cmd, core/state, eth, tests, trie: improve state reader (#27428)

The state availability is checked during the creation of a state reader.

-    In hash-based database, if the specified root node does not exist on disk disk, then
    the state reader won't be created and an error will be returned.

-    In path-based database, if the specified state layer is not available, then the
    state reader won't be created and an error will be returned.

This change also contains a stricter semantics regarding the `Commit` operation: once it has been performed, the trie is no longer usable, and certain operations will return an error.

tests/fuzzers/stacktrie/trie_fuzzer.go

@@ -221,7 +221,7 @@ func (f *fuzzer) fuzz() int {
 		panic(fmt.Sprintf("roots differ: (trie) %x != %x (stacktrie)", rootA, rootC))
 	}
 	trieA, _ = trie.New(trie.TrieID(rootA), dbA)
-	iterA := trieA.NodeIterator(nil)
+	iterA := trieA.MustNodeIterator(nil)
 	for iterA.Next(true) {
 		if iterA.Hash() == (common.Hash{}) {
 			if _, present := nodeset[string(iterA.Path())]; present {

tests/fuzzers/trie/trie-fuzzer.go

@@ -179,7 +179,7 @@ func runRandTest(rt randTest) error {
 			origin = hash
 		case opItercheckhash:
 			checktr := trie.NewEmpty(triedb)
-			it := trie.NewIterator(tr.NodeIterator(nil))
+			it := trie.NewIterator(tr.MustNodeIterator(nil))
 			for it.Next() {
 				checktr.MustUpdate(it.Key, it.Value)
 			}

tests/state_test_util.go

@@ -204,6 +204,11 @@ func (t *StateTest) Run(subtest StateSubtest, vmconfig vm.Config, snapshotter bo
 	if logs := rlpHash(statedb.Logs()); logs != common.Hash(post.Logs) {
 		return snaps, statedb, fmt.Errorf("post state logs hash mismatch: got %x, want %x", logs, post.Logs)
 	}
+	// Re-init the post-state instance for further operation
+	statedb, err = state.New(root, statedb.Database(), snaps)
+	if err != nil {
+		return nil, nil, err
+	}
 	return snaps, statedb, nil
 }
 
@@ -275,9 +280,7 @@ func (t *StateTest) RunNoVerify(subtest StateSubtest, vmconfig vm.Config, snapsh
 	//   the coinbase gets no txfee, so isn't created, and thus needs to be touched
 	statedb.AddBalance(block.Coinbase(), new(big.Int))
 	// Commit block
-	statedb.Commit(config.IsEIP158(block.Number()))
-	// And _now_ get the state root
-	root := statedb.IntermediateRoot(config.IsEIP158(block.Number()))
+	root, _ := statedb.Commit(config.IsEIP158(block.Number()))
 	return snaps, statedb, root, err
 }