U4-8551 - import NuCache code

src/Umbraco.Core/Cache/DictionaryCacheProvider.cs

@@ -0,0 +1,151 @@
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text.RegularExpressions;
+using Umbraco.Core.Plugins;
+
+namespace Umbraco.Core.Cache
+{
+    class DictionaryCacheProvider : ICacheProvider
+    {
+        private readonly ConcurrentDictionary<string, Lazy<object>> _items
+            = new ConcurrentDictionary<string, Lazy<object>>();
+
+        public void ClearAllCache()
+        {
+            _items.Clear();
+        }
+
+        public void ClearCacheItem(string key)
+        {
+            Lazy<object> item;
+            _items.TryRemove(key, out item);
+        }
+
+        public void ClearCacheObjectTypes(string typeName)
+        {
+            var type = TypeFinder.GetTypeByName(typeName);
+            if (type == null) return;
+            var isInterface = type.IsInterface;
+
+            Lazy<object> item;
+            foreach (var kvp in _items
+                .Where(x =>
+                {
+                    // entry.Value is Lazy<object> and not null, its value may be null
+                    // remove null values as well, does not hurt
+                    // get non-created as NonCreatedValue & exceptions as null
+                    var value = DictionaryCacheProviderBase.GetSafeLazyValue(x.Value, true);
+
+                    // if T is an interface remove anything that implements that interface
+                    // otherwise remove exact types (not inherited types)
+                    return value == null || (isInterface ? (type.IsInstanceOfType(value)) : (value.GetType() == type));
+                }))
+                _items.TryRemove(kvp.Key, out item);
+        }
+
+        public void ClearCacheObjectTypes<T>()
+        {
+            var typeOfT = typeof(T);
+            var isInterface = typeOfT.IsInterface;
+
+            Lazy<object> item;
+            foreach (var kvp in _items
+                .Where(x =>
+                {
+                    // entry.Value is Lazy<object> and not null, its value may be null
+                    // remove null values as well, does not hurt
+                    // compare on exact type, don't use "is"
+                    // get non-created as NonCreatedValue & exceptions as null
+                    var value = DictionaryCacheProviderBase.GetSafeLazyValue(x.Value, true);
+
+                    // if T is an interface remove anything that implements that interface
+                    // otherwise remove exact types (not inherited types)
+                    return value == null || (isInterface ? (value is T) : (value.GetType() == typeOfT));
+                }))
+                _items.TryRemove(kvp.Key, out item);
+        }
+
+        public void ClearCacheObjectTypes<T>(Func<string, T, bool> predicate)
+        {
+            var typeOfT = typeof(T);
+            var isInterface = typeOfT.IsInterface;
+
+            Lazy<object> item;
+            foreach (var kvp in _items
+                .Where(x =>
+                {
+                    // entry.Value is Lazy<object> and not null, its value may be null
+                    // remove null values as well, does not hurt
+                    // compare on exact type, don't use "is"
+                    // get non-created as NonCreatedValue & exceptions as null
+                    var value = DictionaryCacheProviderBase.GetSafeLazyValue(x.Value, true);
+                    if (value == null) return true;
+
+                    // if T is an interface remove anything that implements that interface
+                    // otherwise remove exact types (not inherited types)
+                    return (isInterface ? (value is T) : (value.GetType() == typeOfT))
+                            // run predicate on the 'public key' part only, ie without prefix
+                            && predicate(x.Key, (T)value);
+                }))
+                _items.TryRemove(kvp.Key, out item);
+        }
+
+        public void ClearCacheByKeySearch(string keyStartsWith)
+        {
+            Lazy<object> item;
+            foreach (var ikvp in _items
+                .Where(kvp => kvp.Key.InvariantStartsWith(keyStartsWith)))
+                _items.TryRemove(ikvp.Key, out item);
+        }
+
+        public void ClearCacheByKeyExpression(string regexString)
+        {
+            Lazy<object> item;
+            foreach (var ikvp in _items
+                .Where(kvp => Regex.IsMatch(kvp.Key, regexString)))
+                _items.TryRemove(ikvp.Key, out item);
+        }
+
+        public IEnumerable<object> GetCacheItemsByKeySearch(string keyStartsWith)
+        {
+            return _items
+                .Where(kvp => kvp.Key.InvariantStartsWith(keyStartsWith))
+                .Select(kvp => DictionaryCacheProviderBase.GetSafeLazyValue(kvp.Value))
+                .Where(x => x != null);
+        }
+
+        public IEnumerable<object> GetCacheItemsByKeyExpression(string regexString)
+        {
+            return _items
+                .Where(kvp => Regex.IsMatch(kvp.Key, regexString))
+                .Select(kvp => DictionaryCacheProviderBase.GetSafeLazyValue(kvp.Value))
+                .Where(x => x != null);
+        }
+
+        public object GetCacheItem(string cacheKey)
+        {
+            Lazy<object> result;
+            _items.TryGetValue(cacheKey, out result); // else null
+            return result == null ? null : DictionaryCacheProviderBase.GetSafeLazyValue(result); // return exceptions as null
+        }
+
+        public object GetCacheItem(string cacheKey, Func<object> getCacheItem)
+        {
+            var result = _items.GetOrAdd(cacheKey, k => DictionaryCacheProviderBase.GetSafeLazy(getCacheItem));
+
+            var value = result.Value; // will not throw (safe lazy)
+            var eh = value as DictionaryCacheProviderBase.ExceptionHolder;
+            if (eh == null)
+                return value;
+
+            // and... it's in the cache anyway - so contrary to other cache providers,
+            // which would trick with GetSafeLazyValue, we need to remove by ourselves,
+            // in order NOT to cache exceptions
+
+            _items.TryRemove(cacheKey, out result);
+            throw eh.Exception; // throw once!
+        }
+    }
+}