Extract ConcurrentLfuCore with generic node and policy (#520)

Author: bitfaster

BitFaster.Caching.UnitTests/Lfu/ConcurrentLfuSoakTests.cs

@@ -307,32 +307,33 @@ private async Task RunIntegrityCheckAsync(ConcurrentLfu<int, string> lfu, int it
             RunIntegrityCheck(lfu, this.output);
         }
 
-
         private static void RunIntegrityCheck<K,V>(ConcurrentLfu<K,V> cache, ITestOutputHelper output)
         {
-            new ConcurrentLfuIntegrityChecker<K, V>(cache).Validate(output);
+            new ConcurrentLfuIntegrityChecker<K, V, AccessOrderNode<K, V>, AccessOrderPolicy<K, V>>(cache.Core).Validate(output);
         }
     }
 
-    public class ConcurrentLfuIntegrityChecker<K, V>
+    internal class ConcurrentLfuIntegrityChecker<K, V, N, P>
+        where N : LfuNode<K, V>
+        where P : struct, INodePolicy<K, V, N>
     {
-        private readonly ConcurrentLfu<K, V> cache;
+        private readonly ConcurrentLfuCore<K, V, N, P> cache;
 
         private readonly LfuNodeList<K, V> windowLru;
         private readonly LfuNodeList<K, V> probationLru;
         private readonly LfuNodeList<K, V> protectedLru;
 
-        private readonly StripedMpscBuffer<LfuNode<K, V>> readBuffer;
-        private readonly MpscBoundedBuffer<LfuNode<K, V>> writeBuffer;
+        private readonly StripedMpscBuffer<N> readBuffer;
+        private readonly MpscBoundedBuffer<N> writeBuffer;
 
-        private static FieldInfo windowLruField = typeof(ConcurrentLfu<K, V>).GetField("windowLru", BindingFlags.NonPublic | BindingFlags.Instance);
-        private static FieldInfo probationLruField = typeof(ConcurrentLfu<K, V>).GetField("probationLru", BindingFlags.NonPublic | BindingFlags.Instance);
-        private static FieldInfo protectedLruField = typeof(ConcurrentLfu<K, V>).GetField("protectedLru", BindingFlags.NonPublic | BindingFlags.Instance);
+        private static FieldInfo windowLruField = typeof(ConcurrentLfuCore<K, V, N, P>).GetField("windowLru", BindingFlags.NonPublic | BindingFlags.Instance);
+        private static FieldInfo probationLruField = typeof(ConcurrentLfuCore<K, V, N, P>).GetField("probationLru", BindingFlags.NonPublic | BindingFlags.Instance);
+        private static FieldInfo protectedLruField = typeof(ConcurrentLfuCore<K, V, N, P>).GetField("protectedLru", BindingFlags.NonPublic | BindingFlags.Instance);
 
-        private static FieldInfo readBufferField = typeof(ConcurrentLfu<K, V>).GetField("readBuffer", BindingFlags.NonPublic | BindingFlags.Instance);
-        private static FieldInfo writeBufferField = typeof(ConcurrentLfu<K, V>).GetField("writeBuffer", BindingFlags.NonPublic | BindingFlags.Instance);
+        private static FieldInfo readBufferField = typeof(ConcurrentLfuCore<K, V, N, P>).GetField("readBuffer", BindingFlags.NonPublic | BindingFlags.Instance);
+        private static FieldInfo writeBufferField = typeof(ConcurrentLfuCore<K, V, N, P>).GetField("writeBuffer", BindingFlags.NonPublic | BindingFlags.Instance);
 
-        public ConcurrentLfuIntegrityChecker(ConcurrentLfu<K, V> cache)
+        public ConcurrentLfuIntegrityChecker(ConcurrentLfuCore<K, V, N, P> cache)
         {
             this.cache = cache;
 
@@ -341,8 +342,8 @@ public ConcurrentLfuIntegrityChecker(ConcurrentLfu<K, V> cache)
             this.probationLru = (LfuNodeList<K, V>)probationLruField.GetValue(cache);
             this.protectedLru = (LfuNodeList<K, V>)protectedLruField.GetValue(cache);
 
-            this.readBuffer = (StripedMpscBuffer<LfuNode<K, V>>)readBufferField.GetValue(cache);
-            this.writeBuffer = (MpscBoundedBuffer<LfuNode<K, V>>)writeBufferField.GetValue(cache);
+            this.readBuffer = (StripedMpscBuffer<N>)readBufferField.GetValue(cache);
+            this.writeBuffer = (MpscBoundedBuffer<N>)writeBufferField.GetValue(cache);
         }
 
         public void Validate(ITestOutputHelper output)

BitFaster.Caching.UnitTests/Lfu/ConcurrentLfuTests.cs

@@ -26,6 +26,30 @@ public ConcurrentLfuTests(ITestOutputHelper output)
             this.output = output;
         }
 
+        [Fact]
+        public void WhenCapacityIsLessThan3CtorThrows()
+        {
+            Action constructor = () => { var x = new ConcurrentLfu<int, string>(2); };
+
+            constructor.Should().Throw<ArgumentOutOfRangeException>();
+        }
+
+        [Fact]
+        public void WhenCapacityIsValidCacheIsCreated()
+        {
+            var x = new ConcurrentLfu<int, string>(3);
+
+            x.Capacity.Should().Be(3);
+        }
+
+        [Fact]
+        public void WhenConcurrencyIsLessThan1CtorThrows()
+        {
+            Action constructor = () => { var x = new ConcurrentLfu<int, string>(0, 20, new ForegroundScheduler(), EqualityComparer<int>.Default); };
+
+            constructor.Should().Throw<ArgumentOutOfRangeException>();
+        }
+
         [Fact]
         public void DefaultSchedulerIsThreadPool()
         {
@@ -548,7 +572,11 @@ public void WhenItemsAddedGenericEnumerateContainsKvps()
             cache.GetOrAdd(1, k => k + 1);
             cache.GetOrAdd(2, k => k + 1);
 
-            cache.Should().BeEquivalentTo(new[] { new KeyValuePair<int, int>(1, 2), new KeyValuePair<int, int>(2, 3) });
+            var enumerator = cache.GetEnumerator();
+            enumerator.MoveNext().Should().BeTrue();
+            enumerator.Current.Should().Be(new KeyValuePair<int, int>(1, 2));
+            enumerator.MoveNext().Should().BeTrue();
+            enumerator.Current.Should().Be(new KeyValuePair<int, int>(2, 3));
         }
 
         [Fact]

BitFaster.Caching/BitFaster.Caching.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;netcoreapp3.1;net6.0</TargetFrameworks>
-    <LangVersion>9.0</LangVersion>
+    <LangVersion>10.0</LangVersion>
     <Authors>Alex Peck</Authors>
     <Company />
     <Product>BitFaster.Caching</Product>