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 cacheKey := reflect2.RTypeOf(obj) 64 decoder := iter.cfg.getDecoderFromCache(cacheKey) 65 if decoder == nil { 66 typ := reflect2.TypeOf(obj) 67 if typ.Kind() != reflect.Ptr { 68 iter.ReportError("ReadVal", "can only unmarshal into pointer") 69 return 70 } 71 decoder = iter.cfg.DecoderOf(typ) 72 } 73 ptr := reflect2.PtrOf(obj) 74 if ptr == nil { 75 iter.ReportError("ReadVal", "can not read into nil pointer") 76 return 77 } 78 decoder.Decode(ptr, iter) 79} 80 81// WriteVal copy the go interface into underlying JSON, same as json.Marshal 82func (stream *Stream) WriteVal(val interface{}) { 83 if nil == val { 84 stream.WriteNil() 85 return 86 } 87 cacheKey := reflect2.RTypeOf(val) 88 encoder := stream.cfg.getEncoderFromCache(cacheKey) 89 if encoder == nil { 90 typ := reflect2.TypeOf(val) 91 encoder = stream.cfg.EncoderOf(typ) 92 } 93 encoder.Encode(reflect2.PtrOf(val), stream) 94} 95 96func (cfg *frozenConfig) DecoderOf(typ reflect2.Type) ValDecoder { 97 cacheKey := typ.RType() 98 decoder := cfg.getDecoderFromCache(cacheKey) 99 if decoder != nil { 100 return decoder 101 } 102 ctx := &ctx{ 103 frozenConfig: cfg, 104 prefix: "", 105 decoders: map[reflect2.Type]ValDecoder{}, 106 encoders: map[reflect2.Type]ValEncoder{}, 107 } 108 ptrType := typ.(*reflect2.UnsafePtrType) 109 decoder = decoderOfType(ctx, ptrType.Elem()) 110 cfg.addDecoderToCache(cacheKey, decoder) 111 return decoder 112} 113 114func decoderOfType(ctx *ctx, typ reflect2.Type) ValDecoder { 115 decoder := getTypeDecoderFromExtension(ctx, typ) 116 if decoder != nil { 117 return decoder 118 } 119 decoder = createDecoderOfType(ctx, typ) 120 for _, extension := range extensions { 121 decoder = extension.DecorateDecoder(typ, decoder) 122 } 123 decoder = ctx.decoderExtension.DecorateDecoder(typ, decoder) 124 for _, extension := range ctx.extraExtensions { 125 decoder = extension.DecorateDecoder(typ, decoder) 126 } 127 return decoder 128} 129 130func createDecoderOfType(ctx *ctx, typ reflect2.Type) ValDecoder { 131 decoder := ctx.decoders[typ] 132 if decoder != nil { 133 return decoder 134 } 135 placeholder := &placeholderDecoder{} 136 ctx.decoders[typ] = placeholder 137 decoder = _createDecoderOfType(ctx, typ) 138 placeholder.decoder = decoder 139 return decoder 140} 141 142func _createDecoderOfType(ctx *ctx, typ reflect2.Type) ValDecoder { 143 decoder := createDecoderOfJsonRawMessage(ctx, typ) 144 if decoder != nil { 145 return decoder 146 } 147 decoder = createDecoderOfJsonNumber(ctx, typ) 148 if decoder != nil { 149 return decoder 150 } 151 decoder = createDecoderOfMarshaler(ctx, typ) 152 if decoder != nil { 153 return decoder 154 } 155 decoder = createDecoderOfAny(ctx, typ) 156 if decoder != nil { 157 return decoder 158 } 159 decoder = createDecoderOfNative(ctx, typ) 160 if decoder != nil { 161 return decoder 162 } 163 switch typ.Kind() { 164 case reflect.Interface: 165 ifaceType, isIFace := typ.(*reflect2.UnsafeIFaceType) 166 if isIFace { 167 return &ifaceDecoder{valType: ifaceType} 168 } 169 return &efaceDecoder{} 170 case reflect.Struct: 171 return decoderOfStruct(ctx, typ) 172 case reflect.Array: 173 return decoderOfArray(ctx, typ) 174 case reflect.Slice: 175 return decoderOfSlice(ctx, typ) 176 case reflect.Map: 177 return decoderOfMap(ctx, typ) 178 case reflect.Ptr: 179 return decoderOfOptional(ctx, typ) 180 default: 181 return &lazyErrorDecoder{err: fmt.Errorf("%s%s is unsupported type", ctx.prefix, typ.String())} 182 } 183} 184 185func (cfg *frozenConfig) EncoderOf(typ reflect2.Type) ValEncoder { 186 cacheKey := typ.RType() 187 encoder := cfg.getEncoderFromCache(cacheKey) 188 if encoder != nil { 189 return encoder 190 } 191 ctx := &ctx{ 192 frozenConfig: cfg, 193 prefix: "", 194 decoders: map[reflect2.Type]ValDecoder{}, 195 encoders: map[reflect2.Type]ValEncoder{}, 196 } 197 encoder = encoderOfType(ctx, typ) 198 if typ.LikePtr() { 199 encoder = &onePtrEncoder{encoder} 200 } 201 cfg.addEncoderToCache(cacheKey, encoder) 202 return encoder 203} 204 205type onePtrEncoder struct { 206 encoder ValEncoder 207} 208 209func (encoder *onePtrEncoder) IsEmpty(ptr unsafe.Pointer) bool { 210 return encoder.encoder.IsEmpty(unsafe.Pointer(&ptr)) 211} 212 213func (encoder *onePtrEncoder) Encode(ptr unsafe.Pointer, stream *Stream) { 214 encoder.encoder.Encode(unsafe.Pointer(&ptr), stream) 215} 216 217func encoderOfType(ctx *ctx, typ reflect2.Type) ValEncoder { 218 encoder := getTypeEncoderFromExtension(ctx, typ) 219 if encoder != nil { 220 return encoder 221 } 222 encoder = createEncoderOfType(ctx, typ) 223 for _, extension := range extensions { 224 encoder = extension.DecorateEncoder(typ, encoder) 225 } 226 encoder = ctx.encoderExtension.DecorateEncoder(typ, encoder) 227 for _, extension := range ctx.extraExtensions { 228 encoder = extension.DecorateEncoder(typ, encoder) 229 } 230 return encoder 231} 232 233func createEncoderOfType(ctx *ctx, typ reflect2.Type) ValEncoder { 234 encoder := ctx.encoders[typ] 235 if encoder != nil { 236 return encoder 237 } 238 placeholder := &placeholderEncoder{} 239 ctx.encoders[typ] = placeholder 240 encoder = _createEncoderOfType(ctx, typ) 241 placeholder.encoder = encoder 242 return encoder 243} 244func _createEncoderOfType(ctx *ctx, typ reflect2.Type) ValEncoder { 245 encoder := createEncoderOfJsonRawMessage(ctx, typ) 246 if encoder != nil { 247 return encoder 248 } 249 encoder = createEncoderOfJsonNumber(ctx, typ) 250 if encoder != nil { 251 return encoder 252 } 253 encoder = createEncoderOfMarshaler(ctx, typ) 254 if encoder != nil { 255 return encoder 256 } 257 encoder = createEncoderOfAny(ctx, typ) 258 if encoder != nil { 259 return encoder 260 } 261 encoder = createEncoderOfNative(ctx, typ) 262 if encoder != nil { 263 return encoder 264 } 265 kind := typ.Kind() 266 switch kind { 267 case reflect.Interface: 268 return &dynamicEncoder{typ} 269 case reflect.Struct: 270 return encoderOfStruct(ctx, typ) 271 case reflect.Array: 272 return encoderOfArray(ctx, typ) 273 case reflect.Slice: 274 return encoderOfSlice(ctx, typ) 275 case reflect.Map: 276 return encoderOfMap(ctx, typ) 277 case reflect.Ptr: 278 return encoderOfOptional(ctx, typ) 279 default: 280 return &lazyErrorEncoder{err: fmt.Errorf("%s%s is unsupported type", ctx.prefix, typ.String())} 281 } 282} 283 284type lazyErrorDecoder struct { 285 err error 286} 287 288func (decoder *lazyErrorDecoder) Decode(ptr unsafe.Pointer, iter *Iterator) { 289 if iter.WhatIsNext() != NilValue { 290 if iter.Error == nil { 291 iter.Error = decoder.err 292 } 293 } else { 294 iter.Skip() 295 } 296} 297 298type lazyErrorEncoder struct { 299 err error 300} 301 302func (encoder *lazyErrorEncoder) Encode(ptr unsafe.Pointer, stream *Stream) { 303 if ptr == nil { 304 stream.WriteNil() 305 } else if stream.Error == nil { 306 stream.Error = encoder.err 307 } 308} 309 310func (encoder *lazyErrorEncoder) IsEmpty(ptr unsafe.Pointer) bool { 311 return false 312} 313 314type placeholderDecoder struct { 315 decoder ValDecoder 316} 317 318func (decoder *placeholderDecoder) Decode(ptr unsafe.Pointer, iter *Iterator) { 319 decoder.decoder.Decode(ptr, iter) 320} 321 322type placeholderEncoder struct { 323 encoder ValEncoder 324} 325 326func (encoder *placeholderEncoder) Encode(ptr unsafe.Pointer, stream *Stream) { 327 encoder.encoder.Encode(ptr, stream) 328} 329 330func (encoder *placeholderEncoder) IsEmpty(ptr unsafe.Pointer) bool { 331 return encoder.encoder.IsEmpty(ptr) 332} 333