/* * Copyright ConsenSys AG. * * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the * specific language governing permissions and limitations under the License. * * SPDX-License-Identifier: Apache-2.0 */ package org.hyperledger.besu.ethereum.trie; import org.apache.tuweni.bytes.Bytes; class GetVisitor<V> implements PathNodeVisitor<V> { private final Node<V> NULL_NODE_RESULT = NullNode.instance(); @Override public Node<V> visit(final ExtensionNode<V> extensionNode, final Bytes path) { final Bytes extensionPath = extensionNode.getPath(); final int commonPathLength = extensionPath.commonPrefixLength(path); assert commonPathLength < path.size() : "Visiting path doesn't end with a non-matching terminator"; if (commonPathLength < extensionPath.size()) { // path diverges before the end of the extension, so it cannot match return NULL_NODE_RESULT; } return extensionNode.getChild().accept(this, path.slice(commonPathLength)); } @Override public Node<V> visit(final BranchNode<V> branchNode, final Bytes path) { assert path.size() > 0 : "Visiting path doesn't end with a non-matching terminator"; final byte childIndex = path.get(0); if (childIndex == CompactEncoding.LEAF_TERMINATOR) { return branchNode; } return branchNode.child(childIndex).accept(this, path.slice(1)); } @Override public Node<V> visit(final LeafNode<V> leafNode, final Bytes path) { final Bytes leafPath = leafNode.getPath(); if (leafPath.commonPrefixLength(path) != leafPath.size()) { return NULL_NODE_RESULT; } return leafNode; } @Override public Node<V> visit(final NullNode<V> nullNode, final Bytes path) { return NULL_NODE_RESULT; } }