Clear the product view cache when product discounts begin or end

modules/EasyAbp.EShop.Products/src/EasyAbp.EShop.Products.Application/EasyAbp/EShop/Products/Products/ProductAppService.cs

@@ -82,7 +82,7 @@ namespace EasyAbp.EShop.Products.Products
 
             var dto = await MapToGetOutputDtoAsync(product);
 
-            await LoadDtoExtraDataAsync(product, dto);
+            await LoadDtoExtraDataAsync(product, dto, Clock.Now);
             await LoadDtosProductGroupDisplayNameAsync(new[] { dto });
 
             UnitOfWorkManager.Current.OnCompleted(async () => { await ClearProductViewCacheAsync(product.StoreId); });
@@ -116,7 +116,7 @@ namespace EasyAbp.EShop.Products.Products
 
             var dto = await MapToGetOutputDtoAsync(product);
 
-            await LoadDtoExtraDataAsync(product, dto);
+            await LoadDtoExtraDataAsync(product, dto, Clock.Now);
             await LoadDtosProductGroupDisplayNameAsync(new[] { dto });
 
             UnitOfWorkManager.Current.OnCompleted(async () => { await ClearProductViewCacheAsync(product.StoreId); });
@@ -201,7 +201,7 @@ namespace EasyAbp.EShop.Products.Products
 
             var dto = await MapToGetOutputDtoAsync(product);
 
-            await LoadDtoExtraDataAsync(product, dto);
+            await LoadDtoExtraDataAsync(product, dto, Clock.Now);
             await LoadDtosProductGroupDisplayNameAsync(new[] { dto });
 
             return dto;
@@ -232,7 +232,7 @@ namespace EasyAbp.EShop.Products.Products
 
             var dto = await MapToGetOutputDtoAsync(product);
 
-            await LoadDtoExtraDataAsync(product, dto);
+            await LoadDtoExtraDataAsync(product, dto, Clock.Now);
             await LoadDtosProductGroupDisplayNameAsync(new[] { dto });
 
             return dto;
@@ -257,13 +257,14 @@ namespace EasyAbp.EShop.Products.Products
 
             var products = await AsyncExecuter.ToListAsync(query);
 
+            var now = Clock.Now;
             var items = new List<ProductDto>();
 
             foreach (var product in products)
             {
                 var productDto = await MapToGetListOutputDtoAsync(product);
 
-                await LoadDtoExtraDataAsync(product, productDto);
+                await LoadDtoExtraDataAsync(product, productDto, now);
 
                 items.Add(productDto);
             }
@@ -296,21 +297,23 @@ namespace EasyAbp.EShop.Products.Products
             return productDto;
         }
 
-        protected virtual async Task<ProductDto> LoadDtoExtraDataAsync(Product product, ProductDto productDto)
+        protected virtual async Task<ProductDto> LoadDtoExtraDataAsync(Product product, ProductDto productDto,
+            DateTime now)
         {
             await LoadDtoInventoryDataAsync(product, productDto);
-            await LoadDtoPriceDataAsync(product, productDto);
+            await LoadDtoPriceDataAsync(product, productDto, now);
 
             return productDto;
         }
 
-        protected virtual async Task<ProductDto> LoadDtoPriceDataAsync(Product product, ProductDto productDto)
+        protected virtual async Task<ProductDto> LoadDtoPriceDataAsync(Product product, ProductDto productDto,
+            DateTime now)
         {
             foreach (var productSku in product.ProductSkus)
             {
                 var productSkuDto = productDto.ProductSkus.First(x => x.Id == productSku.Id);
 
-                var priceDataModel = await _productManager.GetRealPriceAsync(product, productSku);
+                var priceDataModel = await _productManager.GetRealPriceAsync(product, productSku, now);
 
                 productSkuDto.PriceWithoutDiscount = priceDataModel.PriceWithoutDiscount;
                 productSkuDto.Price = priceDataModel.DiscountedPrice;
@@ -364,7 +367,7 @@ namespace EasyAbp.EShop.Products.Products
 
             var dto = await MapToGetOutputDtoAsync(product);
 
-            await LoadDtoExtraDataAsync(product, dto);
+            await LoadDtoExtraDataAsync(product, dto, Clock.Now);
             await LoadDtosProductGroupDisplayNameAsync(new[] { dto });
 
             UnitOfWorkManager.Current.OnCompleted(async () => { await ClearProductViewCacheAsync(product.StoreId); });
@@ -389,7 +392,7 @@ namespace EasyAbp.EShop.Products.Products
 
             var dto = await MapToGetOutputDtoAsync(product);
 
-            await LoadDtoExtraDataAsync(product, dto);
+            await LoadDtoExtraDataAsync(product, dto, Clock.Now);
             await LoadDtosProductGroupDisplayNameAsync(new[] { dto });
 
             UnitOfWorkManager.Current.OnCompleted(async () => { await ClearProductViewCacheAsync(product.StoreId); });
@@ -411,7 +414,7 @@ namespace EasyAbp.EShop.Products.Products
 
             var dto = await MapToGetOutputDtoAsync(product);
 
-            await LoadDtoExtraDataAsync(product, dto);
+            await LoadDtoExtraDataAsync(product, dto, Clock.Now);
             await LoadDtosProductGroupDisplayNameAsync(new[] { dto });
 
             UnitOfWorkManager.Current.OnCompleted(async () => { await ClearProductViewCacheAsync(product.StoreId); });

modules/EasyAbp.EShop.Products/src/EasyAbp.EShop.Products.Application/EasyAbp/EShop/Products/Products/ProductViewAppService.cs

@@ -117,31 +117,80 @@ namespace EasyAbp.EShop.Products.Products
         {
             var products = await _productRepository.GetListAsync(x => x.StoreId == storeId, true);
 
+            var now = Clock.Now;
+
             using var uow = UnitOfWorkManager.Begin(true, true);
 
             await _repository.DeleteAsync(x => x.StoreId == storeId, true);
 
+            var productViews = new List<ProductView>();
+
             foreach (var product in products)
             {
                 var productView = ObjectMapper.Map<Product, ProductView>(product);
 
-                await FillPriceInfoWithRealPriceAsync(product, productView);
+                await FillPriceInfoWithRealPriceAsync(product, productView, now);
 
-                await _repository.InsertAsync(productView);
+                productViews.Add(await _repository.InsertAsync(productView));
             }
 
             await uow.SaveChangesAsync();
             await uow.CompleteAsync();
 
-            await _cache.SetAsync(await GetCacheKeyAsync(storeId), new ProductViewCacheItem(),
+            var duration = await GetCacheDurationOrNullAsync(productViews, now);
-                new DistributedCacheEntryOptions
+
+            if (duration.HasValue)
+            {
+                await _cache.SetAsync(await GetCacheKeyAsync(storeId), new ProductViewCacheItem(),
+                    new DistributedCacheEntryOptions
+                    {
+                        AbsoluteExpirationRelativeToNow = duration
+                    });
+            }
+        }
+
+        protected async Task<TimeSpan?> GetCacheDurationOrNullAsync(List<ProductView> productViews,
+            DateTime now)
+        {
+            // refresh the cache when a new discount takes effect or an old discount ends.
+            var minFromTime = productViews.SelectMany(x => x.ProductDiscounts)
+                .Where(x => x.FromTime.HasValue && x.FromTime > now).MinBy(x => x.FromTime)?.FromTime;
+            var minToTime = productViews.SelectMany(x => x.ProductDiscounts)
+                .Where(x => x.ToTime.HasValue && x.ToTime > now).MinBy(x => x.ToTime)?.ToTime;
+
+            DateTime? nextTime;
+            if (minFromTime.HasValue)
+            {
+                if (minToTime.HasValue)
+                {
+                    nextTime = minFromTime < minToTime ? minFromTime : minToTime;
+                }
+                else
                 {
-                    AbsoluteExpirationRelativeToNow = TimeSpan.FromSeconds(Convert.ToInt32(
+                    nextTime = minFromTime;
-                        await SettingProvider.GetOrNullAsync(ProductsSettings.ProductView.CacheDurationSeconds)))
+                }
-                });
+            }
+            else
+            {
+                nextTime = minToTime;
+            }
+
+            // use `Clock.Now` to achieve higher timeliness.
+            var duration = nextTime.HasValue ? nextTime - Clock.Now : null;
+
+            if (duration <= TimeSpan.Zero)
+            {
+                return null;
+            }
+
+            var defaultDuration = TimeSpan.FromSeconds(Convert.ToInt32(
+                await SettingProvider.GetOrNullAsync(ProductsSettings.ProductView.CacheDurationSeconds)));
+
+            return duration.HasValue && duration.Value < defaultDuration ? duration : defaultDuration;
         }
 
-        protected virtual async Task FillPriceInfoWithRealPriceAsync(Product product, ProductView productView)
+        protected virtual async Task FillPriceInfoWithRealPriceAsync(Product product, ProductView productView,
+            DateTime now)
         {
             if (product.ProductSkus.IsNullOrEmpty())
             {
@@ -156,7 +205,7 @@ namespace EasyAbp.EShop.Products.Products
             foreach (var productSku in product.ProductSkus)
             {
                 var overrideProductDiscounts = false;
-                var priceDataModel = await _productManager.GetRealPriceAsync(product, productSku);
+                var priceDataModel = await _productManager.GetRealPriceAsync(product, productSku, now);
 
                 if (min is null || priceDataModel.DiscountedPrice < min.Value)
                 {

modules/EasyAbp.EShop.Products/src/EasyAbp.EShop.Products.Domain/EasyAbp/EShop/Products/Products/IProductManager.cs

@@ -13,23 +13,23 @@ namespace EasyAbp.EShop.Products.Products
         Task<Product> UpdateAsync(Product product, IEnumerable<Guid> categoryIds = null);
 
         Task DeleteAsync(Product product);
-        
+
         Task DeleteAsync(Guid id);
 
         Task<Product> CreateSkuAsync(Product product, ProductSku productSku);
-        
+
         Task<Product> UpdateSkuAsync(Product product, ProductSku productSku);
-        
+
         Task<Product> DeleteSkuAsync(Product product, ProductSku productSku);
-        
+
         Task<bool> IsInventorySufficientAsync(Product product, ProductSku productSku, int quantity);
-        
+
         Task<InventoryDataModel> GetInventoryDataAsync(Product product, ProductSku productSku);
 
         Task<bool> TryIncreaseInventoryAsync(Product product, ProductSku productSku, int quantity, bool reduceSold);
-        
+
         Task<bool> TryReduceInventoryAsync(Product product, ProductSku productSku, int quantity, bool increaseSold);
 
-        Task<PriceDataModel> GetRealPriceAsync(Product product, ProductSku productSku);
+        Task<PriceDataModel> GetRealPriceAsync(Product product, ProductSku productSku, DateTime now);
     }
 }

modules/EasyAbp.EShop.Products/src/EasyAbp.EShop.Products.Domain/EasyAbp/EShop/Products/Products/PriceDataModel.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using Volo.Abp.Timing;
 
 namespace EasyAbp.EShop.Products.Products;
 
@@ -24,14 +23,14 @@ public class PriceDataModel : IHasFullDiscountsInfo
 
     public List<OrderDiscountPreviewInfoModel> OrderDiscountPreviews { get; } = new();
 
-    public PriceDataModel(decimal priceWithoutDiscount, IClock clock)
+    public PriceDataModel(decimal priceWithoutDiscount, DateTime now)
     {
         if (PriceWithoutDiscount < decimal.Zero)
         {
             throw new OverflowException();
         }
 
-        Now = clock.Now;
+        Now = now;
         PriceWithoutDiscount = priceWithoutDiscount;
     }
 }

modules/EasyAbp.EShop.Products/src/EasyAbp.EShop.Products.Domain/EasyAbp/EShop/Products/Products/ProductDiscountContext.cs

@@ -1,4 +1,4 @@
-using Volo.Abp.Timing;
+using System;
 
 namespace EasyAbp.EShop.Products.Products;
 
@@ -10,10 +10,10 @@ public class ProductDiscountContext
 
     public PriceDataModel PriceDataModel { get; }
 
-    public ProductDiscountContext(Product product, ProductSku productSku, decimal priceFromPriceProvider, IClock clock)
+    public ProductDiscountContext(Product product, ProductSku productSku, decimal priceFromPriceProvider, DateTime now)
     {
         Product = product;
         ProductSku = productSku;
-        PriceDataModel = new PriceDataModel(priceFromPriceProvider, clock);
+        PriceDataModel = new PriceDataModel(priceFromPriceProvider, now);
     }
 }

modules/EasyAbp.EShop.Products/src/EasyAbp.EShop.Products.Domain/EasyAbp/EShop/Products/Products/ProductManager.cs

@@ -268,11 +268,12 @@ namespace EasyAbp.EShop.Products.Products
                 .TryReduceInventoryAsync(model, quantity, increaseSold, isFlashSale);
         }
 
-        public virtual async Task<PriceDataModel> GetRealPriceAsync(Product product, ProductSku productSku)
+        public virtual async Task<PriceDataModel> GetRealPriceAsync(Product product, ProductSku productSku,
+            DateTime now)
         {
             var price = await _productPriceProvider.GetPriceAsync(product, productSku);
 
-            var context = new ProductDiscountContext(product, productSku, price, Clock);
+            var context = new ProductDiscountContext(product, productSku, price, now);
 
             // Todo: provider execution ordering.
             foreach (var provider in LazyServiceProvider.LazyGetService<IEnumerable<IProductDiscountProvider>>())