db: don't use internal types in ScanInternal

This change updates the ScanInternal function signature
to not use the internal keyspan.Key type. Instead we use
the rangekey.Key type alias that exports it.

Also update the pointCollapsingIter to just call SeekGE
in NextPrefix instead of panicking.

Necessary for cockroachdb/cockroach#103028.

db.go

@@ -22,6 +22,7 @@ import (
 	"github.com/cockroachdb/pebble/internal/manifest"
 	"github.com/cockroachdb/pebble/internal/manual"
 	"github.com/cockroachdb/pebble/objstorage"
+	"github.com/cockroachdb/pebble/rangekey"
 	"github.com/cockroachdb/pebble/record"
 	"github.com/cockroachdb/pebble/sstable"
 	"github.com/cockroachdb/pebble/vfs"
@@ -1183,7 +1184,7 @@ func (d *DB) ScanInternal(
 	lower, upper []byte,
 	visitPointKey func(key *InternalKey, value LazyValue) error,
 	visitRangeDel func(start, end []byte, seqNum uint64) error,
-	visitRangeKey func(start, end []byte, keys []keyspan.Key) error,
+	visitRangeKey func(start, end []byte, keys []rangekey.Key) error,
 	visitSharedFile func(sst *SharedSSTMeta) error,
 ) error {
 	iter := d.newInternalIter(nil /* snapshot */, &scanInternalOptions{

scan_internal.go

@@ -15,6 +15,7 @@ import (
 	"github.com/cockroachdb/pebble/internal/keyspan"
 	"github.com/cockroachdb/pebble/internal/manifest"
 	"github.com/cockroachdb/pebble/objstorage"
+	"github.com/cockroachdb/pebble/rangekey"
 	"github.com/cockroachdb/pebble/sstable"
 )
 
@@ -591,10 +592,10 @@ func (p *pointCollapsingIterator) Next() (*base.InternalKey, base.LazyValue) {
 
 // NextPrefix implements the InternalIterator interface.
 func (p *pointCollapsingIterator) NextPrefix(succKey []byte) (*base.InternalKey, base.LazyValue) {
-	// TODO(bilal): Implement this. It'll be similar to SeekGE, except we'll call
+	// TODO(bilal): Implement this optimally. It'll be similar to SeekGE, except we'll call
 	// the child iterator's NextPrefix, and have some special logic in case pos
 	// is pcIterPosNext.
-	panic("unimplemented")
+	return p.SeekGE(succKey, base.SeekGEFlagsNone)
 }
 
 // Prev implements the InternalIterator interface.
@@ -852,7 +853,7 @@ func scanInternalImpl(
 	iter *scanInternalIterator,
 	visitPointKey func(key *InternalKey, value LazyValue) error,
 	visitRangeDel func(start, end []byte, seqNum uint64) error,
-	visitRangeKey func(start, end []byte, keys []keyspan.Key) error,
+	visitRangeKey func(start, end []byte, keys []rangekey.Key) error,
 	visitSharedFile func(sst *SharedSSTMeta) error,
 ) error {
 	if visitSharedFile != nil && (lower == nil || upper == nil) {

scan_internal_test.go

@@ -19,6 +19,7 @@ import (
 	"github.com/cockroachdb/pebble/internal/keyspan"
 	"github.com/cockroachdb/pebble/internal/testkeys"
 	"github.com/cockroachdb/pebble/objstorage/shared"
+	"github.com/cockroachdb/pebble/rangekey"
 	"github.com/cockroachdb/pebble/sstable"
 	"github.com/cockroachdb/pebble/vfs"
 	"github.com/stretchr/testify/require"
@@ -31,7 +32,7 @@ func TestScanInternal(t *testing.T) {
 			ctx context.Context,
 			lower, upper []byte, visitPointKey func(key *InternalKey, value LazyValue) error,
 			visitRangeDel func(start, end []byte, seqNum uint64) error,
-			visitRangeKey func(start, end []byte, keys []keyspan.Key) error,
+			visitRangeKey func(start, end []byte, keys []rangekey.Key) error,
 			visitSharedFile func(sst *SharedSSTMeta) error) error
 	}
 	batches := map[string]*Batch{}
@@ -243,7 +244,7 @@ func TestScanInternal(t *testing.T) {
 			}, func(start, end []byte, seqNum uint64) error {
 				fmt.Fprintf(&b, "%s-%s#%d,RANGEDEL\n", start, end, seqNum)
 				return nil
-			}, func(start, end []byte, keys []keyspan.Key) error {
+			}, func(start, end []byte, keys []rangekey.Key) error {
 				s := keyspan.Span{Start: start, End: end, Keys: keys}
 				fmt.Fprintf(&b, "%s\n", s.String())
 				return nil

snapshot.go

@@ -9,7 +9,7 @@ import (
 	"io"
 	"math"
 
-	"github.com/cockroachdb/pebble/internal/keyspan"
+	"github.com/cockroachdb/pebble/rangekey"
 )
 
 // Snapshot provides a read-only point-in-time view of the DB state.
@@ -68,7 +68,7 @@ func (s *Snapshot) ScanInternal(
 	lower, upper []byte,
 	visitPointKey func(key *InternalKey, value LazyValue) error,
 	visitRangeDel func(start, end []byte, seqNum uint64) error,
-	visitRangeKey func(start, end []byte, keys []keyspan.Key) error,
+	visitRangeKey func(start, end []byte, keys []rangekey.Key) error,
 	visitSharedFile func(sst *SharedSSTMeta) error,
 ) error {
 	if s.db == nil {