Pass read only span to SQLite raw to avoid allocation

benchmark/EFCore.Sqlite.Benchmarks/Binding/BlobBindingTests.cs

@@ -0,0 +1,63 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.ComponentModel;
+using System.Threading.Tasks;
+using BenchmarkDotNet.Attributes;
+using Microsoft.Data.Sqlite;
+
+// ReSharper disable ReturnValueOfPureMethodIsNotUsed
+
+namespace Microsoft.EntityFrameworkCore.Benchmarks.Binding;
+
+[DisplayName(nameof(BlobBindingTests))]
+[MemoryDiagnoser]
+public class BlobBindingTests
+{
+    private SqliteConnection _connection;
+
+    [Params(100_000, 1_000_000, 10_000_000, 100_000_000)]
+    public int BlobSize { get; set; }
+
+    [GlobalSetup]
+    public void OpenConnection()
+    {
+        SQLitePCL.raw.SetProvider(new SQLitePCL.SQLite3Provider_e_sqlite3());
+        _connection = new SqliteConnection("Data Source=:memory:");
+        _connection.Open();
+        using var command = _connection.CreateCommand();
+        command.CommandText = "CREATE TABLE Files (FileId INTEGER PRIMARY KEY, Data BLOB NOT NULL)";
+        command.ExecuteNonQuery();
+    }
+
+    [GlobalCleanup]
+    public void CloseConnection()
+    {
+        _connection.Dispose();
+    }
+
+    [IterationSetup]
+    public void ClearTable()
+    {
+        using var command = _connection.CreateCommand();
+        command.CommandText = "DELETE FROM Files";
+        command.ExecuteNonQuery();
+    }
+
+    [Benchmark]
+    public async Task OversizedByteArray()
+    {
+        using var command = _connection.CreateCommand();
+        command.CommandText = "INSERT INTO Files (Data) VALUES (@Data)";
+
+        var buffer = new byte[BlobSize + 1]; // add one to ensure the array size is different from the parameter size
+
+        var parameter = command.CreateParameter();
+        parameter.ParameterName = "@Data";
+        parameter.Size = BlobSize;
+        parameter.Value = buffer;
+        command.Parameters.Add(parameter);
+
+        await command.ExecuteNonQueryAsync();
+    }
+}

benchmark/EFCore.Sqlite.Benchmarks/EFCore.Sqlite.Benchmarks.csproj

@@ -16,6 +16,10 @@
     <ProjectReference Include="..\..\src\EFCore.Sqlite.Core\EFCore.Sqlite.Core.csproj" />
   </ItemGroup>
 
+  <ItemGroup>
+    <PackageReference Include="SQLitePCLRaw.bundle_e_sqlite3" />
+  </ItemGroup>
+
   <ItemGroup>
     <None Update="AdventureWorks2014.db">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>

src/Microsoft.Data.Sqlite.Core/SqliteParameterBinder.cs

@@ -10,16 +10,16 @@ namespace Microsoft.Data.Sqlite;
 internal class SqliteParameterBinder(sqlite3_stmt stmt, sqlite3 handle, int index, object value, int? size, SqliteType? sqliteType)
     : SqliteValueBinder(value, sqliteType)
 {
-    protected override void BindBlob(byte[] value)
+    protected override void BindBlob(ReadOnlySpan<byte> value)
     {
         var blob = value;
         if (ShouldTruncate(value.Length))
         {
-            blob = new byte[size!.Value];
-            Array.Copy(value, blob, size.Value);
+            blob = value.Slice(0, size!.Value);
         }
 
         var rc = sqlite3_bind_blob(stmt, index, blob);
+
         SqliteException.ThrowExceptionForRC(rc, handle);
     }
 

src/Microsoft.Data.Sqlite.Core/SqliteResultBinder.cs

@@ -1,14 +1,15 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System;
 using SQLitePCL;
 using static SQLitePCL.raw;
 
 namespace Microsoft.Data.Sqlite;
 
 internal class SqliteResultBinder(sqlite3_context ctx, object? value) : SqliteValueBinder(value)
 {
-    protected override void BindBlob(byte[] value)
+    protected override void BindBlob(ReadOnlySpan<byte> value)
         => sqlite3_result_blob(ctx, value);
 
     protected override void BindDoubleCore(double value)

src/Microsoft.Data.Sqlite.Core/SqliteValueBinder.cs

@@ -35,7 +35,7 @@ protected virtual void BindDouble(double value)
 
     protected abstract void BindText(string value);
 
-    protected abstract void BindBlob(byte[] value);
+    protected abstract void BindBlob(ReadOnlySpan<byte> value);
 
     protected abstract void BindNull();