GODRIVER-3455 Reflection-free default type encoder

bson/array_codec.go

@@ -15,16 +15,6 @@ import (
 // arrayCodec is the Codec used for bsoncore.Array values.
 type arrayCodec struct{}
 
-// EncodeValue is the ValueEncoder for bsoncore.Array values.
-func (ac *arrayCodec) EncodeValue(_ EncodeContext, vw ValueWriter, val reflect.Value) error {
-	if !val.IsValid() || val.Type() != tCoreArray {
-		return ValueEncoderError{Name: "CoreArrayEncodeValue", Types: []reflect.Type{tCoreArray}, Received: val}
-	}
-
-	arr := val.Interface().(bsoncore.Array)
-	return copyArrayFromBytes(vw, arr)
-}
-
 // DecodeValue is the ValueDecoder for bsoncore.Array values.
 func (ac *arrayCodec) DecodeValue(_ DecodeContext, vr ValueReader, val reflect.Value) error {
 	if !val.CanSet() || val.Type() != tCoreArray {

bson/bsoncodec.go

@@ -139,6 +139,20 @@ func (fn ValueEncoderFunc) EncodeValue(ec EncodeContext, vw ValueWriter, val ref
 	return fn(ec, vw, val)
 }
 
+// reflectFreeValueEncoder is a reflect-free version of ValueEncoder.
+type reflectFreeValueEncoder interface {
+	EncodeValue(ec EncodeContext, vw ValueWriter, val any) error
+}
+
+// reflectFreeValueEncoderFunc is an adapter function that allows a function
+// with the correct signature to be used as a reflectFreeValueEncoder.
+type reflectFreeValueEncoderFunc func(ec EncodeContext, vw ValueWriter, val any) error
+
+// EncodeValue implements the reflectFreeValueEncoder interface.
+func (fn reflectFreeValueEncoderFunc) EncodeValue(ec EncodeContext, vw ValueWriter, val any) error {
+	return fn(ec, vw, val)
+}
+
 // ValueDecoder is the interface implemented by types that can decode BSON to a provided Go type.
 // Implementations should ensure that the value they receive is settable. Similar to ValueEncoderFunc,
 // ValueDecoderFunc is provided to allow the use of a function with the correct signature as a

bson/byte_slice_codec.go

@@ -12,28 +12,13 @@ import (
 )
 
 // byteSliceCodec is the Codec used for []byte values.
-type byteSliceCodec struct {
-	// encodeNilAsEmpty causes EncodeValue to marshal nil Go byte slices as empty BSON binary values
-	// instead of BSON null.
-	encodeNilAsEmpty bool
-}
+type byteSliceCodec struct{}
 
 // Assert that byteSliceCodec satisfies the typeDecoder interface, which allows it to be
 // used by collection type decoders (e.g. map, slice, etc) to set individual values in a
 // collection.
 var _ typeDecoder = &byteSliceCodec{}
 
-// EncodeValue is the ValueEncoder for []byte.
-func (bsc *byteSliceCodec) EncodeValue(ec EncodeContext, vw ValueWriter, val reflect.Value) error {
-	if !val.IsValid() || val.Type() != tByteSlice {
-		return ValueEncoderError{Name: "ByteSliceEncodeValue", Types: []reflect.Type{tByteSlice}, Received: val}
-	}
-	if val.IsNil() && !bsc.encodeNilAsEmpty && !ec.nilByteSliceAsEmpty {
-		return vw.WriteNull()
-	}
-	return vw.WriteBinary(val.Interface().([]byte))
-}
-
 func (bsc *byteSliceCodec) decodeType(_ DecodeContext, vr ValueReader, t reflect.Type) (reflect.Value, error) {
 	if t != tByteSlice {
 		return emptyValue, ValueDecoderError{

bson/codec_cache.go

@@ -58,6 +58,39 @@ func (c *typeEncoderCache) Clone() *typeEncoderCache {
 	return cc
 }
 
+type reflectFreeTypeEncoderCache struct {
+	cache sync.Map // map[reflect.Type]typeReflectFreeEncoderCache
+}
+
+func (c *reflectFreeTypeEncoderCache) Store(rt reflect.Type, enc reflectFreeValueEncoder) {
+	c.cache.Store(rt, enc)
+}
+
+func (c *reflectFreeTypeEncoderCache) Load(rt reflect.Type) (reflectFreeValueEncoder, bool) {
+	if v, _ := c.cache.Load(rt); v != nil {
+		return v.(reflectFreeValueEncoder), true
+	}
+	return nil, false
+}
+
+func (c *reflectFreeTypeEncoderCache) LoadOrStore(rt reflect.Type, enc reflectFreeValueEncoder) reflectFreeValueEncoder {
+	if v, loaded := c.cache.LoadOrStore(rt, enc); loaded {
+		enc = v.(reflectFreeValueEncoder)
+	}
+	return enc
+}
+
+func (c *reflectFreeTypeEncoderCache) Clone() *reflectFreeTypeEncoderCache {
+	cc := new(reflectFreeTypeEncoderCache)
+	c.cache.Range(func(k, v interface{}) bool {
+		if k != nil && v != nil {
+			cc.cache.Store(k, v)
+		}
+		return true
+	})
+	return cc
+}
+
 type typeDecoderCache struct {
 	cache sync.Map // map[reflect.Type]ValueDecoder
 }

bson/default_value_decoders_test.go

@@ -3414,20 +3414,22 @@ func TestDefaultValueDecoders(t *testing.T) {
 			// the top-level to decode to registered type when unmarshalling to interface{}
 
 			topLevelReg := &Registry{
-				typeEncoders: new(typeEncoderCache),
-				typeDecoders: new(typeDecoderCache),
-				kindEncoders: new(kindEncoderCache),
-				kindDecoders: new(kindDecoderCache),
+				typeEncoders:            new(typeEncoderCache),
+				typeDecoders:            new(typeDecoderCache),
+				kindEncoders:            new(kindEncoderCache),
+				kindDecoders:            new(kindDecoderCache),
+				reflectFreeTypeEncoders: new(reflectFreeTypeEncoderCache),
 			}
 			registerDefaultEncoders(topLevelReg)
 			registerDefaultDecoders(topLevelReg)
 			topLevelReg.RegisterTypeMapEntry(Type(0), reflect.TypeOf(M{}))
 
 			embeddedReg := &Registry{
-				typeEncoders: new(typeEncoderCache),
-				typeDecoders: new(typeDecoderCache),
-				kindEncoders: new(kindEncoderCache),
-				kindDecoders: new(kindDecoderCache),
+				typeEncoders:            new(typeEncoderCache),
+				typeDecoders:            new(typeDecoderCache),
+				kindEncoders:            new(kindEncoderCache),
+				kindDecoders:            new(kindDecoderCache),
+				reflectFreeTypeEncoders: new(reflectFreeTypeEncoderCache),
 			}
 			registerDefaultEncoders(embeddedReg)
 			registerDefaultDecoders(embeddedReg)
@@ -3470,10 +3472,11 @@ func TestDefaultValueDecoders(t *testing.T) {
 			// type information is not available.
 
 			reg := &Registry{
-				typeEncoders: new(typeEncoderCache),
-				typeDecoders: new(typeDecoderCache),
-				kindEncoders: new(kindEncoderCache),
-				kindDecoders: new(kindDecoderCache),
+				typeEncoders:            new(typeEncoderCache),
+				typeDecoders:            new(typeDecoderCache),
+				kindEncoders:            new(kindEncoderCache),
+				kindDecoders:            new(kindDecoderCache),
+				reflectFreeTypeEncoders: new(reflectFreeTypeEncoderCache),
 			}
 			registerDefaultEncoders(reg)
 			registerDefaultDecoders(reg)
@@ -3564,10 +3567,11 @@ func TestDefaultValueDecoders(t *testing.T) {
 
 		// Use a registry that has all default decoders with the custom interface{} decoder that always errors.
 		nestedRegistry := &Registry{
-			typeEncoders: new(typeEncoderCache),
-			typeDecoders: new(typeDecoderCache),
-			kindEncoders: new(kindEncoderCache),
-			kindDecoders: new(kindDecoderCache),
+			typeEncoders:            new(typeEncoderCache),
+			typeDecoders:            new(typeDecoderCache),
+			kindEncoders:            new(kindEncoderCache),
+			kindDecoders:            new(kindDecoderCache),
+			reflectFreeTypeEncoders: new(reflectFreeTypeEncoderCache),
 		}
 		registerDefaultDecoders(nestedRegistry)
 		nestedRegistry.RegisterTypeDecoder(tEmpty, ValueDecoderFunc(emptyInterfaceErrorDecode))
@@ -3721,10 +3725,11 @@ func TestDefaultValueDecoders(t *testing.T) {
 			)
 
 			reg := &Registry{
-				typeEncoders: new(typeEncoderCache),
-				typeDecoders: new(typeDecoderCache),
-				kindEncoders: new(kindEncoderCache),
-				kindDecoders: new(kindDecoderCache),
+				typeEncoders:            new(typeEncoderCache),
+				typeDecoders:            new(typeDecoderCache),
+				kindEncoders:            new(kindEncoderCache),
+				kindDecoders:            new(kindDecoderCache),
+				reflectFreeTypeEncoders: new(reflectFreeTypeEncoderCache),
 			}
 			registerDefaultDecoders(reg)
 			reg.RegisterTypeMapEntry(TypeBoolean, reflect.TypeOf(mybool(true)))
@@ -3795,10 +3800,11 @@ func buildDocument(elems []byte) []byte {
 
 func buildDefaultRegistry() *Registry {
 	reg := &Registry{
-		typeEncoders: new(typeEncoderCache),
-		typeDecoders: new(typeDecoderCache),
-		kindEncoders: new(kindEncoderCache),
-		kindDecoders: new(kindDecoderCache),
+		typeEncoders:            new(typeEncoderCache),
+		typeDecoders:            new(typeDecoderCache),
+		kindEncoders:            new(kindEncoderCache),
+		kindDecoders:            new(kindDecoderCache),
+		reflectFreeTypeEncoders: new(reflectFreeTypeEncoderCache),
 	}
 	registerDefaultEncoders(reg)
 	registerDefaultDecoders(reg)