code cleanup + review comments

Author: Thejas-bhat

index/scorch/unadorned.go

@@ -168,10 +168,6 @@ func (i *unadornedPostingsIterator1Hit) BytesWritten() uint64 {
 
 func (i *unadornedPostingsIterator1Hit) ResetBytesRead(uint64) {}
 
-// Implement OptimizablePostingsIterator so a 1-hit iterator produced by one
-// optimization pass (e.g. the unadorned conjunction/disjunction Finish) can be
-// re-optimized when it feeds into a nested conjunction/disjunction, rather than
-// aborting the outer optimization on a failed type assertion.
 func (i *unadornedPostingsIterator1Hit) ActualBitmap() *roaring.Bitmap { return nil }
 
 func (i *unadornedPostingsIterator1Hit) DocNum1Hit() (uint64, bool) {
@@ -198,23 +194,6 @@ type ResetablePostingsIterator interface {
 	ResetIterator()
 }
 
-// Compile-time guarantee that every postings-iterator type placed into an
-// optimized termFieldReader's per-segment iterator slice implements
-// OptimizablePostingsIterator, so a nested conjunction/disjunction optimization
-// composes it instead of silently aborting on a failed type assertion.
-//
-// The two stateful iterators must additionally be resettable so termFieldReader
-// reuse rewinds them; the empty iterator is stateless and intentionally opts out
-// (ResetIterator is invoked via an optional type assertion).
-var (
-	_ segment.OptimizablePostingsIterator = (*emptyPostingsIterator)(nil)
-	_ segment.OptimizablePostingsIterator = (*unadornedPostingsIteratorBitmap)(nil)
-	_ segment.OptimizablePostingsIterator = (*unadornedPostingsIterator1Hit)(nil)
-
-	_ ResetablePostingsIterator = (*unadornedPostingsIteratorBitmap)(nil)
-	_ ResetablePostingsIterator = (*unadornedPostingsIterator1Hit)(nil)
-)
-
 type UnadornedPosting struct {
 	docNum uint64
 }

search/collector/topn.go

@@ -83,9 +83,6 @@ type TopNCollector struct {
 
 	nestedStore *collectStoreNested
 
-	// fastPrepare is true when a hit needs only basicPrepare plus the shared
-	// score sort value (see canFastPrepare) — set once in Collect after loadID
-	// is known. Applies only to score-sorted queries with no field-loading needs.
 	fastPrepare bool
 }
 
@@ -341,6 +338,10 @@ func (hc *TopNCollector) Collect(ctx context.Context, searcher search.Searcher,
 	}
 
 	hc.needDocIds = hc.needDocIds || loadID
+
+	// fastPrepare is set to true when a hit needs only basicPrepare plus the shared
+	// score sort value (see canFastPrepare). Applies only to score-sorted queries
+	//  with no field-loading needs.
 	hc.fastPrepare = hc.canFastPrepare()
 	select {
 	case <-ctx.Done():
@@ -499,7 +500,6 @@ func (hc *TopNCollector) basicPrepare(d *search.DocumentMatch) {
 }
 
 func (hc *TopNCollector) canFastPrepare() bool {
-
 	return len(hc.neededFields) == 0 && !hc.needDocIds &&
 		len(hc.sort) == 1 && hc.cachedScoring[0]
 }