replace counter by specific query to avoid load each items in memory (#611)

* replace counter by specific query to avoid load each items in memory

* Create IBasketQueryService

src/ApplicationCore/Interfaces/IBasketQueryService.cs

@@ -0,0 +1,9 @@
+using System.Threading.Tasks;
+
+namespace Microsoft.eShopWeb.ApplicationCore.Interfaces
+{
+    public interface IBasketQueryService
+    {
+        Task<int> CountTotalBasketItems(string username);
+    }
+}

src/ApplicationCore/Interfaces/IOrderRepository.cs

@@ -1,11 +0,0 @@
-using Microsoft.eShopWeb.ApplicationCore.Entities.OrderAggregate;
-using System.Threading.Tasks;
-
-namespace Microsoft.eShopWeb.ApplicationCore.Interfaces
-{
-
-    //public interface IOrderRepository : IAsyncRepository<Order>
-    //{
-    //    Task<Order> GetByIdWithItemsAsync(int id);
-    //}
-}

src/Infrastructure/Data/BasketQueryService.cs

@@ -0,0 +1,27 @@
+using Microsoft.EntityFrameworkCore;
+using Microsoft.eShopWeb.ApplicationCore.Interfaces;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace Microsoft.eShopWeb.Infrastructure.Data
+{
+    public class BasketQueryService : IBasketQueryService
+    {
+        private readonly CatalogContext _dbContext;
+
+        public BasketQueryService(CatalogContext dbContext)
+        {
+            _dbContext = dbContext;
+        }
+
+        public async Task<int> CountTotalBasketItems(string username)
+        {
+            var totalItems = await _dbContext.Baskets
+                .Where(basket => basket.BuyerId == username)
+                .SelectMany(item => item.Items)
+                .SumAsync(sum => sum.Quantity);
+
+            return totalItems;
+        }
+    }
+}

src/Infrastructure/Data/EfRepository.cs

@@ -1,12 +1,5 @@
-using Ardalis.Specification;
+using Ardalis.Specification.EntityFrameworkCore;
-using Ardalis.Specification.EntityFrameworkCore;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.eShopWeb.ApplicationCore.Entities;
 using Microsoft.eShopWeb.ApplicationCore.Interfaces;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 
 namespace Microsoft.eShopWeb.Infrastructure.Data
 {
@@ -16,79 +9,4 @@ namespace Microsoft.eShopWeb.Infrastructure.Data
         {
         }
     }
-    /// <summary>
-    /// "There's some repetition here - couldn't we have some the sync methods call the async?"
-    /// https://blogs.msdn.microsoft.com/pfxteam/2012/04/13/should-i-expose-synchronous-wrappers-for-asynchronous-methods/
-    /// </summary>
-    /// <typeparam name="T"></typeparam>
-    // public class EfRepository<T> : IAsyncRepository<T> where T : BaseEntity, IAggregateRoot
-    // {
-    //     protected readonly CatalogContext _dbContext;
-
-    //     public EfRepository(CatalogContext dbContext)
-    //     {
-    //         _dbContext = dbContext;
-    //     }
-
-    //     public virtual async Task<T> GetByIdAsync(int id, CancellationToken cancellationToken = default)
-    //     {
-    //         var keyValues = new object[] { id };
-    //         return await _dbContext.Set<T>().FindAsync(keyValues, cancellationToken);
-    //     }
-
-    //     public async Task<IReadOnlyList<T>> ListAllAsync(CancellationToken cancellationToken = default)
-    //     {
-    //         return await _dbContext.Set<T>().ToListAsync(cancellationToken);
-    //     }
-
-    //     public async Task<IReadOnlyList<T>> ListAsync(ISpecification<T> spec, CancellationToken cancellationToken = default)
-    //     {
-    //         var specificationResult = ApplySpecification(spec);
-    //         return await specificationResult.ToListAsync(cancellationToken);
-    //     }
-
-    //     public async Task<int> CountAsync(ISpecification<T> spec, CancellationToken cancellationToken = default)
-    //     {
-    //         var specificationResult = ApplySpecification(spec);
-    //         return await specificationResult.CountAsync(cancellationToken);
-    //     }
-
-    //     public async Task<T> AddAsync(T entity, CancellationToken cancellationToken = default)
-    //     {
-    //         await _dbContext.Set<T>().AddAsync(entity, cancellationToken);
-    //         await _dbContext.SaveChangesAsync(cancellationToken);
-
-    //         return entity;
-    //     }
-
-    //     public async Task UpdateAsync(T entity, CancellationToken cancellationToken = default)
-    //     {
-    //         _dbContext.Entry(entity).State = EntityState.Modified;
-    //         await _dbContext.SaveChangesAsync(cancellationToken);
-    //     }
-
-    //     public async Task DeleteAsync(T entity, CancellationToken cancellationToken = default)
-    //     {
-    //         _dbContext.Set<T>().Remove(entity);
-    //         await _dbContext.SaveChangesAsync(cancellationToken);
-    //     }
-
-    //     public async Task<T> FirstAsync(ISpecification<T> spec, CancellationToken cancellationToken = default)
-    //     {
-    //         var specificationResult = ApplySpecification(spec);
-    //         return await specificationResult.FirstAsync(cancellationToken);
-    //     }
-
-    //     public async Task<T> FirstOrDefaultAsync(ISpecification<T> spec, CancellationToken cancellationToken = default)
-    //     {
-    //         var specificationResult = ApplySpecification(spec);
-    //         return await specificationResult.FirstOrDefaultAsync(cancellationToken);
-    //     }
-
-    //     private IQueryable<T> ApplySpecification(ISpecification<T> spec)
-    //     {
-    //         var evaluator = new SpecificationEvaluator<T>();
-    //         return evaluator.GetQuery(_dbContext.Set<T>().AsQueryable(), spec);
-    //     }
-    // }
 }

src/Infrastructure/Data/OrderRepository.cs

@@ -1,22 +0,0 @@
-using Microsoft.EntityFrameworkCore;
-using Microsoft.eShopWeb.ApplicationCore.Entities.OrderAggregate;
-using Microsoft.eShopWeb.ApplicationCore.Interfaces;
-using System.Threading.Tasks;
-
-namespace Microsoft.eShopWeb.Infrastructure.Data
-{
-    //public class OrderRepository : EfRepository<Order>, IOrderRepository
-    //{
-    //    public OrderRepository(CatalogContext dbContext) : base(dbContext)
-    //    {
-    //    }
-
-    //    public Task<Order> GetByIdWithItemsAsync(int id)
-    //    {
-    //        return _dbContext.Orders
-    //            .Include(o => o.OrderItems)
-    //            .ThenInclude(i => i.ItemOrdered)
-    //            .FirstOrDefaultAsync(x => x.Id == id);
-    //    }
-    //}
-}

src/Web/Configuration/ConfigureCoreServices.cs

@@ -13,13 +13,12 @@ namespace Microsoft.eShopWeb.Web.Configuration
         public static IServiceCollection AddCoreServices(this IServiceCollection services,
             IConfiguration configuration)
         {
-            //services.AddScoped(typeof(IAsyncRepository<>), typeof(EfRepository<>));
             services.AddScoped(typeof(IReadRepository<>), typeof(EfRepository<>));
             services.AddScoped(typeof(IRepository<>), typeof(EfRepository<>));
 
             services.AddScoped<IBasketService, BasketService>();
             services.AddScoped<IOrderService, OrderService>();
-            //services.AddScoped<IOrderRepository, OrderRepository>();
+            services.AddScoped<IBasketQueryService, BasketQueryService>();
             services.AddSingleton<IUriComposer>(new UriComposer(configuration.Get<CatalogSettings>()));
             services.AddScoped(typeof(IAppLogger<>), typeof(LoggerAdapter<>));
             services.AddTransient<IEmailSender, EmailSender>();

src/Web/Services/BasketViewModelService.cs

@@ -14,14 +14,17 @@ namespace Microsoft.eShopWeb.Web.Services
     {
         private readonly IRepository<Basket> _basketRepository;
         private readonly IUriComposer _uriComposer;
+        private readonly IBasketQueryService _basketQueryService;
         private readonly IRepository<CatalogItem> _itemRepository;
 
         public BasketViewModelService(IRepository<Basket> basketRepository,
             IRepository<CatalogItem> itemRepository,
-            IUriComposer uriComposer)
+            IUriComposer uriComposer,
+            IBasketQueryService basketQueryService)
         {
             _basketRepository = basketRepository;
             _uriComposer = uriComposer;
+            _basketQueryService = basketQueryService;
             _itemRepository = itemRepository;
         }
 
@@ -86,11 +89,9 @@ namespace Microsoft.eShopWeb.Web.Services
 
         public async Task<int> CountTotalBasketItems(string username)
         {
-            var basketSpec = new BasketWithItemsSpecification(username);
+            var counter = await _basketQueryService.CountTotalBasketItems(username);
-            var basket = await _basketRepository.GetBySpecAsync(basketSpec);
+
-            if (basket == null)
+            return counter;
-                return 0;
-            return basket.Items.Sum(i => i.Quantity);
         }
     }
 }