value will be `None`. """ return self._impl.get_message_id() @property def payload(self) -> Union[bytes, DbObject]: """ Specifies the payload that will be enqueued or the payload that was dequeued when using a queue. When enqueuing, the value is checked to ensure that it conforms to the type expected by that queue. For RAW queues, the value can be a bytes object or a string. If the value is a string it will be converted to bytes in the encoding UTF-8. """ return self._impl.payload @payload.setter def payload(self, value: Any) -> None: if isinstance(value, DbObject): self._impl.set_payload_object(value._impl) elif not isinstance(value, (str, bytes)): self._impl.set_payload_json(value) else: if isinstance(value, str): value_bytes = value.encode() elif isinstance(value, bytes): value_bytes = value self._impl.set_payload_bytes(value_bytes) self._impl.payload = value @property def priority(self) -> int: """ Specifies the priority of the message. A smaller number indicates a higher priority. The priority can be any integer, including negative numbers. The default value is zero. """ return self._impl.get_priority() @priority.setter def priority(self, value: int) -> None: self._impl.set_priority(value) @property def recipients(self) -> list: """ A list of recipient names can be associated with a message at the time a message is enqueued. This allows a limited set of recipients to dequeue each message. The recipient list associated with the message overrides the queue subscriber list, if there is one. The recipient names need not be in the subscriber list but can be, if desired. To dequeue a message, the consumername attribute can be set to one of the recipient names. The original message recipient list is not available on dequeued messages. All recipients have to dequeue a message before it gets removed from the queue. Subscribing to a queue is like subscribing to a magazine: each subscriber can dequeue all the messages placed into a specific queue, just as each magazine subscriber has access to all its articles. Being a recipient, however, is like getting a letter: each recipient is a designated target of a particular message. """ return self._recipients @recipients.setter def recipients(self, value: list) -> None: self._impl.set_recipients(value) self._recipients = value @property def state(self) -> int: """ Specifies the state of the message at the time of the dequeue. It will be one of the values MSG_WAITING, MSG_READY, MSG_PROCESSED or MSG_EXPIRED. """ return self._impl.get_state()