Added support for halfvec type to EF Core

src/Pgvector.EntityFrameworkCore/CHANGELOG.md

@@ -1,5 +1,6 @@
 ## 0.2.1 (unreleased)
 
+- Added support for `halfvec` type
 - Added support for compiled models
 
 ## 0.2.0 (2023-11-24)

src/Pgvector.EntityFrameworkCore/HalfvecTypeMapping.cs

@@ -0,0 +1,19 @@
+using Microsoft.EntityFrameworkCore.Storage;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Storage.Internal.Mapping;
+using NpgsqlTypes;
+
+namespace Pgvector.EntityFrameworkCore;
+
+public class HalfvecTypeMapping : RelationalTypeMapping
+{
+    public static HalfvecTypeMapping Default { get; } = new();
+
+    public HalfvecTypeMapping() : base("halfvec", typeof(HalfVector)) { }
+
+    public HalfvecTypeMapping(string storeType) : base(storeType, typeof(HalfVector)) { }
+
+    protected HalfvecTypeMapping(RelationalTypeMappingParameters parameters) : base(parameters) { }
+
+    protected override RelationalTypeMapping Clone(RelationalTypeMappingParameters parameters)
+        => new HalfvecTypeMapping(parameters);
+}

src/Pgvector.EntityFrameworkCore/HalfvecTypeMappingSourcePlugin.cs

@@ -0,0 +1,11 @@
+using Microsoft.EntityFrameworkCore.Storage;
+
+namespace Pgvector.EntityFrameworkCore;
+
+public class HalfvecTypeMappingSourcePlugin : IRelationalTypeMappingSourcePlugin
+{
+    public RelationalTypeMapping? FindMapping(in RelationalTypeMappingInfo mappingInfo)
+        => mappingInfo.ClrType == typeof(HalfVector)
+            ? new HalfvecTypeMapping(mappingInfo.StoreTypeName ?? "halfvec")
+            : null;
+}

src/Pgvector.EntityFrameworkCore/VectorDbContextOptionsExtension.cs

@@ -17,6 +17,7 @@ public void ApplyServices(IServiceCollection services)
             .TryAdd<IMethodCallTranslatorPlugin, VectorDbFunctionsTranslatorPlugin>();
 
         services.AddSingleton<IRelationalTypeMappingSourcePlugin, VectorTypeMappingSourcePlugin>();
+        services.AddSingleton<IRelationalTypeMappingSourcePlugin, HalfvecTypeMappingSourcePlugin>();
     }
 
     public void Validate(IDbContextOptions options) { }

tests/Pgvector.CSharp.Tests/EntityFrameworkCoreTests.cs

@@ -36,6 +36,9 @@ public class Item
 
     [Column("embedding", TypeName = "vector(3)")]
     public Vector? Embedding { get; set; }
+
+    [Column("half_embedding", TypeName = "halfvec(3)")]
+    public HalfVector? HalfEmbedding { get; set; }
 }
 
 public class EntityFrameworkCoreTests
@@ -49,15 +52,16 @@ public async Task Main()
         var databaseCreator = ctx.GetService<IRelationalDatabaseCreator>();
         databaseCreator.CreateTables();
 
-        ctx.Items.Add(new Item { Embedding = new Vector(new float[] { 1, 1, 1 }) });
-        ctx.Items.Add(new Item { Embedding = new Vector(new float[] { 2, 2, 2 }) });
-        ctx.Items.Add(new Item { Embedding = new Vector(new float[] { 1, 1, 2 }) });
+        ctx.Items.Add(new Item { Embedding = new Vector(new float[] { 1, 1, 1 }), HalfEmbedding = new HalfVector(new Half[] { (Half)1, (Half)1, (Half)1 }) });
+        ctx.Items.Add(new Item { Embedding = new Vector(new float[] { 2, 2, 2 }), HalfEmbedding = new HalfVector(new Half[] { (Half)2, (Half)2, (Half)2 }) });
+        ctx.Items.Add(new Item { Embedding = new Vector(new float[] { 1, 1, 2 }), HalfEmbedding = new HalfVector(new Half[] { (Half)1, (Half)1, (Half)2 }) });
         ctx.SaveChanges();
 
         var embedding = new Vector(new float[] { 1, 1, 1 });
         var items = await ctx.Items.FromSql($"SELECT * FROM efcore_items ORDER BY embedding <-> {embedding} LIMIT 5").ToListAsync();
         Assert.Equal(new int[] { 1, 3, 2 }, items.Select(v => v.Id).ToArray());
         Assert.Equal(new float[] { 1, 1, 1 }, items[0].Embedding!.ToArray());
+        Assert.Equal(new Half[] { (Half)1, (Half)1, (Half)1 }, items[0].HalfEmbedding!.ToArray());
 
         items = await ctx.Items.OrderBy(x => x.Embedding!.L2Distance(embedding)).Take(5).ToListAsync();
         Assert.Equal(new int[] { 1, 3, 2 }, items.Select(v => v.Id).ToArray());