Fix race condition in ViewCount with atomic SQL updates

Directory.Packages.props

@@ -5,6 +5,7 @@
 	<ItemGroup>
 		<PackageVersion Include="Azure.Communication.Sms" Version="1.1.0-beta.2" />
 		<PackageVersion Include="coverlet.collector" Version="6.0.4" />
+		<PackageVersion Include="Dapper.StrongName" Version="2.1.66" />
 		<PackageVersion Include="Microsoft.AspNetCore.Diagnostics.Elm" Version="0.2.2" />
 		<PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.14.0-preview-25107-01" />
 		<PackageVersion Include="Microsoft.Extensions.Configuration.UserSecrets" Version="8.0.1" />

src/OrchardCoreContrib.ViewCount/OrchardCoreContrib.ViewCount.csproj

@@ -37,6 +37,7 @@
 		<PackageReference Include="OrchardCore.DisplayManagement" />
 		<PackageReference Include="OrchardCoreContrib.Abstractions" />
 		<PackageReference Include="OrchardCoreContrib.Infrastructure.Abstractions" />
+		<PackageReference Include="Dapper.StrongName" />
 	</ItemGroup>
 
 </Project>

src/OrchardCoreContrib.ViewCount/Services/ViewCountService.cs

@@ -4,6 +4,9 @@
 using OrchardCoreContrib.Infrastructure;
 using OrchardCoreContrib.ViewCount.Handlers;
 using OrchardCoreContrib.ViewCount.Models;
+using System.Data.Common;
+using YesSql;
+using Dapper;
 
 namespace OrchardCoreContrib.ViewCount.Services;
 
@@ -17,6 +20,7 @@ namespace OrchardCoreContrib.ViewCount.Services;
 /// </remarks>
 public class ViewCountService(
     IContentManager contentManager,
+    ISession session,
     IEnumerable<IViewCountContentHandler> handlers,
     ILogger<ViewCountService> logger) : IViewCountService
 {
@@ -42,12 +46,93 @@ public async Task ViewAsync(ContentItem contentItem)
 
         await handlers.InvokeAsync((handler, context) => handler.ViewingAsync(context), context, logger);
 
-        contentItem.Content.ViewCountPart.Count = ++count;
+        // Perform atomic increment directly in the database to avoid race conditions
+        await IncrementViewCountAtomicallyAsync(contentItem.ContentItemId);
 
-        await contentManager.UpdateAsync(contentItem);
+        // Reload the content item to get the updated count
+        contentItem = await contentManager.GetAsync(contentItem.ContentItemId);
+        viewCountPart = contentItem?.As<ViewCountPart>();
+
+        if (viewCountPart != null)
+        {
+            count = viewCountPart.Count;
+        }
 
         context = new ViewCountContentContext(contentItem, count);
 
         await handlers.InvokeAsync((handler, context) => handler.ViewedAsync(context), context, logger);
     }
+
+    private async Task IncrementViewCountAtomicallyAsync(string contentItemId)
+    {
+        var dialect = session.Store.Configuration.SqlDialect;
+        var tablePrefix = session.Store.Configuration.TablePrefix;
+        var schema = session.Store.Configuration.Schema;
+        var documentTable = $"{tablePrefix}{nameof(ContentItem)}Document";
+
+        string sql;
+
+        // Use database-specific JSON update functions for atomic increment
+        if (dialect.Name == "SqlServer")
+        {
+            sql = $@"
+                UPDATE {dialect.QuoteForTableName(documentTable, schema)}
+                SET {dialect.QuoteForColumnName("Content")} = JSON_MODIFY(
+                    {dialect.QuoteForColumnName("Content")},
+                    '$.ViewCountPart.Count',
+                    CAST(ISNULL(JSON_VALUE({dialect.QuoteForColumnName("Content")}, '$.ViewCountPart.Count'), '0') AS INT) + 1
+                )
+                WHERE JSON_VALUE({dialect.QuoteForColumnName("Content")}, '$.ContentItemId') = @ContentItemId";
+        }
+        else if (dialect.Name == "Sqlite")
+        {
+            sql = $@"
+                UPDATE {dialect.QuoteForTableName(documentTable, schema)}
+                SET {dialect.QuoteForColumnName("Content")} = json_set(
+                    {dialect.QuoteForColumnName("Content")},
+                    '$.ViewCountPart.Count',
+                    CAST(COALESCE(json_extract({dialect.QuoteForColumnName("Content")}, '$.ViewCountPart.Count'), 0) AS INTEGER) + 1
+                )
+                WHERE json_extract({dialect.QuoteForColumnName("Content")}, '$.ContentItemId') = @ContentItemId";
+        }
+        else if (dialect.Name == "MySql")
+        {
+            sql = $@"
+                UPDATE {dialect.QuoteForTableName(documentTable, schema)}
+                SET {dialect.QuoteForColumnName("Content")} = JSON_SET(
+                    {dialect.QuoteForColumnName("Content")},
+                    '$.ViewCountPart.Count',
+                    CAST(COALESCE(JSON_EXTRACT({dialect.QuoteForColumnName("Content")}, '$.ViewCountPart.Count'), 0) AS UNSIGNED) + 1
+                )
+                WHERE JSON_EXTRACT({dialect.QuoteForColumnName("Content")}, '$.ContentItemId') = @ContentItemId";
+        }
+        else if (dialect.Name == "PostgreSql")
+        {
+            sql = $@"
+                UPDATE {dialect.QuoteForTableName(documentTable, schema)}
+                SET {dialect.QuoteForColumnName("Content")} = jsonb_set(
+                    {dialect.QuoteForColumnName("Content")},
+                    '{{ViewCountPart,Count}}',
+                    to_jsonb(COALESCE(({dialect.QuoteForColumnName("Content")}#>>'{{ViewCountPart,Count}}')::int, 0) + 1)
+                )
+                WHERE {dialect.QuoteForColumnName("Content")}->>'ContentItemId' = @ContentItemId";
+        }
+        else
+        {
+            logger.LogError("Unsupported SQL dialect '{DialectName}' for atomic view count updates. Supported dialects are: SqlServer, Sqlite, MySql, PostgreSql.", dialect.Name);
+            throw new NotSupportedException($"The SQL dialect '{dialect.Name}' is not supported for atomic view count updates.");
+        }
+
+        // Use existing session connection managed by YesSql.
+        // Do not dispose the connection as YesSql manages its lifecycle within the session's transaction scope.
+        var connection = await session.CreateConnectionAsync();
+
+        var commandDefinition = new CommandDefinition(
+            commandText: sql,
+            parameters: new { ContentItemId = contentItemId },
+            transaction: session.CurrentTransaction
+        );
+
+        await connection.ExecuteAsync(commandDefinition);
+    }
 }