From 6cc239b8f286b9b095cb9ed32113cbd80e7de1b3 Mon Sep 17 00:00:00 2001
From: Jadyn <jadyn.wong@live.com>
Date: Sun, 17 Jul 2022 12:41:41 +0800
Subject: [PATCH] `DefaultProductInventoryProvider` using `DistributedLock`

---
 .../EasyAbp.EShop.Products.Domain.csproj      |  1 +
 .../DefaultProductInventoryProvider.cs        | 41 ++++++++++++++++++-
 2 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/modules/EasyAbp.EShop.Products/src/EasyAbp.EShop.Products.Domain/EasyAbp.EShop.Products.Domain.csproj b/modules/EasyAbp.EShop.Products/src/EasyAbp.EShop.Products.Domain/EasyAbp.EShop.Products.Domain.csproj
index 2dab26aa..663bb9c9 100644
--- a/modules/EasyAbp.EShop.Products/src/EasyAbp.EShop.Products.Domain/EasyAbp.EShop.Products.Domain.csproj
+++ b/modules/EasyAbp.EShop.Products/src/EasyAbp.EShop.Products.Domain/EasyAbp.EShop.Products.Domain.csproj
@@ -8,6 +8,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.Bcl.AsyncInterfaces" Version="6.0.*" />
     <PackageReference Include="NodaMoney" Version="$(NodaMoneyVersion)" />
     <PackageReference Include="EasyAbp.Abp.Trees.Domain" Version="$(EasyAbpAbpTreesModuleVersion)" />
     <PackageReference Include="Volo.Abp.AutoMapper" Version="$(AbpVersion)" />
diff --git a/modules/EasyAbp.EShop.Products/src/EasyAbp.EShop.Products.Domain/EasyAbp/EShop/Products/Products/DefaultProductInventoryProvider.cs b/modules/EasyAbp.EShop.Products/src/EasyAbp.EShop.Products.Domain/EasyAbp/EShop/Products/Products/DefaultProductInventoryProvider.cs
index 613a434c..9f420ea2 100644
--- a/modules/EasyAbp.EShop.Products/src/EasyAbp.EShop.Products.Domain/EasyAbp/EShop/Products/Products/DefaultProductInventoryProvider.cs
+++ b/modules/EasyAbp.EShop.Products/src/EasyAbp.EShop.Products.Domain/EasyAbp/EShop/Products/Products/DefaultProductInventoryProvider.cs
@@ -3,7 +3,9 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 using EasyAbp.EShop.Products.ProductInventories;
+using Microsoft.Extensions.Logging;
 using Volo.Abp.DependencyInjection;
+using Volo.Abp.DistributedLocking;
 using Volo.Abp.EventBus.Distributed;
 using Volo.Abp.Guids;
 using Volo.Abp.MultiTenancy;
@@ -13,6 +15,14 @@ namespace EasyAbp.EShop.Products.Products
 {
     public class DefaultProductInventoryProvider : IProductInventoryProvider, ITransientDependency
     {
+        /// <summary>
+        /// The <see cref="GetLockKeyAsync(InventoryQueryModel)"/> lock key format.
+        /// <para>{0}: Tenant ID</para>
+        /// <para>{1}: Product ID</para>
+        /// <para>{2}: ProductSku ID</para>
+        /// </summary>
+        public const string DefaultProductInventoryLockKeyFormat = "eshop-product-inventory-{0}-{1}-{2}";
+
         public static string DefaultProductInventoryProviderName { get; set; } = "Default";
         public static string DefaultProductInventoryProviderDisplayName { get; set; } = "Default";
         public static string DefaultProductInventoryProviderDescription { get; set; } = "Default";
@@ -24,17 +34,23 @@ namespace EasyAbp.EShop.Products.Products
         private readonly ICurrentTenant _currentTenant;
         private readonly IDistributedEventBus _distributedEventBus;
         private readonly IProductInventoryRepository _productInventoryRepository;
+        private readonly IAbpDistributedLock _distributedLock;
+        private readonly ILogger<DefaultProductInventoryProvider> _logger;
 
         public DefaultProductInventoryProvider(
             IGuidGenerator guidGenerator,
             ICurrentTenant currentTenant,
             IDistributedEventBus distributedEventBus,
-            IProductInventoryRepository productInventoryRepository)
+            IProductInventoryRepository productInventoryRepository,
+            IAbpDistributedLock distributedLock,
+            ILogger<DefaultProductInventoryProvider> logger)
         {
             _guidGenerator = guidGenerator;
             _currentTenant = currentTenant;
             _distributedEventBus = distributedEventBus;
             _productInventoryRepository = productInventoryRepository;
+            _distributedLock = distributedLock;
+            _logger = logger;
         }
 
         [UnitOfWork]
@@ -62,6 +78,15 @@ namespace EasyAbp.EShop.Products.Products
         public virtual async Task<bool> TryIncreaseInventoryAsync(InventoryQueryModel model, int quantity,
             bool decreaseSold)
         {
+            await using var handle = await _distributedLock.TryAcquireAsync(await GetLockKeyAsync(model), TimeSpan.FromSeconds(30));
+
+            if (handle == null)
+            {
+                _logger.LogWarning("TryIncreaseInventory failed to acquire lock for product inventory: {TenantId},{ProductId},{ProductSkuId}",
+                    model.TenantId, model.ProductId, model.ProductSkuId);
+                return false;
+            }
+
             var productInventory = await GetOrCreateProductInventoryAsync(model.ProductId, model.ProductSkuId);
 
             return await TryIncreaseInventoryAsync(model, productInventory, quantity, decreaseSold);
@@ -71,6 +96,15 @@ namespace EasyAbp.EShop.Products.Products
         public virtual async Task<bool> TryReduceInventoryAsync(InventoryQueryModel model, int quantity,
             bool increaseSold)
         {
+            await using var handle = await _distributedLock.TryAcquireAsync(await GetLockKeyAsync(model), TimeSpan.FromSeconds(30));
+
+            if (handle == null)
+            {
+                _logger.LogWarning("TryReduceInventory failed to acquire lock for product inventory: {TenantId},{ProductId},{ProductSkuId}",
+                    model.TenantId, model.ProductId, model.ProductSkuId);
+                return false;
+            }
+
             var productInventory = await GetOrCreateProductInventoryAsync(model.ProductId, model.ProductSkuId);
 
             return await TryReduceInventoryAsync(model, productInventory, quantity, increaseSold);
@@ -158,5 +192,10 @@ namespace EasyAbp.EShop.Products.Products
                 newInventory,
                 sold));
         }
+
+        protected virtual Task<string> GetLockKeyAsync(InventoryQueryModel model)
+        {
+            return Task.FromResult(string.Format(DefaultProductInventoryLockKeyFormat, model.TenantId, model.ProductId, model.ProductSkuId));
+        }
     }
 }
\ No newline at end of file