snapshot of https://github.com/ent/ent.git (master, 2026-09-15; blobs > 131072B omitted)

dialect/gremlin/encoding/graphson/map.go

@@ -0,0 +1,116 @@
+// Copyright 2019-present Facebook Inc. All rights reserved.
+// This source code is licensed under the Apache 2.0 license found
+// in the LICENSE file in the root directory of this source tree.
+
+package graphson
+
+import (
+	"unsafe"
+
+	jsoniter "github.com/json-iterator/go"
+	"github.com/modern-go/reflect2"
+)
+
+// EncoderOfMap returns a value encoder of a map type.
+func (ext encodeExtension) EncoderOfMap(typ reflect2.Type) jsoniter.ValEncoder {
+	mapType := typ.(reflect2.MapType)
+	return &mapEncoder{
+		mapType: mapType,
+		keyEnc:  ext.LazyEncoderOf(mapType.Key()),
+		elemEnc: ext.LazyEncoderOf(mapType.Elem()),
+	}
+}
+
+// DecoratorOfMap decorates a value encoder of a map type.
+func (encodeExtension) DecoratorOfMap(enc jsoniter.ValEncoder) jsoniter.ValEncoder {
+	return typeEncoder{enc, mapType}
+}
+
+type mapEncoder struct {
+	mapType reflect2.MapType
+	keyEnc  jsoniter.ValEncoder
+	elemEnc jsoniter.ValEncoder
+}
+
+func (enc *mapEncoder) Encode(ptr unsafe.Pointer, stream *jsoniter.Stream) {
+	iter := enc.mapType.UnsafeIterate(ptr)
+	if !iter.HasNext() {
+		stream.WriteEmptyArray()
+		return
+	}
+
+	stream.WriteArrayStart()
+	for {
+		key, elem := iter.UnsafeNext()
+		enc.keyEnc.Encode(key, stream)
+		stream.WriteMore()
+		enc.elemEnc.Encode(elem, stream)
+		if !iter.HasNext() {
+			break
+		}
+		stream.WriteMore()
+	}
+	stream.WriteArrayEnd()
+}
+
+func (enc *mapEncoder) IsEmpty(ptr unsafe.Pointer) bool {
+	return !enc.mapType.UnsafeIterate(ptr).HasNext()
+}
+
+// DecoderOfMap returns a value decoder of a map type.
+func (ext decodeExtension) DecoderOfMap(typ reflect2.Type) jsoniter.ValDecoder {
+	mapType := typ.(reflect2.MapType)
+	keyType, elemType := mapType.Key(), mapType.Elem()
+	return &mapDecoder{
+		mapType:  mapType,
+		keyType:  keyType,
+		elemType: elemType,
+		keyDec:   ext.LazyDecoderOf(keyType),
+		elemDec:  ext.LazyDecoderOf(elemType),
+	}
+}
+
+// DecoratorOfMap decorates a value decoder of a map type.
+func (decodeExtension) DecoratorOfMap(dec jsoniter.ValDecoder) jsoniter.ValDecoder {
+	return typeDecoder{dec, mapType}
+}
+
+type mapDecoder struct {
+	mapType  reflect2.MapType
+	keyType  reflect2.Type
+	elemType reflect2.Type
+	keyDec   jsoniter.ValDecoder
+	elemDec  jsoniter.ValDecoder
+}
+
+func (dec *mapDecoder) Decode(ptr unsafe.Pointer, iter *jsoniter.Iterator) {
+	mapType := dec.mapType
+	if mapType.UnsafeIsNil(ptr) {
+		mapType.UnsafeSet(ptr, mapType.UnsafeMakeMap(0))
+	}
+
+	var key unsafe.Pointer
+	if !iter.ReadArrayCB(func(iter *jsoniter.Iterator) bool {
+		if key == nil {
+			key = dec.keyType.UnsafeNew()
+			dec.keyDec.Decode(key, iter)
+			return iter.Error == nil
+		}
+
+		elem := dec.elemType.UnsafeNew()
+		dec.elemDec.Decode(elem, iter)
+		if iter.Error != nil {
+			return false
+		}
+
+		mapType.UnsafeSetIndex(ptr, key, elem)
+		key = nil
+		return true
+	}) {
+		return
+	}
+
+	if key != nil {
+		iter.ReportError("decode map", "odd number of map items")
+	}
+}