reafactor: improve IDistributedCache impl

Author: cnblogs-dudu

src/Enyim.Caching/DistributedCache.cs

@@ -1,11 +1,8 @@
-using Microsoft.Extensions.Caching.Distributed;
-using Microsoft.Extensions.Logging;
-using System.Threading.Tasks;
-using System.Threading;
-using Enyim.Caching.Memcached;
-using Microsoft.Extensions.Caching.Memory;
+using Enyim.Caching.Memcached;
+using Microsoft.Extensions.Caching.Distributed;
 using System;
-using Microsoft.Extensions.Options;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace Enyim.Caching
 {
@@ -40,10 +37,17 @@ async Task<byte[]> IDistributedCache.GetAsync(string key, CancellationToken toke
         void IDistributedCache.Set(string key, byte[] value, DistributedCacheEntryOptions options)
         {
             ulong tmp = 0;
+
+            if (!HasSlidingExpiration(options))
+            {
+                PerformStore(StoreMode.Set, key, value, 0, ref tmp, out var status0);
+                return;
+            }
+
             var expiration = GetExpiration(options);
             PerformStore(StoreMode.Set, key, value, expiration, ref tmp, out var status);
 
-            if (options.SlidingExpiration.HasValue)
+            if (options != null && options.SlidingExpiration.HasValue)
             {
                 var sldExp = options.SlidingExpiration.Value;
                 Add(GetSlidingExpirationKey(key), sldExp.ToString(), sldExp);
@@ -52,6 +56,12 @@ void IDistributedCache.Set(string key, byte[] value, DistributedCacheEntryOption
 
         async Task IDistributedCache.SetAsync(string key, byte[] value, DistributedCacheEntryOptions options, CancellationToken token = default(CancellationToken))
         {
+            if (!HasSlidingExpiration(options))
+            {
+                await PerformStoreAsync(StoreMode.Set, key, value, 0);
+                return;
+            }
+
             var expiration = GetExpiration(options);
             await PerformStoreAsync(StoreMode.Set, key, value, expiration);
 
@@ -62,6 +72,23 @@ void IDistributedCache.Set(string key, byte[] value, DistributedCacheEntryOption
             }
         }
 
+        private static bool HasSlidingExpiration(DistributedCacheEntryOptions options)
+        {
+            if (options == null)
+            {
+                return false;
+            }
+
+            if ((options.SlidingExpiration.HasValue == false || options.SlidingExpiration.Value == TimeSpan.Zero) &&
+               options.AbsoluteExpiration.HasValue == false &&
+               options.AbsoluteExpirationRelativeToNow.HasValue == false)
+            {
+                return false;
+            }
+
+            return true;
+        }
+
         public void Refresh(string key)
         {
             var sldExpKey = GetSlidingExpirationKey(key);

src/Enyim.Caching/MemcachedClient.cs

@@ -84,6 +84,11 @@ private void StartPool()
 
         public event Action<IMemcachedNode> NodeFailed;
 
+        public bool Add(string key, object value)
+        {
+            return Store(StoreMode.Add, key, value);
+        }
+
         public bool Add(string key, object value, int cacheSeconds)
         {
             return Store(StoreMode.Add, key, value, TimeSpan.FromSeconds(cacheSeconds));
@@ -99,6 +104,11 @@ public bool Add(string key, object value, TimeSpan timeSpan)
             return Store(StoreMode.Add, key, value, timeSpan);
         }
 
+        public async Task<bool> AddAsync(string key, object value)
+        {
+            return await StoreAsync(StoreMode.Add, key, value);
+        }
+
         public async Task<bool> AddAsync(string key, object value, int cacheSeconds)
         {
             return await StoreAsync(StoreMode.Add, key, value, TimeSpan.FromSeconds(cacheSeconds));
@@ -551,6 +561,11 @@ public bool Store(StoreMode mode, string key, object value, TimeSpan validFor)
             return PerformStore(mode, key, value, MemcachedClient.GetExpiration(validFor, null), ref tmp, out status).Success;
         }
 
+        public async Task<bool> StoreAsync(StoreMode mode, string key, object value)
+        {
+            return (await PerformStoreAsync(mode, key, value, 0)).Success;
+        }
+
         public async Task<bool> StoreAsync(StoreMode mode, string key, object value, DateTime expiresAt)
         {
             return (await PerformStoreAsync(mode, key, value, MemcachedClient.GetExpiration(null, expiresAt))).Success;