Null checks and hardening

Author: JunTaoLuo

src/Microsoft.AspNetCore.ResponseCaching/ResponseCache/DefaultResponseCacheEntrySerializer.cs

@@ -108,18 +108,17 @@ public static void Write(BinaryWriter writer, IResponseCacheEntry entry)
 
             if (entry is CachedResponse)
             {
-                writer.Write(nameof(CachedResponse));
                 WriteCachedResponse(writer, entry as CachedResponse);
             }
             else if (entry is CachedVaryBy)
             {
-                writer.Write(nameof(CachedVaryBy));
                 WriteCachedVaryBy(writer, entry as CachedVaryBy);
             }
         }
 
         private static void WriteCachedResponse(BinaryWriter writer, CachedResponse entry)
         {
+            writer.Write(nameof(CachedResponse));
             writer.Write(entry.StatusCode);
             writer.Write(entry.Headers.Count);
             foreach (var header in entry.Headers)
@@ -134,6 +133,7 @@ private static void WriteCachedResponse(BinaryWriter writer, CachedResponse entr
 
         private static void WriteCachedVaryBy(BinaryWriter writer, CachedVaryBy entry)
         {
+            writer.Write(nameof(CachedVaryBy));
             writer.Write(entry.Headers);
         }
     }

src/Microsoft.AspNetCore.ResponseCaching/ResponseCache/DistributedResponseCache.cs

@@ -1,6 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
 using Microsoft.Extensions.Caching.Distributed;
 
 namespace Microsoft.AspNetCore.ResponseCaching
@@ -11,30 +12,50 @@ public class DistributedResponseCache : IResponseCache
 
         public DistributedResponseCache(IDistributedCache cache)
         {
+            if (cache == null)
+            {
+                throw new ArgumentNullException(nameof(cache));
+            }
+
             _cache = cache;
         }
 
         public IResponseCacheEntry Get(string key)
         {
-            var serializedEntry = _cache.Get(key);
-            if (serializedEntry != null)
+            try
             {
-                return DefaultResponseCacheSerializer.Deserialize(serializedEntry);
+                return DefaultResponseCacheSerializer.Deserialize(_cache.Get(key));
             }
-            else
+            catch
             {
+                // TODO: Log error
                 return null;
             }
         }
 
         public void Remove(string key)
         {
-            _cache.Remove(key);
+            try
+            {
+                _cache.Remove(key);
+            }
+            catch
+            {
+                // TODO: Log error
+            }
         }
 
+        // TODO: Set expiry policy in the underlying cache?
         public void Set(string key, IResponseCacheEntry entry)
         {
-            _cache.Set(key, DefaultResponseCacheSerializer.Serialize(entry));
+            try
+            {
+                _cache.Set(key, DefaultResponseCacheSerializer.Serialize(entry));
+            }
+            catch
+            {
+                // TODO: Log error
+            }
         }
     }
 }

src/Microsoft.AspNetCore.ResponseCaching/ResponseCache/IResponseCacheEntry.cs

@@ -5,6 +5,7 @@ namespace Microsoft.AspNetCore.ResponseCaching
 {
     public interface IResponseCacheEntry
     {
+        // TODO: Retain this in case we cache by a hash of the key instead.
         string Key { get; set; }
     }
 }

src/Microsoft.AspNetCore.ResponseCaching/ResponseCache/MemoryResponseCache.cs

@@ -1,6 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
 using Microsoft.Extensions.Caching.Memory;
 
 namespace Microsoft.AspNetCore.ResponseCaching
@@ -11,22 +12,49 @@ public class MemoryResponseCache : IResponseCache
 
         public MemoryResponseCache(IMemoryCache cache)
         {
+            if (cache == null)
+            {
+                throw new ArgumentNullException(nameof(cache));
+            }
+
             _cache = cache;
         }
 
         public IResponseCacheEntry Get(string key)
         {
-            return _cache.Get<IResponseCacheEntry>(key);
+            try
+            {
+                return _cache.Get<IResponseCacheEntry>(key);
+            }
+            catch
+            {
+                // TODO: Log error
+                return null;
+            }
         }
 
         public void Remove(string key)
         {
-            _cache.Remove(key);
+            try
+            {
+                _cache.Remove(key);
+            }
+            catch
+            {
+                // TODO: Log error
+            }
         }
 
         public void Set(string key, IResponseCacheEntry entry)
         {
-            _cache.Set(key, entry);
+            try
+            {
+                _cache.Set(key, entry);
+            }
+            catch
+            {
+                // TODO: Log error
+            }
         }
     }
 }