revise interfaces, update comments

internal/client/consensus/grandpa/finality_proof.go

@@ -184,7 +184,7 @@ func proveFinality[
 				block)
 			return nil, nil //nolint
 		}
-		justification := justifications.IntoJustification(primitives.GrandpaEngineID)
+		justification := justifications.EncodedJustification(primitives.GrandpaEngineID)
 		if justification != nil {
 			encJustification = *justification
 			justBlock = val.inner.BlockNumber

internal/client/consensus/grandpa/finality_proof_test.go

@@ -299,7 +299,7 @@ func TestFinalityProof_UsingAuthoritySetChangesWorks(t *testing.T) {
 		ConsensusEngineID:    primitives.GrandpaEngineID,
 		EncodedJustification: scale.MustMarshal(grandpaJust8),
 	}
-	blockchainBackend.EXPECT().Justifications(block8.Hash()).Return(&runtime.Justifications{justification}, nil)
+	blockchainBackend.EXPECT().Justifications(block8.Hash()).Return(runtime.Justifications{justification}, nil)
 
 	blockchainBackend.EXPECT().ExpectBlockHashFromID(uint64(7)).Return(block7.Hash(), nil)
 	blockchainBackend.EXPECT().ExpectHeader(block7.Hash()).Return(block7.Header(), nil)

internal/client/consensus/grandpa/justification.go

@@ -140,7 +140,7 @@ func NewJustificationFromCommit[
 					fmt.Errorf("%w: invalid precommits for target commit", errBadJustification)
 			}
 
-			currentHeader := *header
+			currentHeader := header
 
 			// NOTE: this should never happen as we pick the lowest block
 			// as base and only traverse backwards from the other blocks

internal/client/consensus/grandpa/justification_test.go

@@ -123,7 +123,7 @@ func TestJustification_fromCommit(t *testing.T) {
 		"",
 		runtime.Digest{})
 
-	client.EXPECT().Header(hash.H256("b")).Return(&header, nil)
+	client.EXPECT().Header(hash.H256("b")).Return(header, nil)
 	_, err = NewJustificationFromCommit[hash.H256, uint64](
 		client,
 		2,
@@ -142,7 +142,7 @@ func TestJustification_fromCommit(t *testing.T) {
 		runtime.Digest{})
 
 	client = mocks.NewHeaderBackend[hash.H256, uint64](t)
-	client.EXPECT().Header(hash.H256("b")).Return(&header, nil)
+	client.EXPECT().Header(hash.H256("b")).Return(header, nil)
 
 	expAncestries := make([]runtime.Header[uint64, hash.H256], 0)
 	expAncestries = append(expAncestries, generic.NewHeader[uint64, hash.H256, runtime.BlakeTwo256](

internal/primitives/blockchain/backend.go

@@ -10,21 +10,21 @@ import (
 	"github.com/ChainSafe/gossamer/internal/primitives/runtime/generic"
 )
 
-// Blockchain database header backend. Does not perform any validation.
+// Header is the blockchain database header backend. Does not perform any validation.
 type HeaderBackend[Hash runtime.Hash, N runtime.Number] interface {
-	// Get block header. Returns `None` if block is not found.
-	Header(hash Hash) (*runtime.Header[N, Hash], error)
+	// Get block header. Returns `nil` if block is not found.
+	Header(hash Hash) (runtime.Header[N, Hash], error)
 
 	// Get blockchain info.
 	Info() Info[Hash, N]
 
 	// Get block status.
 	Status(hash Hash) (BlockStatus, error)
 
-	// Get block number by hash. Returns `None` if the header is not in the chain.
+	// Get block number by hash. Returns `nil` if the header is not in the chain.
 	Number(hash Hash) (*N, error)
 
-	// Get block hash by number. Returns `None` if the header is not in the chain.
+	// Get block hash by number. Returns `nil` if the header is not in the chain.
 	Hash(number N) (*Hash, error)
 
 	// Convert an arbitrary block ID into a block hash.
@@ -48,12 +48,12 @@ type HeaderBackend[Hash runtime.Hash, N runtime.Number] interface {
 // Blockchain database backend. Does not perform any validation.
 type Backend[Hash runtime.Hash, N runtime.Number] interface {
 	HeaderBackend[Hash, N]
-	// HeaderMetaData[Hash, N]
+	// HeaderMetadata[Hash, N]
 
-	// Get block body. Returns `None` if block is not found.
-	Body(hash Hash) (*[]runtime.Extrinsic, error)
-	// Get block justifications. Returns `None` if no justification exists.
-	Justifications(hash Hash) (*runtime.Justifications, error)
+	// Get block body. Returns `nil` if block is not found.
+	Body(hash Hash) ([]runtime.Extrinsic, error)
+	// Get block justifications. Returns `nil` if no justification exists.
+	Justifications(hash Hash) (runtime.Justifications, error)
 	// Get last finalized block hash.
 	LastFinalized() (Hash, error)
 
@@ -64,30 +64,29 @@ type Backend[Hash runtime.Hash, N runtime.Number] interface {
 
 	// Returns displaced leaves after the given block would be finalized.
 	//
-	// The returned leaves do not contain the leaves from the same height as `block_number`.
+	// The returned leaves do not contain the leaves from the same height as `blockNumber`.
 	DisplacedLeavesAfterFinalizing(blockNumber N) ([]Hash, error)
 
-	// Return hashes of all blocks that are children of the block with `parent_hash`.
+	// Return hashes of all blocks that are children of the block with `parentHash`.
 	Children(parentHash Hash) ([]Hash, error)
 
 	// Get the most recent block hash of the longest chain that contains
-	// a block with the given `base_hash`.
+	// a block with the given `baseHash`.
 	//
 	// The search space is always limited to blocks which are in the finalized
 	// chain or descendents of it.
 	//
-	// Returns `Ok(None)` if `base_hash` is not found in search space.
-	// TODO: document time complexity of this, see [#1444](https://github.com/paritytech/substrate/issues/1444)
+	// Returns `nil` if `basehash` is not found in search space.
 	LongestContaining(baseHash Hash, importLock *sync.RWMutex) (*Hash, error)
 
 	// Get single indexed transaction by content hash. Note that this will only fetch transactions
 	// that are indexed by the runtime with `storage_index_transaction`.
-	IndexedTransaction(hash Hash) (*[]byte, error)
+	IndexedTransaction(hash Hash) ([]byte, error)
 
 	// Check if indexed transaction exists.
 	HasIndexedTransaction(hash Hash) (bool, error)
 
-	BlockIndexedBody(hash Hash) (*[][]byte, error)
+	BlockIndexedBody(hash Hash) ([][]byte, error)
 }
 
 // Blockchain info
@@ -113,7 +112,7 @@ type Info[H, N any] struct {
 	BlockGap *[2]N
 }
 
-// Block status.
+// BlockStatus is block status.
 type BlockStatus uint
 
 const (