1package jsoniter
2
3import (
4	"fmt"
5	"reflect"
6	"unsafe"
7
8	"github.com/modern-go/reflect2"
9)
10
11// ValDecoder is an internal type registered to cache as needed.
12// Don't confuse jsoniter.ValDecoder with json.Decoder.
13// For json.Decoder's adapter, refer to jsoniter.AdapterDecoder(todo link).
14//
15// Reflection on type to create decoders, which is then cached
16// Reflection on value is avoided as we can, as the reflect.Value itself will allocate, with following exceptions
17// 1. create instance of new value, for example *int will need a int to be allocated
18// 2. append to slice, if the existing cap is not enough, allocate will be done using Reflect.New
19// 3. assignment to map, both key and value will be reflect.Value
20// For a simple struct binding, it will be reflect.Value free and allocation free
21type ValDecoder interface {
22	Decode(ptr unsafe.Pointer, iter *Iterator)
23}
24
25// ValEncoder is an internal type registered to cache as needed.
26// Don't confuse jsoniter.ValEncoder with json.Encoder.
27// For json.Encoder's adapter, refer to jsoniter.AdapterEncoder(todo godoc link).
28type ValEncoder interface {
29	IsEmpty(ptr unsafe.Pointer) bool
30	Encode(ptr unsafe.Pointer, stream *Stream)
31}
32
33type checkIsEmpty interface {
34	IsEmpty(ptr unsafe.Pointer) bool
35}
36
37type ctx struct {
38	*frozenConfig
39	prefix   string
40	encoders map[reflect2.Type]ValEncoder
41	decoders map[reflect2.Type]ValDecoder
42}
43
44func (b *ctx) caseSensitive() bool {
45	if b.frozenConfig == nil {
46		// default is case-insensitive
47		return false
48	}
49	return b.frozenConfig.caseSensitive
50}
51
52func (b *ctx) append(prefix string) *ctx {
53	return &ctx{
54		frozenConfig: b.frozenConfig,
55		prefix:       b.prefix + " " + prefix,
56		encoders:     b.encoders,
57		decoders:     b.decoders,
58	}
59}
60
61// ReadVal copy the underlying JSON into go interface, same as json.Unmarshal
62func (iter *Iterator) ReadVal(obj interface{}) {
63	depth := iter.depth
64	cacheKey := reflect2.RTypeOf(obj)
65	decoder := iter.cfg.getDecoderFromCache(cacheKey)
66	if decoder == nil {
67		typ := reflect2.TypeOf(obj)
68		if typ.Kind() != reflect.Ptr {
69			iter.ReportError("ReadVal", "can only unmarshal into pointer")
70			return
71		}
72		decoder = iter.cfg.DecoderOf(typ)
73	}
74	ptr := reflect2.PtrOf(obj)
75	if ptr == nil {
76		iter.ReportError("ReadVal", "can not read into nil pointer")
77		return
78	}
79	decoder.Decode(ptr, iter)
80	if iter.depth != depth {
81		iter.ReportError("ReadVal", "unexpected mismatched nesting")
82		return
83	}
84}
85
86// WriteVal copy the go interface into underlying JSON, same as json.Marshal
87func (stream *Stream) WriteVal(val interface{}) {
88	if nil == val {
89		stream.WriteNil()
90		return
91	}
92	cacheKey := reflect2.RTypeOf(val)
93	encoder := stream.cfg.getEncoderFromCache(cacheKey)
94	if encoder == nil {
95		typ := reflect2.TypeOf(val)
96		encoder = stream.cfg.EncoderOf(typ)
97	}
98	encoder.Encode(reflect2.PtrOf(val), stream)
99}
100
101func (cfg *frozenConfig) DecoderOf(typ reflect2.Type) ValDecoder {
102	cacheKey := typ.RType()
103	decoder := cfg.getDecoderFromCache(cacheKey)
104	if decoder != nil {
105		return decoder
106	}
107	ctx := &ctx{
108		frozenConfig: cfg,
109		prefix:       "",
110		decoders:     map[reflect2.Type]ValDecoder{},
111		encoders:     map[reflect2.Type]ValEncoder{},
112	}
113	ptrType := typ.(*reflect2.UnsafePtrType)
114	decoder = decoderOfType(ctx, ptrType.Elem())
115	cfg.addDecoderToCache(cacheKey, decoder)
116	return decoder
117}
118
119func decoderOfType(ctx *ctx, typ reflect2.Type) ValDecoder {
120	decoder := getTypeDecoderFromExtension(ctx, typ)
121	if decoder != nil {
122		return decoder
123	}
124	decoder = createDecoderOfType(ctx, typ)
125	for _, extension := range extensions {
126		decoder = extension.DecorateDecoder(typ, decoder)
127	}
128	decoder = ctx.decoderExtension.DecorateDecoder(typ, decoder)
129	for _, extension := range ctx.extraExtensions {
130		decoder = extension.DecorateDecoder(typ, decoder)
131	}
132	return decoder
133}
134
135func createDecoderOfType(ctx *ctx, typ reflect2.Type) ValDecoder {
136	decoder := ctx.decoders[typ]
137	if decoder != nil {
138		return decoder
139	}
140	placeholder := &placeholderDecoder{}
141	ctx.decoders[typ] = placeholder
142	decoder = _createDecoderOfType(ctx, typ)
143	placeholder.decoder = decoder
144	return decoder
145}
146
147func _createDecoderOfType(ctx *ctx, typ reflect2.Type) ValDecoder {
148	decoder := createDecoderOfJsonRawMessage(ctx, typ)
149	if decoder != nil {
150		return decoder
151	}
152	decoder = createDecoderOfJsonNumber(ctx, typ)
153	if decoder != nil {
154		return decoder
155	}
156	decoder = createDecoderOfMarshaler(ctx, typ)
157	if decoder != nil {
158		return decoder
159	}
160	decoder = createDecoderOfAny(ctx, typ)
161	if decoder != nil {
162		return decoder
163	}
164	decoder = createDecoderOfNative(ctx, typ)
165	if decoder != nil {
166		return decoder
167	}
168	switch typ.Kind() {
169	case reflect.Interface:
170		ifaceType, isIFace := typ.(*reflect2.UnsafeIFaceType)
171		if isIFace {
172			return &ifaceDecoder{valType: ifaceType}
173		}
174		return &efaceDecoder{}
175	case reflect.Struct:
176		return decoderOfStruct(ctx, typ)
177	case reflect.Array:
178		return decoderOfArray(ctx, typ)
179	case reflect.Slice:
180		return decoderOfSlice(ctx, typ)
181	case reflect.Map:
182		return decoderOfMap(ctx, typ)
183	case reflect.Ptr:
184		return decoderOfOptional(ctx, typ)
185	default:
186		return &lazyErrorDecoder{err: fmt.Errorf("%s%s is unsupported type", ctx.prefix, typ.String())}
187	}
188}
189
190func (cfg *frozenConfig) EncoderOf(typ reflect2.Type) ValEncoder {
191	cacheKey := typ.RType()
192	encoder := cfg.getEncoderFromCache(cacheKey)
193	if encoder != nil {
194		return encoder
195	}
196	ctx := &ctx{
197		frozenConfig: cfg,
198		prefix:       "",
199		decoders:     map[reflect2.Type]ValDecoder{},
200		encoders:     map[reflect2.Type]ValEncoder{},
201	}
202	encoder = encoderOfType(ctx, typ)
203	if typ.LikePtr() {
204		encoder = &onePtrEncoder{encoder}
205	}
206	cfg.addEncoderToCache(cacheKey, encoder)
207	return encoder
208}
209
210type onePtrEncoder struct {
211	encoder ValEncoder
212}
213
214func (encoder *onePtrEncoder) IsEmpty(ptr unsafe.Pointer) bool {
215	return encoder.encoder.IsEmpty(unsafe.Pointer(&ptr))
216}
217
218func (encoder *onePtrEncoder) Encode(ptr unsafe.Pointer, stream *Stream) {
219	encoder.encoder.Encode(unsafe.Pointer(&ptr), stream)
220}
221
222func encoderOfType(ctx *ctx, typ reflect2.Type) ValEncoder {
223	encoder := getTypeEncoderFromExtension(ctx, typ)
224	if encoder != nil {
225		return encoder
226	}
227	encoder = createEncoderOfType(ctx, typ)
228	for _, extension := range extensions {
229		encoder = extension.DecorateEncoder(typ, encoder)
230	}
231	encoder = ctx.encoderExtension.DecorateEncoder(typ, encoder)
232	for _, extension := range ctx.extraExtensions {
233		encoder = extension.DecorateEncoder(typ, encoder)
234	}
235	return encoder
236}
237
238func createEncoderOfType(ctx *ctx, typ reflect2.Type) ValEncoder {
239	encoder := ctx.encoders[typ]
240	if encoder != nil {
241		return encoder
242	}
243	placeholder := &placeholderEncoder{}
244	ctx.encoders[typ] = placeholder
245	encoder = _createEncoderOfType(ctx, typ)
246	placeholder.encoder = encoder
247	return encoder
248}
249func _createEncoderOfType(ctx *ctx, typ reflect2.Type) ValEncoder {
250	encoder := createEncoderOfJsonRawMessage(ctx, typ)
251	if encoder != nil {
252		return encoder
253	}
254	encoder = createEncoderOfJsonNumber(ctx, typ)
255	if encoder != nil {
256		return encoder
257	}
258	encoder = createEncoderOfMarshaler(ctx, typ)
259	if encoder != nil {
260		return encoder
261	}
262	encoder = createEncoderOfAny(ctx, typ)
263	if encoder != nil {
264		return encoder
265	}
266	encoder = createEncoderOfNative(ctx, typ)
267	if encoder != nil {
268		return encoder
269	}
270	kind := typ.Kind()
271	switch kind {
272	case reflect.Interface:
273		return &dynamicEncoder{typ}
274	case reflect.Struct:
275		return encoderOfStruct(ctx, typ)
276	case reflect.Array:
277		return encoderOfArray(ctx, typ)
278	case reflect.Slice:
279		return encoderOfSlice(ctx, typ)
280	case reflect.Map:
281		return encoderOfMap(ctx, typ)
282	case reflect.Ptr:
283		return encoderOfOptional(ctx, typ)
284	default:
285		return &lazyErrorEncoder{err: fmt.Errorf("%s%s is unsupported type", ctx.prefix, typ.String())}
286	}
287}
288
289type lazyErrorDecoder struct {
290	err error
291}
292
293func (decoder *lazyErrorDecoder) Decode(ptr unsafe.Pointer, iter *Iterator) {
294	if iter.WhatIsNext() != NilValue {
295		if iter.Error == nil {
296			iter.Error = decoder.err
297		}
298	} else {
299		iter.Skip()
300	}
301}
302
303type lazyErrorEncoder struct {
304	err error
305}
306
307func (encoder *lazyErrorEncoder) Encode(ptr unsafe.Pointer, stream *Stream) {
308	if ptr == nil {
309		stream.WriteNil()
310	} else if stream.Error == nil {
311		stream.Error = encoder.err
312	}
313}
314
315func (encoder *lazyErrorEncoder) IsEmpty(ptr unsafe.Pointer) bool {
316	return false
317}
318
319type placeholderDecoder struct {
320	decoder ValDecoder
321}
322
323func (decoder *placeholderDecoder) Decode(ptr unsafe.Pointer, iter *Iterator) {
324	decoder.decoder.Decode(ptr, iter)
325}
326
327type placeholderEncoder struct {
328	encoder ValEncoder
329}
330
331func (encoder *placeholderEncoder) Encode(ptr unsafe.Pointer, stream *Stream) {
332	encoder.encoder.Encode(ptr, stream)
333}
334
335func (encoder *placeholderEncoder) IsEmpty(ptr unsafe.Pointer) bool {
336	return encoder.encoder.IsEmpty(ptr)
337}
338