Merge pull request #68 from francoispqt/afiune-afiune/add-interface-decoder

Afiune afiune/add interface decoder

Author: francoispqt

decode.go

@@ -215,6 +215,12 @@ func Unmarshal(data []byte, v interface{}) error {
 		dec.data = make([]byte, len(data))
 		copy(dec.data, data)
 		_, err = dec.decodeArray(vt)
+	case *interface{}:
+		dec = borrowDecoder(nil, 0)
+		dec.length = len(data)
+		dec.data = make([]byte, len(data))
+		copy(dec.data, data)
+		err = dec.decodeInterface(vt)
 	default:
 		return InvalidUnmarshalError(fmt.Sprintf(invalidUnmarshalErrorMsg, reflect.TypeOf(vt).String()))
 	}
@@ -318,6 +324,8 @@ func (dec *Decoder) Decode(v interface{}) error {
 		_, err = dec.decodeArray(vt)
 	case *EmbeddedJSON:
 		err = dec.decodeEmbeddedJSON(vt)
+	case *interface{}:
+		err = dec.decodeInterface(vt)
 	default:
 		return InvalidUnmarshalError(fmt.Sprintf(invalidUnmarshalErrorMsg, reflect.TypeOf(vt).String()))
 	}
@@ -523,6 +531,11 @@ func (dec *Decoder) AddArray(v UnmarshalerJSONArray) error {
 	return dec.Array(v)
 }
 
+// AddInterface decodes the next key to a interface{}.
+func (dec *Decoder) AddInterface(v *interface{}) error {
+	return dec.Interface(v)
+}
+
 // Int decodes the next key to an *int.
 // If next key value overflows int, an InvalidUnmarshalError error will be returned.
 func (dec *Decoder) Int(v *int) error {
@@ -868,6 +881,16 @@ func (dec *Decoder) Array(value UnmarshalerJSONArray) error {
 	return nil
 }
 
+// Interface decodes the next key to an interface{}.
+func (dec *Decoder) Interface(value *interface{}) error {
+	err := dec.decodeInterface(value)
+	if err != nil {
+		return err
+	}
+	dec.called |= 1
+	return nil
+}
+
 // Non exported
 
 func isDigit(b byte) bool {

decode_interface.go

@@ -0,0 +1,111 @@
+package gojay
+
+// TODO @afiune for now we are using the standard json unmarshaling but in
+// the future it would be great to implement one here inside this repo
+import (
+	"encoding/json"
+)
+
+// DecodeInterface reads the next JSON-encoded value from its input and stores it in the value pointed to by i.
+//
+// i must be an interface poiter
+func (dec *Decoder) DecodeInterface(i *interface{}) error {
+	if dec.isPooled == 1 {
+		panic(InvalidUsagePooledDecoderError("Invalid usage of pooled decoder"))
+	}
+	err := dec.decodeInterface(i)
+	return err
+}
+
+func (dec *Decoder) decodeInterface(i *interface{}) error {
+	start, end, err := dec.getObject()
+	if err != nil {
+		dec.cursor = start
+		return err
+	}
+
+	// if start & end are equal the object is a null, don't unmarshal
+	if start == end {
+		return nil
+	}
+
+	object := dec.data[start:end]
+	if err = json.Unmarshal(object, i); err != nil {
+		return err
+	}
+
+	dec.cursor = end
+	return nil
+}
+
+// @afiune Maybe return the type as well?
+func (dec *Decoder) getObject() (start int, end int, err error) {
+	// start cursor
+	start = dec.cursor
+	for ; dec.cursor < dec.length || dec.read(); dec.cursor++ {
+		switch dec.data[dec.cursor] {
+		case ' ', '\n', '\t', '\r', ',':
+			continue
+		// is null
+		case 'n':
+			dec.cursor++
+			err = dec.assertNull()
+			if err != nil {
+				return
+			}
+			// Set start & end to the same cursor to indicate the object
+			// is a null and should not be unmarshal
+			start = dec.cursor
+			end = dec.cursor
+			dec.cursor++
+			return
+		case 't':
+			dec.cursor++
+			err = dec.assertTrue()
+			if err != nil {
+				return
+			}
+			end = dec.cursor
+			dec.cursor++
+			return
+		// is false
+		case 'f':
+			dec.cursor++
+			err = dec.assertFalse()
+			if err != nil {
+				return
+			}
+			end = dec.cursor
+			dec.cursor++
+			return
+		// is an object
+		case '{':
+			dec.cursor++
+			end, err = dec.skipObject()
+			dec.cursor = end
+			return
+		// is string
+		case '"':
+			dec.cursor++
+			start, end, err = dec.getString()
+			start--
+			dec.cursor = end
+			return
+		// is array
+		case '[':
+			dec.cursor++
+			end, err = dec.skipArray()
+			dec.cursor = end
+			return
+		case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '-':
+			end, err = dec.skipNumber()
+			dec.cursor = end
+			return
+		default:
+			err = dec.raiseInvalidJSONErr(dec.cursor)
+			return
+		}
+	}
+	err = dec.raiseInvalidJSONErr(dec.cursor)
+	return
+}