docs: Add XML documentation to BuildingBlocks APIs (#1201)

* docs: Add XML documentation to Caching module

- ICacheService: Document all interface methods
- CacheServiceExtensions: Document GetOrSet patterns
- Extensions: Document AddHeroCaching DI registration
- DistributedCacheService: Document implementation details
- HybridCacheService: Document L1/L2 caching strategy

Part of #1176

* docs: Add XML documentation to Core/Domain module

- IEntity, BaseEntity, AggregateRoot: Entity and DDD base types
- IDomainEvent, DomainEvent, IHasDomainEvents: Domain event patterns
- IAuditableEntity: Audit metadata interface
- ISoftDeletable: Soft delete support
- IHasTenant: Multi-tenancy marker

Generated by Codex CLI with --full-auto flag

Part of #1176

* docs: Add XML documentation to Exceptions module

* docs: Add XML documentation to Context module

* docs: Add XML documentation to Common module

* docs: Add XML documentation to Abstractions module

* docs: Add XML documentation to Persistence core module

* docs: Add XML documentation to Persistence specifications, pagination, and interceptors

---------

Co-authored-by: jarvis <jarvis@codewithmukesh.com>

Author: iammukeshm

src/BuildingBlocks/Caching/CacheServiceExtensions.cs

@@ -1,6 +1,20 @@
-namespace FSH.Framework.Caching;
+namespace FSH.Framework.Caching;
+
+/// <summary>
+/// Extension methods for <see cref="ICacheService"/> providing cache-aside pattern implementations.
+/// </summary>
 public static class CacheServiceExtensions
 {
+    /// <summary>
+    /// Gets an item from cache, or sets it using the provided callback if not found.
+    /// Implements the cache-aside pattern synchronously.
+    /// </summary>
+    /// <typeparam name="T">The type of the cached item.</typeparam>
+    /// <param name="cache">The cache service instance.</param>
+    /// <param name="key">The unique cache key.</param>
+    /// <param name="getItemCallback">A callback function to retrieve the item if not in cache.</param>
+    /// <param name="slidingExpiration">Optional sliding expiration for the cached item.</param>
+    /// <returns>The cached item or the newly retrieved and cached item.</returns>
     public static T? GetOrSet<T>(this ICacheService cache, string key, Func<T?> getItemCallback, TimeSpan? slidingExpiration = null)
     {
         ArgumentNullException.ThrowIfNull(cache);
@@ -23,6 +37,17 @@ public static class CacheServiceExtensions
         return value;
     }
 
+    /// <summary>
+    /// Asynchronously gets an item from cache, or sets it using the provided task if not found.
+    /// Implements the cache-aside pattern asynchronously.
+    /// </summary>
+    /// <typeparam name="T">The type of the cached item.</typeparam>
+    /// <param name="cache">The cache service instance.</param>
+    /// <param name="key">The unique cache key.</param>
+    /// <param name="task">An async function to retrieve the item if not in cache.</param>
+    /// <param name="slidingExpiration">Optional sliding expiration for the cached item.</param>
+    /// <param name="cancellationToken">Cancellation token for the operation.</param>
+    /// <returns>The cached item or the newly retrieved and cached item.</returns>
     public static async Task<T?> GetOrSetAsync<T>(this ICacheService cache, string key, Func<Task<T>> task, TimeSpan? slidingExpiration = null, CancellationToken cancellationToken = default)
     {
         ArgumentNullException.ThrowIfNull(cache);
@@ -44,4 +69,4 @@ public static class CacheServiceExtensions
 
         return value;
     }
-}
+}

src/BuildingBlocks/Caching/DistributedCacheService.cs

@@ -1,10 +1,15 @@
-using Microsoft.Extensions.Caching.Distributed;
+using Microsoft.Extensions.Caching.Distributed;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using System.Text;
 using System.Text.Json;
 
 namespace FSH.Framework.Caching;
+
+/// <summary>
+/// Implementation of <see cref="ICacheService"/> using distributed cache (Redis or in-memory).
+/// Provides JSON serialization for cached objects with configurable expiration policies.
+/// </summary>
 public sealed class DistributedCacheService : ICacheService
 {
     private static readonly Encoding Utf8 = Encoding.UTF8;
@@ -14,6 +19,12 @@ public sealed class DistributedCacheService : ICacheService
     private readonly ILogger<DistributedCacheService> _logger;
     private readonly CachingOptions _opts;
 
+    /// <summary>
+    /// Initializes a new instance of <see cref="DistributedCacheService"/>.
+    /// </summary>
+    /// <param name="cache">The underlying distributed cache implementation.</param>
+    /// <param name="logger">Logger for cache operations.</param>
+    /// <param name="opts">Caching configuration options.</param>
     public DistributedCacheService(
         IDistributedCache cache,
         ILogger<DistributedCacheService> logger,
@@ -26,6 +37,7 @@ public DistributedCacheService(
         _opts = opts.Value;
     }
 
+    /// <inheritdoc />
     public async Task<T?> GetItemAsync<T>(string key, CancellationToken ct = default)
     {
         key = Normalize(key);
@@ -42,6 +54,7 @@ public DistributedCacheService(
         }
     }
 
+    /// <inheritdoc />
     public async Task SetItemAsync<T>(string key, T value, TimeSpan? sliding = default, CancellationToken ct = default)
     {
         key = Normalize(key);
@@ -57,6 +70,7 @@ public async Task SetItemAsync<T>(string key, T value, TimeSpan? sliding = defau
         }
     }
 
+    /// <inheritdoc />
     public async Task RemoveItemAsync(string key, CancellationToken ct = default)
     {
         key = Normalize(key);
@@ -65,6 +79,7 @@ public async Task RemoveItemAsync(string key, CancellationToken ct = default)
         { _logger.LogWarning(ex, "Cache remove failed for {Key}", key); }
     }
 
+    /// <inheritdoc />
     public async Task RefreshItemAsync(string key, CancellationToken ct = default)
     {
         key = Normalize(key);
@@ -76,11 +91,24 @@ public async Task RefreshItemAsync(string key, CancellationToken ct = default)
         catch (Exception ex) when (ex is not OperationCanceledException)
         { _logger.LogWarning(ex, "Cache refresh failed for {Key}", key); }
     }
+
+    /// <inheritdoc />
     public T? GetItem<T>(string key) => GetItemAsync<T>(key).GetAwaiter().GetResult();
+
+    /// <inheritdoc />
     public void SetItem<T>(string key, T value, TimeSpan? sliding = default) => SetItemAsync(key, value, sliding).GetAwaiter().GetResult();
+
+    /// <inheritdoc />
     public void RemoveItem(string key) => RemoveItemAsync(key).GetAwaiter().GetResult();
+
+    /// <inheritdoc />
     public void RefreshItem(string key) => RefreshItemAsync(key).GetAwaiter().GetResult();
 
+    /// <summary>
+    /// Builds cache entry options with configured expiration settings.
+    /// </summary>
+    /// <param name="sliding">Optional sliding expiration override.</param>
+    /// <returns>Configured cache entry options.</returns>
     private DistributedCacheEntryOptions BuildEntryOptions(TimeSpan? sliding)
     {
         var o = new DistributedCacheEntryOptions();
@@ -96,6 +124,12 @@ private DistributedCacheEntryOptions BuildEntryOptions(TimeSpan? sliding)
         return o;
     }
 
+    /// <summary>
+    /// Normalizes the cache key by applying the configured prefix.
+    /// </summary>
+    /// <param name="key">The original cache key.</param>
+    /// <returns>The normalized key with prefix applied.</returns>
+    /// <exception cref="ArgumentNullException">Thrown when key is null or whitespace.</exception>
     private string Normalize(string key)
     {
         if (string.IsNullOrWhiteSpace(key)) throw new ArgumentNullException(nameof(key));

src/BuildingBlocks/Caching/Extensions.cs

@@ -1,12 +1,27 @@
-using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Options;
 using StackExchange.Redis;
 
 namespace FSH.Framework.Caching;
 
+/// <summary>
+/// Extension methods for registering caching services in the dependency injection container.
+/// </summary>
 public static class Extensions
 {
+    /// <summary>
+    /// Adds FullStackHero caching services to the service collection.
+    /// Configures a hybrid L1/L2 cache with in-memory (L1) and Redis or distributed memory (L2).
+    /// </summary>
+    /// <param name="services">The service collection to add caching services to.</param>
+    /// <param name="configuration">The application configuration containing caching options.</param>
+    /// <returns>The service collection for chaining.</returns>
+    /// <remarks>
+    /// If Redis connection string is configured in <see cref="CachingOptions"/>, Redis is used for L2 cache.
+    /// Otherwise, falls back to in-memory distributed cache for L2.
+    /// The <see cref="HybridCacheService"/> is registered to provide both sync and async cache operations.
+    /// </remarks>
     public static IServiceCollection AddHeroCaching(this IServiceCollection services, IConfiguration configuration)
     {
         ArgumentNullException.ThrowIfNull(configuration);
@@ -47,4 +62,4 @@ public static IServiceCollection AddHeroCaching(this IServiceCollection services
 
         return services;
     }
-}
+}

src/BuildingBlocks/Caching/HybridCacheService.cs

@@ -7,6 +7,15 @@
 
 namespace FSH.Framework.Caching;
 
+/// <summary>
+/// A hybrid cache implementation combining L1 (in-memory) and L2 (distributed) caching.
+/// Provides fast local access with distributed cache backup for multi-instance scenarios.
+/// </summary>
+/// <remarks>
+/// The hybrid approach uses memory cache for fast L1 access and automatically populates
+/// it from the L2 distributed cache on cache misses. Write operations update both caches.
+/// Memory cache uses 80% of the distributed cache sliding expiration for faster refresh.
+/// </remarks>
 public sealed class HybridCacheService : ICacheService
 {
     private static readonly Encoding Utf8 = Encoding.UTF8;
@@ -17,6 +26,13 @@ public sealed class HybridCacheService : ICacheService
     private readonly ILogger<HybridCacheService> _logger;
     private readonly CachingOptions _opts;
 
+    /// <summary>
+    /// Initializes a new instance of <see cref="HybridCacheService"/>.
+    /// </summary>
+    /// <param name="memoryCache">The L1 in-memory cache.</param>
+    /// <param name="distributedCache">The L2 distributed cache (Redis or memory-based).</param>
+    /// <param name="logger">Logger for cache operations.</param>
+    /// <param name="opts">Caching configuration options.</param>
     public HybridCacheService(
         IMemoryCache memoryCache,
         IDistributedCache distributedCache,
@@ -31,6 +47,11 @@ public HybridCacheService(
         _opts = opts.Value;
     }
 
+    /// <inheritdoc />
+    /// <remarks>
+    /// First checks L1 memory cache, then falls back to L2 distributed cache.
+    /// If found in L2, the item is automatically populated into L1 for subsequent fast access.
+    /// </remarks>
     public async Task<T?> GetItemAsync<T>(string key, CancellationToken ct = default)
     {
         key = Normalize(key);
@@ -66,6 +87,10 @@ public HybridCacheService(
         }
     }
 
+    /// <inheritdoc />
+    /// <remarks>
+    /// Writes to both L1 memory cache and L2 distributed cache simultaneously.
+    /// </remarks>
     public async Task SetItemAsync<T>(string key, T value, TimeSpan? sliding = default, CancellationToken ct = default)
     {
         key = Normalize(key);
@@ -86,6 +111,10 @@ public async Task SetItemAsync<T>(string key, T value, TimeSpan? sliding = defau
         }
     }
 
+    /// <inheritdoc />
+    /// <remarks>
+    /// Removes from both L1 memory cache and L2 distributed cache.
+    /// </remarks>
     public async Task RemoveItemAsync(string key, CancellationToken ct = default)
     {
         key = Normalize(key);
@@ -102,6 +131,7 @@ public async Task RemoveItemAsync(string key, CancellationToken ct = default)
         }
     }
 
+    /// <inheritdoc />
     public async Task RefreshItemAsync(string key, CancellationToken ct = default)
     {
         key = Normalize(key);
@@ -116,11 +146,23 @@ public async Task RefreshItemAsync(string key, CancellationToken ct = default)
         }
     }
 
+    /// <inheritdoc />
     public T? GetItem<T>(string key) => GetItemAsync<T>(key).GetAwaiter().GetResult();
+
+    /// <inheritdoc />
     public void SetItem<T>(string key, T value, TimeSpan? sliding = default) => SetItemAsync(key, value, sliding).GetAwaiter().GetResult();
+
+    /// <inheritdoc />
     public void RemoveItem(string key) => RemoveItemAsync(key).GetAwaiter().GetResult();
+
+    /// <inheritdoc />
     public void RefreshItem(string key) => RefreshItemAsync(key).GetAwaiter().GetResult();
 
+    /// <summary>
+    /// Builds distributed cache entry options with configured expiration settings.
+    /// </summary>
+    /// <param name="sliding">Optional sliding expiration override.</param>
+    /// <returns>Configured distributed cache entry options.</returns>
     private DistributedCacheEntryOptions BuildDistributedEntryOptions(TimeSpan? sliding)
     {
         var o = new DistributedCacheEntryOptions();
@@ -136,6 +178,11 @@ private DistributedCacheEntryOptions BuildDistributedEntryOptions(TimeSpan? slid
         return o;
     }
 
+    /// <summary>
+    /// Gets memory cache expiration options, set to 80% of distributed cache expiration
+    /// for faster refresh cycles.
+    /// </summary>
+    /// <returns>Memory cache entry options with sliding expiration.</returns>
     private MemoryCacheEntryOptions GetMemoryCacheExpiration()
     {
         var options = new MemoryCacheEntryOptions();
@@ -147,6 +194,12 @@ private MemoryCacheEntryOptions GetMemoryCacheExpiration()
         return options;
     }
 
+    /// <summary>
+    /// Normalizes the cache key by applying the configured prefix.
+    /// </summary>
+    /// <param name="key">The original cache key.</param>
+    /// <returns>The normalized key with prefix applied.</returns>
+    /// <exception cref="ArgumentNullException">Thrown when key is null or whitespace.</exception>
     private string Normalize(string key)
     {
         if (string.IsNullOrWhiteSpace(key)) throw new ArgumentNullException(nameof(key));

src/BuildingBlocks/Caching/ICacheService.cs

@@ -1,12 +1,70 @@
-namespace FSH.Framework.Caching;
+namespace FSH.Framework.Caching;
+
+/// <summary>
+/// Provides caching operations for storing and retrieving items from cache.
+/// Supports both synchronous and asynchronous operations.
+/// </summary>
 public interface ICacheService
 {
+    /// <summary>
+    /// Asynchronously retrieves an item from the cache.
+    /// </summary>
+    /// <typeparam name="T">The type of the cached item.</typeparam>
+    /// <param name="key">The unique cache key.</param>
+    /// <param name="ct">Cancellation token for the operation.</param>
+    /// <returns>The cached item if found; otherwise, null.</returns>
     Task<T?> GetItemAsync<T>(string key, CancellationToken ct = default);
+
+    /// <summary>
+    /// Asynchronously stores an item in the cache.
+    /// </summary>
+    /// <typeparam name="T">The type of the item to cache.</typeparam>
+    /// <param name="key">The unique cache key.</param>
+    /// <param name="value">The value to cache.</param>
+    /// <param name="sliding">Optional sliding expiration. Uses default if not specified.</param>
+    /// <param name="ct">Cancellation token for the operation.</param>
     Task SetItemAsync<T>(string key, T value, TimeSpan? sliding = default, CancellationToken ct = default);
+
+    /// <summary>
+    /// Asynchronously removes an item from the cache.
+    /// </summary>
+    /// <param name="key">The unique cache key to remove.</param>
+    /// <param name="ct">Cancellation token for the operation.</param>
     Task RemoveItemAsync(string key, CancellationToken ct = default);
+
+    /// <summary>
+    /// Asynchronously refreshes the sliding expiration of a cached item.
+    /// </summary>
+    /// <param name="key">The unique cache key to refresh.</param>
+    /// <param name="ct">Cancellation token for the operation.</param>
     Task RefreshItemAsync(string key, CancellationToken ct = default);
+
+    /// <summary>
+    /// Retrieves an item from the cache synchronously.
+    /// </summary>
+    /// <typeparam name="T">The type of the cached item.</typeparam>
+    /// <param name="key">The unique cache key.</param>
+    /// <returns>The cached item if found; otherwise, null.</returns>
     T? GetItem<T>(string key);
+
+    /// <summary>
+    /// Stores an item in the cache synchronously.
+    /// </summary>
+    /// <typeparam name="T">The type of the item to cache.</typeparam>
+    /// <param name="key">The unique cache key.</param>
+    /// <param name="value">The value to cache.</param>
+    /// <param name="sliding">Optional sliding expiration. Uses default if not specified.</param>
     void SetItem<T>(string key, T value, TimeSpan? sliding = default);
+
+    /// <summary>
+    /// Removes an item from the cache synchronously.
+    /// </summary>
+    /// <param name="key">The unique cache key to remove.</param>
     void RemoveItem(string key);
+
+    /// <summary>
+    /// Refreshes the sliding expiration of a cached item synchronously.
+    /// </summary>
+    /// <param name="key">The unique cache key to refresh.</param>
     void RefreshItem(string key);
-}
+}