Enabling pointer struct fields of all types as quasi options via 2-type union [null, ...]

.gitignore

@@ -30,3 +30,6 @@ thumbs.db
 *fuzz.zip
 fuzzes/**/crashers
 fuzzes/**/suppressions
+
+# IntelliJ
+*.iml

datum_reader.go

@@ -235,14 +235,18 @@ func (reader sDatumReader) mapArray(field Schema, reflectField reflect.Value, de
 		return reflect.ValueOf(arrayLength), err
 	}
 
-	array := reflect.MakeSlice(reflectField.Type(), 0, 0)
+	indirectArrayType := reflectField.Type()
+	if reflectField.Type().Kind() == reflect.Ptr {
+		indirectArrayType = indirectArrayType.Elem()
+	}
+	array := reflect.MakeSlice(indirectArrayType, 0, 0)
 	pointer := reflectField.Type().Elem().Kind() == reflect.Ptr
 	for {
 		if arrayLength == 0 {
 			break
 		}
 
-		arrayPart := reflect.MakeSlice(reflectField.Type(), int(arrayLength), int(arrayLength))
+		arrayPart := reflect.MakeSlice(indirectArrayType, int(arrayLength), int(arrayLength))
 		var i int64
 		for ; i < arrayLength; i++ {
 			current := arrayPart.Index(int(i))
@@ -282,8 +286,12 @@ func (reader sDatumReader) mapMap(field Schema, reflectField reflect.Value, dec
 		return reflect.ValueOf(mapLength), err
 	}
 	elemType := reflectField.Type().Elem()
-	elemIsPointer := (elemType.Kind() == reflect.Ptr)
-	resultMap := reflect.MakeMap(reflectField.Type())
+	elemIsPointer := elemType.Kind() == reflect.Ptr
+	indirectMapType := reflectField.Type()
+	if reflectField.Type().Kind() == reflect.Ptr {
+		indirectMapType = indirectMapType.Elem()
+	}
+	resultMap := reflect.MakeMap(indirectMapType)
 
 	// dest is an element type value used as the destination for reading values into.
 	// This is required for using non-primitive types as map values, because map values are not addressable
@@ -360,7 +368,14 @@ func (reader sDatumReader) mapUnion(field Schema, reflectField reflect.Value, de
 	if unionIndex < 0 || int(unionIndex) >= len(types) {
 		return reflect.Value{}, fmt.Errorf("Invalid union index %d", unionIndex)
 	}
-	return reader.readValue(types[unionIndex], reflectField, dec)
+
+	value, err := reader.readValue(types[unionIndex], reflectField, dec)
+	if reflectField.Kind() == reflect.Ptr && value.Kind() != reflect.Ptr && value.IsValid() {
+		ref := reflect.New(reflectField.Type().Elem())
+		ref.Elem().Set(value)
+		value = ref
+	}
+	return value, err
 }
 
 func (reader sDatumReader) mapFixed(field Schema, dec Decoder) (reflect.Value, error) {

datum_writer.go

@@ -145,7 +145,7 @@ func (writer *SpecificDatumWriter) writeBoolean(v reflect.Value, enc Encoder, s
 		return fmt.Errorf("Invalid boolean value: %v", v.Interface())
 	}
 
-	enc.WriteBoolean(v.Interface().(bool))
+	enc.WriteBoolean(dereference(v).Interface().(bool))
 	return nil
 }
 
@@ -154,7 +154,7 @@ func (writer *SpecificDatumWriter) writeInt(v reflect.Value, enc Encoder, s Sche
 		return fmt.Errorf("Invalid int value: %v", v.Interface())
 	}
 
-	enc.WriteInt(v.Interface().(int32))
+	enc.WriteInt(dereference(v).Interface().(int32))
 	return nil
 }
 
@@ -163,7 +163,7 @@ func (writer *SpecificDatumWriter) writeLong(v reflect.Value, enc Encoder, s Sch
 		return fmt.Errorf("Invalid long value: %v", v.Interface())
 	}
 
-	enc.WriteLong(v.Interface().(int64))
+	enc.WriteLong(dereference(v).Interface().(int64))
 	return nil
 }
 
@@ -172,7 +172,7 @@ func (writer *SpecificDatumWriter) writeFloat(v reflect.Value, enc Encoder, s Sc
 		return fmt.Errorf("Invalid float value: %v", v.Interface())
 	}
 
-	enc.WriteFloat(v.Interface().(float32))
+	enc.WriteFloat(dereference(v).Interface().(float32))
 	return nil
 }
 
@@ -181,7 +181,7 @@ func (writer *SpecificDatumWriter) writeDouble(v reflect.Value, enc Encoder, s S
 		return fmt.Errorf("Invalid double value: %v", v.Interface())
 	}
 
-	enc.WriteDouble(v.Interface().(float64))
+	enc.WriteDouble(dereference(v).Interface().(float64))
 	return nil
 }
 
@@ -190,7 +190,7 @@ func (writer *SpecificDatumWriter) writeBytes(v reflect.Value, enc Encoder, s Sc
 		return fmt.Errorf("Invalid bytes value: %v", v.Interface())
 	}
 
-	enc.WriteBytes(v.Interface().([]byte))
+	enc.WriteBytes(dereference(v).Interface().([]byte))
 	return nil
 }
 
@@ -199,14 +199,17 @@ func (writer *SpecificDatumWriter) writeString(v reflect.Value, enc Encoder, s S
 		return fmt.Errorf("Invalid string value: %v", v.Interface())
 	}
 
-	enc.WriteString(v.Interface().(string))
+	enc.WriteString(dereference(v).Interface().(string))
 	return nil
 }
 
 func (writer *SpecificDatumWriter) writeArray(v reflect.Value, enc Encoder, s Schema) error {
 	if !s.Validate(v) {
 		return fmt.Errorf("Invalid array value: %v", v.Interface())
 	}
+	if v.Kind() == reflect.Ptr {
+		v = v.Elem()
+	}
 
 	if v.Len() == 0 {
 		enc.WriteArrayNext(0)
@@ -229,7 +232,9 @@ func (writer *SpecificDatumWriter) writeMap(v reflect.Value, enc Encoder, s Sche
 	if !s.Validate(v) {
 		return fmt.Errorf("Invalid map value: %v", v.Interface())
 	}
-
+	if v.Kind() == reflect.Ptr {
+		v = v.Elem()
+	}
 	if v.Len() == 0 {
 		enc.WriteMapNext(0)
 		return nil
@@ -280,7 +285,7 @@ func (writer *SpecificDatumWriter) writeFixed(v reflect.Value, enc Encoder, s Sc
 	}
 
 	// Write the raw bytes. The length is known by the schema
-	enc.WriteRaw(v.Interface().([]byte))
+	enc.WriteRaw(dereference(v).Interface().([]byte))
 	return nil
 }
 
@@ -370,6 +375,8 @@ func (writer *GenericDatumWriter) writeBoolean(v interface{}, enc Encoder) error
 	switch value := v.(type) {
 	case bool:
 		enc.WriteBoolean(value)
+	case *bool:
+		enc.WriteBoolean(*value)
 	default:
 		return fmt.Errorf("%v is not a boolean", v)
 	}
@@ -381,6 +388,8 @@ func (writer *GenericDatumWriter) writeInt(v interface{}, enc Encoder) error {
 	switch value := v.(type) {
 	case int32:
 		enc.WriteInt(value)
+	case *int32:
+		enc.WriteInt(*value)
 	default:
 		return fmt.Errorf("%v is not an int32", v)
 	}
@@ -392,6 +401,8 @@ func (writer *GenericDatumWriter) writeLong(v interface{}, enc Encoder) error {
 	switch value := v.(type) {
 	case int64:
 		enc.WriteLong(value)
+	case *int64:
+		enc.WriteLong(*value)
 	default:
 		return fmt.Errorf("%v is not an int64", v)
 	}
@@ -403,6 +414,8 @@ func (writer *GenericDatumWriter) writeFloat(v interface{}, enc Encoder) error {
 	switch value := v.(type) {
 	case float32:
 		enc.WriteFloat(value)
+	case *float32:
+		enc.WriteFloat(*value)
 	default:
 		return fmt.Errorf("%v is not a float32", v)
 	}
@@ -414,6 +427,8 @@ func (writer *GenericDatumWriter) writeDouble(v interface{}, enc Encoder) error
 	switch value := v.(type) {
 	case float64:
 		enc.WriteDouble(value)
+	case *float64:
+		enc.WriteDouble(*value)
 	default:
 		return fmt.Errorf("%v is not a float64", v)
 	}
@@ -425,6 +440,8 @@ func (writer *GenericDatumWriter) writeBytes(v interface{}, enc Encoder) error {
 	switch value := v.(type) {
 	case []byte:
 		enc.WriteBytes(value)
+	case *[]byte:
+		enc.WriteBytes(*value)
 	default:
 		return fmt.Errorf("%v is not a []byte", v)
 	}
@@ -436,6 +453,8 @@ func (writer *GenericDatumWriter) writeString(v interface{}, enc Encoder) error
 	switch value := v.(type) {
 	case string:
 		enc.WriteString(value)
+	case *string:
+		enc.WriteString(*value)
 	default:
 		return fmt.Errorf("%v is not a string", v)
 	}
@@ -445,6 +464,9 @@ func (writer *GenericDatumWriter) writeString(v interface{}, enc Encoder) error
 
 func (writer *GenericDatumWriter) writeArray(v interface{}, enc Encoder, s Schema) error {
 	rv := reflect.ValueOf(v)
+	if rv.Kind() == reflect.Ptr {
+		rv = rv.Elem()
+	}
 	if rv.Kind() != reflect.Slice && rv.Kind() != reflect.Array {
 		return errors.New("Not a slice or array type")
 	}
@@ -469,6 +491,9 @@ func (writer *GenericDatumWriter) writeArray(v interface{}, enc Encoder, s Schem
 
 func (writer *GenericDatumWriter) writeMap(v interface{}, enc Encoder, s Schema) error {
 	rv := reflect.ValueOf(v)
+	if rv.Kind() == reflect.Ptr {
+		rv = rv.Elem()
+	}
 	if rv.Kind() != reflect.Map {
 		return errors.New("Not a map type")
 	}
@@ -584,9 +609,13 @@ func (writer *GenericDatumWriter) writeFixed(v interface{}, enc Encoder, s Schem
 	if !fs.Validate(reflect.ValueOf(v)) {
 		return fmt.Errorf("Invalid fixed value: %v", v)
 	}
+	switch value := v.(type) {
+	case []byte:
+		enc.WriteRaw(value)
+	case *[]byte:
+		enc.WriteRaw(*value)
+	}
 
-	// Write the raw bytes. The length is known by the schema
-	enc.WriteRaw(v.([]byte))
 	return nil
 }
 

generic_record.go

@@ -15,7 +15,9 @@ limitations under the License. */
 
 package avro
 
-import "encoding/json"
+import (
+	"encoding/json"
+)
 
 // AvroRecord is an interface for anything that has an Avro schema and can be serialized/deserialized by this library.
 type AvroRecord interface {