#------------------------------------------------------------------------------
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#
# Portions Copyright 2007-2015, Anthony Tuininga. All rights reserved.
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#------------------------------------------------------------------------------
# raw_aq.py
#
# Demonstrates how to use advanced queuing with RAW data. It makes use of a
# RAW queue created in the sample setup.
#------------------------------------------------------------------------------

import oracledb
import sample_env

# this script is currently only supported in python-oracledb thick mode
oracledb.init_oracle_client(lib_dir=sample_env.get_oracle_client())

QUEUE_NAME = "DEMO_RAW_QUEUE"
PAYLOAD_DATA = [
    "The first message",
    "The second message",
    "The third message",
    "The fourth and final message"
]

connection = oracledb.connect(user=sample_env.get_main_user(),
                              password=sample_env.get_main_password(),
                              dsn=sample_env.get_connect_string())

# create a queue
with connection.cursor() as cursor:

    queue = connection.queue(QUEUE_NAME)
    queue.deqoptions.wait = oracledb.DEQ_NO_WAIT
    queue.deqoptions.navigation = oracledb.DEQ_FIRST_MSG

    # dequeue all existing messages to ensure the queue is empty, just so that
    # the results are consistent
    while queue.deqone():
        pass

# enqueue a few messages
print("Enqueuing messages...")
with connection.cursor() as cursor:

    for data in PAYLOAD_DATA:
        print(data)
        queue.enqone(connection.msgproperties(payload=data))
    connection.commit()

# dequeue the messages
print("\nDequeuing messages...")
with connection.cursor() as cursor:

    while True:
        props = queue.deqone()
        if not props:
            break
        print(props.payload.decode())
    connection.commit()
    print("\nDone.")