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path: root/src/encoding/json/decode.go
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Diffstat (limited to 'src/encoding/json/decode.go')
-rw-r--r--src/encoding/json/decode.go62
1 files changed, 34 insertions, 28 deletions
diff --git a/src/encoding/json/decode.go b/src/encoding/json/decode.go
index 710c835547..420a07e154 100644
--- a/src/encoding/json/decode.go
+++ b/src/encoding/json/decode.go
@@ -361,40 +361,47 @@ func (d *decodeState) scanWhile(op int) int {
return newOp
}
-// discardObject and discardArray are dummy data targets
-// used by the (*decodeState).value method, which
-// accepts a zero reflect.Value to discard a value.
-// The (*decodeState).object and (*decodeState).array methods,
-// however, require a valid reflect.Value destination.
-// These are the target values used when the caller of value
-// wants to skip a field.
-//
-// Because these values refer to zero-sized objects
-// and thus can't be mutated, they're safe for concurrent use
-// by different goroutines unmarshalling skipped fields.
-var (
- discardObject = reflect.ValueOf(struct{}{})
- discardArray = reflect.ValueOf([0]interface{}{})
-)
-
// value decodes a JSON value from d.data[d.off:] into the value.
-// It updates d.off to point past the decoded value. If v is
-// invalid, the JSON value is discarded.
+// it updates d.off to point past the decoded value.
func (d *decodeState) value(v reflect.Value) {
+ if !v.IsValid() {
+ _, rest, err := nextValue(d.data[d.off:], &d.nextscan)
+ if err != nil {
+ d.error(err)
+ }
+ d.off = len(d.data) - len(rest)
+
+ // d.scan thinks we're still at the beginning of the item.
+ // Feed in an empty string - the shortest, simplest value -
+ // so that it knows we got to the end of the value.
+ if d.scan.redo {
+ // rewind.
+ d.scan.redo = false
+ d.scan.step = stateBeginValue
+ }
+ d.scan.step(&d.scan, '"')
+ d.scan.step(&d.scan, '"')
+
+ n := len(d.scan.parseState)
+ if n > 0 && d.scan.parseState[n-1] == parseObjectKey {
+ // d.scan thinks we just read an object key; finish the object
+ d.scan.step(&d.scan, ':')
+ d.scan.step(&d.scan, '"')
+ d.scan.step(&d.scan, '"')
+ d.scan.step(&d.scan, '}')
+ }
+
+ return
+ }
+
switch op := d.scanWhile(scanSkipSpace); op {
default:
d.error(errPhase)
case scanBeginArray:
- if !v.IsValid() {
- v = discardArray
- }
d.array(v)
case scanBeginObject:
- if !v.IsValid() {
- v = discardObject
- }
d.object(v)
case scanBeginLiteral:
@@ -512,7 +519,8 @@ func (d *decodeState) array(v reflect.Value) {
d.off--
d.next()
return
- case reflect.Array, reflect.Slice:
+ case reflect.Array:
+ case reflect.Slice:
break
}
@@ -791,9 +799,7 @@ func (d *decodeState) literal(v reflect.Value) {
d.off--
d.scan.undo(op)
- if v.IsValid() {
- d.literalStore(d.data[start:d.off], v, false)
- }
+ d.literalStore(d.data[start:d.off], v, false)
}
// convertNumber converts the number literal s to a float64 or a Number