From 2362b0dbf7b4da5a3923a6ad13f424b669faff3b Mon Sep 17 00:00:00 2001
From: liangshiwei <liangshiw@outlook.com>
Date: Tue, 3 Aug 2021 15:39:32 +0800
Subject: [PATCH] Implement delayed jobs for RabbitMQ integration

---
 .../AbpRabbitMqBackgroundJobOptions.cs        |  6 ++++
 .../Abp/BackgroundJobs/RabbitMQ/JobQueue.cs   | 22 +++++++++---
 .../RabbitMQ/JobQueueConfiguration.cs         | 35 +++++++++++++++----
 3 files changed, 53 insertions(+), 10 deletions(-)

diff --git a/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/AbpRabbitMqBackgroundJobOptions.cs b/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/AbpRabbitMqBackgroundJobOptions.cs
index 8d588debe9..82c505f050 100644
--- a/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/AbpRabbitMqBackgroundJobOptions.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/AbpRabbitMqBackgroundJobOptions.cs
@@ -15,10 +15,16 @@ namespace Volo.Abp.BackgroundJobs.RabbitMQ
         /// </summary>
         public string DefaultQueueNamePrefix { get; set; }
 
+        /// <summary>
+        /// Default value: "AbpBackgroundJobsDelayed."
+        /// </summary>
+        public string DefaultDelayedQueueNamePrefix { get; set;}
+
         public AbpRabbitMqBackgroundJobOptions()
         {
             JobQueues = new Dictionary<Type, JobQueueConfiguration>();
             DefaultQueueNamePrefix = "AbpBackgroundJobs.";
+            DefaultDelayedQueueNamePrefix = "AbpBackgroundJobsDelayed.";
         }
     }
 }
diff --git a/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/JobQueue.cs b/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/JobQueue.cs
index 3d7e8c05ff..1d16e12683 100644
--- a/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/JobQueue.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/JobQueue.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Extensions.DependencyInjection;
@@ -64,7 +65,8 @@ namespace Volo.Abp.BackgroundJobs.RabbitMQ
             return AbpRabbitMqBackgroundJobOptions.JobQueues.GetOrDefault(typeof(TArgs)) ??
                    new JobQueueConfiguration(
                        typeof(TArgs),
-                       AbpRabbitMqBackgroundJobOptions.DefaultQueueNamePrefix + JobConfiguration.JobName
+                       AbpRabbitMqBackgroundJobOptions.DefaultQueueNamePrefix + JobConfiguration.JobName,
+                       AbpRabbitMqBackgroundJobOptions.DefaultDelayedQueueNamePrefix + JobConfiguration.JobName
                    );
         }
 
@@ -133,6 +135,9 @@ namespace Volo.Abp.BackgroundJobs.RabbitMQ
             var result = QueueConfiguration.Declare(ChannelAccessor.Channel);
             Logger.LogDebug($"RabbitMQ Queue '{QueueConfiguration.QueueName}' has {result.MessageCount} messages and {result.ConsumerCount} consumers.");
 
+            // Declare delayed queue
+            QueueConfiguration.DeclareDelayed(ChannelAccessor.Channel);
+
             if (AbpBackgroundJobOptions.IsJobExecutionEnabled)
             {
                 Consumer = new AsyncEventingBasicConsumer(ChannelAccessor.Channel);
@@ -154,12 +159,21 @@ namespace Volo.Abp.BackgroundJobs.RabbitMQ
             BackgroundJobPriority priority = BackgroundJobPriority.Normal,
             TimeSpan? delay = null)
         {
-            //TODO: How to handle priority & delay?
+            //TODO: How to handle priority
+
+            var routingKey = QueueConfiguration.QueueName;
+            var basicProperties = CreateBasicPropertiesToPublish();
+
+            if (delay.HasValue)
+            {
+                routingKey = QueueConfiguration.DelayedQueueName;
+                basicProperties.Expiration = delay.Value.TotalMilliseconds.ToString();
+            }
 
             ChannelAccessor.Channel.BasicPublish(
                 exchange: "",
-                routingKey: QueueConfiguration.QueueName,
-                basicProperties: CreateBasicPropertiesToPublish(),
+                routingKey: routingKey,
+                basicProperties: basicProperties,
                 body: Serializer.Serialize(args)
             );
 
diff --git a/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/JobQueueConfiguration.cs b/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/JobQueueConfiguration.cs
index 959952de22..453c3f9257 100644
--- a/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/JobQueueConfiguration.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs.RabbitMQ/Volo/Abp/BackgroundJobs/RabbitMQ/JobQueueConfiguration.cs
@@ -1,4 +1,6 @@
 using System;
+using System.Collections.Generic;
+using RabbitMQ.Client;
 using Volo.Abp.RabbitMQ;
 
 namespace Volo.Abp.BackgroundJobs.RabbitMQ
@@ -9,21 +11,42 @@ namespace Volo.Abp.BackgroundJobs.RabbitMQ
 
         public string ConnectionName { get; set; }
 
+        public string DelayedQueueName { get; set; }
+
         public JobQueueConfiguration(
-            Type jobArgsType, 
-            string queueName, 
+            Type jobArgsType,
+            string queueName,
+            string delayedQueueName,
             string connectionName = null,
             bool durable = true,
             bool exclusive = false,
             bool autoDelete = false)
             : base(
-                queueName, 
-                durable, 
-                exclusive, 
+                queueName,
+                durable,
+                exclusive,
                 autoDelete)
         {
             JobArgsType = jobArgsType;
             ConnectionName = connectionName;
+            DelayedQueueName = delayedQueueName;
+        }
+
+        public virtual QueueDeclareOk DeclareDelayed(IModel channel)
+        {
+            var delayedArguments = new Dictionary<string, object>(Arguments)
+            {
+                ["x-dead-letter-routing-key"] = QueueName,
+                ["x-dead-letter-exchange"] = string.Empty
+            };
+
+            return channel.QueueDeclare(
+                queue: DelayedQueueName,
+                durable: Durable,
+                exclusive: Exclusive,
+                autoDelete: AutoDelete,
+                arguments: delayedArguments
+            );
         }
     }
-}
\ No newline at end of file
+}