From 937b86135996e0955cda7a8bd99667d4bbb9fef0 Mon Sep 17 00:00:00 2001
From: Sipke Schoorstra <sipkeschoorstra@outlook.com>
Date: Thu, 15 Apr 2021 21:38:10 +0200
Subject: [PATCH] Optimize workflow registry loading by only considering older
 versions for which there are non-finished workflow instances pending

---
 .../Services/ServiceBusQueuesStarter.cs        | 11 -----------
 .../Elsa.Core/Services/WorkflowRegistry.cs     | 18 +++++++++++++++++-
 2 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/src/activities/Elsa.Activities.AzureServiceBus/Services/ServiceBusQueuesStarter.cs b/src/activities/Elsa.Activities.AzureServiceBus/Services/ServiceBusQueuesStarter.cs
index d8f2779a1..5b6db2caf 100644
--- a/src/activities/Elsa.Activities.AzureServiceBus/Services/ServiceBusQueuesStarter.cs
+++ b/src/activities/Elsa.Activities.AzureServiceBus/Services/ServiceBusQueuesStarter.cs
@@ -65,7 +65,6 @@ namespace Elsa.Activities.AzureServiceBus.Services
             using var scope = _scopeFactory.CreateScope();
             var workflowRegistry = scope.ServiceProvider.GetRequiredService<IWorkflowRegistry>();
             var workflowBlueprintReflector = scope.ServiceProvider.GetRequiredService<IWorkflowBlueprintReflector>();
-            var workflowInstanceStore = scope.ServiceProvider.GetRequiredService<IWorkflowInstanceStore>();
             var workflows = await workflowRegistry.ListAsync(cancellationToken);
 
             var query =
@@ -76,10 +75,6 @@ namespace Elsa.Activities.AzureServiceBus.Services
 
             foreach (var workflow in query)
             {
-                // If a workflow is not published, only consider it for processing if it has at least one non-ended workflow instance.
-                if (!workflow.IsPublished && !await WorkflowHasNonFinishedWorkflowsAsync(workflow, workflowInstanceStore, cancellationToken))
-                    continue;
-
                 var workflowBlueprintWrapper = await workflowBlueprintReflector.ReflectAsync(scope.ServiceProvider, workflow, cancellationToken);
 
                 foreach (var activity in workflowBlueprintWrapper.Filter<AzureServiceBusQueueMessageReceived>())
@@ -102,11 +97,5 @@ namespace Elsa.Activities.AzureServiceBus.Services
                 }
             }
         }
-
-        private static async Task<bool> WorkflowHasNonFinishedWorkflowsAsync(IWorkflowBlueprint workflowBlueprint, IWorkflowInstanceStore workflowInstanceStore, CancellationToken cancellationToken)
-        {
-            var count = await workflowInstanceStore.CountAsync(new NonFinalizedWorkflowSpecification().WithWorkflowDefinition(workflowBlueprint.Id), cancellationToken);
-            return count > 0;
-        }
     }
 }
\ No newline at end of file
diff --git a/src/core/Elsa.Core/Services/WorkflowRegistry.cs b/src/core/Elsa.Core/Services/WorkflowRegistry.cs
index 216f86e5f..d5eedb389 100644
--- a/src/core/Elsa.Core/Services/WorkflowRegistry.cs
+++ b/src/core/Elsa.Core/Services/WorkflowRegistry.cs
@@ -5,6 +5,8 @@ using System.Runtime.CompilerServices;
 using System.Threading;
 using System.Threading.Tasks;
 using Elsa.Models;
+using Elsa.Persistence;
+using Elsa.Persistence.Specifications.WorkflowInstances;
 using Elsa.Services.Models;
 using Open.Linq.AsyncExtensions;
 
@@ -13,10 +15,12 @@ namespace Elsa.Services
     public class WorkflowRegistry : IWorkflowRegistry
     {
         private readonly IEnumerable<IWorkflowProvider> _workflowProviders;
+        private readonly IWorkflowInstanceStore _workflowInstanceStore;
 
-        public WorkflowRegistry(IEnumerable<IWorkflowProvider> workflowProviders)
+        public WorkflowRegistry(IEnumerable<IWorkflowProvider> workflowProviders, IWorkflowInstanceStore workflowInstanceStore)
         {
             _workflowProviders = workflowProviders;
+            _workflowInstanceStore = workflowInstanceStore;
         }
 
         public async Task<IEnumerable<IWorkflowBlueprint>> ListAsync(CancellationToken cancellationToken) => await GetWorkflowsInternalAsync(cancellationToken).ToListAsync(cancellationToken);
@@ -36,7 +40,19 @@ namespace Elsa.Services
 
             foreach (var provider in providers)
             await foreach (var workflow in provider.GetWorkflowsAsync(cancellationToken).WithCancellation(cancellationToken))
+            {
+                // If a workflow is not published, only consider it for processing if it has at least one non-ended workflow instance.
+                if (!workflow.IsPublished && !await WorkflowHasNonFinishedWorkflowsAsync(workflow, cancellationToken))
+                    continue;
+                
                 yield return workflow;
+            }
+        }
+        
+        private async Task<bool> WorkflowHasNonFinishedWorkflowsAsync(IWorkflowBlueprint workflowBlueprint, CancellationToken cancellationToken)
+        {
+            var count = await _workflowInstanceStore.CountAsync(new NonFinalizedWorkflowSpecification().WithWorkflowDefinition(workflowBlueprint.Id), cancellationToken);
+            return count > 0;
         }
     }
 }
\ No newline at end of file