Extend Memory cache entry with options

src/HttpClient.Cache/CacheEntryExtensions.cs

@@ -1,8 +1,38 @@
 namespace HttpClient.Cache;
 
-internal static class CacheEntryExtensions
+public static class CacheEntryExtensions
 {
-    internal static ICacheEntry AddExpirationToken(this ICacheEntry entry, IChangeToken token)
+    public static ICacheEntry SetValue(this ICacheEntry entry, object value)
+    {
+        entry.Value = value;
+        return entry;
+    }
+
+    public static ICacheEntry SetPriority(this ICacheEntry entry, CacheEntryPriority priority)
+    {
+        entry.Priority = priority;
+        return entry;
+    }
+
+    public static ICacheEntry SetAbsoluteExpiration(this ICacheEntry entry, DateTimeOffset expiredAt)
+    {
+        entry.AbsoluteExpiration = expiredAt;
+        return entry;
+    }
+
+    public static ICacheEntry SetAbsoluteExpiration(this ICacheEntry entry, TimeSpan expiredAt)
+    {
+        entry.AbsoluteExpirationRelativeToNow = expiredAt;
+        return entry;
+    }
+
+    public static ICacheEntry SetSlidingExpiration(this ICacheEntry entry, TimeSpan slidingExpiration)
+    {
+        entry.SlidingExpiration = slidingExpiration;
+        return entry;
+    }
+
+    public static ICacheEntry AddExpirationToken(this ICacheEntry entry, IChangeToken? token)
     {
         if (token == null)
         {
@@ -12,4 +42,16 @@ internal static ICacheEntry AddExpirationToken(this ICacheEntry entry, IChangeTo
         entry.ExpirationTokens.Add(token);
         return entry;
     }
+
+    public static ICacheEntry RegisterPostEvictionCallback(this ICacheEntry entry, PostEvictionDelegate? callback,
+        object? state)
+    {
+        if (callback == null)
+        {
+            throw new ArgumentNullException(nameof(callback));
+        }
+
+        entry.PostEvictionCallbacks.Add(new PostEvictionCallbackRegistration(callback, state));
+        return entry;
+    }
 }

src/HttpClient.Cache/HttpClient.Cache.csproj

@@ -47,7 +47,7 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <None Include="README.md" Pack="true" PackagePath=""/>
+        <None Include="README.md" Pack="true" PackagePath="" />
     </ItemGroup>
 
     <ItemGroup>

src/HttpClient.Cache/InMemory/Clock/DefaultSystemClock.cs

@@ -0,0 +1,12 @@
+namespace HttpClient.Cache.InMemory.Clock;
+
+/// <summary>
+/// Presents current UTC time
+/// </summary>
+internal class DefaultSystemClock: ISystemClock
+{
+    /// <summary>
+    /// Current UTC now offset.
+    /// </summary>
+    public DateTimeOffset UtcNow => DateTimeOffset.UtcNow;
+}

src/HttpClient.Cache/InMemory/MemoryCache.cs

@@ -6,16 +6,16 @@ namespace HttpClient.Cache.InMemory;
 public sealed class MemoryCache : IMemoryCache
 {
     private readonly ISystemClock _clock;
-    private readonly ConcurrentDictionary<object, CacheEntry> _cacheEntries;
-    private readonly Action<CacheEntry> _entryExpirationNotification;
+    private readonly ConcurrentDictionary<object, MemoryCacheEntry> _cacheEntries;
+    private readonly Action<MemoryCacheEntry> _entryExpirationNotification;
 
     private readonly TimeSpan _expirationScanFrequency;
-    private readonly Action<CacheEntry> _setEntry;
+    private readonly Action<MemoryCacheEntry> _setEntry;
 
     private bool _isDisposed;
     private DateTimeOffset _lastExpirationScan;
 
-    private ICollection<KeyValuePair<object, CacheEntry>> CacheEntries => _cacheEntries;
+    private ICollection<KeyValuePair<object, MemoryCacheEntry>> CacheEntries => _cacheEntries;
 
     public MemoryCache() 
         : this(new MemoryCacheOptions())
@@ -29,11 +29,11 @@ public MemoryCache(MemoryCacheOptions options)
             throw new ArgumentNullException(nameof(options));
         }
 
-        _cacheEntries = new ConcurrentDictionary<object, CacheEntry>();
+        _cacheEntries = new ConcurrentDictionary<object, MemoryCacheEntry>();
         _setEntry = SetEntry;
         _entryExpirationNotification = EntryExpired;
 
-        _clock = options.Clock ?? new SystemClock();
+        _clock = options.Clock ?? new DefaultSystemClock();
         _expirationScanFrequency = options.ExpirationScanFrequency;
         _lastExpirationScan = _clock.UtcNow;
     }
@@ -52,7 +52,7 @@ public ICacheEntry CreateEntry(object key)
             throw new ObjectDisposedException(typeof(MemoryCache).FullName);
         }
 
-        return new CacheEntry(key, _setEntry, _entryExpirationNotification);
+        return new MemoryCacheEntry(key, _setEntry, _entryExpirationNotification);
     }
 
     public bool TryGetValue(object key, out object? value)
@@ -71,7 +71,7 @@ public bool TryGetValue(object key, out object? value)
         var currentTime = _clock.UtcNow;
 
         bool isEntryFound = false;
-        if (_cacheEntries.TryGetValue(key, out CacheEntry? entry))
+        if (_cacheEntries.TryGetValue(key, out MemoryCacheEntry? entry))
         {
             if (entry.IsExpired(currentTime) && entry.EvictionReason != EvictionReason.Replaced)
             {
@@ -101,7 +101,7 @@ public void Remove(object key)
             throw new ArgumentNullException(nameof(key));
         }
 
-        if (_cacheEntries.TryRemove(key, out CacheEntry? cacheEntry))
+        if (_cacheEntries.TryRemove(key, out MemoryCacheEntry? cacheEntry))
         {
             cacheEntry.ExpireEntryByReason(EvictionReason.Removed);
             cacheEntry.InvokeEvictionCallbacks();
@@ -120,7 +120,7 @@ public void Clear()
         var keys = _cacheEntries.Keys.ToList();
         foreach (object key in keys)
         {
-            if (_cacheEntries.TryRemove(key, out CacheEntry? cacheEntry))
+            if (_cacheEntries.TryRemove(key, out MemoryCacheEntry? cacheEntry))
             {
                 cacheEntry.ExpireEntryByReason(EvictionReason.Removed);
                 cacheEntry.InvokeEvictionCallbacks();
@@ -135,7 +135,7 @@ public void Dispose()
         Dispose(true);
     }
 
-    private void SetEntry(CacheEntry entry)
+    private void SetEntry(MemoryCacheEntry entry)
     {
         if (_isDisposed)
         {
@@ -162,7 +162,7 @@ private void SetEntry(CacheEntry entry)
 
         entry.LastAccessed = currentTime;
 
-        if (_cacheEntries.TryGetValue(entry.Key, out CacheEntry? cacheEntry))
+        if (_cacheEntries.TryGetValue(entry.Key, out MemoryCacheEntry? cacheEntry))
         {
             cacheEntry.ExpireEntryByReason(EvictionReason.Replaced);
         }
@@ -207,17 +207,17 @@ private void SetEntry(CacheEntry entry)
         StartScanForExpiredItems();
     }
 
-    private void RemoveEntry(CacheEntry entry)
+    private void RemoveEntry(MemoryCacheEntry entry)
     {
-        if (!CacheEntries.Remove(new KeyValuePair<object, CacheEntry>(entry.Key, entry)))
+        if (!CacheEntries.Remove(new KeyValuePair<object, MemoryCacheEntry>(entry.Key, entry)))
         {
             return;
         }
 
         entry.InvokeEvictionCallbacks();
     }
 
-    private void EntryExpired(CacheEntry entry)
+    private void EntryExpired(MemoryCacheEntry entry)
     {
         RemoveEntry(entry);
         StartScanForExpiredItems();
@@ -240,7 +240,7 @@ private void StartScanForExpiredItems()
     private static void ScanForExpiredItems(MemoryCache cache)
     {
         var currentTime = cache._clock.UtcNow;
-        foreach (CacheEntry entry in cache._cacheEntries.Values)
+        foreach (MemoryCacheEntry entry in cache._cacheEntries.Values)
         {
             if (entry.IsExpired(currentTime))
             {

src/HttpClient.Cache/InMemory/CacheEntry.cs → src/HttpClient.Cache/InMemory/MemoryCacheEntry.cs

@@ -2,13 +2,13 @@
 
 namespace HttpClient.Cache.InMemory;
 
-internal class CacheEntry : ICacheEntry
+internal class MemoryCacheEntry : ICacheEntry
 {
     private readonly object _lock = new();
     private static readonly Action<object> ExpirationCallback = ExpirationTokensExpired;
 
-    private readonly Action<CacheEntry> _notifyCacheEntryDisposed;
-    private readonly Action<CacheEntry> _notifyCacheOfExpiration;
+    private readonly Action<MemoryCacheEntry> _notifyCacheEntryDisposed;
+    private readonly Action<MemoryCacheEntry> _notifyCacheOfExpiration;
     private DateTimeOffset? _absoluteExpiration;
     private TimeSpan? _absoluteExpirationRelativeToNow;
     private TimeSpan? _slidingExpiration;
@@ -20,10 +20,10 @@ internal class CacheEntry : ICacheEntry
     private bool _isDisposed;
     private bool _isExpired;
 
-    internal CacheEntry(
+    internal MemoryCacheEntry(
         object key, 
-        Action<CacheEntry> notifyCacheEntryDisposed,
-        Action<CacheEntry> notifyCacheOfExpiration)
+        Action<MemoryCacheEntry> notifyCacheEntryDisposed,
+        Action<MemoryCacheEntry> notifyCacheOfExpiration)
     {
         Key = key ?? throw new ArgumentNullException(nameof(key));
 
@@ -82,9 +82,14 @@ public IList<IChangeToken> ExpirationTokens
         }
     }
 
-    public IList<PostEvictionCallbackRegistration> PostEvictionCallbacks => 
-        _postEvictionCallbacks ?? new List<PostEvictionCallbackRegistration>();
-
+    public IList<PostEvictionCallbackRegistration> PostEvictionCallbacks
+    {
+        get
+        {
+            return _postEvictionCallbacks ??= new List<PostEvictionCallbackRegistration>();
+        }
+    }
+
     internal DateTimeOffset LastAccessed { get; set; }
 
     internal EvictionReason EvictionReason { get; private set; }
@@ -158,7 +163,7 @@ private static void ExpirationTokensExpired(object entry)
     {
         Task.Factory.StartNew(state =>
         {
-            CacheEntry? cacheEntry = state as CacheEntry;
+            MemoryCacheEntry? cacheEntry = state as MemoryCacheEntry;
             cacheEntry?.ExpireEntryByReason(EvictionReason.TokenExpired);
             cacheEntry?._notifyCacheOfExpiration(cacheEntry);
         }, entry, CancellationToken.None, TaskCreationOptions.DenyChildAttach, TaskScheduler.Default);
@@ -222,11 +227,11 @@ internal void InvokeEvictionCallbacks()
             return;
         }
 
-        Task.Factory.StartNew(state => InvokeCallbacks((CacheEntry)state!), this, CancellationToken.None,
+        Task.Factory.StartNew(state => InvokeCallbacks((MemoryCacheEntry)state!), this, CancellationToken.None,
             TaskCreationOptions.DenyChildAttach, TaskScheduler.Default);
     }
 
-    private static void InvokeCallbacks(CacheEntry entry)
+    private static void InvokeCallbacks(MemoryCacheEntry entry)
     {
         var evictionCallbacks =
             Interlocked.Exchange(ref entry._postEvictionCallbacks, null);

src/HttpClient.Cache/InMemory/MemoryCacheEntryExtensions.cs

@@ -0,0 +1,24 @@
+namespace HttpClient.Cache.InMemory;
+
+public static class MemoryCacheEntryExtensions
+{
+    public static ICacheEntry SetOptions(this ICacheEntry entry, MemoryCacheEntryOptions options)
+    {
+        entry.AbsoluteExpiration = options.AbsoluteExpiration;
+        entry.AbsoluteExpirationRelativeToNow = options.AbsoluteExpirationRelativeToNow;
+        entry.SlidingExpiration = options.SlidingExpiration;
+        entry.Priority = options.Priority;
+
+        foreach (var expirationToken in options.ExpirationTokens)
+        {
+            entry.ExpirationTokens.Add(expirationToken);
+        }
+
+        foreach (var evictionCallback in options.PostEvictionCallbacks)
+        {
+            entry.PostEvictionCallbacks.Add(new PostEvictionCallbackRegistration(evictionCallback.EvictionCallback, evictionCallback.State));
+        }
+
+        return entry;
+    }
+}

src/HttpClient.Cache/InMemory/MemoryCacheEntryOptions.cs

@@ -0,0 +1,83 @@
+namespace HttpClient.Cache.InMemory;
+
+/// <summary>
+/// Provides cache entry configuration
+/// </summary>
+public class MemoryCacheEntryOptions
+{
+    private TimeSpan? _absoluteExpirationRelativeToNow;
+
+    private TimeSpan? _slidingExpiration;
+
+    private DateTimeOffset? _absoluteExpiration;
+
+    /// <summary>
+    /// The absolute expiration for cache entry. The point in time where cache entry will no longer be available
+    /// </summary>
+    /// <exception cref="ArgumentOutOfRangeException">Time point must not be in the past</exception>
+    public DateTimeOffset? AbsoluteExpiration
+    {
+        get { return _absoluteExpiration; }
+        set
+        {
+            if (value.HasValue && value.Value < DateTimeOffset.Now)
+                throw new ArgumentOutOfRangeException(nameof(AbsoluteExpiration), value,
+                    "The absolute expiration can not be in the past");
+
+            _absoluteExpiration = value;
+        }
+    }
+
+    /// <summary>
+    /// The absolute expiration due to now. The time period while entity will be available from now.
+    /// </summary>
+    /// <exception cref="ArgumentOutOfRangeException">Time point should be positive and bigger to <see cref="TimeSpan.Zero"/> value</exception>
+    public TimeSpan? AbsoluteExpirationRelativeToNow
+    {
+        get
+        {
+            return _absoluteExpirationRelativeToNow;
+        }
+        set
+        {
+            if ((value.HasValue ? (value.GetValueOrDefault() <= TimeSpan.Zero ? 1 : 0) : 0) != 0)
+                throw new ArgumentOutOfRangeException(nameof(AbsoluteExpirationRelativeToNow), value,
+                    "Relative expiration must be a positive");
+
+            _absoluteExpirationRelativeToNow = value;
+        }
+    }
+
+    /// <summary>
+    /// Cache entry sliding expiration. The un-active time for cache entry. Do not extends the <see cref="AbsoluteExpiration"/> if it set.
+    /// </summary>
+    /// <exception cref="ArgumentOutOfRangeException">Time point should be positive and bigger to <see cref="TimeSpan.Zero"/> value</exception>
+    public TimeSpan? SlidingExpiration
+    {
+        get { return _slidingExpiration; }
+        set
+        {
+            if ((value.HasValue ? (value.GetValueOrDefault() <= TimeSpan.Zero ? 1 : 0) : 0) != 0)
+                throw new ArgumentOutOfRangeException(nameof(SlidingExpiration), value,
+                    "Sliding expiration must be positive");
+
+            _slidingExpiration = value;
+        }
+    }
+
+    /// <summary>
+    /// The cache entry priority. Default value is <see cref="CacheEntryPriority.Normal"/>
+    /// </summary>
+    public CacheEntryPriority Priority { get; set; } = CacheEntryPriority.Normal;
+
+    /// <summary>
+    /// The collection of <see cref="IChangeToken"/> expiration tokens
+    /// </summary>
+    public IList<IChangeToken> ExpirationTokens { get; } = new List<IChangeToken>();
+
+    /// <summary>
+    /// The collection of <see cref="PostEvictionCallbackRegistration"/> eviction callbacks
+    /// </summary>
+    public IList<PostEvictionCallbackRegistration> PostEvictionCallbacks { get; } =
+        new List<PostEvictionCallbackRegistration>();
+}