Implement GetAuthoritesChangesFromBlock

dot/state/block_data.go

@@ -5,6 +5,7 @@ package state
 
 import (
 	"github.com/ChainSafe/gossamer/lib/common"
+	"golang.org/x/exp/slices"
 )
 
 // prefixKey = prefix + hash
@@ -88,7 +89,21 @@ func (bs *BlockState) GetJustification(hash common.Hash) ([]byte, error) {
 }
 
 // GetAuthoritesChangesFromBlock retrieves blocks numbers where authority set changes happened
-func (bs *BlockState) GetAuthoritesChangesFromBlock(blockNumber uint) ([]uint, error) {
-	// TODO: complete me
-	panic("not implemented")
+func (bs *BlockState) GetAuthoritesChangesFromBlock(initialBlockNumber uint) ([]uint, error) {
+	blockNumbers := make([]uint, 0)
+	iter, err := bs.db.NewPrefixIterator(setIDChangePrefix)
+	if err != nil {
+		return nil, err
+	}
+
+	for iter.Next() {
+		blockNumber := common.BytesToUint(iter.Value())
+		if blockNumber >= initialBlockNumber {
+			blockNumbers = append(blockNumbers, blockNumber)
+		}
+	}
+
+	// To ensure the order of the blocks
+	slices.Sort(blockNumbers)
+	return blockNumbers, nil
 }

dot/state/interfaces.go

@@ -21,6 +21,7 @@ type BlockStateDatabase interface {
 	GetPutDeleter
 	Haser
 	NewBatcher
+	NewPrefixIterator(prefix []byte) (database.Iterator, error)
 }
 
 // GetPutter has methods to get and put key values.

internal/database/database.go

@@ -60,6 +60,7 @@ type Table interface {
 	Path() string
 	NewBatch() Batch
 	NewIterator() (Iterator, error)
+	NewPrefixIterator(prefix []byte) (Iterator, error)
 }
 
 const DefaultDatabaseDir = "db"

internal/database/table.go

@@ -59,3 +59,7 @@ func (t *table) NewBatch() Batch {
 func (t *table) NewIterator() (Iterator, error) {
 	return t.db.NewPrefixIterator(t.prefix)
 }
+
+func (t *table) NewPrefixIterator(prefix []byte) (Iterator, error) {
+	return t.db.NewPrefixIterator(append(t.prefix, prefix...))
+}

lib/grandpa/warp_sync.go

@@ -45,7 +45,6 @@ func (np *NetworkProvider) Generate(start common.Hash) ([]byte, error) {
 		// the header should contains a standard scheduled change
 		// otherwise  the set must have changed through a forced changed,
 		// in which case we stop collecting proofs as the chain of trust in authority handoffs was broken.
-
 		header, err := np.backend.GetHeaderByNumber(blockNumber)
 		if err != nil {
 			return nil, err