Adding documentation comments (#416)

Fixes #414

src/Microsoft.Extensions.Caching.Abstractions/DistributedCacheEntryOptions.cs

@@ -5,6 +5,9 @@ using System;
 
 namespace Microsoft.Extensions.Caching.Distributed
 {
+    /// <summary>
+    /// Provides the cache options for an entry in <see cref="IDistributedCache"/>.
+    /// </summary>
     public class DistributedCacheEntryOptions
     {
         private DateTimeOffset? _absoluteExpiration;

src/Microsoft.Extensions.Caching.Abstractions/IDistributedCache.cs

@@ -6,22 +6,70 @@ using System.Threading.Tasks;
 
 namespace Microsoft.Extensions.Caching.Distributed
 {
+    /// <summary>
+    /// Represents a distributed cache of serialized values.
+    /// </summary>
     public interface IDistributedCache
     {
+        /// <summary>
+        /// Gets a value with the given key.
+        /// </summary>
+        /// <param name="key">A string identifying the requested value.</param>
+        /// <returns>The located value or null.</returns>
         byte[] Get(string key);
 
+        /// <summary>
+        /// Gets a value with the given key.
+        /// </summary>
+        /// <param name="key">A string identifying the requested value.</param>
+        /// <param name="token">Optional. The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
+        /// <returns>The <see cref="Task"/> that represents the asynchronous operation, containing the located value or null.</returns>
         Task<byte[]> GetAsync(string key, CancellationToken token = default(CancellationToken));
 
+        /// <summary>
+        /// Sets a value with the given key.
+        /// </summary>
+        /// <param name="key">A string identifying the requested value.</param>
+        /// <param name="value">The value to set in the cache.</param>
+        /// <param name="options">The cache options for the value.</param>
         void Set(string key, byte[] value, DistributedCacheEntryOptions options);
 
+        /// <summary>
+        /// Sets the value with the given key.
+        /// </summary>
+        /// <param name="key">A string identifying the requested value.</param>
+        /// <param name="value">The value to set in the cache.</param>
+        /// <param name="options">The cache options for the value.</param>
+        /// <param name="token">Optional. The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
+        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
         Task SetAsync(string key, byte[] value, DistributedCacheEntryOptions options, CancellationToken token = default(CancellationToken));
 
+        /// <summary>
+        /// Refreshes a value in the cache based on its key, resetting its sliding expiration timeout (if any).
+        /// </summary>
+        /// <param name="key">A string identifying the requested calue.</param>
         void Refresh(string key);
 
+        /// <summary>
+        /// Refreshes a value in the cache based on its key, resetting its sliding expiration timeout (if any).
+        /// </summary>
+        /// <param name="key">A string identifying the requested value.</param>
+        /// <param name="token">Optional. The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
+        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
         Task RefreshAsync(string key, CancellationToken token = default(CancellationToken));
 
+        /// <summary>
+        /// Removes the value with the given key.
+        /// </summary>
+        /// <param name="key">A string identifying the requested value.</param>
         void Remove(string key);
 
+        /// <summary>
+        /// Removes the value with the given key.
+        /// </summary>
+        /// <param name="key">A string identifying the requested value.</param>
+        /// <param name="token">Optional. The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
+        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
         Task RemoveAsync(string key, CancellationToken token = default(CancellationToken));
     }
 }

src/Microsoft.Extensions.Caching.Abstractions/MemoryCacheEntryOptions.cs

@@ -7,6 +7,9 @@ using Microsoft.Extensions.Primitives;
 
 namespace Microsoft.Extensions.Caching.Memory
 {
+    /// <summary>
+    /// Represents the cache options applied to an entry of the <see cref="IMemoryCache"/> instance.
+    /// </summary>
     public class MemoryCacheEntryOptions
     {
         private DateTimeOffset? _absoluteExpiration;