From 3fb1ccf366241b68c455fac3b240a6761982a643 Mon Sep 17 00:00:00 2001
From: Artem Utin <goodbetterthebeast3@gmail.com>
Date: Sat, 6 Aug 2022 22:34:28 +1000
Subject: [PATCH] Added dictionary as a ordering/search method for large enough
 evaluation results

Signed-off-by: Artem Utin <goodbetterthebeast3@gmail.com>
---
 ArchUnitNET/Fluent/ConditionManager.cs | 41 +++++++++++++++++++++-----
 1 file changed, 33 insertions(+), 8 deletions(-)

diff --git a/ArchUnitNET/Fluent/ConditionManager.cs b/ArchUnitNET/Fluent/ConditionManager.cs
index 3c05cf368..2cee964e1 100644
--- a/ArchUnitNET/Fluent/ConditionManager.cs
+++ b/ArchUnitNET/Fluent/ConditionManager.cs
@@ -11,7 +11,6 @@
 using ArchUnitNET.Domain.Extensions;
 using ArchUnitNET.Fluent.Conditions;
 using ArchUnitNET.Fluent.Extensions;
-using ArchUnitNET.Fluent.Freeze;
 using ArchUnitNET.Fluent.Predicates;
 using JetBrains.Annotations;
 
@@ -98,17 +97,41 @@ public IEnumerable<EvaluationResult> EvaluateConditions(IEnumerable<T> filteredO
                 yield break;
             }
 
-            var conditionResults = _conditionElements.Select(conditionElement =>
-                conditionElement.Check(filteredObjectsList, architecture).ToList()).ToList();
+            //rough heuristic - if we have small number of comparisons, we are fine with sequential search
+            //but in large cases its quadratic behavior becomes too slow and building of a dictionary is justified
+            if (filteredObjectsList.Count * _conditionElements.Count > 256)
+            {
+                var conditionResults = _conditionElements.Select(conditionElement =>
+                    conditionElement.Check(filteredObjectsList, architecture).ToDictionary(x => x.ConditionResult.AnalyzedObject))
+                    .ToList();
 
-            foreach (var t in filteredObjectsList)
+                foreach (var t in filteredObjectsList)
+                {
+                    yield return CreateEvaluationResult(FindResultsForObject(conditionResults, t), architecture, archRuleCreator);
+                }
+            }
+            else
             {
-                yield return CreateEvaluationResult(
-                    conditionResults.Select(results => results.Find(x => x.ConditionResult.AnalyzedObject.Equals(t))),
-                    architecture, archRuleCreator);
+                var conditionResults = _conditionElements.Select(conditionElement =>
+                    conditionElement.Check(filteredObjectsList, architecture).ToList()).ToList();
+
+                foreach (var t in filteredObjectsList)
+                {
+                    yield return CreateEvaluationResult(FindResultsForObject(conditionResults, t), architecture, archRuleCreator);
+                }
             }
         }
 
+        private IEnumerable<ConditionElementResult> FindResultsForObject(List<Dictionary<ICanBeAnalyzed, ConditionElementResult>> conditionResults, T canBeAnalyzed)
+        {
+            return conditionResults.Select(results => results[canBeAnalyzed]);
+        }
+
+        private static IEnumerable<ConditionElementResult> FindResultsForObject(List<List<ConditionElementResult>> conditionResults, T t)
+        {
+            return conditionResults.Select(results => results.Find(x => x.ConditionResult.AnalyzedObject.Equals(t)));
+        }
+
         private static EvaluationResult CreateEvaluationResult(
             IEnumerable<ConditionElementResult> conditionElementResults,
             Architecture architecture, ICanBeEvaluated archRuleCreator)
@@ -298,7 +321,7 @@ public override int GetHashCode()
                 }
             }
         }
-
+        
         private class ConditionElementResult
         {
             public readonly ConditionResult ConditionResult;
@@ -311,4 +334,6 @@ public ConditionElementResult(ConditionResult conditionResult, LogicalConjunctio
             }
         }
     }
+
+    
 }
\ No newline at end of file