Add EF Core-style logging for bulk insert operations (#103)

* Initial plan

* Add logging similar to EF Core: BulkInsertExecuted and ExecutedDbCommand log messages

Agent-Logs-Url: https://github.com/PhenX/PhenX.EntityFrameworkCore.BulkInsert/sessions/481b78be-69b9-450e-b8b4-3c7176838952

Co-authored-by: PhenX <42170+PhenX@users.noreply.github.com>

* Apply review fixes for logging and resource disposal

Agent-Logs-Url: https://github.com/PhenX/PhenX.EntityFrameworkCore.BulkInsert/sessions/50f8adc9-2589-4b71-a87e-14db3ec99af9

Co-authored-by: PhenX <42170+PhenX@users.noreply.github.com>

* Update docs and Copilot instructions for logging changes

Agent-Logs-Url: https://github.com/PhenX/PhenX.EntityFrameworkCore.BulkInsert/sessions/056ca3a1-0d57-424f-a270-daf8457b20bd

Co-authored-by: PhenX <42170+PhenX@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: PhenX <42170+PhenX@users.noreply.github.com>

Author: Copilot

.github/copilot-instructions.md

@@ -8,3 +8,9 @@
 - Do not include "issue #N", "triangulate", "hypothesis", or similar investigation language in
   inline code comments or block comments inside method bodies. Such context belongs in the pull
   request description, not in the source code.
+
+## Documentation and tests
+
+- Always update documentation when public APIs change.
+- Always update `README.md` when notable behavior or features are added or modified.
+- Always add or update tests for behavior changes.

README.md

@@ -123,6 +123,25 @@ await dbContext.ExecuteBulkInsertAsync(entities, o =>
 await dbContext.ExecuteBulkInsertReturnEntitiesAsync(entities);
 ```
 
+### Logging
+
+Bulk insert operations emit EF Core-style logs when a logger factory is configured on the `DbContext` options:
+
+```csharp
+services.AddDbContext<MyDbContext>(options =>
+{
+    options
+        .UseSqlite(connectionString)
+        .UseLoggerFactory(loggerFactory)
+        .UseBulkInsertSqlite();
+});
+```
+
+Log events:
+
+* `1004` (`Information`): bulk insert completion with elapsed time and destination table.
+* `1005` (`Debug`): auxiliary SQL commands executed by the library (such as temp-table DDL).
+
 ### Conflict resolution / merge / upsert
 
 Conflict resolution works by specifying columns that should be used to detect conflicts and the action to take when

docs/documentation.md

@@ -84,6 +84,25 @@ await dbContext.ExecuteBulkInsertAsync(entities, o =>
 await dbContext.ExecuteBulkInsertReturnEntitiesAsync(entities);
 ```
 
+## Logging
+
+Bulk insert operations emit EF Core-style logs when a logger factory is configured:
+
+```csharp
+services.AddDbContext<MyDbContext>(options =>
+{
+    options
+        .UseSqlite(connectionString)
+        .UseLoggerFactory(loggerFactory)
+        .UseBulkInsertSqlite();
+});
+```
+
+Log events:
+
+* `1004` (`Information`): bulk insert completion with elapsed time and destination table.
+* `1005` (`Debug`): auxiliary SQL commands executed by the library (for example temp-table SQL).
+
 ### Conflict resolution / merge / upsert
 
 Conflict resolution works by specifying columns that should be used to detect conflicts and the action to take when

src/PhenX.EntityFrameworkCore.BulkInsert.MySql/MySqlBulkInsertProvider.cs

@@ -12,7 +12,7 @@
 namespace PhenX.EntityFrameworkCore.BulkInsert.MySql;
 
 [UsedImplicitly]
-internal class MySqlBulkInsertProvider(ILogger<MySqlBulkInsertProvider> logger) : BulkInsertProviderBase<MySqlServerDialectBuilder, MySqlBulkInsertOptions>(logger)
+internal class MySqlBulkInsertProvider(ILoggerFactory? loggerFactory) : BulkInsertProviderBase<MySqlServerDialectBuilder, MySqlBulkInsertOptions>(loggerFactory)
 {
     //language=sql
     /// <inheritdoc />

src/PhenX.EntityFrameworkCore.BulkInsert.Oracle/OracleBulkInsertProvider.cs

@@ -11,7 +11,7 @@
 namespace PhenX.EntityFrameworkCore.BulkInsert.Oracle;
 
 [UsedImplicitly]
-internal class OracleBulkInsertProvider(ILogger<OracleBulkInsertProvider>? logger) : BulkInsertProviderBase<OracleDialectBuilder, OracleBulkInsertOptions>(logger)
+internal class OracleBulkInsertProvider(ILoggerFactory? loggerFactory) : BulkInsertProviderBase<OracleDialectBuilder, OracleBulkInsertOptions>(loggerFactory)
 {
     /// <inheritdoc />
     protected override string BulkInsertId => "ROWID";

src/PhenX.EntityFrameworkCore.BulkInsert.PostgreSql/PostgreSqlBulkInsertProvider.cs

@@ -15,7 +15,7 @@
 namespace PhenX.EntityFrameworkCore.BulkInsert.PostgreSql;
 
 [UsedImplicitly]
-internal class PostgreSqlBulkInsertProvider(ILogger<PostgreSqlBulkInsertProvider>? logger) : BulkInsertProviderBase<PostgreSqlDialectBuilder, PostgreSqlBulkInsertOptions>(logger)
+internal class PostgreSqlBulkInsertProvider(ILoggerFactory? loggerFactory) : BulkInsertProviderBase<PostgreSqlDialectBuilder, PostgreSqlBulkInsertOptions>(loggerFactory)
 {
     //language=sql
     /// <inheritdoc />

src/PhenX.EntityFrameworkCore.BulkInsert.SqlServer/SqlServerBulkInsertProvider.cs

@@ -10,7 +10,7 @@
 namespace PhenX.EntityFrameworkCore.BulkInsert.SqlServer;
 
 [UsedImplicitly]
-internal class SqlServerBulkInsertProvider(ILogger<SqlServerBulkInsertProvider>? logger) : BulkInsertProviderBase<SqlServerDialectBuilder, SqlServerBulkInsertOptions>(logger)
+internal class SqlServerBulkInsertProvider(ILoggerFactory? loggerFactory) : BulkInsertProviderBase<SqlServerDialectBuilder, SqlServerBulkInsertOptions>(loggerFactory)
 {
     //language=sql
     /// <inheritdoc />

src/PhenX.EntityFrameworkCore.BulkInsert.Sqlite/SqliteBulkInsertProvider.cs

@@ -13,7 +13,7 @@
 namespace PhenX.EntityFrameworkCore.BulkInsert.Sqlite;
 
 [UsedImplicitly]
-internal class SqliteBulkInsertProvider(ILogger<SqliteBulkInsertProvider>? logger) : BulkInsertProviderBase<SqliteDialectBuilder, BulkInsertOptions>(logger)
+internal class SqliteBulkInsertProvider(ILoggerFactory? loggerFactory) : BulkInsertProviderBase<SqliteDialectBuilder, BulkInsertOptions>(loggerFactory)
 {
     private const int MaxParams = 1000;
 

src/PhenX.EntityFrameworkCore.BulkInsert/BulkInsertOptionsExtension.cs

@@ -16,8 +16,8 @@ public DbContextOptionsExtensionInfo Info
 
     public void ApplyServices(IServiceCollection services)
     {
-        services.TryAddSingleton(typeof(ILogger<>), typeof(NullLogger<>));
-        services.AddSingleton<IBulkInsertProvider, TProvider>();
+        services.TryAddSingleton<ILoggerFactory, NullLoggerFactory>();
+        services.AddScoped<IBulkInsertProvider, TProvider>();
     }
 
     public void Validate(IDbContextOptions options)

src/PhenX.EntityFrameworkCore.BulkInsert/BulkInsertProviderBase.cs

@@ -1,3 +1,4 @@
+using System.Diagnostics;
 using System.Runtime.CompilerServices;
 
 using Microsoft.EntityFrameworkCore;
@@ -11,10 +12,12 @@
 
 namespace PhenX.EntityFrameworkCore.BulkInsert;
 
-internal abstract class BulkInsertProviderBase<TDialect, TOptions>(ILogger? logger) : BulkInsertProviderUntyped<TDialect, TOptions>
+internal abstract class BulkInsertProviderBase<TDialect, TOptions>(ILoggerFactory? loggerFactory) : BulkInsertProviderUntyped<TDialect, TOptions>
     where TDialect : SqlDialectBuilder, new()
     where TOptions : BulkInsertOptions, new()
 {
+    private ILogger? _logger;
+    private ILogger? logger => _logger ??= loggerFactory?.CreateLogger(GetType());
     protected virtual string BulkInsertId => "_bulk_insert_id";
 
     protected abstract string AddTableCopyBulkInsertId { get; }
@@ -144,7 +147,15 @@ private async Task<string> PerformBulkInsertAsync<T>(
         activity?.AddTag("tempTable", tempTableRequired);
         activity?.AddTag("synchronous", sync);
 
+        var sw = Stopwatch.StartNew();
         await BulkInsert(sync, context, tableInfo, entities, tableName, columns, options, ctk);
+        sw.Stop();
+
+        if (logger != null)
+        {
+            Log.BulkInsertExecuted(logger, sw.ElapsedMilliseconds, tableName);
+        }
+
         return tableName;
     }
 
@@ -254,16 +265,17 @@ protected virtual Task DropTempTableAsync(bool sync, DbContext dbContext, string
         return Task.CompletedTask;
     }
 
-    protected static async Task ExecuteAsync(
+    protected async Task ExecuteAsync(
         bool sync,
         DbContext context,
         string query,
         CancellationToken ctk)
     {
-        var command = context.Database.GetDbConnection().CreateCommand();
+        using var command = context.Database.GetDbConnection().CreateCommand();
         command.Transaction = context.Database.CurrentTransaction!.GetDbTransaction();
         command.CommandText = query;
 
+        var sw = Stopwatch.StartNew();
         if (sync)
         {
             // ReSharper disable once MethodHasAsyncOverloadWithCancellation
@@ -273,5 +285,11 @@ protected static async Task ExecuteAsync(
         {
             await command.ExecuteNonQueryAsync(ctk);
         }
+        sw.Stop();
+
+        if (logger != null)
+        {
+            Log.ExecutedDbCommand(logger, sw.ElapsedMilliseconds, query);
+        }
     }
 }