//pkg/state fixes for VFS2.

- When encodeState.resolve() determines that the resolved reflect.Value is
  contained by a previously-resolved object, set wire.Ref.Type to the
  containing object's type (existing.obj.Type()) rather than the contained
  value's type (obj.Type()).

- When encodeState.resolve() determines that the resolved reflect.Value
  contains a previously-resolved object, handle cases where the new object
  contains *multiple* previously-resolved objects. (This may cause
  previously-allocated object IDs to become unused; to facilitate this, change
  encodeState.pending to a map, and change the wire format to prefix each
  object with its object ID.)

- Add encodeState.encodedStructs to avoid redundant encoding of structs, since
  deduplication of objects via encodeState.resolve() doesn't work for objects
  instantiated by StateSave() and passed to SaveValue() (i.e. fields tagged
  `state:".(whatever)"`).

- Make unexported array fields deserializable via slices that refer to them by
  casting away their unexportedness in decodeState.decodeObject().

Updates #1663

PiperOrigin-RevId: 338727687

1 files changed, 6 insertions, 4 deletions

diff --git a/pkg/state/state.go b/pkg/state/state.go
index acb629969..6b8540f03 100644
--- a/pkg/state/state.go
+++ b/pkg/state/state.go
@@ -90,10 +90,12 @@ func (e *ErrState) Unwrap() error {
 func Save(ctx context.Context, w wire.Writer, rootPtr interface{}) (Stats, error) {
 	// Create the encoding state.
 	es := encodeState{
-		ctx:        ctx,
-		w:          w,
-		types:      makeTypeEncodeDatabase(),
-		zeroValues: make(map[reflect.Type]*objectEncodeState),
+		ctx:            ctx,
+		w:              w,
+		types:          makeTypeEncodeDatabase(),
+		zeroValues:     make(map[reflect.Type]*objectEncodeState),
+		pending:        make(map[objectID]*objectEncodeState),
+		encodedStructs: make(map[reflect.Value]*wire.Struct),
 	}
 
 	// Perform the encoding.