Add logging for capacity tests

build/dependencies.props

@@ -10,6 +10,8 @@
     <MicrosoftExtensionsDependencyInjectionAbstractionsPackageVersion>3.0.0-alpha1-10584</MicrosoftExtensionsDependencyInjectionAbstractionsPackageVersion>
     <MicrosoftExtensionsDependencyInjectionPackageVersion>3.0.0-alpha1-10584</MicrosoftExtensionsDependencyInjectionPackageVersion>
     <MicrosoftExtensionsFileProvidersPhysicalPackageVersion>3.0.0-alpha1-10584</MicrosoftExtensionsFileProvidersPhysicalPackageVersion>
+    <MicrosoftExtensionsLoggingPackageVersion>3.0.0-alpha1-10584</MicrosoftExtensionsLoggingPackageVersion>
+    <MicrosoftExtensionsLoggingTestingPackageVersion>3.0.0-alpha1-10584</MicrosoftExtensionsLoggingTestingPackageVersion>
     <MicrosoftExtensionsOptionsPackageVersion>3.0.0-alpha1-10584</MicrosoftExtensionsOptionsPackageVersion>
     <MicrosoftExtensionsPrimitivesPackageVersion>3.0.0-alpha1-10584</MicrosoftExtensionsPrimitivesPackageVersion>
     <MicrosoftNETCoreApp20PackageVersion>2.0.9</MicrosoftNETCoreApp20PackageVersion>

src/Microsoft.Extensions.Caching.Memory/MemoryCache.cs

@@ -8,6 +8,7 @@
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Extensions.Internal;
+using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 
 namespace Microsoft.Extensions.Caching.Memory
@@ -74,6 +75,8 @@ public int Count
         // internal for testing
         internal long Size { get => Interlocked.Read(ref _cacheSize); }
 
+        internal ILogger Logger { private get; set; }
+
         private ICollection<KeyValuePair<object, CacheEntry>> EntriesCollection => _entries;
 
         /// <inheritdoc />
@@ -341,18 +344,33 @@ private bool UpdateCacheSizeExceedsCapacity(CacheEntry entry)
 
         private void TriggerOvercapacityCompaction()
         {
+            if (Logger != null)
+            {
+                Logger.LogDebug("Overcapacity compaction triggered");
+            }
             // Spawn background thread for compaction
             ThreadPool.QueueUserWorkItem(s => OvercapacityCompaction((MemoryCache)s), this);
         }
 
         private static void OvercapacityCompaction(MemoryCache cache)
         {
             var currentSize = Interlocked.Read(ref cache._cacheSize);
+
+            if (cache.Logger != null)
+            {
+                cache.Logger.LogDebug($"Overcapacity compaction executing. Current size {currentSize}");
+            }
+
             var lowWatermark = cache._options.SizeLimit * (1 - cache._options.CompactionPercentage);
             if (currentSize > lowWatermark)
             {
                 cache.Compact(currentSize - (long)lowWatermark, entry => entry.Size.Value);
             }
+
+            if (cache.Logger != null)
+            {
+                cache.Logger.LogDebug($"Overcapacity compaction executed. New size {Interlocked.Read(ref cache._cacheSize)}");
+            }
         }
 
         /// Remove at least the given percentage (0.10 for 10%) of the total entries (or estimated memory?), according to the following policy:

src/Microsoft.Extensions.Caching.Memory/Microsoft.Extensions.Caching.Memory.csproj

@@ -14,6 +14,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="$(MicrosoftExtensionsDependencyInjectionAbstractionsPackageVersion)" />
+    <PackageReference Include="Microsoft.Extensions.Logging" Version="$(MicrosoftExtensionsLoggingPackageVersion)" />
     <PackageReference Include="Microsoft.Extensions.Options" Version="$(MicrosoftExtensionsOptionsPackageVersion)" />
   </ItemGroup>
 

test/Microsoft.Extensions.Caching.Memory.Tests/CapacityTests.cs

@@ -6,11 +6,12 @@
 using System.Threading.Tasks;
 using Microsoft.Extensions.Caching.Memory.Infrastructure;
 using Microsoft.Extensions.Internal;
+using Microsoft.Extensions.Logging.Testing;
 using Xunit;
 
 namespace Microsoft.Extensions.Caching.Memory
 {
-    public class CapacityTests
+    public class CapacityTests : LoggedTestBase
     {
         [Fact]
         public void MemoryDistributedCacheOptionsDefaultsTo200MBSizeLimit()
@@ -117,6 +118,8 @@ public async Task DoNotAddIfSizeOverflows()
                 SizeLimit = long.MaxValue
             });
 
+            cache.Logger = Logger;
+
             var entryOptions = new MemoryCacheEntryOptions { Size = long.MaxValue };
             var sem = new SemaphoreSlim(0, 1);
             entryOptions.PostEvictionCallbacks.Add(new PostEvictionCallbackRegistration

test/Microsoft.Extensions.Caching.Memory.Tests/Microsoft.Extensions.Caching.Memory.Tests.csproj

@@ -10,6 +10,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="$(MicrosoftExtensionsDependencyInjectionPackageVersion)" />
+    <PackageReference Include="Microsoft.Extensions.Logging.Testing" Version="$(MicrosoftExtensionsLoggingTestingPackageVersion)" />
   </ItemGroup>
 
 </Project>