SIANXSVC-826: Added direct-reply result backend

Author: beachmachine

.github/workflows/test.yml

@@ -13,14 +13,14 @@ jobs:
       fail-fast: false
       matrix:
         python-version:
-          - "3.6"
           - "3.7"
           - "3.8"
           - "3.9"
           - "3.10"
         celery-version:
           - "5.0"
           - "5.1"
+          - "5.2"
 
     steps:
     - uses: actions/checkout@v2
@@ -51,7 +51,8 @@ jobs:
         ln -s ./tests/test_project/manage.py manage.py
 
         # run tests with coverage
-        coverage run --source='./celery_amqp_backend' manage.py test
+        coverage run --append --source='./celery_amqp_backend' manage.py test --settings=test_project.settings.backend
+        coverage run --append --source='./celery_amqp_backend' manage.py test --settings=test_project.settings.direct_reply_backend
         coverage xml
 
     - name: Upload coverage to Codecov

README.md

@@ -5,16 +5,26 @@ celery-amqp-backend
 [![Test Status](https://github.com/anexia/celery-amqp-backend/actions/workflows/test.yml/badge.svg?branch=main)](https://github.com/anexia/celery-amqp-backend/actions/workflows/test.yml)
 [![Codecov](https://codecov.io/gh/anexia/celery-amqp-backend/branch/main/graph/badge.svg)](https://codecov.io/gh/anexia/celery-amqp-backend)
 
-`celery-amqp-backend` is a rewrite of the Celery's original `amqp://` result backend, which was removed from Celery
-with version 5.0. Celery encourages you to use the newer `rpc://` result backend, as it does not create a new
-result queue for each task and thus is faster in many circumstances. However, it's not always possible to switch
-to the new `rpc://` result backend, as it does have restrictions as follows:
+`celery-amqp-backend` contains two result backens for Celery.
+
+# `AMQPBackend` result backend
+
+The `AMQPBackend` result backend is a rewrite of the Celery's original `amqp://` result backend, which was removed from 
+Celery with version 5.0. Celery encourages you to use the newer `rpc://` result backend, as it does not create a new 
+result queue for each task and thus is faster in many circumstances. However, it's not always possible to switch to the 
+new `rpc://` result backend, as it does have restrictions as follows:
  - `rpc://` does not support chords.
  - `rpc://` results may hold a wrong state.
  - `rpc://` may lose results when using `gevent` or `greenlet`.
 
 The result backend `celery_amqp_backend.AMQPBackend://` does not suffer from the same issues.
 
+# `DirectReplyAMQPBackend` result backend
+
+The `DirectReplyAMQPBackend` result backend makes use of RabbitMQ's direct-reply feature. It is much faster than the
+traditional `AMQPBackend` result backend and should even beat Celery's built-in `rpc://` result backend. However,
+contrary to the `AMQPBackend` result backend it does not support chords.
+
 # Installation
 
 With a [correctly configured](https://pipenv.pypa.io/en/latest/basics/#basic-usage-of-pipenv) `pipenv` toolchain:
@@ -29,7 +39,7 @@ You may also use classic `pip` to install the package:
 pip install celery-amqp-backend
 ```
 
-# Getting started
+# Getting started with `AMQPBackend`
 
 ## Configuration options
 
@@ -57,6 +67,19 @@ Default: `'direct'`
 
 The type of the exchange created by the backend (e.g. `'direct'`, `'topic'` etc.).
 
+# Getting started with `DirectReplyAMQPBackend`
+
+## Important notes
+
+* You must set the `reply_to` property of Celery tasks to `"amq.rabbitmq.reply-to"`.
+* The `DirectReplyAMQPBackend` does not support chords.
+
+## Configuration options
+
+### `result_backend: str`
+
+Set to `'celery_amqp_backend.DirectReplyAMQPBackend://'` to use this result backend.
+
 ## Example configuration
 
 ```python

celery_amqp_backend/__init__.py

@@ -1,2 +1,2 @@
-from .exceptions import *
 from .backend import *
+from .exceptions import *