Merge pull request #1205 from EvilBeaver/feature/lru-cache-eval

Добавлен LRU-кэш для компилируемых Вычислить/Выполнить

Author: EvilBeaver

src/ScriptEngine/Machine/LruCache.cs

@@ -0,0 +1,72 @@
+/*----------------------------------------------------------
+This Source Code Form is subject to the terms of the
+Mozilla Public License, v.2.0. If a copy of the MPL
+was not distributed with this file, You can obtain one
+at http://mozilla.org/MPL/2.0/.
+----------------------------------------------------------*/
+
+using System;
+using System.Collections.Generic;
+
+namespace ScriptEngine.Machine
+{
+    public class LruCache<TKey, TValue>
+    {
+        private readonly int _capacity;
+
+        private readonly Dictionary<TKey, LinkedListNode<CacheItem>> _index =
+            new Dictionary<TKey, LinkedListNode<CacheItem>>();
+
+        private readonly LinkedList<CacheItem> _list = new LinkedList<CacheItem>();
+
+        public LruCache(int capacity)
+        {
+            _capacity = capacity;
+        }
+
+        public bool IsEmpty() => _index.Count == 0;
+
+        public void Clear()
+        {
+            _index.Clear();
+            _list.Clear();
+        }
+
+        public TValue GetOrAdd(TKey key, Func<TKey, TValue> factory)
+        {
+            if (_index.TryGetValue(key, out var listNode))
+            {
+                _list.Remove(listNode);
+                _list.AddFirst(listNode);
+                return listNode.Value.Value;
+            }
+
+            if (_index.Count == _capacity)
+            {
+                var keyOfOld = _list.Last.Value.Key;
+                _index.Remove(keyOfOld);
+                _list.RemoveLast();
+            }
+
+            var newItem = _list.AddFirst(CacheItem.Create(key, factory(key)));
+            _index[key] = newItem;
+            return newItem.Value.Value;
+        }
+
+        private class CacheItem
+        {
+            public static CacheItem Create(TKey key, TValue value) =>
+                new CacheItem(key, value);
+            
+            private CacheItem(TKey key, TValue value)
+            {
+                Key = key;
+                Value = value;
+            } 
+            
+            public TKey Key { get; }
+             
+            public TValue Value { get; }
+        }
+    }
+}

src/ScriptEngine/Machine/MachineInstance.cs

@@ -24,7 +24,8 @@ public class MachineInstance
         private ExecutionFrame _currentFrame;
         private Action<int>[] _commands;
         private Stack<ExceptionJumpInfo> _exceptionsStack;
-        
+        private LruCache<string, LoadedModule> _executeModuleCache = new LruCache<string, LoadedModule>(64);
+
         private LoadedModule _module;
         private ICodeStatCollector _codeStatCollector;
         private MachineStopManager _stopManager;
@@ -200,7 +201,7 @@ public void PrepareDebugContinuation()
 
         public IValue Evaluate(string expression, bool separate = false)
         {
-            var code = CompileExpressionModule(expression);
+            var code = _executeModuleCache.GetOrAdd(expression, CompileExpressionModule);
 
             MachineInstance runner;
             MachineInstance currentMachine;
@@ -1431,7 +1432,7 @@ private void PopTmp(int arg)
         private void Execute(int arg)
         {
             var code = _operationStack.Pop().AsString();
-            var module = CompileExecutionBatchModule(code);
+            var module = _executeModuleCache.GetOrAdd(code, CompileExecutionBatchModule);
             PrepareCodeStatisticsData(module);
 
             var frame = new ExecutionFrame();