#19122: Added ICache.IsValid and ICache.TryGet methods.

Work Item: 19122

--HG--
branch : 1.x

src/Orchard/Caching/Cache.cs

@@ -23,6 +23,24 @@ namespace Orchard.Caching {
             return entry.Result;
         }
 
+        public bool TryGet(TKey key, out TResult value){
+            CacheEntry cacheEntry;
+            if (_entries.TryGetValue(key, out cacheEntry)){
+                value = cacheEntry.Result;
+                return true;
+            }
+            value = default(TResult);
+            return false;
+        }
+
+        public bool IsValid(TKey key){
+            CacheEntry currentEntry;
+            if (_entries.TryGetValue(key, out currentEntry)){
+                return currentEntry.Tokens.Any(t => !t.IsCurrent);
+            }
+            return false;
+        }
+
         private CacheEntry AddEntry(TKey k, Func<AcquireContext<TKey>, TResult> acquire) {
             var entry = CreateEntry(k, acquire);
             PropagateTokens(entry);

src/Orchard/Caching/ICache.cs

@@ -3,5 +3,7 @@
 namespace Orchard.Caching {
     public interface ICache<TKey, TResult> {
         TResult Get(TKey key, Func<AcquireContext<TKey>, TResult> acquire);
+        bool IsValid(TKey key);
+        bool TryGet(TKey key, out TResult value);
     }
 }