cmd/devp2p: more testing of snap trie delivery

cmd/devp2p/internal/ethtest/snap.go

@@ -195,9 +195,62 @@ type trieNodesTest struct {
 	expReject bool
 }
 
+func decodeNibbles(nibbles []byte, bytes []byte) {
+	for bi, ni := 0, 0; ni < len(nibbles); bi, ni = bi+1, ni+2 {
+		bytes[bi] = nibbles[ni]<<4 | nibbles[ni+1]
+	}
+}
+
+// hasTerm returns whether a hex key has the terminator flag.
+func hasTerm(s []byte) bool {
+	return len(s) > 0 && s[len(s)-1] == 16
+}
+
+func keybytesToHex(str []byte) []byte {
+	l := len(str)*2 + 1
+	var nibbles = make([]byte, l)
+	for i, b := range str {
+		nibbles[i*2] = b / 16
+		nibbles[i*2+1] = b % 16
+	}
+	nibbles[l-1] = 16
+	return nibbles
+}
+
+func hexToCompact(hex []byte) []byte {
+	terminator := byte(0)
+	if hasTerm(hex) {
+		terminator = 1
+		hex = hex[:len(hex)-1]
+	}
+	buf := make([]byte, len(hex)/2+1)
+	buf[0] = terminator << 5 // the flag byte
+	if len(hex)&1 == 1 {
+		buf[0] |= 1 << 4 // odd flag
+		buf[0] |= hex[0] // first nibble is contained in the first byte
+		hex = hex[1:]
+	}
+	decodeNibbles(hex, buf[1:])
+	return buf
+}
+
 // TestSnapTrieNodes various forms of GetTrieNodes requests.
 func (s *Suite) TestSnapTrieNodes(t *utesting.T) {
 
+	key := common.FromHex("0x00bf49f440a1cd0527e4d06e2765654c0f56452257516d793a9b8d604dcfdf2a")
+	// helper function to iterate the key, and generate the compact-encoded
+	// trie paths along the way.
+	pathTo := func(length int) snap.TrieNodePathSet {
+		hex := keybytesToHex(key)[:length]
+		hex[len(hex)-1] = 0 // remove term flag
+		hKey := hexToCompact(hex)
+		return snap.TrieNodePathSet{hKey}
+	}
+	var accPaths []snap.TrieNodePathSet
+	for i := 1; i <= 65; i++ {
+		accPaths = append(accPaths, pathTo(i))
+	}
+	empty := emptyCode
 	for i, tc := range []trieNodesTest{
 		{
 			root:      s.chain.RootAt(999),
@@ -243,6 +296,21 @@ func (s *Suite) TestSnapTrieNodes(t *utesting.T) {
 			nBytes:    5000,
 			expHashes: []common.Hash{},
 		},
+		{
+			// The leaf is only a couple of levels down, so the continued trie traversal causes lookup failures.
+			root:   s.chain.RootAt(999),
+			paths:  accPaths,
+			nBytes: 5000,
+			expHashes: []common.Hash{
+				common.HexToHash("0xbcefee69b37cca1f5bf3a48aebe08b35f2ea1864fa958bb0723d909a0e0d28d8"),
+				common.HexToHash("0x4fb1e4e2391e4b4da471d59641319b8fa25d76c973d4bec594d7b00a69ae5135"),
+				empty, empty, empty, empty, empty, empty, empty, empty, empty, empty, empty, empty,
+				empty, empty, empty, empty, empty, empty, empty, empty, empty, empty, empty, empty,
+				empty, empty, empty, empty, empty, empty, empty, empty, empty, empty, empty, empty,
+				empty, empty, empty, empty, empty, empty, empty, empty, empty, empty, empty, empty,
+				empty, empty, empty, empty, empty, empty, empty, empty, empty, empty, empty, empty,
+				empty, empty, empty},
+		},
 	} {
 		if err := s.snapGetTrieNodes(t, &tc); err != nil {
 			t.Errorf("test %d \n #hashes %x\n root: %#x\n bytes: %d\nfailed: %v", i, len(tc.expHashes), tc.root, tc.nBytes, err)
@@ -426,14 +494,14 @@ func (s *Suite) snapGetTrieNodes(t *utesting.T, tc *trieNodesTest) error {
 	if got, want := len(trienodes), len(tc.expHashes); got != want {
 		return fmt.Errorf("wrong trienode count, got %d, want %d\n", got, want)
 	}
-
 	for i, trienode := range trienodes {
 		hasher.Reset()
 		hasher.Write(trienode)
 		hasher.Read(hash)
 		if got, want := hash, tc.expHashes[i]; !bytes.Equal(got, want[:]) {
-			return fmt.Errorf("hash %d wrong, got %#x, want %#x", i, got, want)
+			fmt.Printf("hash %d wrong, got %#x, want %#x\n", i, got, want)
+			err = fmt.Errorf("hash %d wrong, got %#x, want %#x", i, got, want)
 		}
 	}
-	return nil
+	return err
 }

cmd/devp2p/internal/ethtest/suite.go

@@ -130,7 +130,7 @@ func (s *Suite) SnapTests() []utesting.Test {
 		{Name: "TestSnapStatus", Fn: s.TestSnapStatus},
 		{Name: "TestSnapAccountRange", Fn: s.TestSnapGetAccountRange},
 		{Name: "TestSnapGetByteCodes", Fn: s.TestSnapGetByteCodes},
-		{Name: "TestSnapGetByteCodes", Fn: s.TestSnapTrieNodes},
+		{Name: "TestSnapGetTrieNodes", Fn: s.TestSnapTrieNodes},
 	}
 }